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February 1996 Volume 41, Number 2 ISSN 0020-1 324-RECACP A MONTHLY SCIENCE JOURNAL 41 ST YEAR— ESTABLISHED 1956 Editorial Call for 1 Respiratory Care Education: Current 996 Open Forum Abstracts Issues & Future Challenges Final Deadline April 28, 1996! A Commercial Standard for Pulse Oximeters Tracheal Gas Insufflation A New Teaching Feature: Cardiorespiratory Interactions Cardiovascular Anatomy & Physiology The Role 42"'' ^ International Convention November 3-6 • San Diego, California of CRI in Respiratory Care . . ' . AARC's Professor's Rounds in Respiratory Care HING iNG A Tape ESSION Two Ways To Earn Continuing Education Videoconference Broadcast Credit Earn continuing education credit by viewing the program 1. Live 2. Teleconference • Earn continuing education credit by viewing a videotape (provided after the live broadcast) and participating in the scheduled live Telephone Question-and-Answer Session. Satellite • Clinical hocus Respiratory Care Issues Mitnagemeiit of Life-Threatening Asthma with Uavid J. I'icrson, MD, and Richard D. Branson, RRT • Live Broadcast February 20, 12:30 p.m. to 2:00 p.m. •Teleconference March 11, 12:30 p.m. to 1:00 p.m. #3* Managing Demand for Respiratory Care Services with James K. Stoller, MD, and Sam Giordano, MBA, RRT • Live Brcidcast May 21, 12:30 p.m. to 2:00 p.m. • Teleconference June 10, 12:30 p.m. to 1:00 p.m. • #4 Capturing Respiratory' Services Outside the Hospital Part I: Home Care with Moderator Sam Giordano, MBA, RRT • Live Broadcast July 9, 12:30 p.m. to 2:00 p.m. • Teleconference July 29, 12:30 p.m. to 1:00 p.m. #6 • Capturing Respiratory Services Outside the Hospital Part II: Subaatte Care with Kevin Cornish. RRT, and Sam Giordano, MBA, RRT • Live Broadcast October 15, 12:30 p.m. to 2:00 p.m. • Teleconference November 18, 12:30 p.m. to 1:00 p.m. — — Managing the Ventilatw: VC'hat and When with De.in R. Hess, PhD, RRT, and Richard D. Branson, ni- • • RRT — April 12:30 p.m. to 2:00 p.m. Teleconference — April 22, 12:30 p.m. to p.m. Live Broadcast — — :00 1 • Live — — 2, Theory and Application of Neonatal VentiLitian: What, When, and with Rob Chatburn, RRT, and Richard D. Branson, RRT #5< live. Why — August 27, 12:30 p.m. to 2:00 p.m. — September 12:30 p.m. to 1:00 p.m. Broadcast • Teleconference — — 16, Airway Management: #7< Tricks of the Trade with Charles G. Durbin, ML), and David J. Picrson, • Live Broadcast December 10, 12:30 p.m. to 2:00 p.m. • — Teleconference — December 19, 12:30 All times listed are for Eastern Time Zone. p.m. to 1:00 p.m. — Each staff incmber completing CRCE requirements can earn one continuing education credit for viewing each program in the series or a total continuing education credits for viewing the entire series. However, participants must view the program live or participate in the telephone session in .\ccre(iitntion ol seven MD order to receive credit. Registration — Includes technical information, proctor guide, continuing education packet, Live Broadcast S.itellitc Nonmemher AARC Member ôu need will Single Program satellite reception, Ku or C Four All Seven Progr.ims $910 $850 $295 $260 B.ind capahiluies, .tnd a certificate, Clinically Focused and post test. Programs Three Respiratory Care Issues Programs $685 $635 television monitor $550 $485 Single Program .Ml Seven Programs Four Clinically Focused Programs Three Respiratory Care Issues Programs $295 $910 $685 $550 $260 $635 $850 $485 A videoi.tpe of the program will be provided to registered teleconference sites after the live program. The only equipment required for the videotape and Telephone Question-and-Answer Session is a VHS videocassette player, a television monitor, and a telephone/speaker phone with a mute button or conferencing unit. IMPORTANT: You must provide the telephone number of the room where the videotape will be viewed. Teleconterencc Nonmembcr AARC Member Nideotapes'-' Single Nonmemher AARC Member $295 $260 Program All Seven Programs $910 $850 Four Clinically Focused Programs Three Respiratory Care Issues Programs $550 $485 $685 $635 V'ideotape-onK subscribers do not receive continuing education credit. Group Discounts' 1 Facilitv No "''Discount is Discount .tpplicd to each site's registration. 2-25 Sites 26-50 Sites 51+ 25% 30% 40% Discount is not allowed tor multiple lacllities viewing Rexistration Please Register My Site for the Following Programs. Check the Appropriate Bo.xes Below: I.L.^ Live Satellite Broadcast Rej;istration or LJ Teleconference Registration or u Videotape Only (CE Credit 2. 1 I 3. All Seven Programs #2 #1 Method of Pa> ment D Check (payable D n to Four Clinical D Programs G #3 AARC) #-t Not at one site. Available) Three Respiratory Care Issues Programs #5 D #6 D #7 Purchase Order No. Card Number Credit Card: ExpiralKin Date AARC Member Number. Sites C N'isa MasterCard Signature_ . Name Institution .Address C'itN 'State/Zip Teleconlerence Telephone Q&A Participants, Provide a Telephone Number of the Number Room Where Program Is ( Viewed. .). Number ( Mail registration form to: American Association for Respiratory Care, AARC Videoconferences n030 Abies Ln., Dallas, TX 75229 4593 • (214) 243 2272 • Fax (214) 484 2720 1996 Summer Forum Registry Hotel, Naples, FL Ins L Here JL 'k^ .1 i 1 S i ^„ J.. i J. L lies Vt t V. t. ook closely. the reflection of your good judgement. In recognizing that your patients rely upon the most qualified Bennett brings you effective informa- dence and confi- to Dr. C. Price, M.D., CM., and Gail Lang, RRT, of Credit Valley Hospital in Ontario Canada, new trending parameters waste your own energy attempting to estimate the complete daily nutri- accurate assessment of our checks. See your patients more clearly patient's nutritional requirements assisted us in To find out more about our "New making the necessary adjustments to quickly wean him from the ventilator." 7250 Metabolic Monitor energy expenditure. So you won't tional picture fi-om inconclusive spot "In our opinion, the 7250 and clarity. Introducing for the making them with F.R.C.P. Metabolic Monitor provided an clinical decisions, Nellcor Puritan tion tools for According Tools for Greater Insight," contact the world's leading supplier of ventilator systems. Call Nellcor Puritan Bennett Together, with the 7200' Series Ventilator, they comprise at a ventilatory system that gives you more than respiratory and metabolic data. the means to look It gives you beyond the surface to c\aluatc a patient's status at a glance. We even make continuous trending look easy. With the new Graphics 800-255-6773 (U.S.A.) 44-181-577-1870 (Europe) 2.0 619-929-4551 software option, you can opt for a (Far East/ Latin America) breath-by-breath display of metabolic parameters like Oi consumption, CO: NELLCOR PURITAN production, respiratory quotient and BENNETT,. With the new 7250 Metabolic Monitor and Graphics 2.0. trending parameters such as VO, clearly show your patient's response to decreased ventilatory support 7200 and 7250 are Irademarks of Puritan-Bennett. during weaning. ©1995 Nellcor Puritan A-AA221O-00 (9/95) Circle 155 on reader service card Bcnncll. All righti rcsened 32 RE/PIRATOR\J CARE A Monthly Science Journal. Established 1956. Official Journal of the .-Xmerican Association for Respiratoo' Care. Editor Contents BA RRT Pat Brougher 19% Number 2 February ... Volume 41. Associate Editor Kaye Weber MS RRT Editorials Editorial Office 11030 Abies Lane Dallas TX 98 75229 (214)243-2272 Respiratory Care Education: Current Issues and Future Challenge.s hy Lucy Kester and James Editorial Board James K Stoller Ohio Original Contributions MD. Chairman 100 Cleveland Clinic Foundation Cleveland, Ohio Evaluation of a Commercial Standard for Checking Pulse Oximeter Performance by Teresa Richard K SlolU'i—Clcveiaiul. D Branson RRT A Volsko. Robert L Chatburn. and Thomas J Kallstrom—Yoiingstown and Cleveland. Ohio University of Cincinnati Reviews. Overviews, Medical Center Cincinnati. Crystal L Dunlevy EdD The Ohio & Updates Ohio 105 RRT Tracheal Gas Insufflation: Adjunct to Conventional Mechanical Ventilation A Ravenscrafl—Sl Paid. Minnesota State Universit\ by Sue Columbus. Ohio Charles G D tub in Cardiorespiratory Interactions MD Jr The University of Virginia Health Sciences Center 1 1 Foreword: by Barbara Thomas D East PhD LDS Hospital Lake 1 1 Dean R Hess PhD G Wilson, Jon N Meliones. and John M Pahnisano Arbor. Michigan Understanding Cardiorespiratory Interactions: Anatomy and Physiology by Charles A Trant. Frank H Kern, and Jon N Meliones— Cardiovascular Utah City. Teaching Feature for —Durham. North Carolina and Ann University of Utah Salt A New RESPIRATORY CARE Charlottesville. Virginia RRT Durham. North Carolina Massachusetts General Hospital 123 Harvard Medical School Neil Duke R Maclntyre Jr The Role of Cardiorespiratory Respiratory Care by Donald R Black. Barbara Boston. Massachusetts MD G Interactions in Wilson, and Jon N Meliones— Durham. North Carolina University Medical Center Durham. North Carolina Shelley C Mishoe PhD Books, Films. Tapes, RRT 133 Medical College of Georgia Pharmacology & Software for Respiratory reviewed by Hugh S Augusta, Georgia Care Practitioners Mathewson— Kansas Citx. Kansas PhD RRT Joseph L Rati Georgia State University Atlanta. Georgia Respiratory Care • February "96 Vol 41 No 2 83 Here^s one you^ve really got to see! The New JCAHO Their Effect A Videotape in Hospital Standards: on Respiratory Care from the Professor's Rounds Respiratory Core Videoconference Series Featuring Nancy Telford, BS, RRT, Program Manager, Joint Commission on Accreditation of [Healthcare Organizations, with Moderator Sam P Giordano, MBA, RRT, AARC Executive Director The new J995 Aaredilalion Manual impact patient outcomes, and llie lor Hoipilak slondords ore you single chopter Ttirough this overview, thon competence progroms, responsibilities of is now organized around now Pleose send me New JCAHO "The .Viso and the role of directors, department and expectotions on perlormonce improvement. staff. Chorge MasterCord. Cord expires to Purchase Order Please Nate: Videotapei do nol quolily viewer for CRCl credit. Signature Nome/lnstitulion_ City/State/Zip_ Mail to: AARC, 11030 Abies AARC Ln., Dallas, TX 75229-4593 — Spirometry $1 — Oxygen Ttierapy Acute Care Hospital $1 3 — Nasotractneal Suctioning $1 4 — Patient-Ventilator System Cliecks $1 SI 5 — Directed Cough G — In-Vitro pH and Blood Gas Analysis and Hemoximetry 7 — Use ot Positive Airway Pressure Adjuncts to Bronchial Hygiene Therapy SI 8 — Sampling tor Arterial Blood Gas Analysis $1 9 — Endotracheal Suctioning of fvlechanically Ventilated CPG27 CPG28 CPG29 CPG3Q in 243-2272 • FAX (214) 484-2720 Arliticial ~ Incentive Spirometry $1 — Postural Drainage Therapy Airways $ Changes $1 — Transcutaneous Blood Gas Ivloniloring tor Neonatal & Pediatric Patients $1 Body Plethysmography $1 Capillary Blood Gas Sampling tor Neonatal $1 Defibrillation during Resuscitation • Infant/Toddler Pulmonary Function Tests $1 Facility • CPG42 — Polysomnography and Pediatric Patients $ $1 Set in Binder (-f$4.50 for Stiipping Call (214) 243-2272 or with rvlasterCard, \atei Ion (including S35 and HancJIing) American Association for Respiratory Care 11030 Abies Ln., Dallas, TX 75229-4593 — odd 8.2S% $1 1 CPG93 - Complete — Tfxai cuilomfM only, pleoie Ivlechanical Ventilation — Selection of an Aerosol Delivery Device for Neonatal $1 ihippmg chargei). Te\ai cunomen that ore exempt Irow so/es tax Visa, or mull otioch on exemption fax to (214) 484-2720 Purchase Order cenificote. Pficei $1 $1 CPG41 CPG23 - Intermittent Positive Pressure Breathing (IPPB) $1 CPG24 — Application of CPAP to Neonates Via Nasal Prongs or Nasopharyngeal Tube S1 Delivery of Aerosols to the Upper Airway $1 CPG25 Neonatal Time-Triggered, Pressure-Limited, Time-Cycled CPGZG $1 Pediatric Patients in Capnography/Capnometry dunng in • • h — tvlanagement of Airway Emergencies $1 — Assessing Response to Bronchodilator Therapy at Point of Care — Discharge Planning tor the Respiratory Care Patient $1 — Long-Term Invasive Ivlechanical Ventilation the Home $1 • Ivlechanical Ventilation $1 $1 — fvletabolic tvleasurement using Indirect Calorimetry — — $1 in Static — Ventilator Circuit CPG32 CPG33 CPG34 CPG35 — CPG3B CPG37 CPG38 CPG39 CPG4D —- 1 — Bronchial Provocation $1 — Selection of Aerosol Delivery Device $1 CPG14 — Pulse Oximetry $1 CPG15 — Single-Breath Carbon Ivtonoxide Dittusing Capacity the Home or Extended Care CPGIB — Oxygen Therapy CPG17 — Exercise Testing tor Evaluation ot Hypoxemia and/or Desaturation $1 CPG18 — Humiditication during Mechanical Ventilation $1 — Transport ot the filechanically Ventilated Patient $1 CPG19 CPGZO — Resuscitation Acute Care Hospitals $1 — CPG2I Bland Aerosol Administration $1 — CPG22 Fiberoptic Bronchoscopy Assisting $1 — Lung Volumes $1 — Surfactant Replacement Therapy during Ivlechanical Ventilation CPB31 $1 • Adults and Children with CPGll CPG 12 CPG13 • (214) Clinical Practice Guidelines 1 2 CPGIG (S305 nonmembers! (S305 nonmembers) #_ Address CPG CPG — S275 — S275 Card# _ AARC Member Number CPG CPG CPG CPG CPG CPG CPG 90 minutes. Item VC51 Hospital Standards: Their Effect on Respiratory Care." Item VC51 Payment enclosed S_ Chorgetomy learn about slondords reloted to will department leoders ond medical This video olso reviews the inleroclive survey process functions thai integrated into functional diopters rotfier Number wbiecl to chonge without notice $1 February 1996 Managing Editor Ray Masferrer Contents BA RRT ASSISTANT Editor Kris Williams 41, Number 2 Classic Reprints BA 134 Editorial Assistant Linda Barciis Volume Retrospectroscope Redux: Out of the Mouth of Babes BBA /)\ Julius H Comroe Jr— Reprinted, with permission, from the .American Review of Respiralon Disease 1976:114:1001-1009 Section Editors R Fluck Jr MS RRT MS Jastreniski MD Letters Robert Blood Gas Corner Hugh 142 Phil Kitlredfie— Little River. Califcruia MD S Mathevvson D)»g Capsule 142 D Richard Kinreclne 's A Scientific Basis for Therapeutic Wa\t}e RRT RRT Branscni Robert S Campbell Editor as Death Dealer C Anderson — Pitlshnri;h. Response from Steplumic Hinnes Touch? Penn'^ylvania —.Areata. Cidifornia Corner Correction Jack PhD Charles G Wanger MBA RPFT RRT lr\ in 1 1 1 Conected PFT Corner Palricia Charles Test G Durbin JA. Fink JB. MS RRT Ann Doorley MD Birenbaum RRT MD MD James M Hurst MD Robert M Kacmarek PhD RRT Donald R Elton RRT Michael McPeck BS MD John Shigeoka MD id J Jeffrey J 155 AARC 86 Abstracts from Other Journals Advertisers Index & Help Lines 160 160 159 145 148 157 152 144 Ronald B George Da\ determine COPD. 0-\yi;en pre- Respir Care RRT Frank E Biondo BS J to In This Issue Consulting Editors Robert L Chatburn Use of pulse oximetn- 1996:41{l):30-36 )'oiir Railioloi;ie Skill Howard Lant^hein WE. Skorodin MS. Hultmon CI. Jessen scription for Inpo.xemic patients with MD Jr abstract EM. Haiiartx Pierson Ward MEd RRT Meinbership Application Author Index Calendar of Events Call for OPEN FORL'M Abstracts Manuscript Preparation Guide MedWatch New & Products Services Notices Production Ste\e Bow den Donna Knauf Karen Sineleierrv Marketing RESl'IK vr()R\ Dallas Dale Griffiths TX C XKK (ISSN (K)20-I324) published miinlhl> by Daedalus Enlerprises Inc. i'. 75224-4593. lor the American Assixialion lor Respiratory Care. each January. Subscription rates are $65 per year Direelor The contents of in the the Journal are indexed in Hospital US; One \olunie is SSI) in all other countries l ;il I HWI Director ofAdverlising Sales Second Beth Binkley class postage paid at Dallas bei ship Office. TX. PO.STMASTER: Send address changes Daedalus Enterprises Inc. 1 I D.IO L;ine. lor ainnail, add $84). and Health Administration Index. Cumulati\e Index Nursing and Allied Health Literature, and Excerpta Medica. Abridged versions ol RisspiRATORY published in Italian and Japanese, with permission from Daedalus Enterprises Inc. Tim Goldsbury Abies published per year beginning Abies Lane. Dallas TX to to CARE are also RESPIR.ATORV C\Ri;. Mem 75229-4593. Advertising Assisknu Respiratory Care • February "96 Vol 41 No 2 85 ) 1 Abstracts Summaries of Peninent Articles in Other JoumaU Commentaries, and Reviews To Note Editorials, Community-Acquired Pneumonia— JG Banleil, LM Muiuly. N Engl J Med 1995:333(24): 1618- 1624. Pathophysiology of Dyspnea (review) — HL Manning. RM Schwanzstein. N Engl Med J 1995; 333(23):1547-I553. ) ( mittee on Fetus and on Obstetric Practice. Pediatrics 1995:96(5, Part tee Comparison of Dynamic and Passive Measurements of Respiratory Mechanics tilated Keens, Ven- in Newborn Infants — .\ Kugelman, TG R deLemos, M Durand. Pediatr Piilnionol — American Academy of Pediatrics ComNewborn and American College of Obstetricians and Gynecologists Commit- Perinatal Care at the Threshold of Viability statement of 2):974-976. 1 term infants were 689f and 649; of R,„, equation of the regression line was Re + 63 and 20 R,. = cm HjO 0.5 R,, s L-i, + 20, with and r SEE = and the 0.3 R,^ of 25 and of 0.65 and 0.69 (p < 0.0001 p < 0,005), respectively. The 2 methods 1995:20:258. , are noninvasive and were well tolerated. We con- 0.0 inter-quaitile range, 0.0-0.3 in tlie laboratory. ( vs 2.4/lir inter-quiirtile range 1 ( ian difference of 2.4/hr (p med- .24.2). with a < 0.001 ). Study dura- apnea/hypopnea index, desaturation index, lion, respiratory and spontaneous movemenl/arousal and oxygen saturation during sleep were indices, home and Although and clude that passive and dynamic respiratory com- simiUir for ventilated infants depending on whether they are pliance and resistance measured in intubated neither sleep state nor Pco; (transcutaneous or end- ineasured by a dynamic or passive method. The infants are highly correlated, although the values tidal) measured by the passive technique are higher than vMiuld have modified patient those obtained by the dynamic technique. most, mechanics may I'ulnioiiiUA was objective of this study tory differ in intubated compare to respira- mechanics measured by a dynamic technique in newborn ventilated one preterm and 15 tenn tational age, 29.3 weight, 12± ied. 1 .2 ± 0,5 and 13 and 5 infants ± 2.3 and 3.4 39.5 ± 0.4 infants. Thirty- efficiencies, apnea/h\ uration indices. weeks: birth kg; postnatal age. were stud- circuit; tidal volume by gration of (low, and airway pressure directly a pressure transducer. Airway occlusion the following relaxed exhalation FM Duchamie, MD Schloss, RT Brouil- accuracy and practicality of w ith atric obstructive sleep was per- inspiration, and was analyzed to to home determine the sible OSAS once in the 2- 1 apnea syndrome lOSASi 2 yciiis and referred at a cardiorespiratory record- give passive respiratory system compliance (C^) sisted of 2 parts: and resistance (R^). These values were compared ing of saturation (Sô;), pulse rate, pulse vvave- with dynamic respiratory system compliance fonii, electrocardiogram, ( 1 ) popnea is and respiratory inductive Congenital Stridor —G CicliiK-ka-Jarosz. Pediatr Lis, boy/girl ratio was 2:1, Fiberoptic in without an esophageal balloon and on the same standard nocturnal polysomnography including most common form larv Dynamic electroencephalography was pert'ormed. Expe- to large, riences PEDS and the home nificantly Bicore systems did not differ sig- and were well correlated. Mean Cjy„ (P) values in preterm and term infants were 779; and 779; of C^.: the equation of the regression C was Cj^„ = 0.75 - 0.02; and standard was 0.2 and coefficient 0.3 (rl specti\ely. Ttie 86 -I- 0.02 and C.,y„ = 0.78 Cp, error of the estimate mL/cm H;0 (SEE) with a correlation of 0.89 and 0.89 Ip < 0.0001 mean R^. line ). (P) \alucs in pretemi re- and w ith another 62 testing alone reported. At home, were also 1 respectively. home .69f , The iewed and are re\ saturation, respiratory, and 90.0 + 1 7.89?; sleep efUciency than in the laboratory. 9 and ± 3.3% (mean ± video data were obtained 96,4 SD) 99.4 ± w ho underwent children 1 . 1 of the time, was greater at ± 3.99i vs 86. . ( 1 1. bronchoscopy cause of stridor was of ngoma- larv 34 children (65'-; ). The ngomalacia was due floppy arytenoid cartilages; this was observ ed Iw ice as often as other forms of laryngomalacia and boys suffered from more than twice this abnormiility as often as girls. Children with laryngomalacia had significant weight (249; height 89f ( ) deficits in w ith larv ) and comparison with the normal healthy population (p < 0.001). In patients 7.29i w ith a mean difference of 5.09} p < 0.0 The median environmentally induced movement/arousal Index was lower in the hcmie than ± E was performed w hen other diagnostic methods had failed to establish the origin of stridor The which was found respiratory system Szczerbinski, Fifty-two infants and children with stridor were common ventilator settings. T examined. The median age w as 5 months and the lacia, compliance and resistance measured with the and desat- Pulmonol 1995:20:220. most 1 (2) indices, adenotonsillar hyperu-ophy. an 8-hour videotape obtained with the PED.S ssstem IP) within plethysmography: and were suc- accurate and of practical use recording of the sleeping child. In the laboratory, and dsnamic expiratory resistance (R^l studies evaluation of OSAS in patients with hour, (C,i,„) all for pos- home ;ind The home test con- were studied twice, once sleep laboratory. home, testing for pedi- secondary to adenotonsilktr liypertrophy. Twenty- one children aged in, at using a simplified cardiorespiratory montage plus in the routine The objective of this study was information We conclude that home testing, video recording, Pediatr Pulmonol 1995:20:241. lette. inte- tbrmed with a Neonatal (X'clusion Valve (Bicore end of Mograss, pneumo- a tachometer placed between the endotracheal tube at the ndrome .Secondary to AdenotonsllHypertrophy— SV Jacob. A Monelli. MA at lar .4 this management cessfulh recorded despite a wide range of sleep ,\pnea S) 1 home, second group of 62 children, (mean ± SD: ges- Flows were measured through pulmonary monitor) Home Teslin;; for Pediatric Obstructive .Sleep in the ± ±4 days, respectively) and the ventilator case. In the 1 exclusively studied with those obtained by a single-breath occlusion technique was measured laboratory smdies. all but 4 ngomalacia. blood gases were within normal limits. In 18 children (359} (stridor was not caused by laryngomalacia. This group showed RESPIRATORY Care significant etiologic heterogeneity. • February "96 vol 41 How- No 2 5SESS® . ' Flow Meter ^ In status Don't guess. bsthmaticus: NAEP Adult Emergency Guidelines:^ PEFR Assess. 40-70% of predicted vafue after 4 hrs tx in ER. Rapid initiation Consider successful hospitalization. the and close monitoring of therapy are ER management of severe vital to asthma.' That's ASSESS' Peak Flow Meter should be a vital part yoiu- ai-mamentarium. ASSESS lets you — Measure airway obstruction why of easily, accurately, cost-effectively. Peak expii-atoiy flow rate (PEFR) provides an objective, at a fi-action cUnkally relemnt measui-ement of au-flow conventional of of the cost, bulk, and inconvenience spirometry.- And when seconds count, you can covmt on ASSESS to deliver those measurements with superior — accui-acy and reproducibility.'"'' Evaluate response to therapy and need How is From for hospitalization. yom- patient doing? What should you be doing? initial presentation thi-ough dischai-ge, the rugged, — as compact ASSESS gives you the haixl data you need treatment infoi-med make you help to often as you need it — decisions in line with NAEP recommendations.- Help prevent future acute exacerbations. come back when their maintenance therapy and a Keep it on track with ASSESS work, or home, at monitoring regular program of PEFR Patients don't — stays on track. school — as a routine part of your discharge orders. For more information about how ASSESS can help you deliver better asthma cai-e, call HealfhScan Products at 1-800-962-1266. Ai Peters REFERENCES' «(6) 829-849 1992 1 2 Jl Rossrucker t>lalional menlol Asthma Bethesda, IvID; J; Current concepts in manaamg Asthma Education Program- Guidelines U,S Dept. of Health & J flesfi/a the Diagnosis snaMan^ge- status aslhmaticus. lor NIH Pub, No, 9 -3042 Hendler JM, Ogiia^ RG c aL An evaluation Hurrian Services, 1991. m. HealthScan Products Inc, 4 Stiapiro Gardner RM^ and MiniWripht peak flowmeters, ChesI 99(2):35B-362 1991 5 of peak flowmeters at 1,400 m Craoo RO Jackson BR et al,: Evaluation of accuracy and reproducibility Products HealthScan 1993, 5/93 AA710003-0 Cte/ )0i(4): 948-952. 1992. 3 Data on tile, the accuracy of Assess , © Circle 119 on reader service card of STANDARD RANGE 60 to 880 t/mm Peak Flow Meter LOW RANGE 30 to Setting the standard for peak flow monitoring. 390 L/min — . Abstracts ever, identification of the cause of stiidor in these patients important because specific treatment is JECTS: Thirteen healthy, anesthetized mongrel dogs. Three dogs served as controls and were can he offered and prognosis depends on the type immersed but not submerged. and cause of the anatomical and functional abnor- submerged mality present. i4" and Short-Term of Ktfects lerni l.oiiji- INTERVENTIONS: C). placed in the were Tlie remainder cold fresh water or cold in w ater salt DAT.A agents to permit optimal drug therapy. SOURCES: Review ical and of the English language clin- MEDLINE data scientific literature using STUDY SELECTION: search. Literature refer- Catheters were ences were selected through a key word search femoral artery, right carotid arters of sedative therapy, drugs used for sedation, and jugular vein. Electrocardiogram, •mil light internal neurologic disonlers and processes to pro- six'cific Alhiitfro! Aerosol Thcnip) In Cystic Fibrosis: pneumogram. and were mea- vide an in-depth overview of sedative drug mech- A sured continuously during submersion/immer- anisms of action, effects on neurophysiology and Report I'ri'llminary Barbcro, .1 Konig. -I' Gayer. GJ [J Pulmonul ShalTer. Pediatr W5;20:2(lri, I rectal teniperalures MEASUREMENTS & MAIN RESULTS: sion. Cold water submersion with drow ning produced of maintenance albuterol aerosol riic effectiveness therapy in cystic fibrosis (CF) was assessed by comparing spirometric measurenient.s ning and end of begin- at the Peak expiratory flow year. I rates tem- a large initial decrease in carotid artery perature (-7.5° C in the first 2 mins) compared C with immersion). with a minordecrea.se (-0.8° No significant differences were noted in the rate (PF.FR) were measured twice daily to determine of decrease of temperature between drowning bronchodilator responsiveness and spontaneous fresh water diurnal variation (SDV). and were com- results pared with groups of normal and asthmatic chil- CF patients not and salt water. Dunng in cold fresh water drow ning. aspiration prixiuced gniss hemodilution « ith an average increase in body weight of 16.5'i intracranial dynamics, phaniiacokinetics. and toxSpecial emphasis icity profile. ical and was placed on neu- DATA EXTRACTION: rologic side effects. Clin- was reviewed and data scientific literature relevant to neurophysiologic effects of sedative drug therapy were summarized. Recommendaand of p;ir- tions for institution of sedative therapy ticular agents of all cally were made as a DATA SYNTHESIS: pooled data. patients ill w result of analysis Criti- neurologic pathology pre- ith receiving regular albuterol Hematocrit values, serum sodium concentrations, sent as a unique subset of individuals cared for therapy served as a control group. In the treatment and osmolality decreased while serum potassium in concentrations, catecholamines, and free hemo- neurologic patients requires frequent assessment globin increased. All measured biochemical data of the neurologic examination, the goal of seda- dren. group, forced ratoiT \ vital olume capacity second in the first nificantly increased ( (FVCl and FEV ( were ) i sig- and 18.4%. respec- 2.2*;^ 1 forced expi- over the course of the treatment year, as tively) contrasted with a significant decrease during the preceding trol ye;ir. During the study group had a significant decrease FEFi5.75ri. PEFR FEFi.s.vs'j. the last FEV| and significant for FVC, FEV|. increased from the first to week of the year-long observation period (from 71.89; 0.01 in and the difference between treatment and control groups was and CF con- ye;ir the to 78.79; of predicted values, p < Spontaneous diurnal variations were ). nificantly greater in the CF group of normal children; nificantly in study group than a SDV decreased sig- treatment group during the year tlic A bronchodilator response of > of study. sig- I .'i9'f present in 25.89; of CF patient days, but there (except PjQ.) remained during cold trast, salt at viable levels. By con- ti\ an acute care setting. Because monitoring of e therapy should be to enhance, or to minimally w ater drowning, average perturb elicitation of the examination. Neuro- w ith hemo- physiologic disturbances introduce distinct risks body weight increased by only 69; . and require and conccnlration and a shrinkage of vascular vol- for sedation ume. Hematocrit and hemoglobin \akies in- understanding before the initiation of any seda- plasma their identification free tive therapy. Sedative drugs, in particular, act to hemoglobin values remained unchanged. Senim disturb central nervous system function and their sodium concentrations, osmolality, and potas- effects sium concentrations increased rapidly ther neurologic deterioration. by creased cal levels. but 309'r. initial CONCLUSIONS: On cold water, all to criti- submersion in of the experimental animals developed tachypnea immediately, followed by ration with predictable elTecls. aspi- The biochemical and pathophysiologic changes in cold water was drowning approximated those changes reported was for warm water drowning for both fresh and salt exception and continued aspiration may result in diagnostic confusion and fur- The pharmacokinetic common and neurophysiologic actions of the classes of sedative agents, such as benzodiaze- and neuroleptics, as pines, opioids, barbiturates, well as ketamine. propofol. ami cloniiline are dis- Recommendations cussed. are presented based on the specific type of sedation required and the underlying neurologic disturbance. Several spe- examples, including head trauma, neuro- considerable interpatient variability. Frequent bron- water with chodilator responders were accurately predicted of cold water produced extremely rapid core cool - muscuku' disease, and alcohol withdrawal, are pro- by their baseline bronchodilator responsiveness, ing as long as the circulation remained intact. This \idcd. hut not by age or personal or family history of process of acute submersion hypothermia may neurologic examination asthma or atopy. No difference in long-term pulmonary function improvements were noted between frequent and infret|uenl responders. The maintenance albuterol aerosol results suggest that treatinents reversed the progressive course A in lung function double-blind downward CF treatment group. in the placebo-controlled study is required to confirm these preliminary findings, saka. D M Katayama. Bohn. Crit Care M Fujita. Med H Orima. ]^)9y.2M 1 G Barker. the pathophysiologic changes occurring during drowning water and cold bility. trolled salt water u ith DESIGN: Randomized, SETFING: A prospective, conin 2 contrasting laboratory at a universitv-afniiated medical institution. 88 \ la- large SUB- menting sedation lamines increased exponentially of test the in both groups animals. Clinically, their acute effects on circulation, compounded by significant ill Preservation of the paramount is docu- in improvement or deterioration clinical drowning. Concentrations of circulating catecho- in neurologic patient. Phaniiacologic in this unique population of acute care patients requires c;uelul consideration of under- tlie lying neurophysiologic disturbances and potential ad\ erse effects introduced by sedative drugs. hypothermia and extreme anoxia, must hamper the detection of residual circulation 111 at rescue and play a role in sudden ilcath from cold w atci Quality of Fife Measures before and after tack. Sedation for the Critically OF Hanley. Crit Care III M nv to Noscwoilhy. Med Grace. Crit Care Med I la 1445:2.^ ( )BJECTIVE: To assess outcome ted to ;m intensiv e ciirc unit \ review the scientific basis sedation of critically ill neurologic patients by lor sum mari/ing the distinct neurophysiologic disturin this the central nervous I nil R Johnston. A I Shus- W5:2.3: I65.\ ( ICU ol patients ). population and presenting system effects of sedative arious quality of life ailmission to the ICU. |iarison of quality of admission to the ICU. RESPIRATORY CARE • emphasis on measures before and DESIGN: life Prospective before and 1 PATIENTS: ICU over a I after com- year after SETTING: Eleven-bed medical/surgical ICU. admitted to the admit- using a prospective l-ye;u' follow-up. with special OBJECTIVE: To One Year an Intensive Care Nenrologic (12):2038. bances present Admission L Konopad. the absence of drowning. cold fresh reference to submersion experiments cold liquids. in CONCLUSIONS: the critically Patient— MA Mirski. B Mullclman. )\ 2 1:2024. cific age, as reported in cases of cold fresh water towski. OBJECTIVE: To compare dam- protect the brain temporarily from lethal may A Canine Study of Cold Water Drownln); in -WV Conn. K Mi\aFresh >ersos,Sall Water I adult All patients -year period were FEBRUARY "% VOL 41 cli- NO 2 ) Abstracts were enrolled onl> on 1 first admission. Patients < months. At who died w itiiiii admission were excluded. INTER- ing at 7 years of age and those patients 24 hours of VENTIONS: lected before Qualilv of and 6 and life sion. and hospital datii stay; were ICU. ICU admis- their and 1 life) and 12-month and place of residence 2 months after ICU Mean ICU pital length of stay and iology (APACHE tality; and 1 II) score was 14 1 ± 7. .^cute Ph\ Evaluation it\ p < 0.0 1 year after very elderly, per- in the As well, the major- Civ Care Med I995:23( 10): I620-I62I. timony from the presenters as the basis of cussions on tlie testing Care Monitoring Devices ing principles and specific recommendations were made based on the testimony given. MAIN RESULTS: The panel detennined the main coi(stituents of the medical dev ice approval process to be the Food and Drug Administration (FDA), the research and community, and clinical — between inonitoring and interventional device devices. Potential alternatives to randomized, blinded, controlled study designs for device test- Phv siologic Monitoring Devices. Crit Care II 1995;23(I0):I756. Med ing are: (a) nonblinded, randomized, one design); OBJECTIVE: To management protocol-driven study; (b) crossover study (n-of- Cumulative mordevise alternatives to randomized, controlled, clinical trials that clinicians and research experts might find acceptable for patients. Rel- cat- document addresses only monitoring egories. This Coalition for Crit- s- approval of devices used a decrease in the le\el the made Care Excellence: Consensus Confeience on and Related Interventions ical dis- and approval process. Guid- in critical care medicine. by care (c) design; (f) (nmdomized cluster-randomization unit); (d) case-matched contiols; (e) mixed on/off design (before-after); and (g) historical controls. CONCLUSIONS: The panel agreed on the following major recominendations: FDA montlis DATA SOURCES: Tlie Coalition for Critical C;ae (a) the Perceiv ed health status increased o\ er Excellence (Coalition) of the Society of Critical cific Care Medicine organized a consensus conference ucts with the assistance of the Coalition (prior- and ). although tiveness of Critical 3.5%, 6 month 20.6%, were completed for 293 was , I Standards of Ev idtncc for the Safet> and Effec- ± 5.5 . ative to baseline, there ( Health hospital age ±7.4 days. Hos- 1 1 sta> in tlie level device manufacturers. Distinctions were month 25% One year quality of life ques- tionnaires of acti\ 4..^ was 3 ± 4 days, Chronic ICU 5.4%. 2 was DATA SELECTION: The expert panel used tes- have a decrease baseline female and 275 male. 22^) length of stay criteria; cess for testing and appixwa! of monitoring devices, Patients admitted ) Weil. admission. There were 504 patients w ho met the study 20 years (median 54), at CONCLUSION: (89% of patients return home. Sci' ilic rchilal ccliliirial: Life Measures before and One Year after Admission to an Intensive Care Unit. MH of daily living, perceived health, support, and outlook on ICU ity mortality; quality of life (level of activity, activities home. ceived health status increases. collected: duration of ICL' hospital. 6- testimony to a panel of experts regarding the pro- life, at 262 (89%) patients were of activity and activities of daih living ME.ASUREMENTS & MAIN RESULTS: The following year, 1 to intensive care tend to measures were col- 2 months after 1 12 liv- from family or friends, or outlook on gible for incliisKin in this study. Repeat admissions acti\ities the year for patients of dail\ living at 12 > 75 years of age p < 0.0 ( There was no difference in the level 1 of support ni which recognized critical care researchers gave should accelerate publication of spe- guidances for physiologic monitoring prod- ities and content); (b) more multidisciplinary Are Your Pulse Oximeters and Sensors Functioning? ...How Do You Know. The PHANTOM Knows! The NONIN FINGER PHANTOM™ simulates the r;--- light ^^rpre^' and absorption arterial blood flow of the human finger. It is designed to test most pulse oximeters using transmittance type sensors. //i Nonin Medical, Inc. 2605 Fernbrook Lane North, Plymouth, MN 55447-4755 Fax (612) 553-7807 (612) 553-9968 (800) 356-8874 Leaders in Noninvasiv. Medical Monitors J Circle 99 on reader service card RESPIRATORY CARE • FEBRUARY "96 VOL 41 NO 2 89 . . n : 1 ; 1 y ii ) j j \ u j aaI ui = it^ i= d li j iii â.. 7^Jir^^ Abstracts ^Poster Presentations AARC The Education Section is and experience implementing the lool<ing for educational research with models and instructional methods that may be useful in recommendations of the Education Consensus Conferences or other issues in respiratory care education. Special consideration will be given to abstracts and poster presentations that deal with multiskill curriculum and/or core curriculum. The 1996 Summer Forum, scheduled for July 12-14 In Naples, FL, will offer two opportunities for participants to share their scholarly activities with colleagues: 1 Research abstract presentations dealing with respiratory care education. (Paper will be limited to 15 minutes, including five minutes for discussion,) presentations 2. Poster presentations dealing with education models, methods, or materials that can be shared for noncommercial use. (Individual topics and presenters will be briefly introduced: additional time will be allowed for individual review of posters or display materials and interaction with the presenters.) Research abstracts and poster presentation proposals must be submitted by April 15, 1996, for review by the Education Section Review Committee. All abstracts and proposals will be peer -reviewed, and authors will be notified of decisions by May 15. Questions may be directed to the review committee chair, Pat Munzer. «% Proposals must include three components: 1 Cover sheet that includes the following information: a. Type of presentation (research b. Title of c. Names, primary name abstract or poster presentation) presentation titles, of the author work addresses, and day telephone numbers of the authors: the will present the paper and receive correspondence should be who listed first e. A statement of previous presentations or Two true/false questions with answers f. Other information required by funding sources d. 2. Camera-ready copy (without author 3. Camera-ready publications of the identification) for same or similar review by the committee original (with author identification) for possible publication work L L I I U L I V V I t It U lu L ill i; I e L I! In H Abstracts &Poster PRESENmTIONS Research Abstracts abstract double-spaced on plain white paper with one-Inch margins. The abstract should be written as a single paragraph and linnited to 300 words. The research abstract should Include Type the following: a. Title of paper b. Brief description of c. Brief d. Conclusions work statement of methodology and findings Two true/false questions with answers A maximum of two pages of camera-ready charts and e. tables may be attached to aid in the selection of the abstract. Poster Presentations Type abstract double-spaced on plain white be written as a single paragraph and should include the following: On paper with one-Inch margins. The abstract should 50 words. The poster presentation abstract limited to 1 paper a. Title of b. Brief description of the c. Brief statement of how it was developed and implemented d. Brief statement of how It was evaluated e. Recommendations f. Two model, method, or material or judged to be of unique value for future application true/false questions with a separate sheet, describe how answers the information Each manuscript should be double-checked for will be visually presented at the conference. completeness and accuracy before it is submitted. Spell out terms used for the first time, followed by abbreviations referenced testing (NRT). Thereafter, the term may be in parentheses, e.g., norm- abbreviated throughout. Please send the abstract and cover sheet to: Pat Munzer, MS, RRT, Program Director Respiratory Therapy Washburn University 700 College Topeka, KS 66621 (913) 231-1010, ext. 1284 1 I — ) Abstracts research should be incorporated into studies; (c) new commonly accepted clinical device may tools not need to be tested for clinical utility —these accepted tools should be identified by the Coalition; and (d) an independent council ot researchers The controls ib.Wc). Score and the American-European Consensus < 0,01) than the APACHE-matched controls, but was not statistically higher than predicted mortality (p = 0.416). Both the low-risk and the high- Conference definition was significantly better than was the high-risk group groups stayed ICU 3 times as Lung the Although risk to serve as consultants to nianulacturers regard- long as the ing appropriate study design tor the testing ol CONCLUSIONS: devices. See ihe rektleil editorial: Physiologic icall> Monitoring Devices. S Alperl. Crir Care Meil detrimental complications. Although patients value for I995:2.U 10): 1626-1627. requiring "high-risk" interventicms experienced conclude >909r for general medical patients Intrahospital transport of crit- (group 2). the low frequencv of in these safe and carries a is low risk of APACHE-matched Hlnli-Risk Intrahospltal Transport of Critically controls, the increase in mortality does not appear and Outcome of the NecJW S/em. H>do. E Fiscssar) "Road Trip" cher, S Kapur. J Klemperer. PS Barie. Crit Care to Med patients require a greater length of stay in the sur- — U lWs;:3(l()i:lf>60. be directly related to the intrahospital transport. more ill patients is Intrahospital transport of critically critically ICU and ma> gical OBJECTIVE; ICU Patients requiring trcuisport out of the surgical are a ill group of patients. These e.sperience an increased mor- by virtue of the severity of their tality rate ICU .ARDS racy of a higher mortality rate than did Patients: Salet> definitions maintained an accu- all 3 control cohorts. .APACHE-matched patients ill in the surgical when compared with the = 0.027 for both comparisons). Injury Score definition (p strict and clinicians should make themselves available III accuracy of the modified Lung Injury patients, the overall mortality rate (51.4'7( significantly higher (p in patients 3.49; ( a low positive-predictive CONCLUSIONS: We 3 definitions. all Lung that the pean Consensus Conference definition identify similar patients, provided that these diagnoses for ARDS. See the relatcii cdilarial: Measurements of .Medicine. RC Bone. Med IW?:2.if 10): 1619 1620. Multiple Oruan Dvsluiiction Score: Establishing the Relative .\ccuracy of Three Descriptor of a Complex Clinical (ICU) patients within the hospital has been asso- New JC ciated with a high rate of potentially detrimental tre.s.s complications. This study mine was designed to deter- the iK'cuiTence rale of transport-related plications have any and to detemiine on effect luiit com- Definitions of the .Adult Respiratory Dis- Syndrome —M PL Cjoodman, M L .Ackcrson, PE Parsons. Cril Heinig, S Barkin, Med Care \Uiss. patient morbidity and mortality. last few years, new definitions of the adult respiratory distress hundred seventy-five patients were transported been compared ICU operative interventions for diagnostic testing or deemed necessary by surgical or cntical ciu'c team. & MAIN RESULTS: Acute Physiology and Chronic Health Evaluation APACHE III (APACHE) and II scores were determined 24 hours after admission. Transport patients were stratified and high-risk transport groups. into low-risk Patients their MEASUREMENTS were considered a high-risk transport if (ARDS) have been vv any of the older and poten- ith of tially stricter definitions ARDS further stratified into groups .^ sented by the Lung DESIGN: ARDS 1 1 1 ) — against a were then followed during transport for any potentially detrimental their com- need for an increased dose plications, such as a n = 125). Intensive care in a tertiary, university-affil- tent validity to identify patients with lected daily to c\ aluate the performance of these dysfunction score. Seven systems defined the mul- ARDS MEASUREMENTS & MAIN of hypoxemia, static and gen- collected. Tlie V ariables indiv idually tiple tors ity 30 published meeting were identified as patients rence rate of complications was similar groups (low-risk group. i.y/r). The 6..^'7r; mortality rate for was 28.6";^. 0,01 ) which was However, there ( 10.9'; > 92 by When compared with a stricter definition of ARDS. all of accuracy all higher (p < conU'ol patients was no mortality as a number of patients. tive results divided high-risk group. renal tlie total 3 definitions maintained a high degree in those patients with a clearly defined at-risk diagnosis (group I ): Lung Injury Score 90.0^* (959; confidence interval 84-96); ified Lung Injury Score 97.3';'r mod- (959; confidence Descri(> valid- ratio); (b) the (c) bilirtibin concentration): hematologic system (platelet count); and Coma nervous system (Glasgow Scale). In Ihe absence of an adequate descriptor of cardiovascular dvsfunction, we developed variable, the pressure-adjusted heart rate, is a nevv w hich calculated as the product of the heart rate and the ratio of central rial pressure. venous pressure to mean arte- These candidate descriptors of organ dvsfunction were then ev alualed for criterion validitv (ICU sig- Consensus Conference definition 97.39f (959^ ment from the .AP.ACHF.-nialched confidence interval 94-100). For these at-risk of each was not interval 94-100). more than ;md content system (Po./Fio; system (serum (e) the central From overall mortality in reixirts rev ieu ed. system (serum creatinine concentration): and the .American-European The of the low -risk group iiificantlv diflerent in the 2 defined as the true-positive plus the true-nega- transport patients statisticallv direct result of a transport. rate all than the mortality rate for (I l,49r). who The overall occur- ?> aggregate as an organ criteria for construct (a) the respiratory (d) the all in could be identified for 5 of these 7 systems: negative-predictive value, and accuracy of were detennined. Accuracy was and organ dvsfunction syndrome half of the access, a need for additional ventilatory support, did not leave the surgical ICU. optimal descriptors of organ dysfunction. Clinical and laboratory data were col- the hepatic control cohorts identified .ARDS (gniup medical ICU patients w ith- P.ATIENTS: ICl! demographic infonnation were definitions = 692) these studies were evaluated for construct and con- SETTING: ratory pressure, radiographic changes, new All patients (n May 1988 and March 1990. INTERVENTIONS: None. MEASLIREMENTS & MAIN RESULTS: Comput- sensitivity, specificity, positive-predictive value, AP-ACHK-matched PATIENTS: Surgical tertiary-level teach- admitted for > 24 hours between of vasoactive medications, loss of intravenous or cardiopulmonary arrest. SETTING: ICU) of a published between 1969 ;uid 1993. Variables from respiratory system compliance, positive end-expi- eral ( stricter out clearly defined at-risk diagnoses for 2. ing hospital. ill- Systematic literature review; determine their accuracy. RESULTS: Measurements patients DESIGN: ness. MEDLINE mens required The function syndrome as an outcome in critical organ failure that were to and general an objecfive scale to the multiple organ dys- clinical studies of multiple (gniup port. measure the severity of erized database review of Prospective. (ICU) patients = 1995: modified Lung sensus Conference definition definition of n Bernard. Med American-European Con- Injuiy Score, a Injury Score, and the based on the number of defined treatment regito maintain the patient during trans- determine We ARDS — as repre- definitions of iated citv hospital. was to similar patients are cventuallv identified. compared new 1 . Reliable 23(10): 1638. intensive care unit unit .A NV Chnstou. GR prospective cohort study. if Care Outcome Sibbald. Cril Care lung injury. However, these definitions have never ciciirh defined at-nsk diagnoses for high-risk group WJ Spnjng. idenufy patients earlier in their course of acute > 5 cm HiO. or a continuous infusion of norepmephrlne. The syndrome introduced that potentially they required positive end-e\pirator\ pressure of a continuous infusion of dobutainine, DJ Ctwk. Miirshall. CL OBJECTIVE: To develop OBJECTIVES: Over the DESIGN: Prospective, cohort-matched study. SETTING: A 780-bed urban, university teaching hospital. PATIENTS: Seven hundred fifty-nine surgical ICU patients. INTERVENTIONS: One out of the surgical Crii 1995;2.3( I0):I629. these complications it methods are applied to patients with clearly defined at-risk illness. often necessary for optimal patient However, transport of intensive care care. mod- Injury Score, the Injury Score, and the American-Euro- Lung ified produced ) mortalitv rate) using the clinical database. the first half of the database (the develop- set), intervals for the Respiratory Care v ;iriable • most abnormal value were constructed on a scale from February "96 Vol 41 No 2 v*J Show Your Pride T-shirt Slunv pride in \our profession, both eoming and going, with this new tront-and-b<ick design. This 50/50 cotton/pol}-ester blend T-shirt comes in a fashionable stonewasheddcnim color. The design is displayed in navy blue, cream, and white. Wear it with pride! Medium, large, extra large, and extra-extra large available. Item R16 S9.75 ($11.50 nonmembers) Acid $2.50 for extra-cxtni large. ^ \ Sweatshirt ^"^ ™ This luxurious, heavyweight, 50/50 blend navy-blue sweatshirt sports a plaid applique accented with gold embroidery. Medium, large, extra _^ large, and extra-extra large available. Item R19 $25 ($30 nonmembers) J^-'> « \i!d S2. 50 for extra-extra large. To order 2 . Abstracts to 4 so that a value ofO represented essentially mortality rate of < 5%, whereas a value mortality rate of > SCî . ting, work, the fungus Scopidariopsis breviciiidis. hat autocycled rapidly (> 40 breaths/min) function Score (maximum of 24 1. This score cor- cx-curred in control tests in applied on the ICU first mortality day of ICU admission as a prognostic indicator and when cal- ICU stay as an outcome measure. ICU mortality was -25% at 9 to culated over the For the laller, points, 507c at 13 to 16 points, 75':i at 17 to and 100% points, showed score at levels of > 20 0.928 in the development in the validation set. The incremental increase in scores over the course of the ICU stay (calculated as the difference between maximal scores and those scores obtained on the lie. A the day first incremental increase ICU more scores accounted lor in of the explanatory power than admission severity indices. CONCLUSIONS: Tliis multiple measures of dysfunction 6 organ sys- in tems, minors organ dysfunction as the intensivist it and correlates strongly with the ultimate ICU monality and A variable. reflects ICU The hospital mortality. Multiple Organ flysfunction Score, organ dysfunction developing during the stay, which therefore is to therapeutic manipulation. complementary sure w idely available, potentially amenable As an outcome mea- now to predictive scores such a score may find use in epi- demiologic studies of the multiple organ dysfiinction syndrome. Moreover, an insti-ument thai can provide an objecti\ e measure of the severity of organ dysfunction sion and tliat at the time of ICU admis- can quantify subsequent detenoration over the course of the ICU stay may prove an alternative end point for clinical ful as involving critically ill patients. use- trials See the rckilededi- Meamremenis of Medicine. RC Bone. Med IW>::M IOi: 1619-162(1 roriiil: Care Crit the hypothesis that toxic gases sudden are a cause of v\ as found in test grow til. This taining papers exposed result suggests were due tions Davey. I'hislic agar medium. See Hype to con- arsenic, or phosphoms in 23 pol\ \ To cot death cases w ere incubated on increased leak size, and decreased with decreased sensitiv CLUSIONS: ity setting. due ceptible to autocycling to flow compensation lo maintain positive end-expiratory pressure levels in the ference presence of an airway leak. The dif- maximum sen- in autiK-ycling is sitivity setting of each due to the \entilator. and not to intrinsic anisms. growth on the The 3.3-mL/s setting tilator set at 2.5 mL/s at been relea.sed instead at ings. The of Three Flow -Triggered \'entilators Ciit —G Bern- Med Care 1995; mL/s autocycled 4 mL/s, due The ven- to these find- maximum setting at > 10% readily at leak size of Since such a leak si/e was present infants, this selling mech- the least prone the time of this study has ventilator with the in 70%- of should be used with caulion. L'sing these guidelines, autocycling of tilators is likely to 23(10): 1 739. w as autocycling and seems appropriate. to SIDS The- relaled ediloriiil: CON- Flow-triggered ventilators are sus- the test paper reac- of sulphur-con- leak all 3 ven- occur mainly in 8%- of infants with leak size of > 30%. In these cases, lowering OBJECTIVES: To define the spectrum of airway examine the leak in the neonatal population and (Kcurrence rate of autocycling of 3 flow-triggered \'entilators witliin tlie DESIGN: defined spectrum of airleak. and perfonnance of on a mechanical lung ulated clinical conditions. mi.xlel under sim- SETTING: An and research laboratory sive care nursery medical center. versity inten- at a uni- from our intensive care nursery, selected The tracheal tube. due to a test lung studied at the 1.2.5. \ entilators studied. Ventilators mode w ith assist-control the con- breaths/min. Each ventilator trol rate set at was of autiKycling of was subsequently on the set rate of variable si/e. w bile connected to airleak were at ran- determine si/e of airleak around the endo- to may may decrease autocycling, necessitate reintubalion with a larger endotracheal lube. was maximum sensitivity setting, which and 3.3 mL/s and also at (haracltristics of Objects that Cause ing in Children Stool. JS Reilly. JAMA -IL G Chok- A Thome Jr. S D Stool. CL Wilson. Rimell. Rider. 1995;274l 22 1:1763. INTERVENTIONS: Analysis of pulmonary function tests of 50 infants dom, ratory pressure level or Prospective study of pulmonary function tests of intubated infants ventilators the sensitivity setting and/or positive end-expi- for each ventilator, respec- decreased sensitivity setfings was varied (10% 10 45%) OBJECTIVE: To characterize the types, shapes, and sizes of objects causing choking or asphyxiation in children and to compare these characteristics to current standards. DESIGN: To evaluate morbidity, retrospective 5-ye;ir niediciil record suney; SETconsumer prod- to evaluate mortality, data reanalysis. TINGS: Pediatric hospital and uct testing laboratory. P.'XTIENTS: (n = 165) body aspiration or ingestion pital .All who underwent endoscopy at children for foreign Children's Hos- of Pittsburgh (PA) between 1989 and 1993 and children (n = 449) whose deaths due to chok- tracheal tube adapter/connector sideport and/or Lancet compounds used deatli. ith at of auto- ventilator flow -sensing or other soflw are bacterial GP Heldt, rapidly .30%^. In all ventilators, the rate — from antimony, lest this inyl chloride mattress mL/s aulocycled cycling increased w 1 E Knodel. of > 20%; and the ven- at leak size tilator set at 3.3 > mL/s 1 leak size at the ventilator set at 2.5 inL/s autocy- ; cled rapidly si/e of at man-made objects were recorded by the Consumer Product Safety Commission (CPSC) as fire retardants in col mattresses has been proposed as a cause of sudden inlant of > 10% Reality. Lancet 1995:346:1503. llie The ven- ventilator. with the inaximum sensitivity set those without such .4irway Leak Size in Neonates and Autocycling stem. which varies with each tilator to aulocy- sensitivity set- by increasing the orifice size within the endo- EM Johnson. C Sieniawska. Micnobiiil generation of toxic ga-ses 94 tliat in plates a function of the is Mattresses 199.'S:.346:1516. until in to the generation compounds during ory from More sulphur infant death. growth than taining bacterial tively, and Sudden Infant Death Sjndriime DW Wamock. HT Dches. CK C'ani|vll. I\\ Croudace. esis, Our findings of antimony, arsenic, or phosphorus. to 10 niL/s. Airieak si/e (mm Toxic (Jas (leneralidn KG to deposits organ dysfunction score, consuucted using simple phys- risk of were not due 1 mortality rate. In a logistic regression model, this sees instru- papers showed Multiple Organ Dysfunction Score) also demonstrated a strong correlation with the iologic that the colour reactions test derived from antimony, arsenic, or phosphorus and set Chemical and plates. tlie 20 excellent discrimination, as reflected curve of 0.936 was present on mental analyses of exposed do not support The points. rial which no mamess mate- 1 in areas under the receiver operating characteristic grow th was present, but these reactions also rial when both Test hacilliLs spp. paper colour changes occurred w henever bacte- Multiple Organ Dys- related in a graded fashion with the rate, mix of common environmental a to yield a summed were maximum The predominant organism, recovered from all mattresses tested, was not. as claimed in earlier each variable for tendency of the 3 ventilators of 4 rep- These inler\als were Maximal scores relative cle then tested on the second half of the data set (the validation set). papers were test then inserted and the colour reactions recorded. resented marked functional derangement and an ICU ver nitrate and mercuric chloride ICU normal function and was associated with an h\ p<ith- samples Irom malt agar plates aood microbial arowth was obtained. Sil- ing on MAIN OUTCOME the positi\e end-expiralory pressure level (2 to 8 between 1972 and 1992. cm H:0). MEASUREMENTS & MAIN RESULTS: In the infants, airieak size was cal- ME.ASURES: aerodigestive tracts were characterized by loca- culated during synchronous ventilator breaths as tion, minus expiratory) (inspiratory ratory tidal patient). 15.6 ± 1 volume x 100% Mean ± SD 1%. A present in 15 20% in (n 24 (48% ), ) volume/expi- = 25 + 1 1 breaths/ leak size in the infants minimal leak (30% tidal si/c of to 10% was leak size of in 20% 4 (8% and consistency. Three-dimensional objects that had caused asphyxiation were analyzed by computer-simulated models. RESULTS: Of the 165 children treated b\ endoscopy 69%^ were 3 years 7 of age or younger. Foreign bodies most often inlanls. llie ingested or aspirated were food (in 36 children) to ) procedure for removal, and type. Objects causing death were characterized by type, shape, to infants, leak size of (14%), and leak size > .30% was Objects removed from children's 10% 30% in , RESPIRATORS Care • February "96 Vol 41 No 2 1 AUDIO TAPE ORDER FORM Care for Respiratory American Association Missed the 41st Annual Convention and Exhibition? Here is your chance to acquire the valuable information that ordering audio cassettes of the actual programming. 41 St 2-5. 1995 .A.ny Orlando, Florida • 12 Cassettes Any 24 Any 36 FACM. lO lACl-Wini CIlANCl; Single Saturday, December .\ARC'35-001a Lung Volume Reduction Advances E Sherry AARC95-006 AARC95-007 MD. O Bendill. RCP E InterTntra Hospital Transport Jet Ventilation AirTransportof Trauma I-ochi. .-I Jamie Taylor-!ri:arry. 1. COPD AARC95-050 Q AARC95-05 AARC95-052 AARC95-053 COPD MD MD .AARC95-018 A,\RC95-019 Overcoming the Bamers John IVrighi. MB.-i. RRT Care Plan Development Jo/m.V i'o/iii. Afi'. flKr Compiling Objective Data John n right. MB.-t. RRT What Is ARDS. Who Gets It. and What Happens to Them'' Has Outcome Changed'' Kenneih I' Sieinherg. MD to Treatment Siephen /' Transformational Leadership .Sum I Reniiard. (;mr<yi7«y, Q AARC95-054 O AARC95-055 D AARC95-0.S6 p AARC95-057 Q AARC95-058 Joshua New Approaches Affl.-I, K/?r Appropnate Ventilator Management Today'' Seil R D MD A.'VRC95-023 Do AARC95-024 ARDS'' Kenneih P Slewherg. A/7.) What Happens to ARDS Survivors'^ ,\.'\RC95-027 Sunday, December 3, 1995 What Have We Learned about Lung ,\ARC95-028/29 n KtD Barry Make. Outcomes After Exacerbations of COPD (Support Study) .Alfred f- Connors Jr. MD Is AARC95-049 Victims Jern. 4 foc/». /y?r Survival Following Severe Exacerbations of What Q RRT Scientific Basis for Current Tlierapy .SVcp/ira/Z^f/winny A//) M4clnlyre. AARC95-048 RRT AARC95-0I6 AARC95-017 /\ARC95-022 Q .Mark J Heulill. KfD Flight Physiology Natural History of AARC95-020 AARC95-021 AARC95-047 Couriney. \fn. .MS on Transport Teams Jerry Bendill. n Affi Sur\ iving a Joint Venture by Identifying the Crucial Role of O AARC95-046a/b KID and Expanded Capabilities of Pennatal-Pediatnc Mechanical Ventilators Mark. I Heiilill. ,MT} Advances in the Use of High Frequency Osciilalon. .\AKC9S-Qn AARC95-0I3 AARC95-014 5 Joshua Use of High Frequency in the Couriney. A,'\RC95-011 AARC95-01 C Demeni New Modes the AARC95-009 AARC95-0I0 Surger>' Corticosteroids (or Other Drugs) Alter the Course of .\'eil R Madnlyre. Injurs MD from the Management of Near-Drowning'' Jerome H Modell. KfD RCPs Meet the Challenge of the NAEPP. Urban Message-(jetting the Message Out and Breaking the Bamers to Care Thomas I Kallslrom. RRT. .ilvin 1' Thomas. MD School-Based Asthma Management-Strategies for Asthma Care for the Child in School & Panel Discussion Mark W . .'\ARC95-030 Millard. AARC95-031 MD Management of .^cute Respiratory Failure without Intubation Roherl Kacmarek PhD. RRT. David J Pierson. MD Changing the Paradigm The Role of the RCP in Health Promotion/Disease Prevention William F Galvin. MSEd. M AARC95-032 : RRT. AARC95-033/34 AARC95-035/36 CPFT RCPs in the Operating Room. RCPs on the Resuscitation Team Richard D Branson. RRT Charles G Durhin. Jr RCPs in the Hyperbaric Chamber. RCPs in the Subacute Care and Skilled Nursing Facility Setting John CRTT. Dianne ,'\ARC95-037 I. Lewis. MS. M . MD Grayheal. RRT Laboratory and Clinical Expenence in Liquid Ventilation Ronald B Hirschl.MD ,\ARC95-038 Practical Considerations in the Therapeutic Administration of .\ARC95-039 Tracheal Gas Insufflation Sue \nhd.\tA'ti\XnQO\\Ae Roherl AARC95-040 Ventilator Pierson. AARC95-041 AARC95-044 to .-i Kacmarek. PhD. Raveii.scra/l. RRT .\ARC95-077/78 Q AARC95-081 Avoid Barotrauma David J AARC95-082 MD Q AARC95-083 D AARC95-084 D A.'VRC95-085 .4 RN What Outcomes To Measure and How CRTT Q MD Gene Therapy for Cystic Fibrosis /)avi</£ GV/fer Aff) What Are Outcomes and Why Are They Needed':' Jeffrey Sou:a. AARC95-045 Management M 2 Cassettes in 3 MD Ventilation .Shern AARC95-008 William m in 1 FREE Album FREE Albums FREE Albums Audio Cassette S9.00 1995 Cardiology for Automated External Defibnllation Providers Wtlltam Kayc, AARC95-005 Cassettes Phn Afl). AARC95-003 AARC95-004 2, Wake Up America' Keynote Address was offered by can fax. mail or call Nour order directly to Sound Images. Please allow about 21 days for delivery. Annual Con\ention and Exhibition December You I'lanna Zimhel. BS. • $99.00 (Save $16,00) $198.00 (Save $32.00) $297.00 (Save $48.00) 12-Cassette Storage Album S7.00 I 1 n Management of the Pregnant Trauma Patient David I (ii)ldshem. Ml) Management ot the Bum Patient ( H'liyrw CniM'. Ml) Hursl. Management of the HIderly. Injuied Patient .lames AARC95-086 AARC95-087 AARC93-088 a a AARC95-I15 Introduction and Overview; ' M D A.'\RC95-1I()T17 MD D Carlr D AARC95-09I MS. KKl Nutritional Assessment I'am Agmg Geriatric n AARC95- 1 18-120 Managing Bnd-Of-I.ife Issues I'ainck.l Cucchicme Physiology of Alpha -Antitrypsin and Pathophysiology of Deficiency States Michael I Krnwka. Ml) D AARC95-095 Clinical Features of . AARC95-096 1 I reatment Options lor Alpha a l.ung Transplantation for Alpha AARC95-098 Emphysema .Marshall I Herl:. Ml) The 1995 JCAilO Standards - The First Zimhel. I D .'\ARC95-124 D D -Antitrypsin Deficiency AARC95-I2.1 AARC95-I25 AARC95-I26 D Year's Experience AARC95-I27 Improving Organization Performance D AARC95-IU0b Questions and Answers & .ÂRC95-128 D CRIT - Home Care The Impact Equipment Validation .MH.4. AARC95-I29 m 1995 5, Pulmonary the l,ab .latk Wanjier. We Roherl Need Really M in Kaaiiarek. PhD. RRT Tlie Thomas I) East. AARC95-I07 Defining Subacute Care Services; Patients. Settings, and D .ÂRC95-I0S Outcomes Kathleen (inffin. PhD Using Outcome Data to Justify Subacute Care Services Dianne I. I.esny MS. KRI D AARC95-I09 Providing Subacute Services D ,\,\RC95-1 10 AARC95-I11 n .AARC95. 112 I Nilsestiien. Five Things 1 learned PhD. AARC9S-|l,1 Five Things Learned I D AARC95-1 14 I this Learned KKT Five Tilings 1 Learned Might Be (According First this in a Year about Aerosol Therapy .Ion Year about CPR Ihonias Hospitals Yeai about Sleep Apnea Karen this Year about What the to the Federal Zip/Postal ( RC Govenunent) Cheryl .4 it tt\ MAIl Code ) S .Saho. MS. RRT an Acute Hospital Setting Patrick. I Dunne, The Effects of State Licensure and Credentialmg on Home Care .Jdl T.icher. .4 n D AARC95-I32 Washington Update on AARC95-1,^5 Ethical Principles Relevant to the D AARC95-13() AARC95-137 AARC95-Ij8 Home MP.4 Care Cheryl DNAR Advance Directives and ICU lirawn. .4 (iordoti D MH.4 Rubenjeld. Orders David. I Pier\on. The Nuts and Bolts of Withdra\Mng Life Suppoil Cordon D AARC95-I39 Thompson. a AARC95-14(i D AARC95-I4I D AARC95-142 Diaper Changes and Feedings ./ohn Isn't Just RRT Supplemental Oxygen Deliver> .•\lieniate W for Pediatric Patients in Care Sites Mark Wilson. Patient-Dnven Protocols Salver Neonatal oi IIS. MD the Permalal-Pedialrie Setting RKT Pediatnc Mechanical Ventilatory Management Aii\va>Mechanics IIS. m William li Clomb. MD Laboratory Measurement Robert .4 RRT KPTT D ,A.ARC95-I44 Bronchial Provocation Testing: Relationship to Air^vay D AARC95-145 Assessment of Aii^\ay Mechanics Outside the Pulmonary Mechanics Fax .lack Waii);er MII.4. C RRT RPIT lr\'in. PhD D FAX Sound Check (Payable to Images, VS. Funds liic ) in I your order with credit card Please check tapes desired, complclc this form and mail 738S South Revere Parkway, Suite Englevvood, CO 80112 $<),()() 1 2 tape storage S(16 USA With your credit card, call 303-649-181 Mon-Fri 8:00atn - SOOpm Mountain ime 1 album S7 (K) QflANirrY DLSC-OIJNTS FRHH Storage Album $W 00 (save $16,00) FRHF Storage Albums $148 00 (save $32,00) $1 ,00 per tape, $2 00 Inleriialioiuil Checks 24 hours a day TJomcslic D MD Cross-Training T Shipping A\ NV/SOIND IMAGES PHONE: in Any 12 Fapes in Any 24 Tapes in 2 Any 36 Tapes in 3 \-K\V Storage Albums to B^' RUT llraiison. It I'echmcal Directors .lolin AARC95-L11 tnailing there) information to 303-790-4230 -^ Richard POST ANNUAL MEETING PRICING Cardholder ,Signature KA\: i\: D llrown. Card Number m <<• . Future Lxpiratioii Date iVs\ RRT Need RC Function Laboratory Charles ( ravclcrs MD Chest Tubes RtchanI Shehlim. Ml) .\lfl.4 City, Statc/Countt^ I Kiie- Subacute Respiratory Care Services Can Effectively Be 1 D Insert Seleckx. Outside the Hospital Year about Managed Care Mailing Address (no post ottice boxes; include institution Cash M (CRN Wavefonns and Graphics Should Be Monitored and Available .\\\ Mechanically Ventilated Patients in the ICU Robert S Price per tape D Walton. 1-.4CHT. AARC95-L10 Last/l'aniily Daytime rclephonc .4 .lohn .4 this Natnc ) K D n Managed Care Environment RRT Mli.4. .Stemirt. «,V, Hro»n. this Learned RRT Five Tilings RCPs Should Rubenfeld RRT Karnes. liJD. Michael lUiroch. D .lohii RKTd- Dianne I. Lewis. M.S. RKT Are RCPs Really Going To Be Able to Depend on Computers? Thomas D liast, PhD D Kevin. 4 Cornish. RRI D RRT Salio. .KIS. MD M () RRT MD PhD D Five Things .M.S. Oiiicomes Management; Paradigm Shift Dorotin Respiratory Mechanical Consensus Statement from the 1995 Conference on Assessing Innovations on Mechanical Ventilatory Support AARC95-106 S .lolin Preparing for Business Ventures Delnered of KRI. RI'll What Features Do Ventilators:' n IVeher. Vignette; Ml.d. Tuesday, December AARC95-I05 A Hess. PhD. RRT. Kids Anymore Stanley H ,lust tor liRTX- Michael KoroLh MH.-i. Patient Satisfaction Accreditation D Not Validating MD Campbell. I'laniia D Vfaima'/.imhel. US. It's It'', Dean R MD. Kate Durhin.lr. Is on .V\RC95-I00a D What Just Choosing a Design, Language of Managed Care .Inhn K Walton. T.4( HT. RRT Competency Standard Development and Perfonnance Paul KKT D AARC''5-I03 -- RKT CRIT U.S. AARC95-I22 1- Developing and Using an Effective Plan of Care AARC95-099 n D G Pimell. R\..M.S,\. AARC95-097 Kathleen llnnlim. D - he p Value Cystic Fibrosis; Ml) llierapy CInirlte Sinmê. D I Management Augmentation Therapy, Gene Antitrypsin Deficieney AARC95-121 -Antitrypsin Deficiency .lames Sloller. .Ml) Current and Future D Tiel. 1 Alpha Charles for the AARC95-093 AARC95-094 D PhD. RRI Rail. Vignette; Shellel Resiewing the Mentor Dean R Hew. PhD. RKT. Getting Your Abstract .Accepted D D K A MD, Stoller. a Null Hypothesis', is Patient-Dnven Protocols liuîhiimc. IW. /. Enhancing Communication and Teaching Techniques Older Patient I'am 7. Cacchiime. UN. A/.S'.V. C-CiNI' AARC95-092 What Vignette; K RRT Mtshoe. PhD. .lo'.ephl. Population ltie:a/i.\. MS\. ((/AV D C A Literature and Finding a Meeting the Health Care Cliallenges of the AARC95-090 Identifying a Clinical Question and Fonnulating a Hypothesis .lames - - - $297 00 (save $4S 00) minimum, $10 00 maximum $2 00 per tape, $6 00 minimum Abstracts and coins Of 449 children uhose {in 6() children). deaths after aspirating foreign bodies weie reported to the CPSC. were younger than 3 years. Bal- fi5'7f and months of age. RESULTS: Eight hundred fifty- decreased blood pressure compared with the con- two care givers completed surveys during the 5- (+13'*) levels cholesterol lipoprotein group. In multiple regression analyses, the trol improvement objects such as balloons caused a significantly (p metabolism was related primarily < 0.001 higher proportion of deaths ) 3 years or older (6(K< that we could those aged CONCLUSIONS: tion in obesity. suggest th.it weight loss improve coronary artery disease o\erweighl. middle-aged and older men. of any age. Changes in regu- Hemorrhage Intracranial Neonates Treated in use might have prevented up to 14 (M^f) of 101 JN Meliones. EH Kern. siud\ Sec ihc related editorial: , leider. WJ DR — EN Grayck. RM Hansell. Unger- 1 the initial and maximal lactate levels with Ihe occurrence of intracra- Weight Loss Kffi'cts of vs ,\erobic Exercise Trainins on Risk FactorN for Coronary Disease in Healthy, Obese, Middie-.Aged and Older Men: Randomized Controlled .\ Katzel. ER Bleecker. Trial EG Colman. EM — LI Rogiis. JD MMA 1945;274(:4l:im5. Sorkm. .AP Goldberg. hemonhage (ICH) and nial OBJECTIVE: To compare the effects of weight on coronary loss vs aerobic exercise training artery disease risk factors in healthy sedentary, DESIGN: SUBJECTS: A total obese, middle-aged and older men. Randomized controlled trial. of 170 obese (body mass index. 30 ± kg/ni- I [mean + SEM]). middle-aged and older (61 ± years) I INTERVENTIONS: A 9-month diet- men. induced weight loss inler\ ention. 9-month aerobic exercise training program, and a weight- MAIN OUTCOME maintenance control group. MEASURES: Change imal aerobic capacity in ( body composition, max- V'o.max). blood pressure, lipoprotein concentrations, and glucose tolerance. RESULTS: to Forty-four of 73 men randoinized weight loss completed the intervention and had ±0.7 kg; Vo^max. Forty- a I09f inean reduction in weight (-9.5 p < 0.001 ), nine of 71 with no change men randomized in to aerobic exercise completed the intervention, increased V|),max by a mean of 179f (p<0.fJ01 not change completed DESIGN: SETTING: PATIENTS: Eightyfor res- meconium piratory failure due to sepsis, aspira- or persistent pulmonary hypertension of the MEASLIREMENTS: The maximal lactate level were described as mean Head ultrasound choice of sleep position. mean initial higher in 1 maximal: reports lactate + SE (niM). and survival were in RESULTS: The patients who developed ICH (ini- mM vs 6.4 ± 0.8 mM, p = 0.05 and 12.4 ± 2.5 mM vs 7.9 ± 0.8 niM. p = .7 ().(W). Initial elevated and maximal nonsurvivors were also lactate levels (initial: 1.7 1 ± 3 niM vs 6.4±0.7niM, p = O.OI and maximal: 14.8 ±3.3 niM vs 7.8 ± 0.8 mM, p < 0.0 1 ). Platelet counts and ACT did not differ in patients with and without ICH. CONCLUSIONS: Lactate is marker for the development of ICH a useful in patients. In addition, elevated lactates during identify a CON- in infant sleep positioning in the desired direction since the American Academy of Pediatrics statement. However. 549^ of the study infants were being put still to sleep prone. Plasminogen N Engl Med J Acute of Neu- and Stroke rt-PA Stroke Study rological Disorders Group. for Institute Activator Ischemic Stroke- -The National 1995;333|24): 1581. subgroup of patients w ith BACKGROUND: Thrombolytic therapy for acute ischemic stroke has been approached cautiously because there were high rates of innacerebral hemorrhage We in early clinical trials. randomized, double-blind performed a of intravenous trial for ischemic stroke alter recent pilot studies sug- and maximal lactate levels were ECLS ± has been a change pixir was begun within METHODS: The treatment 3 hours of the onset of stroke. tnal had 2 parts. Part I ( which in 291 patients were enrolled) tested whether t-PA had clinical activity, as indicated by an improvement of 4 points over base-line values in the score of the National Institutes of Health stroke scale (NIHSS) or the resolution of the neurologic deficit w ithin 24 hours of the onset of stroke. Part 2 which 333 patients were enrolled) used test statistic to outcome assess clinical ( in a global months, at 3 according to scores on the Barthel index, modified Rankin NIHSS. scale, Glasgow outcome Results. In part I, there scale, was no and significant difference between the group given t-PA and that given placebo in the percentages of patients ECLS with neurologic improvement ECLS a benefit outcome. when gested that t-PA was beneficial months was observed for all at 24 hour^, altliough for the t-PA group 4 outcome measures. In p;in at 3 2, the long-temi clinical benefit of t-PA predicted by the results of pari body composition or Vo;max. pre-ECLS and ECLS management will decrease the occurrence of ICH and improve survival. for a favorable 8 men who loss decreased fasting glucose trations by insulin concen- (OGTT) by S'7t and 26"/^, respectively {p < By contrast, aerobic exercise did not 0.01). improve fasting glucose or insulin concentrations or glucose responses during the OGTT decreased insulin areas by 179r (p < 0.001 In group (p < 0.05). Similarly, weight loss but not aerobic exercise increased high-density Respiratory Care • February '96 30% more patients have minimal or no Pediatrics 1995:96(5):S93. after the onset of stroke occurred in least likely to on the assessment patients given t-PA but only OBJECTIVE: Tii dctemiine prev alent infant sleep American Academy of Pediatrics position statement of 1992 and to the con- confidence As compared with tomatic intracerebral hemorrhage cose and insulin levels and glucose areas with when compared with interval. 1.2 to 2.6). (global odds ratio 1.7; 95'^'( ability at 3 montlis — positions before and after the aerobic exercise outcome, the Pediatric Rese;irch in Office Practices Network. analysis of variance, the decreinent in fasting glu- intervention differed between weight loss and was confirmed A Community-Based Survey of Infant Sleep Position JB Chessare, CE Hunt, C Bourgiiigiioii. but ). I given placebo, patients treated with t-PA were by 18%. and glucose and insulin areas during the oral glucose tolerance trol w ith recombinant tissue plasminogen activator (t-PA) measured through- times (ACTs) were examined. 1 prone ECLS reviewed. Platelet counts and activated clotting tial: in tlie age. Gender, race, family initial lactate measured within 6 hours of initiating out the ECL^S course were collected. Lactate levels fam- of the whether the incorporation of this information into 1 group had no Weight test ECLS two neonatal patients placed on :ind the ft Prospective studies are needed to determine whereas the in the control 2^;^. and did Retrospective chart review. Pediatric intensive care unit. level 1 support (ECUS). life newborn. 4 75'''r signifi- their weight, cant changes in ). their survival in patients treated with extracorporeal tion, however, income, maternal smoking, and birth weight were Tissue OBJECTIVES: To correlate H05. child, Greeley. Pediatrics 1995:96 (5):914. Designing Ihe Death Out of Balloons. SP Baker. J.\M.\ 1995:2741221. same position at the not associated Serum Lactate Correlates with Elevated with Extracorporeal Life Support in this 1 CLUSIONS: There lations regarding products intended for children's deaths risk factors CON- Balloons pose a high risk of a-sphy-x- with more than youngest siblings had been put to sleep results in iation to children Fifty-four percent of the study infants to sleep in the prone position. In These to younger than 3 years. were put ilies the preferred treatment is week smdy. to the reduc- 101 objects causing deaths for use by children CLUSIONS: in younger than 3 lipoproteins analy/e. 14 met current standards Of the years ( 33*^1. vs those 1 in glucose and loons caused 299r of deaths overall. Confomiing placebo (p < 0.001 17% in the ). Symp- w ithin 36 hours 6.4% of 0.6% of patients given Mortality at t-PA grt)up and 21% group (p = 0.30). scales. at dis- 3 months was in the CONCLUSIONS: placebo Despite an DESIGN: increased incidence of symptomatic intracerebral private and hos- hemorrhage, treatment with intravenous t-PA pital-sponsored general pediatric offices. P.AR- within 3 hours of the onset of ischemic stroke TICIPANTS: improved identify determinants of sleep position. cross-sectional survey. Vol 41 No 2 SETTING: parents of infants younger than 7 clinical outcome at 3 months. 97 Editorials Respiratory Care Education: Current Issues and Future Challenges The more-essential features of respiratory care education have remained the same since 1970. Many health-care professions have successfully advanced their educational requirements: however, despite the efforts of practitioners and orga- tomatic of the need for a change in the educational system ;ire comments of graduating students who feel that learning so much technical material in such a limited time is too demanding. On the other hand, facult> members are frustrated by the nizations within the field, a three-tiered system persists in the students" lack of educational foundation in the arts and sci- respiratory care profession: on-the-job trainees (OJTs), res- ences that hinders their ability to participate fully and respiratory piratory therapy technicians, nician programs require 1 yeai' therapists.' Tech- of fomial education, while ther- programs may require 2 years for an associate degree 4 years for a baccalaureate degree. ing.'"' In an Re-Engineering Tool McCarthy and Kircher or to Although the types of education programs have remained "Training teaches an employee stated.* perform repetitive tasks A Respiratory Care Departments" tV)r apist in their learn- "The Outcome Driven Model: article entitled, at cation provides employees competent a w ith a level. Clinical edu- know ledge base they can the field use in evaluating a situation and making appropriate decisions. of respiratory care has steadily increased. In 1984, out of a Recognizing the difference between training and education unchanged, the total number of practitioners entering of 64,445 credentialed respiratory care practitioners, total approximately 35% were 1994, 10 years later, the total had nearly doubled credential. (1 Registered Therapists (RRTs). 25, 1 52 Also of note, in ) By nuinber of credentials awarded with 469^ of those being tine RRT 1994, 3,870 practitioners gradu- is that cuuent trend appears 50% of graduating students are for the entry-level tt) be technicians, eligible only examination for the Certified Respiratory this difference is also a key step in designing an educational program to prepare respiratory therapists (as opposed to training technicians) to participate in the assessment and evaluation of The ated from technician programs, while 3,577 graduated from therapist programs. Therefore, the a key step in devek)ping a functional outcome-driven m(xlel.'" Recognizing ity to results of patients. our study^ designed to assess students" perform patient assessments suggests poorly prepared for this function. ment vital to the is We believe that patient assess- the remaining monary 50% Over care sites and must be emphasized 10 years, we have also seen more than number of credentialed puhnonan in 1984 tt) 8,124 in the past a 509^ increase in the Pulmonary Function Technicians, or RPFT, and the remainder Certified Pulmonary Function Technicians, or CPFT).In an effort to define the future educational needs of the of respiratory care, the Board of Directors of the Amer- field ican Association for Respiratory Care steering committee (A ARC) appointed a organize two Educational Consensus One of the Conferences. was to findings of the ensuing Conferences''' that the future respiratory care curriculum content would be heavily influenced b\ the multiple trends that will encom- rehabilitation, An example in response mendations ington.*^ is With 6()9( sec modified its ECMO), assessment for a broader background written and oral would require 98 skills, and care in alternate in arts and sciences to communication and analytical the minimum emphasize skills. of an associate degree. This Symp- cumculum of the graduating class of the respiratory program to (1 ) expand ment, age appropnatene.ss of care and multicompetency monary function (ie. [X'diatiics skills: (2) skills useful in first jobs, skills in patient assess- and geriatrics), increase emphasis on pul- both the hospital and physician iilfice; (3) incluiie clinical rotations to subacute, skilled nursing, and home care sites, and sleep diagnostics labora- The curriculum has been expanded nomic impact of Consensus Conference conferees delemiined the need its AARC care program choosing alternate care sites for their increased technical skills (such as cardiiidiagnostics and ther- the in alternate respiratory care edu- Consensus Conference recom.Spokane Community College (SCO in Wash- tories. sites, in of a program that has adjusted to the pass a wider scope of practice. In addition to suggesting apeutics and and care-plan formulation cation programs. function technicians (3.639 1994. with 2,707 of these being Registered abil- were success of therapist-dri\en protocols, pul- Therapy Technician (CRTTi credential, while are eligible for the Registry examination. that students to include the eco- alternate care sites as well as the required documentation, legal issues, reiinbursement-billing systems, and patient care plans. ^'et tional another recommendation stemming from the Educa- Consensus Conferences-^'' as neonatal is that specialty areas and pediatric care, adult Respirator-! Care • such critical care, research. Febru.arv "96 Vol 41 No 2 . . Editorials in post-associ- and case management might be best studied therapy and lor the most appropriate delivery method; ate degree courses. may be cogni/aiit of age-related issues and how they impact respiratory the patients' ability to understand and utilize various treat- Restnicturing respiratory therapy education programs be the answer to assess and c\ aluatc their patients regarding indications for in future couecting deficiencies we do to bring our existing body care practitioners, but what can of practitioners to the level of present day expectations' As one approach. Shrake has suggested the following solutions:" ment modalities; adapt hospital policies and procedures to alternate care domains; conduct and participate take ad\ antage of coirespondence or part-time OJTs should • courses offered by U'aditional respiratory schools to enhance nology; their basic educational level. communicate research activities to assure in advances a scientific basis for effectively with all CRTTs should consider enrolling part-time college in members of the body of care team, and contribute to the • respiratory care tech- in health- concern- literature ing respiratory care. courses necessary to qualify for taking the Respiratoiy Care Registry Lucy Kester Exam. MBA RRT Education Coordinator RRTs should • choscopy seek additional 'high-tech" assisting, skills, Section of Respiratory Therapy such as bron- hyperbaric medicine, and sleep medicine, and/or achieve additional degrees in related James areas such as nursing, education, or management. States witli licensure laws ments time, only 9 states Pulmonary/Critical Care Medicine have continuing education require- that all respiratory care practitioners must K Stoller MD Head, Section of Respiratory Therapy fulfill. do not have a licensure law of some tiiis Cleveland Clinic Foundation type.'") Cleveland. Ohio (At Continuing education requirements increase the need for cur- workers rently practicing respiratory care education. It is be obtained seek additional to REFERENCES fortunate that continuing education credits can in a number of ways: ( 1 ) continuing education pro- Wiezalis CP. Toward 1 grams offered by community colleges; and conferences offered by the (2) seminars, AARC. symposia, Times 1994;18(1 state affiliates, hospitals, 2. 3. independent companies; (4) consultant training, AARC Buyer's Guide" lists companies ware, audio cassettes, books, A tool that we have found computer soft- 4. 5. provide training and to 6. a computerized case study program in developing therapist-training Calvin B, Rinker RM, Wojciechowski WV. Meredith RL. Pilbeam SP. Stoller JK. needs of the future. 9. and performance-improvement aspects of 10. Respiratory care education for the future must be expanded of respiratory care practitioners. RCPs and to to meet the changing role It is no longer sufficient for knowledge required AARC Times 1 994: 1 S( 1 0): Is our educational system ade- 1 994,39(1 0):709-71 1. AARC Times 199,';;19(.S):76-78. Shrake KL. Strategies for developing the multicompetent respira- Eicher J AARC Times 1994:18(61:21-26. A. Future challenges for slate hoards for respiratory care. AARC Times 1 1 Arkell D. White G. Retooling an educational program to meet the tory care practitioner. to include the AARC Times McC;irthy TP. Kircher C. Tine outconie-dn\ en model: a re-engineenng protocols? (editorial) RespirCare 8. facilitate therapist-driven protocols. Respiratory care edu- changing with the evolving health care system. quately preparing respiratory care practitioners for therapist-driven which therapists can This technologic advance will : 49-.'i4. review case studies, submit their care plans, and receive a grade in a single session. Year 2001 an action agenda. Dallas: Amer- tool for respiratory care departments. 7. is American Association 199.'^;19(3): 17-20. case studies have been distributed and graded on paper forms one of our supervisors, Dennis Giles, delineating the educational direction for the Proceedings of the second national consensus conference on respi- cation: monitor the consistency of therapists' assessments and care plans for our Respiratory Therapy Consult Service. Although to date, : ican Association for Respiratory Care, 1993. useful in the Cleveland Clinic to Proceedings of a national consensus conference on respiratory care ratory care education. and pamphlets. have used these case studies NBRC for Respiratory Care. 1992. Respiratory Therapy Section has been case study simulations. We AARC a step closer to our future. : future respiratory care practitioner. Dallas: that offer a vari- ety of educational materials, including videos, 1 Svec LM. Respiratory care credentialing: a growing expeneiice. education. Year 2001 sponsored by hospitals or respiratory care departments;'' (5) The 200 Horizons May-June 1993;6-7. and equipment vendors; (3) videoconfcrences offered by the AARC and RCP ):27- 31. Equipment and I99.';:19(7):12-14. supplies: Instructional aid and The Buyer's Guide, AARC Times 1 management support. 994; 8(8):60-62. 1 have knowledge of respiratory therapy treatments their delivery methods. Future respiratoiy therapists must be able to RESPIRATORY CARE • FEBRUARY '96 VOL 41 NO 2 Reprints: James K Stoller MD. Pulmonary/Critical Care Medicine A-90. 9500 Euclid A\e. Cleveland OH 44195. 99 Original Contributions Evaluation of a Commercial Standard for Teresa Checking Pulse Oximeter Performance A Volsko RRT. Robert L Chalhuni RRT, and Thomas J Pulse oximeters are unique amon^ RRT K;illstroiii patient monitors in that they cannot be The purpose of this study «as to determine whether an inexpensive commercial device simulating a human calibrated nor can calibration be verified. finger could produce measurements of oxygen saturation (Spo,) within the METHOD: error specifications supplied by pulse oximeter manufacturers. Five brands of pulse oximeters were evaluated. Phantom to simulate Spo, values of 80%, We used the Nonin Finger 90%, and 97%. Pulse rate was simand 60 beats/min as paced b> a metronome. For each saturation level, 8 measurements (different probes) were made at each pulse rate (n = 24). Bias and imprecision of measurements were evaluated with / and X' tests. Inaccuracy intervals were ulated by manuallv compressing the device at rates of 120, 84, constructed to include RESULTS: level. 95% of future measurements Simulated saturations showed bias than manufacturers" specifications. Total less at the 99% confidence imprecision but more measurement error (expressed as an inaccuracy interval) was within manufacturers" specifications for cases except for the Novametrix vidual measurements may and the BCl occasionally fall at the 80% saturation all level. Indi- outside specified values by chance some saturation levels. CONCT A'SIONS: Spot checks consisting of single measurements with the Finger Phantom are probablv adequate for evaluating the performance of all devices studied. Spot checks using the mean \ alues of repeated measurements could reduce the falsefor some well-functioning oximeters at positive rate. IRcspir Care 1996;4I(2):1()()-I()4| neous readings, and ease of operation have resulted Introduction in favor- among clinicians.- However, pulse oximeters are unique among noninvasive monitors because there is no way to easily calibrate them, to verify calibration, or to assure accuracy when measurements able responses to pulse oximetr) Since its introduction little more than a decade ago,' pulse oximetry has assumed a commanding position among noninvasive monitors in the clinical from critical care to home care. management ol' patients Rapid response, instanta- are questioned.' Webb et aH summarized several studies that attempted to verify the accuracy of pulse oximetry, but, general, the verification techniques described in the in literature are not practical for bedside application. Ms VoWiO is a supervisor in is Respiratory Care Deparlmenl of Si Mr Chattiiirri is Director and Manager of the Respiratory Care fX-partiiient. Rainbow Babies F.li/abctti's Hospital. Kallstrom Itie & Children's Youngstoun. Hospital. Oliio. Mr Chalbmn of Pediatrics. Case Western Reserve is Mr also an instructor in the Fiepartment The purpose of this study Hospital. 1044 100 A that Belmont .Ave. Youngstovvn. OH 44.S01. St F.li/abeth's whether an inex- human linger could were within the error specifications supplied by pulse I'niversity. Cleveland. Ohio. Volsko RRT. Respiratory Care Dept. as to determine produce measurements of oxyhemoglobin saturation (SpO;) oximeter manufacturers. Reprints: Teresa vv pensive commercial de\ice simulating a would be a We hypothesized that such a device useful tool for clinicians to evaluate the function of oximeters and probes used Respir.ator-* C.-\re • in the clinical setting. February "96 Vol 41 No 2 Standard for Checking Pulse Oximeters Measurements were repeated w ith different probes, to avoid any measurement bias due to iiuliv idu.il pix)be characteris- Methods The Nonin Finger Phantom* was used to simulate Spo^ values of 807c, 90%, and 97%. Tliis device is comprised of a fluid tics mixture with "precisely controlled light absorption characThese teristics sandwiched between two glass slices""' (Fig. F. 1 mimic characteristics allow the unit to of arterial blood ities Each Phantom, levels. cial at ). light-absorbing qual- tlie each of the three specified saturation prior to use. was inserted into a spe- holder that allowed stable attachment of an oximeter probe. and Room to yield results representative of the type of probe. temperature was maintained between 70.5° F and 73.5° According to the Finger coiTections of measured Phantom manual.^ no temperature coefficient is 0. 1 6%/° F F and is calibrated Observed bias 77.5" F. (Tlie lemix'iatuie 80% Phantom. 0. 3%/° F for F for the 97% Phantom. Each for the 1 the 909f Phantom, and 0.07%/° Phantom alues are required for ambi- S;i(), \ ent temperatures lielween 67.5" 72.5° F.) at (mean difference between measured and expected saturation values) and imprecision (standard deviation of differences) of measurements were compared ufacuirers" specifications witli I -sample / test and X' Inaccuracy intervals" were calculated ti\ely. inaccuracy interval = A = mean where test, to man- respec- as: A + kS^ difference between measured and expected saturation levels; S^ = standard deviation of differences between measured and expected saturation levels; and k = a constant (equal to 3.017) allow the inaccuracy intenal to include measurements at the 99% confidence chosen to 95% of future level. Values for k depend on the width of the inaccuracy Fig. 1 . The Nonin Finger Phantom sition to in its holder with operator in po- val (ie. the percentage of future in the simulate a pulse. size. For ufacturers" specifications Pulsatile blood pressing the 60 tlat beats/mill, How end of the Phantom at rates of 1 20. S4, and 1 to inter- be included inaccuracy estimate), the confidence level desired. and the sample was simulated by manually ci)m- measurements oximeter brands studied, man- all were based on sample sizes of about .500, with a corresponding value for k of 2.047. taken standard from All oximeters specified a standard devi- tables.'' " paced by a metronome. The Spo, was recorded ation of 2%- for the satuiations in our study range. Thus, the con- observed inaccuracy intervals were graphically compared to a single 'specified" inaccuracy intcrx al of 2.047 x 2% only after a steady-state heiul rate stant to within had been obtained (ie. beat/min of the reference pulse rate for 10 I seconds) and a good waveform with an amplitude equal {o = 4%. three fourths of the scale had been observed. Results Five brands of oximeters and six styles of transmittancetype probes were used in the study: Novametrix with Probe- Type Y, Olimeda with Oxytip Probe. Nellcor with Probe Types D-25 and 1-20, Nonin with Probe 8000K2. and BCI with Finger Probe 3024. The oximeters were operated according to manufacturers" specifications. All probes were inspected and found to be free of cracks or tears. Proper function of each Table ified bias I slmws comparing observed with spec- the data, and imprecision. Calculated inaccuracy intervals are illustrated in Figure 2. specified intervals by the dotted (±4% These for all intervals are compared to oximeter brands) represented lines. probe was verified by the absence of system enor codes when the probe was connected to its appropriate For each oximeter at each saturation was made with 8 different probes of the the 3 pulse rates. This resulted in oximeter level. 1 Discussion unit. measurement same type at each of 24 measurements for each combination of oximeter bnuid. probe type, and saturation level. Each brand of pulse oximeter has oxygen saturation. bration curve fitted *SuppIiers of commercial products are listed tion at the end of the in tlie Product Sources sec- Respiratory Care is The • February "96 Vol 41 No 2 own empirically basic procedure for creating a cali- to record data from healthy human subjects with both arterial lines and oximeter sensors. The subjects' arterial oxygen saturations are then lowered ing an isocapnic hypoxic gas mixture. text. its derived calibration algorithm to relate light transmittance to Once by breath- a stable level of 101 Standard for Checking Pulse Oximeters Table I. Summary Slalislics tor Dilterences between Measured and True Values Standard De\lalion (SD) along with Observed and Specified Mean ol' Repeated Measurements: Obser\ed and Manul'aeturers' Specified Dilference (A). Observed Specified Observed Specitled Oximeter/Pri)be SD SD Mean A Mean A BCI Finger Probe 3024 1.2 Ohineda Oxytip Nellcor D-25 Nellcor 1-20 Nonin 8()0()K2 Novanietrix Y — Standard for Checking Pulse Oximeters cation valid perspectives. This when viewed from both not be true tor error specifications expressed in the would form ""± and 100% con- easy to overlook this fact and assume is it fidence, leading to underestimates of the error of the product or process. For example, using limits of agreement with % of reading."'' Other things to consider in interpreting an error specifi- our data would yield intervals about 30% smaller than tho.se cation include the mathematical limitations of the specification. calculated for inaccuracy intervals. Inaccuracy intervals serve only describes a portion of future measurements. better because they establish limits that include a specified the validation study yield a stan- portion of measurements in a population or process, with such that it For example, from the data if we can dard deviation of 2%, then assiiiiic that this standard deviation represents the standiud deviation of measurements and can interpret between 2% all future below fall in the interval value. However. gi\cn the assumption follow a Gaussian 68% of all future to that naturally clusions. In our study, the imprecision of Finger surements was smaller than manufacturers" specifications, whereas bias was larger. Looking al imprecision only might measurement eiTors 2% error. If 32% we are of all mak- would like to know the error for a larger portion To do this, we may simply double the standard An interv al of 2 standard deviations above and below of readings. deviation. Phantom mea- will true above the support decisions based on oximeter measurements, we comp;uing the obsened and spec- imptirtant to note that imprecision (or bias) alone could lead to wrong con- 2% distribution, this inter\ al represents only measurements have more than life It is ified measurements future measurements. In other words, ing a prescribed degree of confidence. future all as the eiTor specification. it This means that some portion of sample intluence one to conclude that the Finger ful in all applications. to draw Looking at bias the opposite conclusion. of error was much more Phantom was use- only, might cause one Combining the two sources revealing and allowed comparison of inaccuracy intervals. Tlie specified saturation of each Finger Phantom was treated mathematically as the standard or true value for the purposes of future mea- of creating inaccuracy intervals. However, the observed inac- we continue with the same example, this error would then be ± 4%. It could be argued that instead of displaying a single number such as 92% saturation, an oxime- curacy intervals were ultimately compared to the intervals should really display a message such as "saturation between 88% and 96%."" inaccuracy interval the true value predicts the error for about surements. 95% If ter Another point to consider is is our assumption that the sample standard deviation represents the standard deviation of all future measurements. In fact, a sample statistic can only be a point estimate for the corresponding population parameter it and (ie, is known to have some uncertainty associated with repeating the experiment results in a different value tor the statistic). This applies to both bias and imprecision estimates and, hence, to is enor total specifications. Uncertainty represented by the confidence level associated with the estimate. The confidence level increases with the sample size. Most manufacturers use validation-sample of 1 ,000 to I ,.'iO() sizes in the range data points. This allows the user to be confident that the sample standard deviation applies to 99% 68% of future measurements or that 2 standard deviations apply to 95%.* In contrast, to most clinical validation studies are limited inuch smaller sample sizes. Thus, error estimates must be expressed in a way the estimate. For this, that accounts for the uncertainty of it is interval described in the interval is convenient to use the inaccuracy Methods section. The inaccuracy similar to the limits of agreement approach (ie, derived from the pulse oximeter manufacturers" specifications, assuming the ified interval, the rately latter to be 'true." Thus, if an observed within a given manufacturer" s spec- fell Finger Phantom was judged to have accu- reproduced the manufacturer" s specifications and could then be used in the field to spot check oximeter accuracy. Spot checks using single measurements are appropriate because the inacctiracy interval was created in this case to include a large percentage of future individual measurements high con- at a fidence level. If the observed interval or some portion of it falls outside the specified interval, then spot checks with the Finger Phan- tom may yield false-posifive results (ie, falsely indicating an oximeter-probe combination functioning outside manufacturer"s specifications). However, in this case the of several measurements might suffice. Novametrix oximeter with the Y A saturation when connected 80% satura76-84% well-functioning oximeter should read to the 80% Finger Phantom. But Figure 2 indicates that an indi\ idual spot check value might fall outside of the specified interval (eg, reading 85% ration), indicating a malfunctioning oximeter even device is value probe showed an inaccuracy interval larger than the specified interval at the tion level. mean For example, the satu- when the functioning properly. Looking again at the inaccuracy interval for this oxime- we see that the bias relatively small. mean difference ± 2 standard de\'iations) suggested by Bland and Altman," but it contains more information. Studies of ter-probe combination, pulse oximetry and blood gas analyzer performance have several spot-check values might provide a useful alternative is This suggests that a confidence interval for the average of ably because they are easy to calculate and do not require index that can be compared to the specified inaccuracy interval. For example, the 99% confidence interval for a mean of reference to tables. However, limits of agreement are only 5 spot-check values often used limits of agreement as point estimates —no "confidence" Respiratory Care • summary is February statistics, prob- attached to the interval "96 Vol 41 No 2 would uration. This interval is fall between -0.7% and 3.6% sat- within the specified inaccuracy inter- 103 r . Standard for Checking Pulse Oximeters mean of 5 repeated measurements (perhaps with so a val, 5 different probes) could be used to indicate a well-function- using the mean values of repeated measurements could retiuce the false-positive rate. ing oximeter. Two oximeter-probc and BCI-finger probe) study demonstrated ques- in this Siiturulioii .Staiidurd: The use of individual spot- check values for these devices could lead to false-positive tionable inaccuracy intervals. conclusions at the However, consider measurements would lead lie PRODUCT SOURCES combinations (Novametrix-Y probe 80% some of the saturation level above 4V( to taking a well-functioning BCI-Fingcr Ohmeda machine out of ser- and most (d) 80% saturation clinical applications. is already Thus, accept spot checks as valid for all it in the may Ohmeda. A Wiiukesha \VI di\ ismn BOC iil Health Care Inc. CO Nonin Model 8500ni/8000K2, Nonin Medical Inc. Novametrix 700AA', Novametrix Medical Systems be used and would have adjusted the interval downward for Intern.Uional. CA Nellcor N2()(l/D-2.s and 1-20. Nellcor Inc. Pleasanton temperature correction for these two instruments could slightly, BCI .^(124. 37()(l-Oxylip, Louisville vice (rather than continuing to use a malfunctioning device), (c) MN Plymouth Oviineters/ProlK's: (b) the false-positive conclusion . Inc. time. expected that (a) only a small portion of PuKc Oximeter Tesl System Finger Ph;iiiloni Nunin Metlieal Plymouth Inc. MN Wallingford CT danger zone Statistical be practical to the devices studied Soltuart: StatView 4..S. Aliacus Concepts. Berkeley CA and avoid the more rigorous but ciim|ilicated use of confidence intervals for Finally, mean referp:nces values. one needs to keep in iiiiinl the a confidence intenal and an eiror inters val is disiinclion al. between A confidence 1 inter- a prediction about the value of a population parameter (eg, the 2. mean, based on a sample of measurements). Con- nomial blood gas values or length of slay An in .V is 4. inten als ;irc of interest when impoitant on single observations (eg, Enor in c\ more of , and 97% had measurement error (expressed for all cases except for the No\ ametnx and Recent dcxeiopnienls J. II. m WB. Ralston .\C. Runciman Potential em in- pulse oxime- pulse o\ime- in Eftecls of changes in saturation anil signal tjualits New for normal tolerance York: Marcel Dekker .Anaesthesia . Ma.son RL. Gunst RF. Hess JL. Statistical Wiley less & design and anal\sis of exper- Chatburn RL. Hess D. Research and tory care. Philadelphia: 10 "> cirk: Holin statistics for the clinician. In: Bakow ED. Comprehensive WB Saunders Co. McCarthy K. Decker MJ. Kacmarck RM. Hess D, the BC'I at the 80' New Sons. 1989:247-248. Dant/ker DR. Maclntyre NR. as an sampling, limits, Inc. I9S(1:93. iments with applications to engineering and science. ith inaccuracy inter\al) was within maiuifaclLiivrs" specifications Kelleher 29-33. bias than manufacturers" specified val- cry case. Total Webb RK. : J. Anesthesiology I992:76((i): lOIS-KUS. and screening. , I987;79 Odeh RE, Owen DB. Tables 9. impivcisioii hut infants. Pediatrics 7. is 8. staiulaiili/etl saturation levels newborn in Finger Phantom users guide. Plymouth MN: Nonin Medical Inc Chatbum RL. Mea.surement theory: accuracy issues in monitoring. In: Levine. Fromm. Critical care monitoring. Chicago: Mosby. I99.S: .i. Conclusion 9()'/( Pulse oximetry: an alternative method for the J. 6. lunctioning coirectly by analy/iiig a quality control solution). Repealed measurements of Nonin Finger Phantoms w oximetry. .-Vnesthe- pul.se I9y|;46(3):2()7-2I2. changing F|0: based on a pulse 80'/, M. Peabody Severinghaus tiy decisions ;ue to be ba.sed oximeter reading or deciding whether a blootl gas machine ues Jennis try. error interval (in this case, the inaccuracy interval) Evaluation ol Jr. (4):.'i24-528. an ICU). a prediction about the \alue of an indi\ idual measurement. W New assessment of oxygenation fidence intervals are useful for describing group characteristics (eg, Yelderman M. siology l983;59(4):349-352. Strohl 1 KP. Stoller respira- 995: 236- 273. 1 .IK. 1 Pulse oximetry. In: Stoller .IK. Monitoring in lespiralory care. Chicago: Mosby. 1993:3(19-347. saturation level. Spot checks consisting of single measure1 ments v\ith the uating llic 104 Finger Phantom are probably adci|iiate for eval- peilomiancc of all devices in this study. Spot checks I Bland JM. .Mlnian DG. Statistical between two methods of methods clinical lor assessing agieenieni measurement. Lancet I98(i;l (S476):307-3IO. RESPIRATORY CARE • FEBRUARY '% VoL 41 No 2 Reviews, Overviews, & Updates Tracheal Gas Insufflation: Adjunct to Conventional Mechanical Ventilation Sue A Ravenscraft MD Introductioii Methaiiism of Action: TGI Methods of Catheter (Jas Delivery Clinical Studies Technical Aspects Catheter I'lacenient Huiniditlcation Inspired Oxygen Effects Monitoring Conclusions capnia" Introduction is the simplest and most widely applied.'^ adjunctive strategies include inhaled ll is (ALU iiKtrc damage now known not homogeneously thai the all alveoli remain open, and functional com|iartmcnt receives the entire and may be no distributed. In severe cases, is than one third of toiind in acute lung injury tidal this small volume (V-|-) subjected to overdistension, kx;al hyperventilation, and inhibition of suifactant.' of barotrauma (eg, In addition to - more typical tonus pneumothorax and pneumomediastinum) animal experiments have shown that transalveolar pressures that exceed 30-35 cm HiO can cause proteinaceous edema and diffuse alveolar damage in previously normal as well as These observations have stimulated in injured lungs."-* est in alternative ventilatory inter- techniques that recognize the importance of alveolar pressure constraints. Among these, Vps with "permissive hyper- the technique of using smaller nitric gas exchange, and tracheal gas insufflation (TGI). TGI has the potential to make ventilation with lower of reducing the improve ventilatory efficiency have been noted since the 1960s when tracheostomy, which bypassed the upper airway, was employed as a treatment for patients with severe and ventilatory failure.'^ -" In 1968, in anesthetized normal dogs and in MfdiLinc. University of Minnesota, and associated with the Section of Pulnionar\ /Critical Care. St is Paul-Ramsey Medical Center. St Paul. Minnesota. emphysema Stresemann demonstrated humans with failure that the expiratory flushing of the respiratory piDximal dead space decreased inspired minute ventilation with no change PaCO-''"" intt) More recently, oxygen has been insufflated directly V| by 25% and dead space by 377f of transtiacheal oxygen was found to .-' version of this paper Annual New it reduce the inspired minute ventilation has also been in patients -'' LIFECARE Reprints: Sue 640 Jackson I with In the remain- hypoxemia and chronic airflow obstmction.-"* der of this discussion. focus on TGI as an adjunctive technique to full-support volume or pressure-cycled ventilation. Horizons Symposium Orlando, Florida. The from was presented by Dr Ravenscraft during Ihc llh at the )9')5 AARC Annual MeetiiiL! in The convenience, cos- I A in the trachea of s|xintaneously breathing h\'ivrcapnic patients, metics, and oxygen conservation; however, Assistant Piiitesscir ol V ps more efficient. The benefits dead space of the mouth and upper airway to (and, therefore, lower pressures) initial intent is liquid ventilation, extracoiporeal gas exchange, intravenacaval dcci'easing inspired Dr Ravenscraft " Other oxide, partial A Symposium was supported hy an Ravenscraft St. St educational Mechanism of Action: TGI iiianl International Inc. P.ml MN Respiratory Care • MD, Pulmonary & Critical Care Medicine. has been achieved w .S.^lOlO.Sy.'i. February It "96 Vol 41 No 2 known for some time ithout applying phasic that ventilation airway pressure can be — by intio- 105 Tracheal Gas Insufflation ducing high flows of fresh gas near the carina in a valveless system (constant-tlow ventilation). Stable, elevated Pco: t-'iin be maintained for several hours in arterial apneic dogs when ceases in late expiration. During fresh gas flow, an expiratory front develops in this region lar between CO^-rich alveo- gas and CO:-poor fresh catheter gas. It has been demon- very high flows are delivered through catheters positioned strated in beyond the carina.-* If a lung-protective strategy utilizing a frequency shifts being employed. PaCO: rises as ventilatory ing and augmenting the ventilatory effectiveness of TGI.-** small Vx is effi- nonnal animals that vibrating the chest wall at high this front mouthward. improving gas mix- ciency decreases. Because the anatomic dead space remains relatively constant as Vj declines, Vjs small are associated with a high dead-space-to-tidal-volume ratio Vp/Vx). Dur- 60 ( ing ventilation aided by TGI, low-to-moderate continuous or 55 -I phasic flows of fresh gas are introduced near the carina to replace a portion of the CO^-laden expiratory gas residing the anatomic in and apparatus dead space proximal (mouthward) of the catheter tip. As a consequence, less CO2 is tidal breath is improved (Fig. 50 d CL 45 S 40 recycled to the alveoli during the next inspiration, and the ventilatory efficiency of each g < 35 ). I 30 2 No TGI 4 TGI 6 10 8 12 16 14 Vcath (tVmin) End-Expiration Fig, 2. Effect of catheter shape. Arterial Pco. plotted as function of catheter flow mechanically ventilated normal dogs. The straight in TGI catheter (closed circle) is approximately than the inverted catheter (open circle). 25% more effective (Reprinted from Reference 27, with permission.) Methods of Catheter Gas Delivery End-Inspiration Tracheal gas can be deli\ ered throughout the respiratory cycle (continuous flow or only during a specific portion (pha) sic flow) as shown in Figure 3. Continuous-flow TGI is the simplest to implement and understand, yet has the most potenFig. 1 gas in . Principles of tracheal the central airways expiratlon. Ttiis gas is of the next inspiration. ways IS gas is insufflation. With no TGI CO2 laden with (left) the (black dots) at end- tial to cause the TGI-ass(Klated complications discussed under Technical Aspects: Monitoring. During fonn of TGI. the this then rebreathed into the alveoli at the onset With TGI (right), the gas in the central replaced with fresh gas during expiration, and less air- CO2 is rebreathed dunng the next inspiration, effectively lowering the dead space. catheter delivers a constant flow of gas during both inspiration it and expiration. As the catheter flows during inspiration, contributes to the inspiratory Wj decreased a conesponding amount it x [inspiratory tiine (s) Vt must catheter flow (L/s)| and the ventilator-delivered minute ventilation be to is remain constant. Although the flushing of the proximal dead space appears to be the that main effect of TGI. there is adds to a straight TGI catheter's With "distal" effect tilator ability to remove CO2. gas. a catheter directed at the carina, a jet of fresh gas pro- jects for a variable distance beyond the orifice of the catheter. extending the Hushed region and causing ing of gases. This may explain why tip even with the \nm in the may protect the tracheal distal turbulent mix- a straight catheter per- forms more effecti\ely (approximatels an in\erted 2.'^'"; ) than one with orifice placed in the same loca- trachea (Fig. 2).-^ Catheter tip inversion, however, mucosa catheter-iinkiced aulo-PEEP. against jet trauma and reduce The In pressure-controlled \entilation. the catheter another distal ellect of TGI may be As the catheter deli\ ers gas. the ventilator decreases inspiratory gas delivery because the catheter's may tended overpressurization of the system (Fig. its added gas contributes to achie\ing the set pressure (F'ig. 4). catheter-delivered flow during inspiration However, cause unin- 5). During the preset inspirator\ lime, the catheter and \entilator are deli\ering volume simultaneously. When achieved, the \ the preset pressure has been entilator ceases inspiratory flow and the expiratory valve remains closed until the end of the inspiratory time.-'' The TGI limited b> the zone of high resistance to gas transfer that devel- because ops just be\()nd the main carina as bulk flow lYom the lung features, 106 and ven- function together to simultaneously deli\er inspiratory is it catheter. hov\ever. continues to provide flow typicall\ not integrated uitli the \entilator's safety and overpressurization may Respiratory Care • result. February Conditions that '96 Vol 41 No 2 Tracheal Gas Insufflation 02 Continuous TGI 0.1 Phasic TGI 0-1 • Vcaih Bypass ' 14 12 10 8 6 4 2 Full Inspiratory '— ' 1 ' (Umin) Pressure-control ventilation of normal dogs showing the Fig. 4. ventilator-delivered component of tidal volume (Vt) decline as Vt remains f = 40 breaths/min, set pressure 15 cm H2O. (Reprinted from Reference catheter flow (Vcaiti) is increased and the total inspired constant. Ventilator settings: inspiratory time fraction = 0.30, Partial Inspiratory Bypass 29, with permission.) With TGI Pressure-Control Ventilation Total Expiratory Washout End-Expiratory Washout Fig. 3. Flow-time tracings of the various forms of TGI during convolume-cycled ventilation. Tfie shaded areas represent stant-flow, the TGI-catheter flow. Continuous TGI— the catheter gas flows throughout inspiration and expiration. Phasic TGI — the catheter gas flows during selected portions of the respiratory cycle. Forms of phasic TGI include full inspiratory bypass: catheter delivers the entire inspired Vt; partial inspiratory bypass: catheter and ventilator deliver inspired Vt; total expiratory Pressure and flow tracing Fig. 5. Left: of pressure-control ventila- an extended inspiratory time allowing equilibration of airway and alveolar pressure (inspiratory flow reaches zero before the end of the inspiratory period). Right: Addition of continuousflow TGI and overpressurization during inspiration. tion, with washout: catheter gas flows throughout expiration; end-expiratory washout: catheter gas flows thereby bypassing the anatomic dead space proximal to the only at end-expiration. catheter tip. In recent work by Kolobow and a "reversed jet" catheter has promote rapid equilibration of airway and alveolar pressure before the end of the inspiratory period amplify this problem (ie. extended inspiratory times, low resistance, and low respiratory-system compliance). This problem can be identified by examining the airway pressure tracing and can be remedied by placing a pressure relief valve in line to dissipate insufflated flow that produces excess pressure.'" Setting the ventilator pressure limit just above the set pressure usually pre- pulmonary ventilation may hold promise, particularly Phasic inspiratory TGI can inspiratory all or part of expiration (Fig. 3)." Phasic TGI can be used Respiratory Care • as the only source of fresh gas. February "96 Vol 41 No 2 also be ventional ventilation (only part of the Of all catheter). bypass is the forms of phasic the least effective," This in tilator is the TGI, partial inspiratory likely due to the fact that some of the Vj directly near proximal dead space), when the ven- simultaneously delivers the other portion of the inspiratory Vt. with is combined with con- Vj is delivered by delivering the carina (bypassing the TGI neo- neonates and children. and causes variable inspiratory times and alarm actuation. Phasic in and pediatric applications as the only source of fresh gas in a valved system. This technique termed intratracheal although the catheter ration or during been used successfully '' natal vents extreme overpressurization but terminates inspiration flow can be delivered selectively during inspi- colleagues,'- it still COi) back pushes the common dead-space gas (laden into the lunc in front of the newly delivered 107 Tracheal Gas Insufflation Vj. Also, Ibmi of phasic TGI. there in this common is Both continuous-flow TGI and no catheter flow not swept TGI CO2. Second to continuous-flow TGI. phasic expiratory TGI ume during expiration, and the dead space is clear of in total expiratory-washout deli\ered with a straight catheter cause small increases plethysmographically measured end-expiratory lung vol- flow-dependent manner. There are three potential in a has been the most extensively studied. Total cxpiratow catheter' mechanisms flow appears to be as effective as continuous catheter flow" catheter decreases the cross-sectional area of the trachea, for this increase in lung volume.-^ First, the and avoids some of the potential problems generated by the increasing expiratory resistance. Second, completely separate gas source continuously flowing into the tum of patient. As long latory cycle that the is as the end-expiratory portion of the venti- included in the catheter-flush period, it appears the discharging jet stream expirator\' circuit impedes deflation. volume of catheter gas delivered during expiration. tiveness.''* This means be effective but When tracheal 3), the catheter may gas flow is ratio ventilation. still add a small TGI flow (Fig. of the end-expiratory 6). TGI amount of Vx to from the lungs stops This occurs because, at the onset flow, the gas exiting the catheter takes the path of least resistance. Some sense starting the next inspiration, and enters the lung, in a some limited human TGI studies are available. Stresemann applied insufflated at end-expiration only (Fig. may OnK TGI may require a higher catheter flow. the next inspiration, particularly if flow before the Clinical .Studies even when a short expiratory period that employed, such as during inverse still some of the momen- transferred to the alve- catheter flow through the endotracheal tube and oli.'^ Finally, not just the absolute level of catheter flow, determines effec- is is exits through the open expiratory valve, flushing the proximal dead space. in 1969.-- The 1 99 1 . in their P;,c o: TGI. and both during catheter of continuous-flow TGI in flinv. as part We studied the effects 8 patients in respiratory failure and found a 15-25% improvement settings (Fig. 7)." TGI with multiple chest in a patient tubes and a persistent pneumothorax. in ventilated patients Gilbert and colleagues"' used expiratory of a pressure-limiting strategy TGI two to patients recei\ed total expiratory had significant reductions In on small groups of patients TGI Nakos and in Paco: at unchanged \'entilator colleagues'** reported the use of 7 patients with acute lung injury. With a catheter flow of 6 L/min. they found a 259f fall in Pjco: at the same inspired Vj. In a second portion of the experiment, they were able to Vj by 25% and maintain an equivalent Paco> which demonstrated the pressure-sparing effects proposed by other reduce £ 60 - 50 - q I E 40 30 Fig. 6. Simultaneous tracings washout at for an animal during end-expiratory 10 L/min catheter flow. Plethysmographic lung volume volume prior to catheter flow Superimposed tracings of the flows measured in the inspiratory and expiratory limbs of the external circuit (middle). Proximal aira/ay pressure (Paw. bottom). Note that lung volume and proximal airway pressure tracings show pre-mspiratory step changes. These deflections indicate that gas flows both antegrade (volume tracing) and retrograde (flow tracing) from the catheter tip during Baseline relative to the end-expiratory lung Distal 6 L/min (top). this 108 penod. (Reprinted from Reference 31. with permission.) Fig. 7. Patients in respiratory failure (n ing conventional = 8). IVIean volume-cycled ventilation a continuous TGI flow of 6 zontal lines indicate mean [(53.1 (SD), Paco2 dur- ±3.1) torr] and at ±2.1) torr]. The dark horivalues. (Repnnted from Reference 37, Umin [(45.0 with permission.) RL.SPIRAr()R> CARI: • FEBRUARY "96 VUL 41 NO 2 Tracheal Gas Insufflation investigators. Recently Belghith el se\ere able to etfect a decrease in to al''' studied 6 patients w ith ARDS in the setting of pennissi\e hjpercapnia luid were 84 (26) torr. v\ ith mean (SD) Paco: from 108 (32) ton- continuous-tlow pure-o\ygen TGI of only = 20/min. inspiratory time = s. continuous catheter = 6 L/min. Fio; = 0.50 (set on ventilator), the actual Fio: for the patient would be approximately 0.58. When expiraton' phasic TGI is utilized with pure o\v gen. the effect on Fio; frequency is 4 L/min. 1 flow even smaller. Monitoring Technical Aspects TGI Catheter Placement in its current configuration makes routine respiratory monitoring difficult and. potentially, dangerous. Although Optimal catheter position appears few centimeters to be a above the carina.* Moving the catheter near the carina causes a greater "flushable" \olume to lie proximal to the catheter and ad\ances the turbulent zone generated by the catheter closer to the lung periphery. Catheters can be placed bron- TGI appears or. alternatively, appropriate catheter insertion depth can be estimated from a recent chest roentgenogram. Boussignac and colleagues""-'- have de\eloped an endotracheal nibe with capillaries tion to deli\ er TGI embedded in the v\alls that A customized endotracheal tube would tlow. remove problems associated v\'ith the physical presence of a catheter passed through the endotracheal tube. occupies space in tlie can func- endotracheal tube The catheter tine suctioning. adds another source of gas to the and does not respond to the usual ventilator safeguards. Problems arise in both volume and pressure monitoring. As mentioned TGI adds to prev ioush continuous . ered inspiratory Vj. In volume-cycled ume during inspiration and decreasing the ventilator-delivered component of the Vj. In pressure-controlled ventilation, no adjustments need be made because as inspiratory pres- to As described sure builds the ventilator deliv ers less gas. there lier, is when long inspiratory times are used. causes problems mon- TGI Either continuous or expiratory itoring exhaled volumes. Because gas flows during the expiratory period, it adds to expiratory volume and causes a dis- to detect a leak. it appears that tracheally insufflated gas should be conditioned. Shapiro et aH' TGI that have show n and the condi- significantly cools the central airways, tioned gas delivered by the ventilator can not compensate tor oxygen administration this effect. Transtracheal breathing patients has had serious, rare consequences including mucus balls imd U'acheal ifying insufflated gas oped when gas is is granulation.-"-*" 10 cm HjO may exceed forced through the catheters humidifier's leak or burst pressure. -"" 1 Heating and humid- possible, but the high pressures devel- causes leaks in many A pressure in a excess of humidifiers. Oxygen The actual fraction of inspired TGI. especiallv flated. When if oxygen (FioO pure oxygen rather than blended gas continuous insufflation of with rise is insuf- 100% oxygen is Routine monitoring of pressures (auto-PEEP) is the gas continues to flow and a stable pressure In expiratory is with the subsequent Vy. Nomially the gas residing mon dead space at end-expiration contains about gen than the inspired gas. The higher the F|o, tilator, in the 5% set is delivered com- less oxy- on the ven- the less the impact of the catheter delivering pure oxygen. For example. v\ith \entilator settings of Respiratory Care • February '96 Vj = 600 Vol 41 No 2 niL, is never reached. TGI. an end-inspiratory pause may be added the catheter because, if from the ventilator, the is obtaining the signal to begin tlow pause is and the gas has not yet begun considered part of inspirato flow through the catheter. end-expiratory pause for an auto-PEEP measurement typ- cannot be pert'ormed. Another potential danger con- is tinued catheter-gas flow in the setting of an occluded endotracheal tube. The inspiratory phase of the ventilator is pressure-limited and gas flow ceases, but the catheter gas continues Vj and of the anatomic and apparatus dead space gas With continuous TGI. neither of these maneuvers can be performed because to replaced with fresh gas (during expiration) that the and end-expiratory static (plateau) also problematic. to flow to the patient, generating a risk tion, part volume. amount of volume delivered by employed, the catheter gas delivers a portion of the inspired raises the actual Fio: of the tnie. deli\ ered Vj. In addi- set inspired catheter during the expiratory period. ically may exceed the the case, then a low-exhaled- Vj alarm can be set that If this is An Effects ventilators that actually takes into account the tion, Inspired Some exhaled volumes spontaneously in Of even more pneumotachometer can be set to alarm at low is the inability of the expiratory concern Although studies are sparse, ear- the potential for overpressurization, especially crepancy between inhaled and exhaled volumes. Humidification the deliv- ventilation, this can be accounted for by calculating the catheter-delivered vol- luid. tlierefore, increa.ses both inspiratory and expiratory resistance and impedes rou- it patient tip choscopically to be simple, of barotrauma. For TGI be used safely on a longer-term basis, some simple safeguards need to be added to the system. TGI markedly Fig. 8). distorts the capnogiaph Uacing (CO: vs time. Because the catheter is continuously delivering fresh gas during expiration, the end-tidal zero. The capnograph probe of the ventilator, and location in the v it is CO; can even approach typically placed near the Y-piece gives a CO; entilator circuit. If value reflecting that one more C02-Iaden gas from 1(J9 ,, Tracheal Gas Insufflation the periphei7 of the lung capnogia]">hic COi mobihzed during is may \aiue the actual role of capnography in monitoring a patient receiving TGI remains York: Marcel Dekker, 1991:433-449. 3. CO2 removal.'"' Therefore, New Adult respiratory distress syndrome. (editor^) expiration, the remain elevated despite improved Bowlon DL, Kong DL. High tidal volume ventilation produces Med increased lung water in oleic acid-injured rabbit lungs. Crit Care unclear. 1989:17(91:908-911. 4. Cummings JJ. Carlton DP. RG. Poukun FR. Bland RD. Scheerer l.ung overexpansion increases pulmonary microvascular protein perme- young lambs. ability in Patient 7 .S, jder Jl. Adverse effects of kirge tidal acid aspiration. 6. AppI Physiol J 1990;69(2):.'i77-.sX3. Corbndge TC, WVxxl LD. Crawford GP. Chudoha MJ. Yanos Am Rev volume and low PEEP Respir Dis 1990:142(21:31 Dreyfuss D, Basset G, Soler P, Saumon G. J, in S/na- canine l-31.'i. Intermittent positive-pressure hyperventilation with high inflation pressures produces pulmon;iry microvascular injury Am Rev in rats. Respir Dis I9S5;132(4): X8()-.SS4. 7. Dreyfuss D. Soler tidal Saumon G, High Basset G. P. pulmonary edema. Respective inflation pressure effects of high airway pressure, high volume, and positive end-expiratory pressure, .Am Rev Respir Dis 198X;l37(.s):ll.'i9-ll64. 3 4 Time 5 8. (s) Fu Z. Costello ML, Tsukimoto K. Prediletto R. pulmonary 9. Fig. 8. in West JB. High lung volume Costello O. Representative superimposed capnograms from a patient respiratory failure with (lower line) and without (upper line) capillaries, J 6 Am Rev Respir Dis Kudoh I, 1 1 1 987: Med 2, Tracheal gas insufflation has potential to improve the man- also have promise in neonatal ventilation 3, 2 ):3 1 2-3 1 An dog lungs due in to high volume in J. Increased peak airway pres- 1 Care Tsuno K. Prato in lungs of nonadult rabbits: effect of ventilation Med 1990; 18(6 1:6.34-637. Kolobow P. T, Acute lung injury from mechanical ventilation at moderately high airway pressures, where expenmcntal study. .S, Appl Physiol 1984:57(6): 809- 1816, pattern, Crit 1 3.S( Peevy KJ, Hernandez LA. Moise .AA. Parker JC, Barotrauma and microvascular injury agement of acute lung injury by reducing pressure require- 1 Parker JC. Townsley Ml. Rippe B. Taylor AE. Thigpen sures. J 1 level of hypercapnia. Chen 1984:12(.'i):443-446, microvascular permeability Cctndusions the anatomic and apparatus Funiagalli R. Mascheroni D. Prato P, Effect of mechanical ventilation on lung water dogs, Crit Care TGI may Appl Physiol 1992;73(1):123-133. airway pressure during mechanical ventilation. 10, ments or by limiting the MP. T. Moretti AR. Mathieu- V. Joris M, Severe impaimient on lung function induced by high peak L/min continuous TGI flow. (Reprinted from Reference 37, with permission.) Kolobow Elliot increases stress failure in .Appl Physiol 1990: J 69(3):9_«i6-961, dead space make up a sizable 1 4, portion of each breath. Webb HH. Tiemey DF. Experimental pulmonary edema due to intermittent positive pressure ventilation with high inflation pressures. Customized endotracheal tubes may facilitate the safe appli- Am Rev Respir Dis Protection by positive end-expiratory pressure. cation of TGI. 1974:1 10(.'i):556-565. Given the cunent possible complications including damage, overpressurization, and TGI remains an tracheal 1 ."i. 16, investigational technique. Establishing the ultimate clinical utility Feihl F. Perret C. Permissive hypercapnia: we be' difficult routine monitt)ring. Am J Respir Crit Care Med 1 994: 1 how permissive should ."^0(6. Part I ): 1 722- 737, 1 Kacmarek RM. Hickling KG, Permissive hypercapnia, Respir Care l993:38(4):373-387, and safety of TGI I requires careful prospective studies performed in tlie 7. clinical setting. Tuxen DV. Permissive hypercapnic ,Am ventilation. J Respir Crit Care ,\1ed l994:l.'iO(3»:870-874. 1 .S, Brudemian 1. Alkalay I. Stein M. Frank HA. Tracheostomy for acute respiratory failure, Dis Chest 1966:50(4):393-402, 19, 20, I thank ."Mcxander B .Vdams MPH RRT Cullen JH, Ann ACKNOWLEDGMENTS Int An Med evaluation of tracheotomy Lyons H. Becker W. Torres G, emphysema, .Am lor his assistance and critical 2 1 review of the manuscript Stresemann H. in pulmonary emphysema, l963:.'s8:9.S3-960, J Med Tlie management 22, REFERENCES pulmonary washout of anatomical dead space Sattler F. Effect of on ventilation. pH and blood gas composition Respiration 1969:26(2): of severe 1964:36:62-67, 1 in anesthetized dogs. 16-121, Washout of anatomical dead space Streseniiinn E. Votteri B. Sattler F. for alveolar hypoventilation: preliminary case report. Respiration 1969;26(6):42.'i-4.34. fialtiniini L. Pesenli H. et al. A. Honihuici M. Bagliimi S. Rivcilta M. Riissi 23, Relationships hetvvcen lung computed loniographic density, gas exchange, and PLHP in on acute and chronic gas exchange 24, Drcyluss D. .Saumon G. l.ung inerinllalion: jihysiologic and anatomic alterations leading to 110 pulmonary edema. In: /apol WM. Lemaire F in humans. ,Am Rev Respir Dis 1989:l4()(4l:S8,s-890. acute resplratoiv lailure. .'Xnesthcsiol- ogy mSS;6')(6):824-8.'»2. Bergofsky EH. Hurewitz AN, Airw ay insufflation: physiologic effects Couser Jl Jr. ventilation. 2^. Benilitl J. M;ike BJ. Transtracheal oxygen decreases inspired minute Am Rev Respir Dis 989: 1.W( 3 1:627-631. Rassulo 1 J, Celli B, RESPIRATORY CARE • Work of breathing duriuL' direct FEBRUARY "96 tra- VOL 41 NO 2 — . Tracheal Gas Insufflation O: administration in patients with severe chronic lung disease (abstract). Am Rev RespirDis 1990;141:A883. Slutsky AS. Watson J. Leith DE. Brown R. Tracheal insufflation of sure, flow, cheal O^ (TRIO) at low flow 36. A. Ravenscraft SA. Nakos G. Nahum Effect of catheter gas insuftlation m How dogs. direction J Adams AB. Burke WC. Marini CO: removal dunng tracheal on Nahum WC. Crooke PS. Marini JJ. Am Rev Respir Dis ination by an intratracheal catheter. CO: elim- MR. E. Miro AM. Hoffman LA. 39. Tosata F. Pinsky Am J Respir Cril Care 40. Med Burke WC, Nahum Marini JJ. A, Ravenscraft SA. Nakos G, Modes of tracheal gas Adams AB. Marcy 4 in JJ, Bower LK, Lillehei 43. is main- 1994;20:407-413. Fierobe L, Brunei F, Monchi M, Mira JP. Is tracheal extrapulmonary gas exchangers gas in severe Chest 1995;107(5):1416-1419. of catheter position, diameter, and flow rate. Am Rev JI, Med of 1989;8:47-49. pressure during endotracheal gas injection. Shapiro RS. Ravenscraft SA. J Appl Physiol 1989; Nahum A, Adams AB, Manni JJ. Tra- Am J Respir Crit Care Med 1995;151:A427. GG. Wagshul FA, Henderson D, Kime SW. Fatal airway (abslract). Burton obstruction caused by a Nahum A, Burke WC, Adams AB. 45. mucous ball from a transtracheal oxygen Am J Respir Cnt Care Med Solway J, 1996 Pres- JH 2nd. Laser resection of 1992;101(1);269-271. (in press). Wood LD, Schumacker PT. Punzal PA. Myers R, Ries AL, Harrell granulation tissue secondary to transtracheal oxygen catheter. Chest Tracheal gas insufflation: Catheter effectiveness determined A, Sznajder P, Teissere B. Efficiency endotracheal set up allowing a constant additional gas flow. catheter. Chest 1991;99(6):I520-I523. Ravenscraft SA, Shapiro RS, Nahum Med Isabey D. Boussignac G. Harf A. Effect of air entrainment on air- 44. technique of intratracheal pulmonary ventilation. Pediatr Res by expiratory tlush \olume. 35, Kotanidou A. Tsagaris H, Roussos C, Tra- 67(2):771-779. 1993;34(5):6()6-610. JJ. clearance cheal gas insufflation cools and dries gas in the central airways Muller HE. Kolobow T, Mandava S. Jones M, Vitale G, Apngliano M, Yamada K. How to ventilate lungs as small as 12.5% of normal; Manni new way 1993;28(3):484-487. 34. M. Urgences CW, Perlman ND, Kolobow T. Intratracheal pulmonary ventilation and congenital diaphragmatic hemia: a report of two cases. J Pediatr Surg new CO: Rev Respir Dis 1993;148(2): Nahum A, Ravenscraft S.A. Nakos G. Burke WC. Adams AB, Marcy TW, Manni JJ. Tracheal gas insufflation dunng pressure-conU-ol ven- a 42. Wilson JM. Thompson JR. Schnitzer the Am Boussignac G. Bertrand C. Huguenard 1 Comparison of normal dogs. Am Rev insufflation. RespirDis 1993;148(3):562-568. 33. .Adams AB. Nakos G. Marcy RespirDis 1992;146(6):141 1-1418. continuous and phase-specific gas injection 32. Belghith tilation. Effect 1995;151:A428. TW, S, insufflation an alternative to 1992;146(4): Effects of airway insufflation on peak airway pressure during pressure-control ventilation (abstract). 3L Nakos G, Zakinthinos ARDS' Gowski DT. Delgado .^. Tracheal gas insufflation augments tained constant. Intensive Care 965-973. 30. JJ. WC. Nahum Burke S.A. cheal gas insufflation reduces the tidal volume while Paco: Lung mechanics and gas exchange during pressure-control ventilation in dogs. Augmentation of and principles of action Biomed Instrum Technol 1991; 345-351. TW. Adams AB. Ravenscraft SA, Marcy Marini during mechanical ventilation. -''8. A. Burke Ra\ enscraft TW. Eckmann DM. Gavriely N. Intra-airway CO; disunbution during airway insufflation in ventilatory failure. J Appl Physiol 1995;78(2|: 29. Larsson A, Smith R, Bunegin L. Intermittent-flow expi- J. 25(6):45 1-456. 37. Appl Physiol 1993.75(3 1:1238-1 246. 546-554. airway models during conin Appl Physiol 1988:64(5 1:2066-2073. a preliminary communication. thesiology 1985;63(3):278-286. JJ. Gilben J ratory ventilation (IFEV): delivery technique Anes- rates sustains life for several hours. and density relationships stant-flow ventilation. 46. Adams AB. Tracheal gas insufflation. RespirCare 1996:41(4) (in press). CORRECTION In the abstract of the paper by Hagarty Fink JB. Use of pulse oximetry to Respir Care 1996:41 ( I EM. Langbein WE. Skoro(Jin (ietemiine oxygen prescription for MS. Hultman hypoxemic CI. Jessen patients with J A. COPD. ):30-36. the first sentence in the Results section should reati: Average SpO: during the last 30 seconds of WALK'"" ing the lift-push-carry, undress and dress, (WALK "') was significantly lower than dur- and ascending and descending stairs. We regret the error. RESPIRATORY CARE • FEBRUARY "96 VOL 41 NO 2 111 I Cardiorespiratory Barbara Wilson Interactions Foreword: ihis issue. III ture Rl.SlMRAT()K^ CarI' iiilii)duccs a —committed to teaching among relationships A New Teaciiino new the cardiac and respiratory systems, cardiopulmonary disease, and the practice of respiratory Any care. abnomiality that inteniipts the delicate balance between these two organ systems, be it disease or treatment, can cause aca.scade of worsening pathophysiology and undesirable clin- outcomes. Moreover, alterations ical one system can cause fore, we alterations in the in the performance of second system. There- should consider these systems as one — the cardiorespiratory system. RRl'. km Melioncs ML), Feature for RESPIRATORY CARE All facets ol adult, pediatric, and neonatal i"espiratt)ry care fea- and reintbicing the physiologic MEd and John Palmisano RRT, Section Editors may are potential sources for submissions. Cases from any setting — nostic laboratories; to CRI should and rehahilitation/liome ctire. Submissions follow publication guidelines for RESPlR.vroRY CaRI; and include a case study w tions, originate general, subacute, and critical care; diag- ith ilhistiations. figures, equa- and a glossary of terms. We hope you read and enjt)y the introductory articles and We welcome your questions and comments and case study. invite you to contiibute from interactions your own examples of ciudiorespiratory \oiir practice of respiratory care to CRI. Cardiorespiratory interactions (CRI) are the physiologic interplay sy.stem. Barbara between the components of the cardiorespiratory These interactions affect the delivery and of oxygen and the elimination of carbon dioxide. Other such may interactions (; Wilson Pediatric Critical Care & Respiratory Care Services be related to the administration of cardio.|(»ii therapeutic agents, resulting in untoward respiratory events (eg, j8 -blocker therapy of CRI is and bronchospasm). An understanding therapeutic interventions are considered and undertaken to improve oxygen delivery and eliminate carbon dioxide. anticipate and then measure Meliones & MD Anesthesia Medical Director of Pediatric Respiratory Care essential for respiratory care practitioners (RCPs). RCPs must N Associate Professor of Pediatrics As MEd RRT Research Associate utilization Division Chief. F\'diatric Critical Care Duke Children's Duke the physiologic Hospital University Medical Center Durham. North Carolina responses to interventions, and alter the care plan based on patient response. We introduce "CardiorespiiatoiN of three articles,' March. The ' first article is Research Associate a review of cardiovascular anatomy Department of Pediatrics and physiology.' The second in this issue ailicle builds The third presents a and a on the cusses specific cardiorespiratory interactions care.- M Palmisano MA RK John Inteiaclions" in a series third in two presented first in and CSMott dis- Unix respiratory ersil\ Children's Hospital of Michigan Medical Center Ann review of echocardiography as an .'\rbi)r. Michiaan approach to evaluating CRI and respiratoi^ care inteiAentions.' The March in a series Issue of in the clinical As RESPIRATORS Care of case studies to also presents the illustrate the importance i>f first management of patients. Irani with our other teaching features, each submission must have a central focus. ture, that focus Gas Corner." is In the "Test Your Radiologic the radiograph or the focus is CT REFERENCES CRI Skill"" fea- scan. In the "Blood on the blood gas analysis and inter- CA. Korn IH. Melioncs JN. L'ndcisiandinii cardiorespiratory interactions: c;irdiovascularanaloin\ and ph\sioloi;\ |rc\ieu I. Rcspir Care I996:4I12):M.V122. Black DR. Wilson BG. Meliones JN. The role of cardiorespiratory interactions in respiratory care (review). Rcspir Care 199fi;4l(2): 123-132. pretation. In CRI, the focus action, luid the case trate the 112 is on the cardiorespiratory and other supporting material serve importance of thai interaction. inter- to illus- Bengur A\<. Melioncs JN. NcSniith echocardiography Care in the practice J. Kappelcr M. Li J. The role of of respiratory care (review). Respir 19')(i:4l(3):iii press. Respira lOR'i Care • February '9(1 Vol 41 No 2 Understanding Cardiorespiratory Interactions: Anatomy and Cardiovascnlar A Tram MD, bv Charles Frank 1 1 Fhysiolog)' Kern MD, and Jon N Meliones MD Introduction Cardiac Anatomy & Physiology Cardiac Klcctropliysiology Autonomic Nervous System Hemodynamics Myocardial Performance Muscular Contraction-p]xcitation Coupling Myocardial Membrane Receptors Regulation of Myocardial Contractility In Conclusion Introduction An iai- understanding of basic pulmonary and cardiuvascu- piiysiology is essential for full comprehension of the interactions that occur between these ingan systems. In this review, we present cardiovascular anatomy and physiology and the basic theories of hemodynamics and myocardial peiformance. Cardiac Anatomy The human atria and 2 heart is ventiicles.' word meaning ' a & Physiology 4-chambered organ consisting of 2 The term atrium a central room (in a ing recessed walls and multiple openings. term meaning small belly and cles" structural ically nonnal is derived from a Latin is Roman ' house) contain- Ventricle resemblance to the stomach.' heart, systemic a Greek is used because of the ventriIn the venous blood returns anatom- to the right side of the heart and drains into the right atrium (Fig. riizhl atrium (RA) is a thin-walled chamber 1 that receives ). The blood Dr Trant was Senior Feliou in Pediatric Cardiology when tliis paper was written. He is now in private practice in Florence. South Carolina. Drs Kern and Meliones are with the Departments of Anesthesia. Pediatrics, and Respiratory Care. Duke Children's Hospital, Duke University Medical Center, Durham. North Caiolina. Fig. 1. Normal blood pressures and oxygen saturation (circled) data with arrows indicating flow of blood, RA = right atrium; RV = nght ventncle; LA - left atnum; LV = left ventricle; PA = pulmonary artery; Reprints: Jon Duke N Meliones MD. Duke Universitv Medical Center. Respiratory Care • Children's Hospital. Durham NC 277 February "96 PO Box cava; AO ^ aorta; SVC = superior vena cava; IVC = inferior vena M = inean blood pressure. Adapted from References 4 and 5, with U). Vol 41 No .^046. 2 permission. n3 Cardiorespiratory Interactions three large veins: ihe superior I'lDin vena cava (SVC), which aortic arch. The tenu drains the head and upper extremities, the inferior vena cava may have come from (IVC), which drains the lower body, and the coronary sinus, donian knife sheath which The oxyhemoglobin carries myocardial blood. ration in systemic satu- venous blood ranges from 35-55% for blood returning from the coronary sinus to 65-75% for blood returning from the IVC and SVC. Nomial IVC and SVC mean sures aie 2-5 mm Hg. Venous return from the right atrium then pres- passes through a .3-leafcd \alve, the tricuspid valve, before entering the right ventricle (RV). The anatomic arrangement of the valve leaflets prevents backward flow of blood during The volume of blood ejected during the total volume in the ventricle during ventricular contraction. compared systole diastole tion fraction is RV The to A nomial ejec- referred to as the ejection fraction.* is is in the chest cavity). The pri- RV by the RV and the RV is only required low pressures. The systolic pressure generated a low-pressure circuit, is is usually on the order of 20-25 mm Hg. Because pressures are higher than atrial pressures, the a greater muscle ditions of mass than pulmonary the RV has RA. Under pathologic con- ailei^ hypertension or pulnioniu"y stenosis the muscle mass of the reduce RV RV increases in an attempt to RV pulmonary system enters the through the pulmonary valve (a 3-cusped valve). The pulartery arteries. the usual site of is sampling for mixed-venous blood when cardiac output and oxygen consumption measurements are made. Normal mixed-venous oxyhemoglobin saturation obtained from the main branches pulmonary artery fonning an extensive capillary network exchange of carbon dioxide tlie the circulating blood (saturation 999r ) is 65-75% and iuid in the lungs that oxygen between to enter the left atrium (L,-\). left it left ven- a low-pressure structure that supplies blood to the ventricle across the mitral \al\e during diastole. is a bicuspid valve (2-leafed) and The cone-shaped lell a high-pressure \entricle. mm adult. rise to the right subleft common subclavian artery. The aorta then left and becomes the descend- 'tail') ing thoracic aorta. Cardiac Elect rophysiology The cardiac electrical .system consists of .specialized cle tissue that rapidly conducts electrical impulses right atrium to the and ventricular ulus is Hg apex of the ventricles contraction.'' The " to synchronize atrial origin of the electncal stim- a bundle of specialized muscle cells called the sinoatrial (S,A) node. The SA node is the pacemaker of the RA near the junction of the located in the SVC. is at the junc- and ventricular septa provides the only nor- tion of the atrial electrical heart and A second ntxJe of tissue, the atrioventricular (AV) node, located mal mus- from the connection between the atria and ventncles. The AV node delays the signal from the SA node allowing the atria tiation els fill the \ entricles. prior to the ini- of \ enuicular conuaction. The elecuical signal then \id\- from the electrical AV node through the Bundle of His. where the system bifurcates into the right and left bundle branches. These branches provide a pathway for electrical impulses that depolarize and open channels in the brane, initiating muscular contraction of the that in the cell mem- respective ven- Ventricular contraction occurs from the apex of the he;irt. wave of contraction continuing up to the base TTius, a coordinated \entricular contraction occurs maximizes the amount of blood ejected into the aorta. ventricle (LV) u hich The mitral \ ulated & is 3). modulated b\ the autonomic MycK'ardial pert'omiance by two separate and opposing systems: is reg- the sympathetic ever, during conditions o( stress (eg. fear, exercise, sepsis), (PNS). Under nomial conditions, the I'*'"). 130-150 The volume of blood ejected by across the 3-cusped aortic Cardiovascular function ner\()us system'^ (Figs. 2 ejects blood into the The LV is creates systolic pressures rang- in the infant to .Autonomic Nervous System nervous system (SNS) and parasympathetic nervous system so high-pressure systemic arterial system (Fig. normal which gives named because is resembles the hat (mitre) of a bishop."' ing from 50 transverse aorta has three The LA, a rect- angular structure situated directly behind the right and valve left and the lungs. Fully oxygenated blood then returns to the he;ul through the four large pulmon;u7 veins tricles, is The carotid arteries, the turns caudally (towards the ventricle with the for common carotid artery, and the tricles." s ascending aorta.' blood to the head and upper exuem- the innominate artery, clavian and right mm Hg. The pulmonary artery branches numerous times, evenallow Mace- to describe a like the aorta then continues cephalad (towards that supply normal pulmonarv artery pressures range from 20-25/10-12 tually The the head) and turns leftv\ard. ities: much curved adequate time to empty and wall stress. Blood ejected by the monary that recorded by Aristotle and first word used vessels that arise from the aorta are the right and first coronary a crescent-shaped structure located directly mary function of the RV is to pump blood through the pulmonary system. Under normal conditions the pulmonary cirto generate was a Greek 75-80%. beneath the sternum (anterior cuit The aorta mm the Hg in the LV flows al\c into the ascending aorta and PNS predominates. the predominant system that stimulates the SNS. The mycx-ardium and left stellate is ganglia myocardium Howis the directh innervated through the right — SNS nerves (Fig. 2).'' These neurons cause the release of a neurotransmitter, norepinephrine, lesulting in ;ui increase in hc;ul rale and in the force of mycK-ardial contraction. SNS stimulation of the adrenal glands prompts the release of epinephrine into the vascular system. Elevated *See Glossarv following the References section. 114 levels of epinephrine further stimulate an increase in heart rate RESPIRATOR"*' Care • February "96 Vol 41 No 2 Cardiorespiratory Interactions and the force of contraction. This response has been refened to as the "tlght-or-night" response, hi contrast, stimulation of the PNS. acting primaiily through the vagus nerve, causes the which has an inhibitory release of acetylcholine, effect on myocardial performance and causes a decrease in the heart rate and a mild decrease in the force of myocardial contraction (Fis. The PNS. in contrast, tends to decrease systemic vasculai' resistance. The balance between the SNS and PNS helps maintain appropriate oxygen delivery to the tissues. Abnormalities in cither the PNS may Humoral mechanisms 3).'* have physiologic sequelae, such PNS stimulation) SNS stimulation). (eg. the renin-angiotensin system) also responsible lor regulating lulerial pressure luid intravasrelease renin in response to hypoten- The kidneys culiu- \ Illume. "Stress" sion and renal hypoperfusion. Renin then triggers the con- Emotions, i Anticipated O or or tachycardia and hypertension (excessive iu-e ; SNS as bradycardia and hypotensit)n (excessive version of angiotensinogen to angiotensin II —a reaction that Exercise occurs, primarily, in the lungs. Angiotensin II is a potent vasoconstrictor that produces a substantial increase in ailerial presLeft Stellate sure by increasing systemic vascuku' resistance." '"Angiotensin Ganglion n also causes the release of aldosterone from the adrenal Aldosterone is a hormone that Inotropic State and water and an increase I mate gland. causes the retention of sodium in intravascular \ result of renin-angiotensin stimulation olume. The is ulti- an increase in ./J1: ventricular \olume and increased Role in Arrhythmias Hemodvnaniics Sympathetic innervation of the heart. Stress leaiJs to activation of the sympathetic nervous system, acting mainly through (1) the right stellate ganglion to release norepinephrine (NE) to areas Hemodynamics Fig. 2. of the sinus (SA) and atrioventricular (AV) nodes, ganglion to stimulate the to release left epinephrine (E) From Reference ceptors. Q ^ and ventricle, into the 8, with (3) (2) left stellate the adrenal glands blood stream. = beta-1 |3^ arterial pressure. re- is the study of blood in motion. In general, factors that affect the motion of blood include blood flow (Q). the change in pressure across the vascular system (AP), and the resistance (R) sure, to How. Ohni"s law relates flow, pres- and resistance by permission. Vagal Nucleus lOthNen/e Alteration of the diameter (or radius) or length of the vessel by the autonomic nervous system and changes in the viscosity of the bkKxl aftect the resistance to blood flow. Poiseuille A O (1846) described resistance as Nicotinic Receptors o Reduceid Diastolic Atropine /' A ACh Gil ' AV / Ttr" where 8 (Modest) Proteins Cyclic lar ) AMP Changing a constant, and ;r= 3.1416. the length of the blood vessel or the viscosity (hematocrit) of the blood aftects resistance. However, because i R of the heart. The mam direct innervation of the sinus (SA) and atrioventricu- (AV) nodes and lease. is j Parasympathetic innervation (1 by Rate K- Channel Fig. 3. tube Negative Inotropic Effect Receptors action are (r) Blocli i Muscarinic x: G and radius rj). Aihlele's Heart j Inhibition (/.) ( Heart Depolarization SA Node Competitive /-^ length relates to viscosity it (2) prejunctional inhibition of ACh = acetylcholine. From Reference sites of norepinephrine 8. with re- permission. is proportional to the fourth power of the radius of the vessel, even small changes in vessel diameter (2r) can dramatically alter resistance. Vascular resistance opposes the forward flow of blood. The primary cardiovascular system are sites of vascular resistance in the and precapillary level.* at the aiteriokir Muscular arterioles and precapillary sphincters are under autonomic control. Vascular resistance is expressed as the mean The nervous system can also influence vascular tone by altering vascular smooth muscle contraction and relaxation. Stimulation of the lar resistance SNS causes an elevated systemic vascu- bv reducina the diameter of the blood vessel. Respiratory Care • February '96 Vol 41 No 2 pressure drop across a capillaiy bed divided by the blood flow (Ohm's Law)." '- Pulmonary vascular resistance tance across the pulmonary-capillary bed and is is the resis- determined by measuring the mean pulmonaiy-ailerN' and mean left-atrial 115 — Cardiorespiratory Interactions pressures. Noniially tliis is a very low-resistiince system because of intrinsic properties of the lung (Fig. the systemic circulation in ).'" 1 Contrast this with which there are many different cap- beds with different metabolic needs. Vascular resistance illar' of the systemic circulation detemiincd by measuring the is mean ference between the and mean aortic dif- right-atrial pressures divided by the amount of flow through To ensure adequate perfusion of each capillary bed. the sys- the vasculature. and flow ceases. Later the P wave), occurs (after in diastole, atrial contraction pressure again exceeds \entricuku pressure, atrial and blood flows from the atrium to the ventricle (a wave). systole begins (beginning of the sure exceeds QRS pressure imd the atrio\ enuicuhu' atrial \ early phase of systole. Ncntricular pressure is pressure but not higher Duiing iulenal pressure. —no higher than isovolumetric contraction sure system. Vascular resistance, both systemic ;md pulmoniu"y, the aortic valve can be manipulated by closed aortic and mitral valves causes an increase in asodilating or \ asoconstricting drugs. Myocardial Performance (c wave). When The coordination of the electrical and mechanical events in the myocardium were first described by Wig- atrial pres- atrioventricular valve ventricular pressure exceeds aortic pressure, the aortic valve opens, occurring ejection of blood occurs because closed. Ventricular contraction against the is upward displacement of the sure due to atrial phase tliis temic circulation must be both a high-flow and a high-pres- v alve closes blood into the atrium. During the to prevent regurgitation of tli;ui When wa\e) \entricular pres- and \ entricular ejection occurs. Muscular Contraction-Excitation Coupling gers in 1916.'^ Figure 4 illustrates the relationship between the electrocardiograph signal and pressure and volume changes and great vessels during a typical cycle. The P in the heart wave corresponds to atrial depolarization, the tricular depolarization, T wave and the QRS to ven- to ventricular repolarization or recovery. Atrial repolarization also occurs, but the evidence hidden is QRS. in the cell membnine CiJled composed of long myotlbers Muscle cells or myocytes have a special the sarcolemma.'"^ witli Myocytes are each myofiber composed of myofibrils. There aie two kinds — of myofibrils that aie interdigitated to form the myofiber and thin filaments thick Thick filaments are primarily made (Fig. 5 A). up of a protein called myosin, a large molecule ending in a composed of actin and reg- myosin head. Thin filaments are ulatory proteins. During cardiac muscle contraction, the elecElectrocardiogram trical stimulation of the membrane to smcolemma causes open and allow the Tlie influx of calcium leads to the release of in llie sarcoplasmic reticulum.' ion channels in the influx of sodium '^ Calcium binds the configuration of the regulatory proteins and calcium."' more calcium on to ;uid stored chimges the thin filaments I facilitating the E E 5B). This binding changes the contlguration of the myosin head binding of the myosin head to actin'" so that the head flexes, thus rils past each other moving the myosin and -' (Fig. actin fib- and shoilening the myocyte.-"-' Energy, a. in tlie Systole Tliis Diastole fomi of adenosine uiphosphate. binds the actin filament, and prepares the Fig. 4. Electrocardiogram and pressure tracings obtained from catheters in the left ventricle and left The cardiac atrium. cycle traction cycle.-"-' Ventricular to left atrial filling occurs in two phases pressure being tiigher than wave) and active filling during atrial left — passive filling due ventricular pressure (v contraction (a wave). from the aortic diastolic pressure, the at)rtic valve closes. During the next phase of diastole, ventricuku' pressure continues to fall but vcntiicular volume is m;untained. This phase When to as isoN'olumetric relaxation. falls below (mitral atrial iti atrial the is \ is the \entricle higher than \ refeired tills \ myocyte for another con- end of contraction, calcium is removed special pumps in the cell membrane.' '- Tlie regu- sites, and the relaxation phase cover the actin begins.'''-' Relaxation an active process and can consume up to 159^ of the total energy of the hean.-^ ation may be due Some ha\e postulated that part of relax- to a recoil effect.-^ In the intact heart, end- contraction volume may be similar to a compressed spring, the muscle springs back less than equilibrium beginning of relaxation to create a suction ments early \cnlricular volume. So. at like effect that the aug- filling. Myocardial Membrane Receptors passi\eh' because entricular pressure. In the middle pha.se of diastole, atrial and the entricular pressure pressure (v wave), the atrioventricular valve LV) opens and pressure the .-Xt latory prtucins then alter their configuration to is below the myosin head. both by active uptake by the sarcoplasmic retic- cell ulum and by binding The contraction of the myocardium can be di\ ided into tw o main phases, systole and diastole. During eariy diastole, the ventricle relaxes and \entricular pressure falls. As LV pressure falls tlie is divided into systole (ventricular ejection) and diastole (ventricular filling). to causes a confomiational change to the myosin head, releases entricular pressures equalize For many years, intravenous beta-adrenergic-receptor (ÂR)-agonist agents, including dopamine, dohulaminc. and RESPIR.VrORV C.^RE • FEBRUARY % VOL 41 No 2 . Cardiorespiratory Interactions A plasmic second-messenger molecules (Fig. Z Line stimulation of /iARs in the ZLine 10 Myosin nm activation of G protein (Gs) that, in tum. activates adenyl cyclase to increase generation of the second messenger. cAMP (Fig. stimulatory Actin Actin For example, 6). myocardium causes 7). Cyclic AMP acti\ates protein kinases in the sarcoplasm. which then phosphorylate and calcium channels) tractility. When myosin ATPase, target structures (ie, cause increased myocardial con- to receptor stimulation persists, a second regulatory feedback process known as desensitization leads to blunted responsixeness and a decrease in receptor number.-'"--'" Desensitization processes can take on various forms and 3 microanatomy showing (A) the arrangement of the myosin and actin myofibrils during contraction and (B) the interaction of the myosin head with the actin molecules and the action of calcium (Ca**) on the regulatory proteins on the actin filament. The region between 2 Z lines is a sarcomere, the functional unit of the myocyte. SI and S2 are subfragments 1 and 2 of the myosin Fig. 5. Myofibril of these processes ha\ /3AR e been recently described acti\ ation results in —prolonged cAMP generation diminished for a given stimulus (uncoupling), disappearance of receptors from the cell surface through sequestration, and decreased receptor production. '"-" molecule. From Reference 23, with permission. epinephrine ha\e been the inainstay of treatment for patients with low cardiac output syndrome. These agents act by stimulating membrane receptors, celluku' cyclic adenosine in intracellular calcium and which function cAMP results initiates to increase intra- monophosphate (cAMP). The increase in an increase in intracellular myocardial contraction. Agents Cell in 1 Second Messenger Membrane increase myocardial contractility (positive inotropes) act through various mechanisms that ultimately result GDP GTP that an increased intracellular calcium concentration and stimulation of excitation-contraction coupling. Recent ad\ances ular biology techniques in molec- mechanisms by which inotropic agents exert Because of the advances in knowledge about the molecular their effects. Physiologic Effects have allowed research into many of Fig. 6. through a specific the signal transmission U'actility pathways influencing myocardial con- afforded by these techniques, levels of circulating catecholamines can and result in a it now is clear that high ha\e a paradoxic reduced inotropic response effect in selected patients. In particular, patients with chronic congestive heart failure, exposed to binding to membrane membrane effector, activates a cytoplasmic second messenger. An example is the Gs, or G stimulatory, protein, which, in the presence of GTP (guanosine tnphosphate), activates adenyl cyclase, a membrane-effector molecule that generates cyclic AMP. Cyclic AMP activates protein kinases and increases calcium concentrations necessary intracellular traction coupling. patients — Drug, G-protein-coupled receptor receptors, activates guanine nucleotide regulatory proteins, which, GDP for excitation con- = guanosine diphosphate. cardiopulmonary bypass, and neonates represent groups of patients with high levels of circulating catecholamines and reduced responses to exogenous catecholamines. Recent findings have increased our understanding of the molecular mechanisms for this response and ha\ e not Alpha- 1 adrenergic receptors a( of receptors present 1 in AR provides a mcxlest inouopic effect, receptors are linked via but. in some cases, have revealed fertile new tigation that ha\'e therapeutic potential.-'' Of the many found in the areas of inves- -'* the majority belong to the G-protein-coupled-receptor family .-'*-'" This group of receptors mediates several important signal pathways involved with cardiovascular homeostasis (ie. SNS- and PNS-medi- ated adrenergic and muscarinic cholinergic receptor systems). Activated G protein-coupled receptors are nucleotide regulatory proteins (G linked via guanine proteins) to specific mein- brane effectors that are responsible for the generation of cyto- Respiratory Care • February '96 Vol AR Gq results in the hydrolysis 41 No phate (IP3). it receptor phys- appears that these 7). Stimulation of of membrane phospholipids, (DAG) and The liberated IP3 and kinases and mobilize calcium Stimulation of a- 1 proteins (Fig. with liberation of diacylglycerol types of excitable transmembrane proteins sarcolemma of myocytes, a-1 are another group a- AR's not completely understood, but iology poor inotropic response to /3AR-agonisi agents is AR) human myocardium. only supplemented previously existing explanations for the in these patients 1 in a inositol triphos- DAG then activate protein similar fashion to resulting in a positive inotropic effect. As is cAMP, evident from the previous discussion, the sairolemma plays a pivotal role in the signal convergence required tor mytx';udial conU'action because several different receptor systems influence the generation of each inotropic second messenger /3AR-agonist agents rine) (ie. at this site (Fig. 6). dopamine, dobutamine. epineph- mediate the most potent inotropic effects in adults.-" How- 117 Cardiurhspiratory Interactions doses of /?AR-agonist agents, '-These drugs result * * myocardial pijHp VIFl 5Hll R PGE1 ss a^ ET *ng agonists. \ cAMP. from III inhibit- in the cyto- intracellular calcium concentration remains high, and is enhanced. Through these mechelicit important physiologic responses in the absence or presence of intravenous PIP2 j^^^ increased Phosphodiesterase anisms, phosphodiesterase inhibitors DAG in different enzyme phosphodiesterase myocardial contractility cAMP is plasm of the myocyte. By augmenting the length of action of I ATP-.lsnr-^ that cAMP breakdown by inhibitors decrease the rate of ing the action of the I by a mechanism employed by /3AR that II cinitractilil) /JAR-agonist agents. +IP3 u.sed When phosphodiesterase inhibitors are alone they increase the inotropic state of the myocartlium by augmenting the efTicacy of circulating endogenous cateFig. 7. The 12-surface G-protein-coupled {|i^. /J2), receptors- Beta tiistamine 2 (H2). vasoactive intestinal peptide (VIP), 5 hydroxy tryptophane (5HT), and Prostaglandin El (PGE1) vate the and 2 1 Gs G or stimulatory protein and increase G inhibitory protein that inhibits cAMP. Alpha reducing cytosol levels of and angiotensin (Ang II II) all acti- through M1 and somatostatin (SS) stimulation of adenyl cyclase. A1, activate the Gi or cAMP ((x^), 1 and is inositol similar to membrane Gq activates protein kinases it from enhanced effects of the exoge- contractilits also results nous /3AR-agonist agents. '- all protein, to augment ical is the contractility, are of IP3 and DAG and mo- angiotensin-li receptors, of angiotensin example, in I! varies possible that a more potent combination of recep- it tor s) stem and cardiotonic agents exists for the treatment of is low cardiac output using other membrane receptors. For example, there are 1 2 known membrane receptors on myocytes that possess inotropic propeilies. Howe\er. membrane we tiugel only the /JAR- Still However, among (Table the inotropic poten- Alternative approaches to inotropic support ha\ e been limited because available drugs are not highly selective and. therefore, effects, In\esiigation into more may have untoward Table 1, Comparison of the Relative Inotropic Potency of G-Protein- Coupled Receptors /5-2 .Agonists, Receptor durin;; Maximal Stiriuilation with /J-1 and systemic selective forms of these agents holds great promise for the future, spccificallv /JAR dow n-regulation. Regulation of Myocardial Contractility 1). theoret- patient populations. For receptor pharmacologically to augment inotropic state more neonates. angiotensin-II receptors are expressed at lO-fold the adult level." e\er. . which ha\e only 3{)-509f the inotropic potential of /JARs in adults. tial bilizes calcium. underway therapeutic potential of such receptor systems as produce diacylglycerol (DAG) cAMP way in Clinical trials of thyroxin, a nonconventional inotropic The combination the phosphodiesterase inhibitors aie used intravenous j3AR-agonist agents, improved agent that works by several noncatecholamine mechanisms triphosphate (IP3). in ith endothelin (ET), receptors activate the lipids to When conjunction w adenyl cyclase, which activates the second messenger, phospholipase C, which then hydrolyzes cholamines. in patients with Cardiorespiratory Interactions ume. In the intact heart, the stretch is Increased Penpheral proportional to the vol- Resistance ume of \ enous return delivered to the \entricle during diastole. An increase in venous return results in a greater volume of blood in the ventricle, more ventricular stretch, and an increase in preload (Fig. An 8). increase in preload leads to CO. provided the ventri- precise measurement of ven- an increase in stroke volume and cle is not "oxer stretched"." The tricular preload requires quantitation which is difficult return is of ventricular-fiber to measure. Therefore, the 6 6 stretch, volume of venous Unchanged Venous 6 used to approximate preload and can he measured during cardiac catheterization or by echocardiography. In most Return 6 intensive-care situations, end-diastolic ventricular pressure is measured to estimate end-diastolic \entricular volume.'*' f=^ 6 Exercise • 6 Volume Expansion —^ Increased d Venous "N Return Unctianged ^^ \^- LV Pressure Stroke Volume (and Cardiac Output) Preload Eventual Fig. 9. LVH Increased afterload (increased peripheral resistance) leads to increased blood pressure but not to decreased cardiac output unless the resistance exceeds the maximal capacity of the ventricle. Mechano- LVH = left-ventricular hypertrophy. From Reference 23. with permission. Receptor Because blood pressure is the product of the CO. and sys- Heart temic vascular resistance (Ohm's law), any increase Rale in vascular resistance causes an increase in both blood pressure and Starling's Law wall stress. Stroke volume does not usually decrease when afterload increases, unless the afterload in a fall in ventricular Increased preload (increased end-diastolic volunne or Fig. 8. 23, witfi decreases the force opposing ejection and causes an increase in stroke volume and CO.. resistance to ventricular shortening, or afterload, on the pressure gradient that the ventricle depends must overcome generate blood tlow (Fig. 9).'^ In the intact heart, afterload the ventricular wall stress that as long as preload and heart rate do not change. permission. Contractility The excessive and results increased venous return) leads to increased volume loading of the ventricle, increased stroke volume, and increased cardiac output. From Reference is performance.'" A decrease in afterload was described by Laplace to is as erties is a term used to describe the intrinsic prop- of muscle not related to preload or afterload state.'-''" As long as heart rate, preload, change, an increase in contractility exogenous catecholamines) — inotropic and afterload do not (through endogenous or results in an increase in the force of contraction, myocardial oxygen uptake, and cytoplasmic calcium concentration." Wall Stress =-^, are 2T where and r T= = ventricular cavity radius, • February positive Agents that increase contractility inotropic agents and include epinephrine, dopamine, and dobutamine."* However, these P = blood pressure, agents are not pure inotropes because each may also increase heart rate and/or systemic vascular resistance.'^ wall thickness. Respiratory Care considered -" "96 Vol 41 No 2 119 . CARDIORESPIRAIORY INIERACTIONS 19. In Conclusion Babu A. Chem we have described cardiovasculai' anatomy In this review, 20. and physiology, hemodynamics, and myocardial pcrlbiTnancc. By examining one is point, patients t'riim anatomic and pliysioiogic stand- lui 2 1 . physiologic state. (iulati J. The control of muscle troponin C. Biol J 1987:2621 12):581.s-5822. Eisenberg E. Greene LE. The relation of niuscle hiochemisiry w ilh Eisenberg E. Hill TL. Muscle contraction and free energy transduction biological systems. Science I9S.S;227(469()):999-I006. in 22. Tada M. Kat/ AM. Phosphorylation of the sarcoplasmic reticulum and sarcolemma. Annu Rev Physiol 1982; 44:401-423. 23. Opie LH. MyiKardiai contraction and physiologic condition of the patient des|iite frequent, and somein fast muscle physiology. Annu Rev Physiol l9S();42:293-3()9. better able to monitor and assess the patho- times rapid, changes HH, Scordilis SP. Sonnenblick myocardial contraction with skeletal New iology and metabolism. 24. REFKRENCKS WG, Nayler The relaxation. In: heart: phys- York: Raven Press. 1991:176. Williams AJ. Relaxation in heart Some mor- muscle; phological and biochemical considerations. Eur J Cardiol I978;(7. Suppl):3.5-5(). 1. AnderMin RH. TcniiirKilogs. McCartney In: P.iedi.ilncauxliology. Shinebuunie EA. Tynan M. FJ. Anderson RH. (edilorsl. Edinhurgh: Churchill Livingstone. |y,S7:f)5. 2. Van Praagh Van Praagh R, atric cardiology. Fylcr. D In: Nadas' 27. Inc. 1992:17. 3. 4. New York: Hafner Pub- New York: Alan R 7. 28. Liss Inc. I98X. Rudolph .AM. Congenital diseases The ol the heart. Chicago: ^'earbook auricular \eiuiicular bundle ot the human 9. Nadas' pediatric cardiology. Fyler. In: Opie LH. Control of the circulation. Abboud 30. D (editor). New Konier PI. The In: heart: tors). 1 1 1 2. physiology and 3 1 . Progress in G. Calculations used cardiology. in DG (editors), Opie LH. Heart metabolism. 8. West JB . Ua and Invasive In: measurements. CiaiMin -X. 34. New ol the mammalian In: J auricle. 1. The auric- heart: 36. Frank GB. I'he cuirent \ J Phartiiacol 1 37. In: Physiol I983;24.S( 1 In; Cardiac Anesthesia. (editors). Philadelphia: The heart: physi- ):C1-C14. iew of the source of trigger calcium in exci- J 1 HA, F, Dieterich newborns with JB Lip- Fell JJ, Dressier HT, refractory postoperative low-out- Cardiothorac Surg I992;6(6):31 1-317. RW. Bumpus FM. human Husain A. Angiotensin Endocrinol hearts. J Clin );.54-66. v alucs in the right heart and associated in healthy subjects. J Opie LH. Ventricular function. \ essels together New Med L;ibClin In; The 1 heart: 958;5 1:72-90. physiology and York: Raven Press. 1991:301. Colan SD. Assessment of ventricular and myocardial performance. ley Nadas' pediatric cardiology. Fyler and Belfus Glower DD. et al. York: Raven Press. 1991:67. 98n;29( 8):2.399-2406. 1 I, Barran-Boyes BG. WixxJ EH. Cardiac output and ivlaled measurements In; D (editor). Philadelphia: Han- Inc. 1992:17. Spratt JA, Snow ND, Kabas JS. Davis JV\ Olsen CO. . Linearity of the Frank-Starling relationship in the intact heart: the concept of preload recruitable stroke work. Circuhition 1985; Fabiato A. Calcium-induced release of calcium from the cardiac sar- Am JG receptors in normal and failing gen mixtures 35. physiology and York: Raven Press. 1991:27. Opic LH. Channels, pumps, and exchangers. New Res Cardiol 1992;S7( heart. Basic with an analysis of the hemiKlynamic response to the inhalation of oxy- Physiol 1916;40:228-229. The in Urata H. Healy B. Stewart metabolism. and organelles. cells human Fnedel N, Berdjis Ci, Enoximone and pressure lebiger. 199(1:913. tation-contraction coupling in vertebrate skeletal muscle. Biochcin 120 33. Bncker Baltimore: Williams (editor). auricular systole. .Am coplasmic reticulum. 1 Hausdort et al. del is cry of the respiratory gases. In: Physio- ology and metabolism. 17. (edi- 198.'i:.M6. myogram and lamb. 2559-2567, 32. put states (LOS). Euro cardiac catheterization. Philadelphia: WiggcrsCJ.The physiology ular 16. cardiovas- Yu PN. Goodwin JE practice of |iediaUic c;udiology West JB. LIptake and andWilkins. ft- in rellex T.A. Cardiac catheten/alion: heiiiod\ naiiiic McNam;iia in the Schwinn DA, Leone BJ, Spahn DR, Chestnut LC, Page SO, McRae Metab 1989;69( The science and MA. Rudolph AM. myocardial contractile reser\e Schwinn DA. Cardiac pharmacology. 1989:17.';. logical basis of medical practice. 1 the non-failing II JT. 14. in investigation of the heart. Oxford: Blackwcll Scientific Publications Vargo in receptors during cardiopulmonaiy bypass. Circulation 1991 ;S4(6): Retle.x control ol Philadelphia: Lea and Hebiger. I978;(7):.'>5. .Miller In: 13. In: Chin T. Brett C. Heymann Sidi D. RL. Liggett SB. Desensitization of myocardial beta-adrenergic DD. Mark AL. Schmid PG. Hole ot autonomic nervous system cular control. York: Raven pincottCo, 1994:21-60. York: Raven Press. 1991:52. F.M. Heisiad DF. Estafanous FG. Barash PG. 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Determinants of the diastolic pressure-volume relation. Circ 26. Morphologic analoniy. S. 2-'>. 7 1(51:994-1 009. 38. Weiner N. Norepinephrine, epinephrine, and amines. In: Goodman the syiupathomimetic The pharmacological basis of therapeutics. Gilmaii .AG. LS. Rail TW. Murad F (editors). New York: McMillan '96 Vol Publishing Co. 1985, RESPiKAfoKY Care • February 4! No 2 CARD10RESPIRArC)R\ INTERACTIONS Glossary for Cardiovascular Anatomy actin: a protein component the fibers of muscle cells. Actin boinul to tial which make up ot thni tilanicnts. precursor of fiber shortening myosin — muscle is the essen & Physiology increase mycKaidial contractility (inotropic state) or para- doxically decrease it, in certain patients. contraetioii. contractility: inotropic state of the myocardium. af'terload: formerly, the arterial pressure or some oihei- cnereome while sure of the force that a \entricie must con- related to preload monic artery impedance, peripheral vascular resistance, and mass and viscosity of blood. It is now more rigorously ex- tractility dial It by Laplace's Law from internal ladius ami wall thick- losa of the adrenal cortex. Its major action to facilitate potas- is exchange for sodium in the distal renal tubule, causing sodium reabsorption and potassium and hydrogen loss. Its siimi it cular is stimulated by angiotensin may \ myocar- oxygen uptake, and cytoplasmic calcium concentration. the ability or property of is muscle to shorten or ilevelop increased tension. On tricles. and conin through endogenous or exogenous catecholamines diastole: the period during aldosterone: a steroid homione produced by the zona glomeiti- release as heart rale, required to produce the transmural (across the is pressure required for systolic ejection. heart) As long results in an increase in the force of contraction, pressed in terms of the wall stress--ie, the tension per unit ness) that aftcrload. oi- preload, and al'terload do not change, an increase cross-sectional area in the ventricular muscle fibers (calculated term mea- it during systolic ejection; contributed to by aortic or pul- tracts A used to describe the intrinsic pi'operties of the muscle not be active in II, the (between the left side, left which the atria diastole begins empty when into the ven- the aortic valve \entricle and aorta) closes and ends when systole begins with the closing of the mitral valve (between the left w ith atrium and ventricle). Diastole alternates rhythmically systole or contraction of the heart. a potent vasoconstrictor, regulating arterial pressure and intravas- ejection fraction, systolic: the fraction of the blood volume, contained olume. during its in the \ entiicle at the end of dia.stole, that is expelled volume divided by endvolume, normally 0J5-0.m. ie, 75-80%. With the contraction, the stroke ie, anjjiotensinogen: precursor of angiotensin: a tetradecapeptide diastolic formed by the onset of congestive heiul failure, the ejection fraction decreases, liver (formerly a-globulin) that angiotensin is considered to be a circulating converted by renin to angiotensin I and/or sometimes to as little as 0,10 ( 10%). in severe cases. II. excitation-contraction coupling: the release of calcium ions atrioventricular (AV) node: a bundle of specialized muscle cells located at the junction of the atrial lar septa. The AV and ventricu- node provides the only normal atrioventricular electrical connection, delaying the signal from the sinoatrial and fill node to allow the atria adequate time to empty myosin. This muscle contraction and is is to facilitate an essential step in also one that can be altered by diseases of the heart muscle and by the administration of catecholamines and aminoglycosides. inotropic state: cardiac index: the amount of blood ejected by the heart in of time (cardiac output, L/min) divided by the body surface area; usually expressed in ful for the binding of actin to the \entricles, prior to the initiation of ventricular contraction. a unit from the tubules of the sarcoplasmic reticulum L min isovolumetric contraction: ventricle standardizing measurements of cardiac output so that volume) comparisons among patients of different in"-. It is si/e are possible. In the left heart, from the time the mitral valve closes until the aortic valve opens, the use- ' .See contractility. in the is contracting. However, no blood is until the pressure in the left ventricle outflow tract (aorta), left ejected (iso- exceeds that causing the aortic valve to open and allow ejection. cardiac output: the amount of blood ejected by the heart a unit of time, usually expressed in in isovolumetric relaxation: the period of constant ventricu- L/min. lar volume from the time aortic valve closes until the mitral catecholamines: pyrocatechols with an alkylamine side chain. valve opens again. Examples of biochemical interest are epinephrine, norepinephrine, and dopamine and dohulamine. These agents can tricle Respiratory Care • Febriiary "% Vol 41 No 2 A rapid pressure drop occurs in the ven- because of myocardial relaxation without a concomitant \iilume chaiiize. 121 . Cardiorespiratory Interactions Laplace, Law of: In the intact heart, ventricular wall stress = afterload = preload: the amount of stretching the myocardium undergoes prior to contraction. It is diastolic ventricular 2t' where and = r T= is P = blood ventricular cavity radius. estimated by the measurement of endvolume. In the intact heart, the stretch proportional to the volume of venous return delivered to the ventricle during diastole. pressure, wall thickness. renin-angiotensin system: the humoral effectors of vascu- myosin: one of the proteins of muscle traction. Its binding to actin change fiber essential for con- and subsequent conformational results in muscle-fiber shortening known as muscle contraction. lar tone and volume. Renin, synthesized in the adrenal cortex, is released in and stimulates the production of angiotensins. These hormones act to raise ventricular their direct action Ohm's Law: See Vascular resistance: R= is response to hypoperfusion and hypotension the blood-flow analogue of sarcolemma: Ohm's Law. which unit of current. If some is the membrane of muscle cells (myocytes). states that the ratio of the drop in distance of the wire for each one extrapolates, vascular resistance is the ratio of the pressure gradient across a capillary bed to the blood flow through indirect action through aldosterone. AP the resistance of a conducting wire electrical potential across volume and blood pressure through on the vessels and an sinoatrial (SA) node: the origin of the electrical stimulus that causes myocardial contraction a — the heart's pacemaker. bundle of specialized myocytes located in the right It is atrium near the junction of the superior vena cava. it. stroke volume: the volume of blood ejected from the heart Poiseuille's Law: If all other factors are held constant, the with each contraction, expressed in liters. rate of flow (Q). through a cylindrical tube of length. L. and radius, /, is directly proportional to the driving pressure, the pressure difference down AP. the length of the tube: supraventricular tachycardia: a higher than normal heart rate that originates 'above the ventricle', or atrioventricular node or the atrium Q =î£__?, or more simply, Q = ie, in the sinoatrial itself. — R rjLS systole: the phase of the heart beat during This implies that cardiac output or blood flow is directly proportional to the force of myocardial contraction. cles contract. In the left ventricle, it is which the \ entri- the period that begins with the closure of the mitral valve and ends w ith the closure of the aortic valve. phosphorylation: a biochemical process by which adenosine tnphosphate (ATP) donates its tenninal energy-rich phos- transmural pressure: pressure inside phate group to any of a number of acceptor molecules, enabling ture them bonds (eg, tein kinases in the ( ie. phospho- oxidation) of various substrates (pro- sarcoplasm of muscle myosin, ATPase, and calcium channels myocardial contractu itv. 122 a compressible struc- on the structure from outside. Pml^'exl- pyrophosphates) from the energy released by the dehydrogenation late the pressure exerted subsequent enzyme-catalyzed biochemical to take place in reactions. In myocytes, formation of high-energy ric minus cells) to vascular resistance: See Ohm's Law. phosphory- cause increased ventricular tachycardia: ventricular contraction emanating from a focus located in the \'entricle. Respirators Care • February "96 Vol 41 No 2 The Role of Cardiorespiratory Interactions Donald R Black MD, Barbara G Wilson MEd Care in Respiratory N Meliones MD RRT, and Jon Introduction — Oxygen Transport & Utilization Supply Oxygen Delivery The Supply Oxygen Content — & Demand Cardiac Output Preload Contractility Right Ventricular Afterload Left Ventricular Afterload Oxygen Consumption —The Demand Effect of Cardiovascular Abnormalities on Do,, Vo,, In diovascular and respiratory systems function together Introduction changes The importance L-ardiorespiratoi^ interactions in iif agement of critically ill patients & Vco: Summary now is recognized. tlie in one system lead to changes —how in the other. man- The car- Oxygen Transport & Utilization —Supply & Demand diovascular and respiratory systems are intimately entwined and have as to common goals the delivery of adequate oxygen meet the metabolic demand of the of carbon dioxide.' ' tissues When oxygen equate to meet the oxygen and the elimination deli\ery demand of the (DoO is inad- tissues, anaerobic metabolism occurs. Anaerobic metabolism results in the pro- Oxygen is transported to the tissues by the tissues for aerobic metabolism. gen delivered output (CO. minute, and ). to the tissues the the ''"* blood and in used depends primarily on the cardiac amount of blood ejected from the oxygen content of this blood D03 can be is The amount of oxyheart each (Q,(>). and. there- altered by changitig either the CO. or duction of lactic acid, and the resulting metabolic acidosis can fore. lead to multioigan dysfunction."" Acidosis causes a fmlher reduc- Do^can be considered the "oxygen supply." The formulas used tion in Do: or results in maldistribution of blood flow. These to calculate these values are given in Table I . C;,o:- The major com- a cascade of worsening Dq,- Under- ponents of C,,c), lue oxyhemoglobin saturation (Sô;) '^^ hemo- standing the mechanisms of oxygen delivery adequate to meet globin concentration (Hb). Tlie partial pressure of oxygen dis- abnormalities can result in the tissue needs requires an understanding of how the car- solved in the pkisma (PioO contributes little to CaO: at sea level. Another important component of oxygen utilization is oxygen consumption (Vq;) or the arnount of oxygen used by the tissues for aerobic metabolism. V(), can be considered the Dr Black was Senior Fellow was wrilten. He is now Springfield. Missouri. in Pediatric Critical this paper "oxygen demand' of the patient. The relationship between oxygen supply (Dq:) and oxygen demand Vq:) is critical, ( in private practice at St Dr Meliones is Anesthesia. Medical Director of Pedi Chief Pediatric Critical Care; Critical Care when Ms '' ssociate Professor of Pediatrics iric Wilson Center, & Respiratory Care, and Division is and abnormalities in this relationship result in pathophysiologic disturbances.' Research Associate. Pediatric Care and Respiratory Care Services Duke University Medical John's Health Center. — Duke Children's Hospital. Durham. North Carolina. N Meliones MD. Duke Children's Hospital. PC Box 3046. Duke Universitv Medical Center. Durham NC 2771(1. Reprints: Jon Respiratory Care • February "96 Vol 41 No 2 *See Glossary following the References section. 123 ^ I Cardiorespiratory Interactions Table hirmulas 1. ConmumK L'sed To Assess Cardiovaseular Function Symbol Variable Arterial oxygen content (ml, Formula* CaO: Cardiac output (niL/tiiinl CO. Oxygen consumption (ml./min) Vo: Oxygen Dq, delivery (niL/mlni ( .34 1 X Hb X CO. X (C,0; - Cto:) C.O.xCo: ( CpcO; (CpcO: Qpa Starling forces Pô,) Volume Heart rate x Stroke Qs£ Shunt fraction (niL/mni) + (0.003 x SaO;) (mm Hg) - CaO ;) ~ CvO;) K[(Pcap -P,m)-0(ff.a,,-'r„„(| Venous oxygen content (ml,l (1..M CvO: X Hb X Su,,) + (0.003 X P,o,) blood flow; 'Sao; = o-\yhenw2lobin saturation of arterial blood; PjO; = partial pressure of oxygen in arterial blood; Cjo. = mixed-venous oxygen content; 0,>, = systemic = retlection eoefficicnl representing the ability of the capilQpa = pulmonary blood How; CpcO: = pulmonary capillarv oxygen content; K = protein-nitraluin coelTicient; = lary wall to block protein migration; Pcap = capillary hydrostatic pressure; Pi„, = Interstitial hydrostatic pressure; ;!^jp = colloid osmotic pressure of proteins in blood; ;ri„, colloid osmotic pressure of proteins Oxygen Delivery in interstiiium; SvO; = oxyhemoglobin saturation of venous blood; Pvo; = partial pressure of oxygen in venous blood. —The Supply Under usual not alter the heart rate Oxyjjen Cctntent. ration oxyhemoglobin satu- or hemoglobin concentration result in signifi- (S.,c);) cant increases in contributes increases in Siiuill little Cao- However, because dissolved oxygen to the total oxygen content of the blood, at standard temperature and pressure, increases in PaO: effect only a small increase in CaO:- The primary mechanism for increasing Cjo, is to increase Sao. This is do clinical conditions, respirator) inter\ entions rate (KX'urs with the even though minor phases of breathing — \ ariation in heart slows during inspi- it ration and quickens during expiration because of the changes However, that breathing induces in intrathoracic pressure. respiratory interxentions can significantls alter Do- by their effect on the determinants of stroke \olume — preload, contractility, and afterload (Table 2). usually accomplished by increasing the fraction of inspired oxygen Table (Fio;). Respuatory Interventions To Imprine Oxygen Delivery 2. Breathing higher-than-rooin-air concentrations of oxygen T Stroke can result in a reduction in pttlmonar\' \ascular resistance secondary to a reduction in pulmonary artery pressure. However systemic arterial pressure and vascular resistance may increase. The increase tion in heiirt rate tion in cardiac output. an important role who have in aortic pressure restills in a and stroke soiume and the potential These physiologic changes may play in the management of infants HFJVifPa„> exhibit a decrease in gen causes pulmonary monary bkxxl nov\ to incivase at ( 15-20 mL/kg) i Pa, T pH T PIP. Pa„ TVt( 15-20 mL/kg) Oxide Nitric heart syn- in Fk),. tiscular resistance to fall \ T V, cm H:0 tP,W:.PaO: T Expiratory time and children left Do, with increases rate! 4- 10-15 TComractilitv iPIP.Paw i Afterload congenital heart disease with intracardiac shunt. For example, many patients with hypoplastic drome i Paw" (J^PEEP. T Preload reduc- for reduc- Left Venlricle Riatit Ventricle Vol time Oxy- and pul- Pj„ = mean air«a\ volume; HFJV = pressure; PEEP = positive cnd-expiraUiry high-frequency jet ventilation; PIP partial pressure ol alveolar pressure; = peak airway oxygen; Pao; = panial pressure of V| = tidal pressure; PaO: = arterial oxygen. the expense of systemic bkxKl flow. .Mthough these patients de\elop ele\alcd Cao- because of the higher SaO:- Do; reduced systemic CO. is actualls decreased because ol'the This example serves to underscore the impoilance of utKlctsltintling the cardiorespiiatory effects of respiraloty interxentions. CaO;- although important, one only hean o\er earlier, is the 124 CO. \ olume in the heart prior to Increasing ihe \oltime contraction in the \entricle stretch of the \entricular Fig. ( ).'''' 1 (preload) results in myocardium, which increases the force of contraction and causes an increase in stroke vol- ileleniiinani of Dq:- Cardiac Output. the is Preload. Stroke \olume can be altered b\ changing the anuHini of is a unit of time the quantits of blood ejected by (commoiiK L/min) and. as staled product of the heart rate and stroke xnlume. decieased. the tbrce ot con- ume. Con\ ersel> traction decreased, and stroke \i)lume is does not change. stroke \ . if preload CO. is falls. If heart rate follows the increase or decrease in olume. Respir.vior^ Care • February "96 Vol 41 No 2 : Cardiorespiratory Interactions conditions in which End-Systolic Pressure-Volume Curve left ventricular preload can augment right ventricle left decreased, the is ventricular preload because of this series relationship. I There E E no is ventilcle in seiies with the tight ventricle. There- fore, small pressure gradients right atrium ular filling. can result When resistance to flow 2). As in between the systemic veins and dramatic changes the right atrial pressure in right ventric- zero, there is and systemic venous return right atrial pressure increases, there is is is no inaximal (Fig. increased resis- End-Diastolic Pressure-Volume Curve tance to flow resulting in decreased venous return and tight ventricular preload. Left Ventricular Fig, 1, Volume (mL) changes ventricular in left pressure during the cardiac cycle. During diastole the and left volume (preload) at Point A. During the tion A to Point is first — the pressure occurs left ventricle ventricular pressure increases from Point D, along the end-diastolic pressure-volume curve, diastolic E volume during the carand the Y-axis depicts the changes in left ventricular diac cycle, fills, X of tfie left ventricle. Tfie X- Pressure-volume relationship axis depicts the B with no reached phase in change the in until the left Spontaneous Breathing ventricular end- Systole at Point A, is initiated of systole, isovolumetric contracleft ventricle increases from Point ventricular volume. At Point B. ABC left ventricular pressure increases greater than aortic pressure, the opens, and left ventricular ejection occurs. As strol<e volume is ejected from the left ventricle, the left ventricular volume decreases until the pressure-volume curve intersects the end-systolic pressure-volume curve (Point C). At Point C. systole ends and diastole begins. Left ventricular pressure decreases with no change in ventricular volume (isovolumetric relaxation), and the aortic valve closes as left ventricular pressure decreases to Point aortic valve D. This cycle is then repeated with the area within the equal to the stroke worl< required to eject the ABCD loop — volume volThe stroke volume strolê ume at Point A minus the volume at Point B. can be increased by increasing the volume in the ventricle prior to contraction (end-diastolic volume or preload). When the left ventricle IS provided with an increased volume, the preload is increased to Point A' pnor to contraction. As the ventncle contracts, isovoluuntil it achieves a pressure B' that metric contraction again occurs to overcome atterload. If afterload has not changed. and the remainder of the pressure-volume relationship is as before. However, the stroke volume is increased and is equal to the difference between the volume at A' and the volume at D, The increased stroke volume due to the increased preload is reflected by the shaded area. (tVlodified from Reference 6, with permission.) is necessary B= (Maximal) Venous Return Venous Fig. 2. return to the right heart occurs passively pends on a pressure gradient from the systemic veins When right atrial pressure (Pra) is zero, there is no impedance to flow back to the right heart, and venous return is maximal (Point A). As right atrial pressure decreases, and mean systemic venous pressure (Pvems) is held constant, there is a progressive reduction in venous return. When right athal pressure exceeds mean systemic venous pressure, venous return ceases. Dunng spontaneous breathing, right atrial pressure is low and systemic venous return is high (Point B). During positive pressure ventilation (PPV). intrathoracic pressure and P,a increase resulting in reduced venous return (Point C). (Modified from Reference 2. atrium. with permission.) B', During spontaneous breathing, and there heart. is little right atrial pressure is low, resistance to flow into the right side of the During PPV. the increased intrathoracic pressure mitted to the right he;ul. causing an increase Positive pressure ventilation changes in (PPV) can cause both light sentncuku- and influence of PPV on nght ventriculai' preload Venous sive significant left \'entncLilai' pi'eload. is Tlic well documented. return to the right side of the heart is The same as right atrium. determinants of right ventricular preload are not the left because venous ventricle operates in series with the right ventrileft return, ventricular preload depends on which Respiratory Care is • pulmonary derived from the right ventricle. In February "96 Vol CO.. and CO. PPV (PEEP) can decrease trans- venous return and positive end-expi- right ventricular preload. Dq,. can be variable, particularly ventricular dysfunction. A in patients with right reduction of right ventricular may result in a marked decrease of may benefit from ventilation strate- preload in these patients D02, and these patients gies that reduce intrathoracic pressure and increase preload. the determinants of left ventricular preload. The atrium (preload). Thus, ratory pressure relatively pas- and occurs primarily because of the pressure gradients between the systemic venous system and the to the right is in right atrial pressure. TTiis increase in right atiial pressure reduces cle and de- to the right 41 No A more dramatic response in patients to these ventilatoi^ with right ventricular dysfunction is manipulations seen in patients with hypovolemia. 125 CARDIORESPIRATORY' INTERACTIONS The changes to PPV occur that in left ventriciiliu- preload in response are not well understood. Investigators have proposed three physiologic principles lo support the notion that left ventricular preload is PPV decreased during can only eject the ventricle left because right ventriculiu- output it ventricular preload The 1 ) ( receives There- decreased dunng PPV. is amount of blood the left ventricle receives a decreased left that right ventricle (\cntricular interdependence). from the fore, and PEEP; of blood quiintity antl Right ventricular afterload falls. (2) and systolic pressure increase during PPV. The increase in right ventricular pressure results in conformational changes in the intra\entricular compliance septum and a decrease produce a reduction that in left ventricular preload. (3) Because in of the increase in intrathoracic pressure, direct compression of the left \ One and improve left- ventricular heart left can result in compression of lung contents.^ Compression of lung contents results in blood's being forced into the left side of the heart resulting in augmentation of left heart tilling. augmentation Thoracic-pump a high-liiial-\'olume ven- accomplished with is tilatory strategy (V-, - 15-20 niL/kg). However, contribute to ventilator-induced lung injui^ this strategy if high peak- airway pressures are generated.'' Contractility. Another important modulator of stroke \ olume is the contractile or inotropic state of the myocardium. a negative inotrope (eg. For any given preload and afterload. propanolol) decrea.ses the force of contraction and decreases CO.; whereas, a positive inotrope (eg, dopamine) increases the force of ventricular contraction and increases determinant of contractility the is the CO. One amount of blood How to myocardium, or the coroniuy blood flow. Right ventricular coronaiy flow occurs primarily during systole and. therelore. depends on the difference in systolic aorta and right \entnclc. Because pressure between the PPV results in increased right ventricular pressure, the pressure dilference the aorta and right ventricle is between decreased, and right ventric- tractile force. As a result, right ventricular conCO.. and Do, decrease when intrathoracic pressure PPV ular coronary flow falls. cle is high. (LV) has v ery little direct effect on left ventri- contractility. Right Ventricular .Xfterload. The force opposing tricular ejection is the v afterload load is is is v en- ascular resistance or afterload. This has been an area of intense investigation tion circuit — pulmonarv vas- ume in is low, pulmonary vascular resistance is high because, the under-inflated lung, blood vessels that supplv the lung are long and tortuous and because hypoxic pulmonary vasoconstriction lung V olume is also present at low lung decreases, decreases. and pulmonary vascular resistance As lung volumes continue capillaries, increases. As hypoxic pulmonary vascK'on- llalion of the alveoli can occur, with monary (Fig. 4). increases, the blood vessels lend to straighten, their capacitance increases, striction volumes The total and resistance to increase, hyperin- compression of the pulin these small vessels pulmonai'y vascular resistance is a func- preload con- Cardiopulmonary resuscitation research has demi)n- strated that an increase in intrathoracic pressure may pulmonary tion of both small- and laree-vessel resistances. entricle occurs that can reduce preload. of using thoracic-pump augmentation to impro\e filling. ol the Pulmonary vascular resistance is influenced by several factors, including lung volume. When lung vol- respirator) intenention designed to counteract the negative effects of PPV sists by the resistance cular resistance. in recent years. When increased, the force opposing ventricular ejec- increased, and stroke volume tails (Fig. })}' If after- reduced, the force opposing ventricular ejection reduced, and CO. increases. Right v is entricular performance has been extensively studied and responses lo small changes in afterload with significant changes been documented. Rinht v in CO. entricular afterload and Do: have is determined End-Systolic Pressure-Volume Curve Cardiorespiratory Interactions ventricular preload and an increase in right ventricular after- may load. Ventilatory strategies to induce alkalemia require high levels of intrathoracic pressure. Various ventilatory have been employed strategies pH Total that has been used successfully PVR attempts to alkalinize the in One while minimizing intrathoracic pressure. frequency jet ventilation. strategy in this clinical setting is high- High-frequency jet ventilation has been shown to reduce pulmonary vascular resistance comLarge Vessel Resistance pared to PPV These in selected patient populations.'"* were primarily related to the reduction in effects mean-airway and intrathoracic pressures that occuired during high-frequency Complete FRC Lung Maximum Collapse Volume Expansion compared jet ventilation tricular afterload Fig. 4. Pulmonary vascular resistance (PVR) depends on lung ume and the sum of the resistances contributed PPV. to Another respiratory intervention vol- by the large to medium-sized pulmonary vessels and pulmonary capillaries. At lung volumes less than functional residual capacity (FRC), PVR is high due to hypoxic pulmonary vasoconstriction and the increased resistance contributed by the tortuous large and medium-sized vessels. As lung volume increases compressing the pulmonary capillaries, PVR falls. High lung volumes are associated with an increase in PVR due to increased resistance contributed by compression of the pulmonary capillaries. (Modified from Reference 20, with permission.) Nitric oxide (NO) is is alter right ven- an endothelium-derived relaxation fac- selective vasodilator that inhaled, The systemic properties of is rapidly inactivated a non- is reduction in pulmoniuy vascular resistiuice. circulation NO because it protected from the vasodilating is is inactivated reaches the systemic circulation. monaiy NO by hemoglobin. NO causes rapid dilation of the pulmonaiy iuter- ies that results in a it can can be administered as an inhaled gas.'-"' tor that When that the inhalation of certain medical gases. va.scular resistance has by hemoglobin before A prompt reduction been demonstrated in pul- after inhala- NO by newboins with primary pulmonary artery hyper- tion of tension and in patients with pulmonary artery hypertension after surgery for congenital heart disease." ratory time should be as long as possible in patients with right ventricular dysfunction. One of the most It successful approaches to reduce right ventricular afterload is the manipulation of cardiorespiratory interactions to lower Therapy directed sists pulmonary vascular resistance. reducing right ventricular afterload con- of increasing pH. lowering PaCO:- increasing alveo- and lar at ide arterial partial pressure of oxygen, and minimizing Some studies suggest that increaspH significantly reduces right ventricular afterload. Drummond et al'"" showed that by reducing Paco; to 20 torr and increasing pH to 7.6, a consistent reduction in pulintrathoracic pressures. ing is pH at 40 torr, however, been used has. CO: anism (respiratory or metabolic) pulmonary can also result affects oxygen delivered These effects are more dramatic to the airway (Fdo:) in neonatal and pediatric Animal studies have demonstrated more potent pulmonary vasodilator in patients than in adults. that oxygen is neonates than it a is in adults," Respiratory manipulations designed to decrease afterload should be accomplished at the lowest intrathoracic pressure possible because an increase in intrathoracic pressure Respiratory Care • may in pulmonaty result in a reduction of pulmonary results in an increa.se blood flow and more stable shunt flow in patients with a single ventricle. Left Ventricular Afterload. Left ventricular afterload depends on left — — and ventiicular myocardial wall tension sure generated by the ventricle during systole the presis estimated by' ^'" left ventricular afterload = Piv - Pimraihoracic. where Plv = may result in a decrease in right February '96 Piniraihoratic = left ventricular systolic pressure and intrathoracic pressure. pulmonary vascular a reduction in right ventricular afterload. in Paco: vascular resistance and resis- increase in both Pao: i»nd PaO: by adjust- ing the fraction of with congenital heart 7.5-7.6 while maintaining PacO: resulted in a similar reduction in An in patients concentration results in an increase in Paco: and PaCO:- In addition, increasing tance indicating that alkalemia. irrespective of the mech- resistance.'- Carbon diox- disease to reduce pulmonar}' blocxl ni>w.'-'^ Increasing inspired monary vascular resistance and right ventricular afterload was achieved. In addition, manipulating serum bicarbonate levels to achieve a '^ rarely used as an inhaled gas in the intensive care unit. Vol 41 No 2 Left ventricular afterload can be reduced either by decreasing aortic pressure and, thus, left ventricular pressure or by increasing intrathoracic pressure. The effects of PPV on left ventricular afterload is complex because the systemic arterial system has both intrathoracic and extrathoracic components. As intrathoracic pressure increases during sure is PPV, the increased intrathoracic pres- transmitted to the intrathoracic blood vessels. Left ventricular wall tension remains the both the Pi V generated and the same because Pintrathoracic the changes generated are equal. 127 Cardiorespiratory Interactions ing depends on the adetjuacy of ventilator-patient synehroni/ation. For example, When a patient's spontaneous breathing effort is not synchrowail tension = LV Plv ( K'lJ mm Hg) - P.mraihi.racic ( 10 w ith ni/ed mm Hg) = 90 mm Hg. the ventilator-initiated breaths, an increase in Work of breathing and Vq^ occurs. of breathing occurs work when respiratory muscle contraction persists through inspiration, -ir intrathoracic pressure mm increased by 30 is Hg, Effect of Cardiovascular Abnormalities LV Pi V ( 1 30 mm Hg) - = wall tension P„„r.,ih„racic (41) on mm mm Hg) = 90 Changes However, the extralhoracic increase in ailerial system also arterial pressure due to propagation of the increased When intrathoracic pressure into the peripheral circiut. increase in intrathoracic pressure results in ailerial pressure, aoilic nomic elops an ile\ pressure is ner% ous system, decreasing the marked increase a in autoregulatetl b\ the auto- LV contractile loree by stimulation of aortic baroreceptors.'*''^ This results in a retlex aortic pressure and reduction of decrease in pressure. When aortic pressure falls due pressure gradient ilial falls. to this reflex action, effect For example on CO. tem has on Pi V (100 mm Hg) - P,„,n„honK.c (10 Hg) = 90 mm Hg. mm Hg and tem as in It aortic pressure returns to 100 mm Pl\ 100 ( mm Hg)- = wall tension P„u.aiho,.,cic (-10 and mm Hg. C.,o,. in the govern the flow of (Table interstitiuin tluiel in ).-'-^ 1 in the capillaries in forces, and because force to the interstitium. - persistent increase in intrathoracic pressure results in a decrease in left ventricular afterloati sure auloregulation. these complex Under usual because of aortic pres- clinical contlitions. interactions result in only a slight change ventricular afterload because intrathoracic pressure left compared to left ventricular pressine, over only 1-2 cardiac cycles, which time tor autoregulation. However, is however. if is in low and inspiration occurs may not allow enough intrathoracic pressmx' high ami persists over multiple e;udiac cycles, left ventiieular This (F,ni)- —The Demand push the hydro- The the differences greater than usually results P,,,,. fluid shifts out of the capillaries into force tending to promote tluid entiv into osmotic the ciilloid is pressure iliffcrence between the capillaries and interstitium ( jz^jfi - Ttutt This force depends on a number of factors includ- ) ing the retlection coefficient of the capillary Under normal is membrane stiiuim. w hich (0) to that quantitates the ability block the passage of proteins. contlitions, the net effect of Starling's forces amount of net to proiDote a small is tliix then removeil bv the ever, in conditions of tricular dvsfunction illaries Con.suniptittn is opposed by is left atrial of Iv lluitl mph in mav into the inter- system. hv pertension and/or How- left ven- (myocardial infarction, cardiomyopathy, mitral stenosis) hydrostatic pressure in the afterload can be reiiuced. Oxygen and out of the cap- the net effect of the hydro- Pint, is P^-ip is promote The (Pc;,,,). the interstitium P^.,,p frequently Tlie force tending to of the capillaries and into the interstitium pressure is intensive care unit. Star- the capillaries anil out of the interstitium A the alv eolar level be caused by the cardiov ascular sys- who ;ire in patients hydrostatic pressure in a net nmi Hg) = 60 may both of which reduce . static forces LV at Cardiogenic or hydrostatic pulmoniiry edema between these Hg, drugs can help afterloail. In aildition. eciiain pulmonary edema and maldistribution of puinionary blood flow fluid out the and respiiatorv mechanics. The direct effect the cardiovascular sys- C.O. can he increased by optimizing preload, and peifusion mismatch static the miralhoiacic prcssiue increases by 30 most depends on matching ventilation and perfusion. Venlilation- illaries mm Vc()2 C.O. Adequate gas exchange to optimize encountered = wall tension the is D(),. contractility, ling's forces LV & the cartliovasctilar system can cause signifi- in cant alterations in Do,, Vo,, and the transmyocar- ventricular systolic pressure falls, left ventricular left b(),,V(),, Hg. increase tiramatically. When hvdrostalic pressure in the capillaries this pulmonary cap- (kcuin the increase (1\,||,) results in excessive flow of lluid nito the interstitium due to Starling's forces. to o|itimi/iiig the balance Another approach gen suppiv and oxygen ilcntand D(), the is to decrease the oxygen needs of oxygen demand of the pcricxis of respiratorv' in patients w respiratory muscles failure, how ever, compensate ing the in patients between oxy- Because the distance between the capillaries and the alveoli compromised is the tissues. Normally, this is low. During oxygen demand can increase dramatically. C;irdiovascular rescIê to ith mav be inadequate with an alreailv low Do,. In reduc- work of breathing, mechanical ventilation decreases oxygen needs and improves the balance between oxygen supply and oxviicn demand.-"-' However, a reduction of the work of breath- 128 so small, excessive tluid in the interstitium communicates through the spaces to the perivascular and peri- interstitial bronchial spaces and across the alveolar epithelium into the alveoli. \\ hen pulmonary edema and atelectasis |X'rsisl. m;uked mismatch occurs, and gas exchange is ).-'-' A reduction in gas exchange impaireil (West Zone decreases arterial oxygen saturation, C-.o-, and Do,, and ventilation-perfusion I increases Paco?- Cardiovascular dysfunction also results in mechanics with a retluction in lung alterations of respiiatorv RE.SPIK \T()R^ CARF • FHBRI'ARY '% VoL 41 No 2 . Cardiorespiratory Interactions Meliones JN. Snider AR. Bove EL. Rosenthal A. Rosen DA. Lon- volume (primarily functional residual capacity) and a reduction in lung compliance. These changes may increase work gitudinal results following after first-stage palliation for hypo- demand used balance. Viirious entilatory manipulations \ w ith pulmonary edema, to treat patients IV- ha\e been including at However, the most effective therapy improN ing nnocardial peiformance and reducing K. The end-systolic pressure-volume relation of the ventricle: definition, modifications, and clinical use. Circulation 1981:63(6): 1223-1227. Sagawa K. Suga H. Shoukas .AA. BakaUir KM. End-systolic presratio: a new index of ventricular contractility Am J Car- directed is 15(1. Sagawa PEEP and high-tidal-volume ventilation, to restore functional residual capacity.- syndrome. Circulation 1990:82(5. Supp!):IV-15I- plastic left heart of breathing and Vq:- further worsening the oxygen-supply- sure/volume . Pcap-''"'' diol 1977:40(5):748-753. Another cardiovascular abnormality that results in respicompromise is a reduction in pulmonary blood flow, Koehler RC. Chandra N. Guerci AD. Tsitlik ratory which must be adequate bon dioxide at exchange of oxygen and for the monary Zone 3).-' This '"* in patients w ith occur is in patients who resistance. P,,n:. As described and minimizing ill patients. iol Pmtraihoracic- Summary who care With every intervention by interactions. feature is The to illustrate the respiratoiy therapists, in patient can be made to optimize these importance of cardiorespiratory 16. inter- 2. New Rohotham Bamea Appcl PL. Krani HB. Bishop M. Ahraliani E. JL. Lixleld 1 ): W. Holland B. Pemiutt S. Rahson JL. left 21 The L. MR. 4. MK. Roberts Jr. Chen TY. Kawai N. Wain JD Lang Jr. nitric oxide Dupus P. Shimouchi A. in tlie hypoxic LM, Vlahakes P. Bigatello GJ. Zapol WM. in congenital heart disease. Circulation 1993:87(2): Pinsky MR. Summer WR. in hypoplastic left-heart Cardiac augmentation by phasic high Pinsky man. Chest 1983:84(41:370-375. MR. Summer WR. Wise RA. Augmentation of cardiac by elevation of intrathoracic pressure. Maclntyre NR. Ho L. Weaning J func- Appl Physiol 1983:54 mechanical ventilatoPi support. .Anesth Maclntyre NR. Pressure support ventilation: effects on ventilatory JJ. Rodriguez RM. Lamb V. The inspiratory workload of patient-initiated mechanical ventilation. Rev Respir arterial How variation dur- Philadelphia: 23. Aw Rev Respir Dis 1986: West JB. Dollery CT. Distribution of blood flow relation to vascular WB .Saun- West & ders. 1981. February J. 134(51:902-909. Guyton AC. Te.xtbook of medical physiology. • FW. Callow Fontan procedure. Circulation 1991:84(5. Suppl):III-364- EI-Lessy HN. Pulmonary vascular control Marini effects of positive end-respiratory ventricular performance. .\m Appl Physiol 1984:56(5): 1237-1 245. Respiratory Care Custer JR. Moler 447-457. MacGregor D. Bromberger- Determinants of pulmonary ing respiration. J Am Rev Respir Dis reflexes and ventilatory-muscle workloads. Respir Care 1987:32(6): 145-159. Dis 1980;121(4):677-683. Pinsky lanibs versus sheep. Report 1990;3(2):21 1-215. Hemo- transport monitoring to titrate ttierapy in sep- Horiz 1993;1( pressure on right and .3. newborn (41:950-955. 20, shock. CO: .Appl Phys- 40(7):737-742. 18 REFERENCES tic H" and J High-frequency jet ventilation improves cardiac function JD Roberts tion dynamic and oxygen in asoconstriction. Influence of alveolar oxygen on pulmonary CA. intrathoracic pressure support in WC. \ syndrome: hypoxic- and hypercarbic-gas therapy. Respir Care 1995; 19 Shtiemaker 1-20. 447-453. to optimization of these inter- interesting presentations that illustrate et al. Inhaled these principles. 1 ): 1 and acidotic newborn lamb. Circ Res 1993;72(2):246-254. management of patients, describe how outcomes due We welcome 1984:7( Inhaled nitnc oxide reverses pulmonary vasoconstnction one measures these interactions, and demonstrate improve- actions. pulmonary vasodilator drugs. m-368. 17 ments JE. Neonatal Meliones JN. Bove EL. Dekeon after the for critically goal of the Cardiorespiratory Interactions actions in the clinical Pediatr 198l;98(4): 1973:34(3):318-323. Custer JR, Hales LR. 15 that attempts J I985;I32(2):326-33I. cardiorespiratory interactions must be carefully considered and measured so Phibbs RA. The inde- pulmonary hypertension. Dev Pharmacol Ther status. vasoconstriction in essential for clinicians is GA, Heymann M,\. concentrations on hypoxic pulmonary understanding of (he interactions of the cardiorespiratory system Gregory Malik .AB. Kidd SL. Independent effects of changes 14 An Intemiittent positive pres- Rev Respir Dis 1985:132(41:880-884. Drummond WH. Lock Current 13, In Saumon G. 603-608. include increasing pH. lowering Paco:- increasing Pao: and Am Drummond WH. infants with persistent pulmonary blood If improve pulmonary blood flow are pulmonary vascular may earlier, these P. after cardiac pendent effects of hyperventilation, tolazoline. and dopamine on 11 directed at lowering Dreyfus D. Bassett G. Soler rats. 10. inadequate, SaO:. CaO:, and Dq: are decreased. Res- piratory manipulations to 1983:67(2):266-275. with pul- right ventricular congenital heart disease ha\e decreased pulmonary blood flow. flow aiTcst in dogs. Circulation sure hyperventilation produces pulmonary microvascular injury in pulmonary emboli, artery hypiertension. dysfunction, or may ventilated but not per- is Tray siman RJ. Rogers J. of cerebral perfusion by simultaneous chest compression and lung inflation with abdominal binding car- the alveolar level. Ventilation-perfusion mismatch occurs when a segment of lung fused (West MC, et al. Augmentation "96 Vol 41 No 2 and alveolar pressures. JB. Respiratory physiology J in isolated lung: Appl Physiol 964; 19:713. 1 — the essentials. Baltimore: Williams Wilkins. 1979. 129 Cardiorespiratory Interactions Glossary for The Role of aerobic metabolism: a form of cellular respiration molecular oxygen are produced. is When in which CRI Respiratory Care in colloid osmotic pressure: also oncotic pressure: osmotic pres- consumed and caibon dioxide and water sure due to plasma proteins. molecular oxygen vent to is una\ ailable (anaer- now from Osmosis is the tendency of sol- an area of lesser concentration of solute to obic condition), the rate of cellular respiration increases but one of greater concentration of solute. Osmotic pressure (k) becomes then less efficient, producing can cause lactic acid; this is measurement of the that tendency. profound metabolic acidosis and death. congenital heart disease: existing alkalosis: a pathophysiologic tissue disorder characterized by tlie loss of hydrogen ions. It may result from increased bicarbonate ion concentration (metabolic alkalosis), or by reduced CO2 due to hyperventilation in blood is at birth, referring to itary (genetic) or influenced tation, up to the moment by e\ents occurring during ges- of birth. contractility: inotropic state of the myociudium. to describe the intrinsic properties anaerobic metabolism: See aerobic metabolism. to preload or afterload. baroreceptors: nervous system tissue that is sensitive to pressure .stimulation. In the circulatory system baroreceptors respond and volume by eliciting vasodilation or vasoconstriction. piratory system It is — analogous compliance of the to the capacity of a lung unit for res- volume al a given pressure. as heart rate, preload, and afterin contractility the force of contraction, myocardial through endoge- in an increase in oxygen uptake, and cytoplasmic calcium concentration. The ability or property of mus- develop increased tension. coronary blood flow: blood flow myocardium: one to the of the detemiinants of right \entricul;ircontractilit\ (inotropic state). For example, right ventricular coronary flow occurs primarily during systole and. therefore, depends on the systolic pressure difference cardiac output: the amount of blood ejected by the Uicle each minute. and heart A term used of the muscle not related nous or exogenous catecholamines results cle to shorten or capacitance: the capacity of an electrical circuit to hold an As long do not change, an increase load electrical charge. anoma- be either hered- (respiratory alkalosis). Alkalosis termed, alkalemia. to regulate blood pressure may of the cardiovascular system, which lies is It the product of the stroke left volume ven- (LTbeat) rate (beats/min): cle. between the aorta and During positive-pressure ventilation, reduced because intrathoracic pressure \entncular contractile force, cardiac is right ventri- this difference is increased and right t)utput. and oxygen delivery are reduced, as a result. Positive-pressure ventilation has volume (L) [- X beats little !i;i nun min beat effect on entrinsic left ventricular systolic function. high-frequency ventilation: positive pressure ventilation using cardiomyopathy: degeneration of the to contractile failure unable to pump heart — congestive heart blood at a rate muscle failure. that leads The heart is high enough to satisfy the metabolic demands of the body. left ventricle associated with by signs of overall cardiac as well as by its systolic function of the dilatation; failure. latory, or tlow-inteiTupter ventilators. gests that the lower mean-airway pressure required when jet ventilators are used reduces cardiomyopathy, dilated: decreased \\ ith usualK manifested congestise findings, fatigue. indica(i\e of a low output state. may be jet. oscilSome literature sug- frequencies higher than 150/min. Devices hydrostatic pressure: pulmonary \ In the capillaries, ascular resistance. it is the force tending to push liquid out of the capillaries ami into the interstitium (Pc;ip). In fluid out the interstitium. it is the force tending to forces are opposing, and the difference between cardiomyopathy, hypertrophic: thickennig of the ventricular septum and walls of the ril left ventricle with free wall resulting in narrow ing of the left ventricular outflow tract and tolic 130 compliance is dynamic outflow greatly impaired. favors P^:ap. promoting a them (Pc.ip- fluid shift towiird the interstitium. marked myofib- disarray; often associated v\ith greater thickening of the septum than of the Pint) push of the interstitium and into the capillaries (Pim). These gradient; dias- hydrostatic pulmonary edema: liquid of increased l\jp. In conditions such as ventricular dysfunction. Pcap in the alveoli left because atnal hypertension high causing exces- or left si\ e flow of lluid into the interstitium. the peribronchial space. Respiratory Care • is February '% Vol 41 No 2 — — ) Cardiorespirator'i Interactions and across the alveolar epithelium into the tilation-perfusion mismatch produced alveoli. The ven- results in impaired oxygen delivered (Do,): hypoplastic left-heart syndrome: a congenital maltorma tion of the heart in which the left ventricle is made is Do, depends piimiuily on CaO:- cardiac output, organ blood flow gas exchange. which oxygen the rate at axailable to the tissues (I7min). . anil Fio;. oxygen demand: See oxygen consumption. essentially non- functioning. In such conditions of ductal-dependent systemic oxygen supply: See oxygen delivery. blood tlow. increased F|0: can cause decreased Dq: because of the resulting change in the ratio of systemic-to-pulmonary positive inotrope: an agent that increases myocardial vascular resistance and blood tlow as pulmonary blood flow inotropic state or contractility and. therefore, the force of increases and systemic blood flow decreases. myocardial contraction inotropic state: See contractility. preload: \olume of blood It is — dopamine. eg, in the heiul at the stait of contraction. normally estimated using end-diastolic pressure and varies Under normal circum- intracardiac shunt: abnormal blood flow through the heart inversely with intrathoracic pressure. because of openings stances, the liuger preload results in greater ventricular stretch- absence of 1 in the atrial and/or ventricular septa, or more chambers, transposition of outflow tracts, ing and larger stroke volume. and other anomalies. pulmonary vascular ventricular afterload: the force against which the \en- left tricle must push to eject the stroke volume: depends on left- ventricular wall tension (the pressure generated during systole |Plv])- estimated by Plv It is - afterload. PVR It is to vary with lung volume, being highest and very high lung \olumes and lowest mitral stenosis: a reduction in the size of the mitral valve left atno\enlricular valve —may at at It is very low functional resid- result in increased Pûp and. reflection coeflicient (0): a numerical value that quantitates . the capillary an ischemic event nitric ual capacity. eventualh hydrostatic pulmonary edema. focal myocardial-cell death myocardial infarction: right ventricular can be reduced with agents such as oxide and with techniques such as induced alkalemia. known Pimrathoracic- resistance: the resistance to blood flow through the pulmonary circuit. commonly caused by due to membrane's ability to block protein migration from the vascular space into the interstitial space. right ventricular afterload: Sec pulmonarj vascular occlusion or spasm of a coronary artery. resistance. negative inotrope: an agent that causes reduced myocardial inotropic state or contractility and. therefore, the lorce of myocardial contraction — eg. propanolol. serum bicarbonate (HCO3): reported in niEq/L (mmol/L). The most ubiquitous buffer base in blood: binds with hydrogen ions nitric oxide (NO): a nonpolar, to produce water and CO:, causing alkalosis. low-molecular-weight gas room and body temperature) that is highly lipid soluble endogenous form, endothelium-derived relaxing factor, has been shown to be the active agent in vascular smooth (at Starling's forces: the balancing act between hydrostatic pres- its sure (promoting movement muscle relaxation. In pressure (promoting movement into the capillary), named Stalling after the scientist who first described the phenomenon. for inhalation, it ing patients with its exogenous form. NO gas available has been found clinically useful in treat- pulmonary hypertension because of its relax- smooth muscle, presumably by lowcalcium levels. However, use of NO ing effect on vascular ering intracellular remains experimental. in to the interstitiumi and osmotic At the arteriolar end of the capillary bed. hydrostatic pressure is higher than osmotic pressure: the venuku' end, the reverse at is true. thoracic pump augmentation: an intervention designed to counteract the effects of positive-pressure ventilation on oxygen consumption by the tissues for ( V(),): the rate of oxygen use (L/min aerobic metabolism. ventricular preload. Large tidal to gen in (Ca()>): the volume (mL) or mass (g) of left- used left to heart filling. oxy- transmyocardial pressure gradient: the pressure difference blood between [1.34 is compress the contents of the lung, forcing blood back the left heart and increasing oxygen content \olume (15-20 niL/kg) Hb(g) S,o;(%)] + [0.003g/torr- Respiratory Care • February '96 PaO:(torr)]. Vol 41 No 2 left-ventricular and intrathoracic pressures. As long as this gradient does not change, left \entricular contractile 131 Cardiorespiratory Interactions force does not change, ever when autoreguiated tic in arch. A and cardiac output is maintained. How- intrathoracic pressure increases, aortic pressure down by is stimulation of baioreceptors in the aor- may tion actually be due to reduced venous return and right ventricular preload. If right-heiirt output output is is reduced, left-heart also reduced. persistent increase in intrathoracic pressure results decreased left-ventricular afterload increasing contractile West zones: A model used tion of force and cardiac output. blood flow the capillaries. In ventricular interdependence: The right and do not function independently. preload that occurs in left ventricles TTie reduction in left ventricuhir response to positive-pressure ventila- (Pa) > 2. the Pa arterial in uneven to explain the distribu- the lung based on pressures affecting Zone the lung apices, alveolar pressure 1. pressure (Pa) > venous pressure (Pv). In mid-lung regions. P;, > Pa > Px . In Zone 3. Zone the lung bases. > Pv > Pa- Jidlr7i^Wryj CARE Special Issues Mechanical Ventilation; Ventilatory Techniques, Pharmacology, & Patient Management Part 1: April Part 2: Strategies 1996 May 1996 RESPIRATOR'! Care • February "96 Vol 41 No 2 Nole to publishers: Send review copies of books, Respiratory Care, Phamiacolog) for Respiratory Care Practitioners, GP by HB and Cottrell Surkin. FA Hardcover, 414 pages. Philadelphia: Davis Co. 1995. $36. Books, Films, Tapes, & Software and Reviews of Books and Other Media Listing lilnis. lapcs. 1030 Abies Lane. Dallas 1 concepts of and software TX to 75229-4593. halt-lilc. clearance, ability are treated descriptively. and bioavail- tral The ters sections agents, antiarrhythmics, antithrombotics, without resort to the underlying chemical thrombolytics. Although these chapters are The third chapter, on is more scientifically provide sufficient introductory knowledge pharmacodynamics, because the clinical practitioner must detailed, illustrating drug-receptor interac- the major medical inter- specialties. comprehensive than those in designed for the program cology and outlines the form and varieties account of the drugs employed curriculum. The selection of topics and the of neurons and the principles of synaptic try expository detail arc always limited by the transmission. texts time constraints of the course of instruction. The ensuing chapters describe the structure of the many intensive care units. Unit 2 follows the conventional sequence of most of the standard works on pharma- pharmacology 3. tliey to enable the practitioner to understand problem forever confronting authors of a Unit and of the conditions that confine patients to and dose-response relationships. tions less How far to go beyond purely respirators' drags is anti- cribe the roles of each participating organ, principles involved. all 4 compnses b chap- anginal drugs, diuretics, antihypertensive respiratory care edu- face with Lliiil on inotropic agents (cardiotonics), on biotransformation and elimination des- cation have always been difficult to define, The boundaries of nenous system. autonomic nervous sys- Unit 5 gives a surprisingly complete psychia- in and anesthesiology. Chapter 24 is a review of sedative-hypnotic, anxiolytic, and antipsychotic agents. Chapter 2.5 deals with have encom- tem, the principal neurotransmitters in- analgesics and the management of pain; and passed a rather broad spectrum of topics that volved, and their respective roles at ganglia the next chapters. 26 and 27, discuss The authors of is this text intended to correlate with the other basic sciences of the respiratory care curriculum. was Prior to publication, the manuscript reviewed by a number of competent educators — their approval constitutes its glance the text first sites. The actions of acetylcholine (nicotinic and muscarinic) are emphasized; adrenergic transmission sidered one proof of the appropriateness of the book for intended purpose. At and neuroeffector more Unit 3 tifying the titioners. is con- is book as a text for respirators' prac- first chapter of the unit (Chap- comprehensive discussion ter 9) is a rather age 2-year curriculum. However, of allergy, although the immunochemical it is lib- and (Kcasion;il vignettes, called tables, charts, Perspectives, that and promote general clinical relevance. rapid reader, was able interest The reviewer, to not a cover the written portion in less than 30 hours. The book is comprising 3 the is first to 8 chapters. The first unit, The Physiologic Basis of Drug entitled Action, divided into 5 units, each a review of general pharmacology; chapter deals with pharmaceutical aspects of drug design, testing, and approval. Because one of the authors is from Canada and the other from the United States, the regulatory bodies of both countries are des- introduction on is bnef The discussion focuses mechanisms of bronchospasm. tlie preamble as a to the ku'gely ensuing chapters on drugs employed for the prevention and treat- is nonmathematicah solubility the effects of and absorbability are simply given empirically. Similarly, the RESPIRATORY CARE • FEBRUARY "96 schedules of controlled drugs in the United States and Canada. The authors have made considerable make the book as understandable effort to to the uninitiated reader as possible. are the generic and trade Not only names of drugs given, but the pronunciation of the generic form usually rendered in phonetic sym- bacterial species, are also pro- adrenergic agonists; and Chap- nounced. A Chapter ter 1 3, 1 2, xanthine bronchodilators. Complete is Other difficult words, such as the separate section showing the symbols and abbreviations used is conve- instructions on the administration of the drugs niently presented at the beginning of the each of these categories are given, pro- book. Indexing and referencing are appro- in viding a valuable reference source for the practitioner. ter The Unit then presents a chap- on glucocorticoids, a chapter on mucoki- netic, surface-active, and antitussive agents; applicable to the treatment of bronchopul- kinetics. the second with prescription writing and the names of I. antimicrobial and chemotherapeutic drugs pH change on first antimuscarinic agents; 1 shown. The second chapter, on phannaco- names of drugs follow the text; the deals with pharmaceutical calculations, and tamines; Chapter fer in the 2 countries these are explicitly generic a brief discussion of analeptic drugs bols. and, finally, 2 chapters are presented on Where local Chapter ment of asthma. Chapter 10 covers antiallergics (mast cell stabilizers) and antihis- dif- cribed. is final used as respiratory stimulants. Two appendices appears to be formidably lengthy for the aver- erally provided with excellent illustrations, (28) fully in the next unit. really the definitive section, iden- The and general anesthetics. The monary The focus upon drugs that affect the cardiovascular VOL 41 NO 2 the book is Above all, quite readable, and should be user-friendly to students of respiratory care pharmacology and to their instructors. Hugh S Mathewson MD Professor Emeritus, Anesthesiology Professor, Respiratory Care Education disease. last 2 units priate for the content of the text. system and tlie cen- University of Kansas Medical Center Kansas City. Kansas 133 ) Classic Reprints Retrospectroscope Out of the Mouth of Babes member is to be a talent seotit or his medical students abilities t'ac- it leaches him that numbers are beltei than guesses when delennine the special it comes treat- main ivsponsibiliiy of I've alv\a\s belicscd thai a ully — to a teaching. in clinical care, in or in research, and then to encourage them to be the very best they can in their field of unusual competence. course, is research. I see no way with research while they are that who now students strongly that, as i)ne I'm who lately has stale, know how again as a recent patient, that I'm place Providing a stiiilcnls w iih it him But t)f this later). do i( also makes at Hiimphn it. Let faxnr faculty own is to marked ;malgesic and 40 years ot the to still hul w in effect. Near the eiui ol'.luly 1 its 799. Dav y wrote: I much nil alterwards returned. it less violence. In a .second instance, a headache was w holly rcmov ed by gas. The pow er of the immediate operation of removing intense physical pain. I ihe gas had a very good opportunity of ascertaining. In cutting school's cntkie. continue their 1 one of the unkickv teeth calletl denies sapi- experienced an extensive inllammalion of the gum, accompanied with great tlown pain, which equally destroyed the power of repose, and of consistent action. when they must now judge for themselves what's good and bad. what to adopt and what to shun. A little blesome. research also teaches the medical siudent the essentiality The pain alw ay s diminished of controlled studies, especially when he must esaluate new inspirations. It when he prepared and in Bristol iiisiaiKc. when hud headache from indiwas immediately removed by the elTecls of two doses of to look after they've it slighter degree of On the nest, modes of therapy. to a l9-ye;ir-old student in Dr. Bed- a large dose of the gas. though no course is one gestion, Lots of w ays. There encourage and teach students scientific education for the from early inhaled large quantities of nitrous oxide and discovered labeled "Critical F.\aluation of Data" in any medical school catalogue and \ei the niosi important job lh\\\ was doe's "'Pneumatic Institution" a better physi- How ? in journals. that being a patient to read .scientitic articles critically data published is give yt)u a few examples: in obiecti\ely of course ask. "Where's the immediate pay-off?" The answer modern times, some very remarkable discoveries have been made by youngsters who were still medical students. Let me helps to identify those research. as a device to recruit researchers but as Some congressmen would direct, of research experience for medical Of course — not produce better future physicians. a device to and out who gen- unusual originality and unusual talents for a career teaches experiments In little bit helps both ways. research (more I I 1 cian of i)ne with no desire to It in e(.|ually in me IVom If research (laboratory or clinical) for cook-book laboratory I opt for go about to w ere dean of a medical school and had complete dictatorial powers. would substitute some months of ment. state pretty been a patient of research that wDuld ha\c presented in the first Now So before favor of doctors (and nurses) all in uinely care for sick people and me also me a letter of protest to the Editor, let ol hospitals. contact that students be research and loo few for taking care of sick people. you write of of anguish from those call forth cries many medical believe that too some medical school. still in even a whispered suggestion involved in research will field, for faculty to determine this special talent of their students unless they have know One and evaluation of to diagnosis, prognosis, the 1 day when the intlamniation was most troubreathed three large doses of nitrous oxide. ( after (he first four or five I teaches him a systematic approach to problem-solving, and once in practice, he'll realize that almost every patient presents a new problem lo him. .And La(cr. in the Conclusictn to Section w rote. ".As nitrous oxide in its 111 ol the same work. Davy extensive operation appears capable of destroy ing physical pain, it may probably be used in w hich no great with adv anlage during surgical operations Reprinted wiih permissidii Rev RespirDis 1476:1 134 14: (it tlic AniL-ncan Lung Association, from .Xni lOOI-KKW. effusion of blood takes place." Gibson (2) surmised. "Unfortunately no one read as far as page fi5(^. Respiratory Care • February or understood this '96 Vol 41 No 2 . : Retrospectroscope By companng proclamation of the surgical anesthetic value of nitrous oxide." for \ it was not until 1 844 that Wells America put in same this obser- William Morton, although alread\ practicing dentistr\ It was in 1846 (as a medhe demonstrated the ical student-dentist) that as a surgical anesthetic agent (3. 4 use of ether first him. '"You will be free of pain during this operation because . even about Morton speaks article Eugene Landis. did his direct ( since then: was not but did teach chemistrv .) the medical department of Har\ ard betw een Morton been able Of equal as a graduate. to confirm that interest 1 is 845-86 do not that no one has he received a dental degree at the Baltimore College of Dental Surgery (now the University of Maryland), or even matriculated there, although he did study dentistry in necticut. (Wells Horace Well's office was in Farmington. Con- the first to use nitrous oxide for pro- in practically to the "islets of is in be the source of insulin) in nerves and another on tactile for ten J.-L.-M. Poiseuille de\ised the mercury manometer for measuring arterial blood pressure w hen he was only 29 years a medical intra-arterial pressure starting with the ascending aorta which he could and insert a ending with the smallest arterv into cannula and proved that intra-aiterial pressure fell but little in these main conduits. Some years measurements on resistance lished Poiseuille's Law to flow later, in he did his classic small tubes and estab- still later cells (later disco\ered 1868 while he was a medical Before (9). this important corpuscles in the skin. Charles Best w as a medical student at the University of Toronto when Banting wheedled the use of a laboratory from summer of 92 Banting also asked assistant. The assistant assigned 1 1 . dogs and a research student Best. Within several Best had discovered insulin still ( months Banting and 10). Jay McLean had been accepted by Johns Hopkins Medical School as a second year student but had to wait a year before he could be admitted. During that year, he did research in Professor William Howell's physiolog> department "to determine if I could solve a problem by myself." covered heparin ( 1 1). to the amazement and professor, a longtime leader in research He did. successful first continuous recording of arterial method in 1950 but the artery to (7). ity in through w hen the needle is withdrawn. this mits recording for long periods of time w itliout discomfort technique per- relatively free mobilit\ of the subject. record, received work using and in Attached to a capacitance manometer, and allows the \ear after Roentgen's disco\ery of x-rays. man A small plastic catheter, inserted into an aner\ is left in in for accurate blood pressure stated: a needle, The the new technique 1 896, to stud>' gastrointestinal motil- 1897: his classic paper on the influence of emotions in May on gastric motility was published a year later ( 1 2a). Incidentally, another medical student. Albert Moser. worked with that same year on esophageal motility ( 12b). He Cannon died of tuber- culosis only five years later. by an ink-writing oscillograph, permits an opportunin.' for observation of any chiuiges tour of the pulse is in He at once went conscious animals by giving them barium to sw allow and studying gastric contractions by roentgenogram. He gave his first account before the American Ph\ siological Society continuous knowledge of blood pressure and provides ratus dis- on blood coagulation. Walter Cannon entered Har\ ard Medical School He He disbelief of his (6). Lysle Peterson received his M.D. degree 1949 published the site discovery, he had already published one study of cutaneous w as medical he measured original the arterioles. student at the University of Berlin degrees student (5). In addition, its every textbook of physiology Langerhans" and Professor Macleod for the in both. the University at Paul Langerhans found the special pancreatic named Harvard, and venu- demonstrates unequivocally that the main it ducing anesthesia.) Although Morton never earned a degree in either medicine or dentistry, he later received honorary old and used 1922-26). Figure 7 from his report, received of resistance to blood tlow listed as a regular But the records of at arteriolar, capillary, for publication in 1925 (8). has been reprinted in However, the Catalogue of Students Attending Medical Lectures at Har\ ard Uni\ ersity in Boston 845-46 does list "Morton" William Thomas Green. Boston; Charles 1 Professor of Physiology blood pressure while a medical student lar of him as a dentist and only a few mention that he w as a medical student. later measurements on or modified fomi T. Jackson, lecturer." (Jackson now is universalh in intensive care units and reco\ery rooms. of Pennsylvania of discoveries by two medical students." IncidentalK practically This method, as modified by Seldinger and others, as a reminder of So 1. Humphrv Davy and of William Morton, as each congressman is wheeled into an operating room for w hate\ er. I would infomi list in the constriction. or distensibilitv of the arterial system. entered Harvard for medical training. member w a\'es infomiation concerning changes in stroke volume, \aso- ation to practical use. facult\ the contour of the pulse subject under different conditions, one can obtain in the con- w ave which may de\ elop. The appa- compact, mobile, and Respiratory Care • '96 Vol his first paper in 1920. a year before he received his B.S. degree and a Rhodes Scholarship. Between then and the end of 1927 (when he received his flexible. February John Fulton w rote 41 No M.D. degree). 135 Retrospectroscope he had 40 publications. 644-page mono- iiicJLiding his classic graph. "Muscular Contraction and the Reflex Control of Movement." published in 926 1 in 1878. In 1877, he discovered the parathyroid glands; he wrote, in part: (13). .About three years ago Josef Breuer began and completed One of his medical training his requirements tor qualification his clinical teachers offered him an age 25. at in Hering's physiology laboratory. 14) and presented his ( work Vienna Academy of Science. Shortly the tound on the thy- I tive tissue capsule as the thyroid, but assistantship that examination revealed an organ of a That year Breuer discovered the Hering-Breuer (or Breuerrefle.x 1877| could be dis- tinguished therefrom b\ a lighter color. allowed him time to work Hering) 1 dog a small organ, hardly as big as a hemp seed, which was enclosed in the same connec- roid gland of a the age of 17 at early in 868 1 thereafter, from structure to vascularity. Breuer gland in superficial and with a very that of the thyroid, The existence of a ... A totally different rich unknown hitherto animals that have so often been a subject ot entered the private practice of medicine but found time for anatomical examination called for a thorough approach research on the semicircular canals. Yet Breuer's greatest to the region in man. achievement was Although the probability of finding something hith- to lay the groundwork for Freud's study of around the thyroid gland even erto unrecognized psychoanalysis. Breuer's biographer wrote: seemed so small that was exclu- it sively with the purpose of completing the investiga- Bclwccii IXSOiiiui Miss ical patient. I physician h) pnosis. in it tions rather than with the this famous therapeutic use of in this ease. Pnx'eeding entirely sides at the intenor border of the thyroid gland an organ to i)l He had been I the I of the size of a small pea, which, judging from empirically. Breuer and his patient discovered with sur- symptom wduld disappear and prise that a if in rior, ne\ er return sory thyroid gland, which the symptom had appeared for the first time showed on that occasion. nations not onlv for the procedure was "talking its to give expression to her feelings The patient's name cure." Breuer later termed Breuer fast met Freud enties. . . . Despite m . . . did not hear about the case of Miss treatment had ended in 1 882. It was I 1 was convinced of the constancy oi also able to show most eases occur on each in that tw side. { o such 17) the late eiglueen-sev- friendship at the time Freud tlieir clo.se exte- exami- a rather [leculiar stmcture. .M'ter several appearance but glands "catharsis." it its lymph gland, nor an accesand upon histological examination did not appear to be a he eould bring her to relate the exact circumstances and hope of finding something make Vienna and he used hyster- new that began a careful examination of this region. So much the greater was my astonishment therefore when In ihe first indi\ idual examined found on both His handling ,'\nnu (). ease started a seientille revolution. lirst ;i Breuer treated }sS2 tixik Anna O. Paul Ehrlich's until the a Freud anollicr twelve first paper, publishcii in 1 877 when he was medical student aged 23. had tremendous impact on the new science of bacteriology since his was the fwsi analytic study years to persuade Breuer to publish a detailed report of the ease. of staining methods (18). In But he [Breuer] was aware of what he had Towards end of his CurrUuluin he the tourth edition last year. For Freud it on started. says: 'This was the seed from which psychoanalysis grew." (15) Maurice Raynaud of s_\ name him in 862 1 first (16). the He was that s> now ndrome bears his then a medical student and his thesis M.D. degree. He wrote, Under the the height in part, won about his patient: en moderate cold, and even of summer, she sees her fingers become intluence ot low colour. . . . more impressionable even than Tlie feet, the hiinds. are regukuly attacketl at meal limes is going on. . . . and whilst The complete disappearance of attacks of local syncope has always been noted by this 1878 thesis based lady as the first index of a commencing pregnancy. practice of technical dyeing might well be expected to from a correct theory. Sir Henry Dale has commented it are alreadv logical problems, even gemis of some of the tlie 136 of Uppsala in at the Univer- 1872 and received his preclinical degree detailed conceptions, which were so largely to dominale ways of thought and plans forexperlmenl. Ehrlich's all the rest of his scientific career. Ehrlich's immediate and most direct application, of the interests and the principles so preeivlouslv iiig ot the in this Tliesis. w hich he had dev eloped w as to the dilferential sl;un- white cells of the bl(K)d and the tissues, showing that the granules in tlie protoplasm of diflerent types could he recognized as oxyphile. basophile or neutKiphile. according lo their respective the linclonal vv Ivar Sandstrom entered medical school and bio- the lines of the theoretical approach to medical components vv affinities tor dves. of which ere acidic or basic in nature, or combinations of both. In these studies, and sity little improvements result v ex-sanguine, completely insensible, and of a whitish yel- digestion in his in the during at and he criticized the histologists because they cared that in described the mmctncal ischemia of the extremities it, for the thfoiy of staining despite the fact that book appeared v\as at first rather unfa\ ourabh' received, but in its it, ... in others hich he made, in this early peritxl. on the nature of the red blood corpuscles and their pathological variations, can be found the basis for a large Respiratory Care • part ot iiKxIeni haema- February "% Vol 41 No 2 . Retrospectroscope of the kidney, for then you toiogy. Clear descriptions will he found, for example, in the earh date, of the presence, at this tain cases of anaemia, of immature red also see this from the renal ducts severed of tlie type may clearly observe cells, its quality same juice way and you and nature. You may arise in this much more easily if >'oii apply a glass lens to your eye for then, when the tubules are compressed, observ e this recent years as "reticulocytes", and more so familiar in may hlood from cer- of their characteristic staining with certain dyes. (19) the urine is very clearly seen welling out as if gush- many little water pipes. things we can confidently infer that ing forth from so But let" far — more important v\ as the concept of the "magic bul- From on to specific receptors of Salvarsan and of cells — these the substance of the kidney, even thiiugh they have called chemicals could be synthesized to attach that specific the basis for his later discover) parenchyma, it ulae and much of modern chemotherapy. nothing else than is capillar.' into the pelvis. a ... mass of canalic- spaces through which the urine flows ... Adam in the Thebesius undoubtedly discovered the channels ities of the heart w ith the coronar\' vessels nnocardium (20). connections kntmn toda) as Thebe- sian essels. connecting the ca\ \ and undoubtedly he discovered them while he two From medical student to professor! The next year, at age 20. Bellini was appointed professor of philosophy and theoretical medicine at Pisa. a medical student at Leyden. Tlie fact that Vieussens. was ities into the cardiac cav- same openings years earlier, found the does not diminish the value of Thebesius' s careful injecVieussens and Ttiebesius found the tion techniques, .^ctually. same small openings connected although Vieussens perfonned to the coronary circulation. for\\ aid injections throtigh the coronar\ arteries, and Thebesius performed retrograde injec- and \eins. tions tlirough the coronary sinus Thomas Young, one of the most eminent of British entists, solved the riddle of visual vear-old medical student: a year later he was elected sci- a 20- accommodation while a Fel- London to honor this achieveknew that vision could be sharp Young before ment. Scientists looking at a near or far object. was person whether a and clear the eyeball itself shortened was that explanation favorite The low of the Royal .Society of or lengthened and so appropriately changed the distance his medical studies in Joseph Black began versity of Glasgow and concunently began of alkalies then in 1 744 at the Uni- his investigation between the lens and the that the intracxrular ciliary showed instead Edinburgh where ness of the ciliary muscle effected a thinning or thickening which culminated mo\ed to On heating limestone or chalk. Black (who belie\ed in ucivliin.ii things and not merely observing) found it became lighter, presumably because it lost "air": limestone lost an cqui\alent amount of air when added acid caused effervescence. But the gas relea.sed was nut air because it extinguished both flame and of the lens, which had elastic properties. discovery of CO: and the beginning ni the of quantitati\e chemistry. life (originally discovered in (21 ). Black had rediscovered CO: 1662 by Van Helmont) and begun the "chemical revolution" of the 1 Paul Bert Bellini. 1 9 \ changed the standard picture of the kidney from a hard, solid, found is \ 1 . 1 78-page volume, "La best known in France he for his 1 the specialty of skin grafting during the uary in the Lcincct (November 20, work on high altitude 1 war of 1870. His obit- 886) speaks only of his fails to mention his defini- hypoxia and hyperbaric environ- ments, or even that he w as a great physiologist (25)! esting that Bert himself did not regiu-d his studies It is inter- on skin grafting as experimental surgery but as a technique for learning that otherwise, tor the substance ot nothing else than an aggregate of an is number of for his work on skin grafting, which he published in 863 while he was a saident in medicine and an assistant to Claude Bernard (24): it was responsible for fostering was how the state of affairs famous today pioneer work on skin grafting and 8th centur\ ears old and a medical suident at Pisa, fleshly organ (22). Bellini is Pression Barometrique." but during his lifetime tive nite (23) stimulation) or relaxed (with none) and the change in thick- he took additional medical courses and continued his research. the kidne\ s Young use for treating patients with stones in the kidne\ and bladder. In 1752 he Lorenzo retina. muscles contracted (because of nerve essels of a kind peculiar to itself. infi- Hav- ing cut through any part of the kidney, certain fibres in a transplanted tissues live in a new environment. It was sense a stepping stone from his Professor's study on the internal environment to Bert's later studies on how changing the external environment (high and low pressures and high and low oxygen tensions) affects body function. or filaments extending from the outer surface to the hollow or pehis are quite plainh visible If therefore further end. that ine them, If you w ill you is. discover a certain saltiness and '>'ou can Respiratory C.\re their with respect to the pelvis, and exam- will find water welling are not afraid to present this to of urine. ... you compress these filaments from test this • also if up evei^where. your tongue, you in some vou cut across February Martin Flack had just completed his preclinical work at Oxfoid w hen he became involved in the search for the sinoauricular node (26). As Gibson (27) relates the story; '96 Vol the taste the 41 body No 2 The village of Borden [in Kent, where Flack lived] was agoa when in 1903 the celebrated anatomist Sir 137 ; Retrospectroscope Arthur Koith took up week-end residence there. With exceptional stability some such low power requirement that sixth sense he learned that the butcher's boy work at [Flack] had just completed his preclinical Oxford and was about in London pital of a reflector and smooth control of London Hos- and scheduled for week-end research in may be operated High illuminating efficiency obtained by for his clinical studies. In a twinklinj; the student found himself admitted to the it by a storage battery. teaching hospital to select a secured by using a lamp of is wide range permit the use of color a Borden the use light intensity over of very fillers high selectivity, thus greatly extending the scope of with Keith. the apparatus. Tlie dnidgerv' of cutting serial sections of 1.^0 moles' . . simplicity . and convenience of operation have been and studying them under the improved by using standard microscope was relieved by daily games of golf, learned ventional absorption cells. hearts, staining them, from James Braid's manual. One evening Complete mechanical Sir Arthur came back from cycling to be told by Flack that be had spotted a new structure in the right auricle. It appeared consistently in all parts, and test-lubes in place of con- rigidity, absence of moving a large safety factor in all important components eliminate the usual causes of unsatisfactory other hearts examined as something performance. resembling an electrical conducting system. Thus was discovered tlie known [also sinoauricular node or ciirdiac pacemaker William MacCallum and Eugene Opie were members first class of the Johns Hopkins University School of Medicine, which entered in 1893 and was graduated in 1897. as the Keith-Flack node]. of the Jan Swammerdam objects floating in floaters as he was was not blood corpuscles, probably still if first and to recognize these year 1665 while in the Harvey had a medical student (28). the presence of capillaries cle, the first to see capillaiies them but he was the to postulate blood really went art)und in a cir- because he never saw them. Malpighi, with the aid of a microscope, described pulmon;iry capillaiies Malpighi also saw bodies floating to be fat globules. Swammerdam. in in a frog in 1661 them but believed them hovve\'er. identified them as red blood cells: While to ( medical students, they still knowledge of piu-asitic 30, 3 1 ). scientists in Of the a scourge at that time. men were 78,000 in 1 880 some birds hematozoan. Malaria was still 1885 had found harbored a similar parasite, a 1 important contributions Laveran had discovered the makirial parasite and European of made infections of red blood cells of birds British Army that in India, 76,000 admitted to hospitals for malarial fever in 1897: there were 15,000 deaths annually in Italy, and there was much malaria in the United States. Knowledge of the life in man was incomplete and the theory was transmitted by a mosquito was only a was not until 1897 that Ross found, in the stom- cycle of the parasite that the parasite I saw a serum in ihe nuniberof orbicular blood, in particles, in which were shape but very regular. These particles also tain another fluid, but a vast conjecture. like flat ovals, seemed to con- the blood. 1 further observed that the more these objects were magnified first discovery as a medical student. year earlier he had discovered the valves sels if and in 1667 he discmered in that the lungs A lymphatic ves- of newborn discovery of MacCallum. that Nkrnson had thought the motile ellated spores; that Kenneth P3velyn. more than two years before he received M.U. degree at McGill University, devised a photoelectric colorimeter that at least for several decades was its type. In 1936 anyone who was pulmonary research and was lucky enough to have a little money bought a spirometer, a Van Slyke manometric apparatus, and an Evelyn photoelectric colorimeter: if he the best instrutnent of in third of these, he oratory bench to use Evelyn suinmari/ed 138 had a stream of visitors to his lab- it. its In in his 1936 paper (29); will be and impor- remembered be flag- fikuiients to had studied them much without filaments. kinds, Working with first that the Hulwridium of birds he seemed to be of two the gametocytes namely one kind which produced the motile aments, and another kind which did not do watching two of these field ... 1897 MacCallum undertook a study of the motile cells, one of each kind so. in the fil- On same of the microscope, he observed (July 1897) that the filaments escaped from one as usual; that it moved about actively for a lime; and then approaching the other gamelocyte actually entered it. Other observations of MacCallum and Opie, made both on Halteridium and on the crescentic gametocytes of the aeslivo-autumnal parasite advantages I It being able to learn anything new about them. noticed had the be able to begin this part of the nar- tant lloat respiration has already occurred before death. his to rative with a brief account of the brilliant become. This was not his his am happy I with a microscope, the fainter their colour appeared to malarial parasite, and he continued work on malarial parasites in birds. Ross, in his Nobel lecture on researches on malaria, delivered December 12. 1902. wrote: and confirmed ures also, according as they were turned about in var- scrum of human ary stage of the when I viewed them sideways they resembled crystalline clubs, and several other fig- ious directions in the It ach of a mosquito, bodies that were probably an evolution- er) . The of man, confirmed fact, as pre\ iously Respiratory Care • this beautiful shown by discov- .Sacharoff that February "96 Vol 41 No 2 Retrospectroscope the filaments contain chromatin was now explained: mo\e about and also the tacts that they escape and They the blood. are. indeed, character of a in warm" sperms which are emit- by ted from the one kind of gametocytcs. the males, and which fertilize the More than the first of w hich w as m but How- XIV. peifomied man in Paiis. mid-June 1667 (and probably the was exonerated. ter elongated and vigorous, and moves transfusion. Moi'eau" across the field This motile form had apparently long been first In 1667 was uied Lamy for manslaugh- wrote a "Letter to M. (published in 1668) excoriating the practice of (3.3) Lamy cautioned against diseases produced by warned of the danger of coagulation. His letter influenced Moreau and the newly formed Academic des Sciences to forbid transfusion in Paris w ithimpurities in the blood and seen by Danilewski and had been called by him a ver- 02) inicidc. in died from a Uansfusion reaction. Denis the case of Halteridiiim of the crow that the female cell, motionless before fertilization, afterwards becomes in vitro. 17th centuiy). recorded transfusion of animal bUxxl to man). His fourth patient MacCallum obser\ed this. in the four transfusions of blood from sheep or calf to of the highest animals. like that deeply rooted still ha\'e and a fomi of sexual reproduction precisely their sexes, blood was ever. Jean-Baptiste Denis, physician to Louis other kind, the females. Thus these minute parasites, among the lowest of creatures. his whose brain was considered "a little too man's personality was detertnined tiian (the concept that a out permission (36); a few years later the French Parliament Some years later. Ross (then Sir Ronald) said about discovei7 by two young medical students: disgraced as a felt man "I this have ever since of scieiicel" (for Ross had erroneously inteipreted the spenii cell vviiggling into the penetrated female spore trying to escape /w;;; cell as a tlagellated it!) (.^3) prohibited transfusion of blood to fusion and Alfred Vogl was a third-year medical student when, in girl with congenital syphilis and juvenile tabes was admitted to the Vienna. His chief asked Vogl to Wenckebach itiject 1 Clinic in ml of salicylate of mercury (an antisyphilitic drug) every other dav. By chance. army surgeon, brushing up on civilian a retired Austrian medicine, told Vogl. morning; it's you can use received this sample "I in the mail this a mercurial antisyphilitic. Novasurol. He did. it." Maybe FoUunately. the nurses of the Wencke- bach Clinic collected urine daily and regularly measured and charted its Nokniie. The patient's urine volume went from .'iOO to 1 .2()() later to 1 .400 to 2.000 when Vogl began ap[5eiued on the chart tnl on consecutive days: four days the injections again, t)f mine volumes (34). tall columns again Vogl then injected Novasurol into a patient with advanced congestive heart whom mea- ger mine output. Within 24 hours the patient had minated more than 10 surol customary diuretics liters! was the And first) put an end to blood knowledge of blood groups and incompatibil- the essential of blood from two sources did not surface until 1 900. and a safe anticoagulant was not available until 1914. Rowland was a medical student when Roentgen discovered x-rays in December able prescience and 1895. Obviously one with remark- he founded the Archives of Clin- initiative, ical Skiaiinipln in 1896. "a series of collotype illustrations with new photog- desciiptive text, illustrative applications of the raphy to ber is Medicine and Surgery." The preface dated April 2. 1 896; in expressed the hope that the manent place of Medical in Skiagraphy gen Ray in in July 1 to the first num- Sydney Rowland. B.A Camb., it. new publication "might take a per- literature." It became the Archives April 1897. then ihe Archives of the Roent- 897. edited by W. S. Hedley and Sydney Row- land. M.A.. M.R.C.S.. and eventually the British Journal of Radiology (192^). Concluding Remarks mercurial diuretics (of which Nova- so. was forbidden by Rome. This fail- failed to increase his ure in it transfusion for almost 150 years and justifiably so. because ity 1919. an emaciated young human beings throughout France. The Royal Society of England then deprecated trans- were discovered: they lemained the most I believe that if without digging further, as the we simply accept immediate "pay-off" of medical student research the effective diuretic until 1957. discovei-y of carbon dioxide, ether, nitrous oxide, insulin, hep- chlorothiazide. arin, mercurial diuretics, and the parathyroid glands; the proof that human when Beyer came up with You won't find the name of Vogl, the medical student, on Saxl's 1920 paper, or on Saxl and Heilig's 1920 article, but that is how a so-so antisyphilitic diiig bccatne etnotions can profoundly affect body function; invention of the mercury manometer for measuring blood pressure; the concept that special chemicals specifically a powerful diiuetic. combine with special components of cells (basic to most chemother- Guillaume Lamy and Sydney Rowland, two other med- apy); learning ical students, had an itnportant intluence on tnedicine with- inate malaria out doing research. somely. But l.amy decided to study medicine at the Faculty of Paris verted some how — to go about skin grafting and how we must add a slightly delayed "pay-off: brilliant career investigators. transfused blood fioin a docile animal (a sheep) to change the and treatment), 1 667. Respiratory Care • February '96 Vol 41 No 2 tic who is it con- hesitant medical school researchers into sure-fire, Lower had performed the first transfusion of blood from dog to dog in England in 1663 (reported in 1666 in the Philosophical Transactions) and on November 23. 1667. had about to elim- research by medical students has paid off hand- willing to wait a And. most important little he himself gets sick and wants the best there a bit to a skep- longer for the "pay-off' (when is in diagnosis of medical student research experience 139 . Retrospectroscope may him with well provide 3. who early on le;uned and know when a physician 4. new knowledge gained human lives. In 1970, 1 ready to save is letter from a Swiss physician who had the early I95()s. in I'ellow, Med Some of your Re.search Fellows may end up in pn- may appear to be and the teaching expended on lliem However, lost. my although scientific thinking alone advance the is that enough not rigorous application its 8. medicine such as 9. J. 1850, 43. 109-1 la 19. Force du Coeur .\ortique. These les Recherches experimentales sur CR tubes de tres petiLs diamelres. mouvement le Acad Sci Paris. C: Peterson. L. H.. Dnpps. R. D.. and Risman. G. method for recording the arterial pressure pulse and blood pressure in man. Am Heart .^ 1949. J7. 771-782. The capillary Landis, E. M.: pressure in frog mesentery as determined Langerhans. Am Beitriige /ur P.: J Physiol. 1926. 75. 548-570. mikroskopischen Anatomic der Bauchspeicheldriise, Inaugural Disserlalion. University of Berlin. practice ver\ happily. I Surg by micro-injection methods. everyday in produced by 1846. 35. 309-317. Paris. 1828. Poiseuille. J.-I..-M.: J. to of medicine, there will be no advance art without at all conviction is J. 1840. //, 961-967. 1041-1048. 7. diti I Surg Recherches sur Poiseuille, J.-L.-M.: des liquides dans vate practice as Med Morton. W. T. G.: Comparative value of sulphuric ether and chlo- No. 166. Didot. 6. reads in part: It Insensibility during surgical operations J.: Boston roform. Boston 5. received a been a research laboratory research in Bigelow. H. inhalation. to read critically, evaluate data objectively, 1869. 10. E. Julius H. C'omroe, Jr. I wish to express my 1 . appreciation to Horace Dav- enport for his account of Albert Moser: to Leroy Vandam for Briti-sh Columbia, who has at the my kindly called to University of 1 2a. in this attention 12b. some young men and women, .V 1 1 (2). 4. 5. perfonned by young investigators because by who would U..S. definitions. I decided to include 16. today be considered medical students This of course excluded many young and European physicians who had completed all British 1 able research leading to a thesis excludes all of those who did Cobum. who wrote 8 monograph on rheumatic fever on the basis of observations made while he was a resident, and Carl Roller, who dis- 1 9. Fulton. 20. I decided to include only truly out- 1 of decades; this means that the I have not even delved into work of thousands of medical student researchers since NIH training grants pennitted many medical stu- 22. summer research experience or even a "drop- J Physiol. B.. Am J Physiol. 1898. means studied by 359-382. /. and Moser. A.: The movements of the food in the 434-1-14. Muscular Contraction and the Reflex Control of Move- Die Selbsleuerung der Alhmung dutch den Nervus vagus, J.: Akad Wissen Wien. Ullmann. About Hering and Breuer, E.: 1868. 5.S. in 909-937. Breathing: Hering-Breuer & Porter, ed.. A. Churchill. London. 1970. pp. 3-15. Raynaud. M.: De I'Asphyxie Locale el de Gangrene Symetrique la Sandstnim. Om en ny kiirtel hos menniskan iK-h aiskilliga diig- V.: 1. F.hrllch. P.: Beitrage zur Kenntnis der .Anilinfarbungen und ihrer Ver- u endung der mikroskopischen Technik. .^rch Mikrosk Anat. in 877, 1 263 -277. Dale. H. H.: Introduction, Himmelweit. C: Thebesius. A. Corde. Black. J.: ed. in The Collected Papers of Paul Ehrlich. Pergamon. London. 1956. Disputatio Medica Inauguralis de Circulo Sanguinis Elzevier. Leyden. 1708. .\. Experiments upon Magnesia Alba. Ouicklime and some Bellini. L.: Exercitalio .Analomica de Stnictura et Usu Renum. Stella. Florence. 1662. 23. Young. T.: Observations on vision. Philos Trans R .Soc Lond. 1 793. S3. 169-181. 24. 1950 when dents to have a rabbits. other Alcaline Substances. William Creech. Edinburgh. 1796. standing research done by medical students that has stood the test The movements of the stomach //)«/.. J. F.: Breuer. in 2 intern). Further. action of cephalin. .Am Sil/ungsber F. covered the local anesthetic properties of cocaine while he was an B.: Cannon. W. /.i his cla.s- sic and Noble. . gdjur. Upsala Lakaref Forh. 1880. /5. 441-471. in their research while serving as interns or residents (such as Alvin 7. requirements some very remarkand an M.D. degree. It also medicine and then engaged R des Exlremites Rignoux. Paris. 1862. 1 to practice The thromboplastic J.: Cannon. W. J. only those J Centenary Symposium. Ciba Foundation Symposium. R. have merely scratched the surface of biomedical research I J. on normal ment. Williams and Wilkins, Baltimore. 1926. see references (27), (36), and especially Gibson's monograph, "Young Endeavour" McLean. esophagus. Retrospectroscope: for other instances of research accomplished by B.. MacletxI. Physiol. 1922. 62. 162-176. of the roentgen rays. 1 of the examples included J. effect of pancreatic extract (insulin) 1916. J/. 250-257. verifying the academic status of Morton; and to William C. Gibson. Professor of Medical History C: The Am J I Note: Banting. F. G.. Best. C. H.. Collip. Bert. P.: De la Greffe Animale. No. 118. J.-B. Baillierc el tils, Paris. 1863. 25. Fulton. J. F.: cock and out" vear. F. Foreword, Buroniclric Pressure. in Bert. P.: A. Hiichcix'k. trans.. College M. A. Hitch- Book Co.. Columbus. Ohio. 1943. 26. Keith. .\.. and Flack. M.: The form and nature of the muscular connections between the primary divisions of the REFKRENCES v ertebrate heart. J .Anat PhysioL 1907.-;/. 172-189. 27. Davy'. H.: Researches. Nitrous Oxide, or Dephlogisticatcd Nllrous Air. J. .lohnson. London. 28. W. C: Young Endeavor. ical .Students Contributions to Science b> of the Past Four Centuries. Charles tleld. Illinois, igss. 140 W. C: Student discoveries Svvammerdam. pulmon:iry and cardiovascular .\:\ and van der .\:\. Leyden. 1737-38. Vol. II. pp. stabilized photoelectric colorimeter with light fil- 832-833. Med- C Thomas. Spring- in the Biblia Naturae, sive Hisloria Insectorum. H. Boer- J.: haave. ed.. van der 1801). Gibson. Gibson, systems. Chest. 1972. 6/. 283-286. Chemical and Philosophical; Chiefly Conceming 29. Evelyn. K, A.: lers. J Biol A Chem. 1936. 115. 63-75. RESPIRATORY CARE • FEBRUARY "96 VOL 41 NO 2 Retrospectroscope 30. 31. MacCallum, W. C: Notes on the pathological changes m the organs of birds infected with haemocytozoa, J Exp Med, 1898, 3. 33. 103-116. 34. Opie. E. L.; On the haemocytozoa of birds, J Exp Med, 1898, December Physiology or Medicine. 1901-1921. 12, Else\'ier, 1 J, 1974. 134, 330-345. Am Heart 1950. jy, 1-4. Lamy, G.: Lettre a M. Moreau contre les prelendues utilites de la transfusion, Paris. 1668. 902, Ams- Med J, Vogl. A.: The discovery of the organic mercurial diuretics. 35 Ross. R.: Reseiirches on malana, Nobel lecture, m Nobei Lectures. and Opie, Johns Hopkins J. 79-101. 32. Harvey, A, M,: Medical students on the march; Brown, MacCallum 36 Gibson. N terdam, 1967, pp, 65-67, Engl W. C: J Student medical researchers and their contributions. Med, 1961. 26-;. 802-810. Call for Abstracts 1996 Respiratory Care Open Forum Deadline: April 28, 1996 Accepted abstracts will be printed in the October 1 996 issue of Respiratory Care Selected authors will present research at the Open Forum during the their 42"^^ International Convention in AARC San Diego. California Respiratory Care • February '% Vol 41 No 2 141 - Lellers addressing lop.cs „f curr™. inleresi or maieriai in RESPIRATORY CARE decline a letter or edit « ithout changing the author's views. Cari:. 1(1.10 .'Vbles 1 Editor As Death Dealer TX Lane, Dallas profession should my time ;is an editor ot this Jourmy work except for one task. loved I 1 hated writing often 1 of rejection to authors. letters a death dealer aiming felt like probably fragile ego. Thai one author same way was revealed uary 1996), \shen "It felt like 1 at a my an airow ihrotigh me heart." for hav- flawed work had been published. me of an incident occtiiTcd several years back when New ing from San Francisco to was Hy- 1 York. The or so of our imprisonment lovingly engaged with papers from his briefcase them, talking to them, writing At last began it 1 was dtill mar- he put the papers away. Then, telling himself as — reading in their had not said a word 1 llie me to hiin, he about his work and about To me performer of that work. sluH — insurance or the like —and did not encourage him. .After a long time he slopped. Then, sensing the imbalance he had created, he gave me me the Great Ameiican do yr)/( list of procedures for which no scientific member forms me my chance, asking Qiiesiion: ".Ami whal am shy, uncomfortable. diffident, snobbish. 1 did not wish to say. "1 be asked llie polite, in way a I tlid not w am to talk. am an editor" and then 1 pro-fonna questions about what an editor does, etc. How could 1 reply to staunch the flow of conversation After a moment I knew what could identify an aspect of ahead (if I might have burst out laughing), ly aiKl dis-tinct-ly, "1 re- am NursSciQ touch. J Holist When therapy. to 1992:70(3. 8. 9. 1 said, What few quantitative studies have either demonstrated its flaws'-'*'' 1 1 2. we cannot Perhaps we have of the past and will reject Clark MJ. Therapeutic touch: is Nurs Res 1984:33 Rosa. L.'\. I'herapeutic touch. Skeptic 994:(3) 1:40-49. Rosa LA. Survey of "research" on ther- touch review committee, health .sci- unprm en this plea to in- Stahlman modality'"^'" into res- Therapeutic touch: fuzzy J. metaphysics (letter). Am J Nurs 199.');95 (7):I7-18. '.' piratory care. 4. Scheiber B. University of Colorado report 1 Wayne C Anderson BA RRT quirer, 1.5. I slow- 1 In- 994; 18(3 1:232-234. Walike BC. Bruno P, Donaldson S, Eret al. lAjttetnpts to embellish a totally unsci- Medical Center a trained killer." entific pnx.-ess with the aura School of Respiratory Care ter). fiight, Am J of science (let- Nurs 1975:75(8): 1275. 1278, 1292. 16. RKKKRKNCES Clanian H. Report of the chancellor's committee on therapeutic touch. Denver: University of Colorado Health .Sciences River. C'alilorma Krieger I), llic rcs[X)nsc ot in \ ivii Center, 1994. human henioglohin loan active healing therapy Scientific Basis for by Therapeutic Touch? on of hands. direct laying Human Di- A7v Haines responds: inensions 1972;1:12-15. 2. Xovember 199.^ issue of RespiRAIORY Care, a letter susiaests that our of therapeutic touch. Skeptical ickson R, Gihlin EC. Hanson RL. Point Park College I 142 P. 1994. learned froin our mistakes 13. corporate an PJ?,*;:?? ences center, university of Colorado. Loveland. CO: Front Range Skeptics. piocedure with such weak underpinnings. Jotirnal Editor. l')(iS-l99,^ In the Clark tic re- afford to support a Phil Kitlredge A Am J Nurs apeutic touch: a report to the therapeu- Pittsburgh. Pennsylvania iltle Krieger D. Therapeutic touch: the im- 1 cannot be taken seriously. days of cost containmcnl and structuring, Geron- 199.5;21(7):.34-4(). (l):37-41. 1 ineffectiveness'''' or have had such serious methodologic that the results Inter- (.'i):784-787. attempts there have St Francis Silence reigned for the rest of the I Nurs and the Instructor guy l):89l-S96. there a scientific basis.' occupation at the Pan primatur of nursing. 10. at actual Testing elec- Snyder M. Egan EC. Burns KR. tol 1 to do. LXX. iors in persons with dementia. J be without merit. been 1 ventions for decreasing agitation behav- finally truly bi/;uTe.' (4):3 1 9-33 1 psyehokinetie effect of therapeutic touch The literature supporting Therapeutic Touch consists of anecdotal reports.' case studies,'-' qualitative (?) research,-"' 1 on germinating corn seed. Psychol Rep submitted to rigorous examination, they were found 1 Geisi CR. Geophysical vari- tromagnetic explanations for a possible tojustify our u.se of such were AM. field using therapeutic Nurs 993: ables and behavior: the inability Many of us believed these procedures Bush 7. applications, IPPB. was post- 1993:6(21:69-78. human energy case reports and anecdotal evidence were was needed Nurs France NE. The child's perception of the 6. the poptilarity of these treatments uate scientific research. all llial Holding sacred space: the nurse JF. operative pain: a Rogerian research study. of matiy respiratoi^' care practitioners to eval- that I99.');9.'i(4): Meehan TC. Therapeutic touch and adtninistered critical my had looked some (besides revenue generation) without using the word "editor." .Staring straight we of therapy bottles, and, in Am J Nurs Pract 1992:6(41:26- ,16. our hair in pressure (NEEP), ultrasonic nebulization. blow niixlalities: as healing environment. Holistic Those of us with gray In these iiiailc Quinn 4. basis can be found. do? This inter- Discover the healing power of 1. therapeutic touch. A factor in thai the next seat spent the first hour although part 26-3-3. Some of these include Dale-Schwartz tubes, CO: inhalations, negative end-expiratory him from probable embaiTassment gins. opinion or Mackey RB. Complenientan, 3. opinion, this simply adds to a growing had rejected 4 years ing saved in The Editors may accept or reflect the author's my despite a lack of evidence of their efficacy. he went on to thank All this reminds provide Therapeutic called the 'laying on of from a letter Btit fellow may simply 5. he wrote. if his published hands')' as a form of 'holistic healing,' In ihc fell early this ye;ir (Jan- received a 1 person whose paper ago. will he considered fur publicalion. letters as 75229-459.1. Touch (formerly Dtiriiiji The content of pretation of inlormation-not standard practice or the Journal's recommendation. Authors of cniicized material will have the opportunity to reply in print. .\<> anonymous letters can be published. Type letter douhle-spaced, mark it "For Publicalion." and mail it to RESPIRATORY Letters nal, . . Pieicc AK, S;ilt7.ni;in scientific basis HA. Conterctiee of the of respiratory therapy. Rev Rcspir Dis 1 ')74; 1 1 (1(6. Pail 1 ): 1 with gray -1. piratory therapist, Respir.atorv am one of those my 24 years as a iês- Like .Mr .Anderson, Am Care • in my hair. I In 1 have seen much February '96 Vol 41 coi-ne No 2 : Letters and go and the focus become more and more on technology. Mr Anderson ticle titles has listed research and ar- and seems to imply that these refute the validity of Therapeutic Part of the list cles by Delores Kreiger Qumn RN which In my Touch. includes research and PhD, and RN arti- PhD. Janet PhD. TC Meehan RN on an Snyderman MD. The piece concerned Dr of a health professional's practice. November issue, I list- ter at Columbia Presbyterian Hospital New York City. Therapeutic Touch of the program and The 'bottom up then, to Touch can decrease lidity I also listed done and colleges and other facilities in which it is taught. In September 199.'S. is learned of another hospital that porating Therapeutic Touch. cisco television station in their is line,' to read, fomi and their is that it become is in- to ask questions, and, own it fits opinions as to the va- into their philosophy of care. Therapeutic Touch that costs the patient, is not an interaction and it equipment except one's hands. requires no 1 am not ad- I vocating that Therapeutic Touch be man- incor- dated by respiratory care departments as part The San Fran- (KPIX) Channel 5, Eyewitness News, had a segment of the job is as ever required to learn tention in the or, for that matter, that anything officially to do with November is available for those it letter No it. was one My in- to relay many hospitals, that who wish to incor- as part of their therapeutic inter- I welcome Mr Anderson's letter of concern. Differing information and opinions should be available about a subject so people can be aware and own make their decisions. For more information on Therapeutic Touch contact: The Nurse Healers and Pro- fessional Associates Inc, lison Park it at all. It is is or use action with patients. PA done PO Box 444, Al- 15101-0444. Stephanie Haines they have usually not ordered and, generally, it information about a holistic intervention, already being used in porate of course, of Therapeutic Touch, and to decide whether celerate the body's es. taught to nurses and is to individual practitioners to that support the statements that Therapeutic own healing processmany hospitals in which it in part is to the families of patients. formed, decrease diastolic blood pressure, and ac- start- ed the Cardiac Complementary Care Cen- ed just six of the clinical research studies anxiety, decrease pain, who Oz, a cardiothoracic surgeon, actually support Therapeutic Touch. letter in the needed basis as part of the scope about integrative medicine with Dr Nancy Mad River Community RRT Hospital Areata. Califomia Mark Your Calendars! Future November 3-6, AARC 1996 (Sunday - Wednesday) San Diego, December New Conventions California 6-9, 1997 Orleans, Louisiana November 1998 Atlanta, Georgia Respiratory Care • February '96 'Vol 41 No 7-10, 143 Notices Df compelilitms. scholarships, fellowships, examination dates, new educational programs, and the like will be charge. Items for the Notices section must reach the Journal 60 days before the desired Notices February I for the April issue, etc). Include Lane. Dallas TX 75229-459.1. all month of publication (January pertinent information and mail notices to RFSPIRATORV CARli I here free of listed lor the Notices Depl. March issue. KWl Abies I ) 1996 Call for Abstracts Respiratory Care • Open Forum Abstract Format and Typing Instructions The American Association for Respirator}' Caie and its science journal. RESPIRATORY CARE, invite submission of brief abstracts related to any aspect of cardit)respiratory care. Tine be reviewed, and selected authors abstracts will \ OPEN FORUM ited to present posters at the title in all AARC explain content. Follow title during the in Respiratory Care. Membership quned for participation. in the of AARC is not re- abstract name. Type or electronically print the abstract \/;/gle spaced in the space provided on the abstract blank. Insert only one letter space between sentences. Text submis- ill be masked (blinded) for re\ iew. tables are to be attached to the abstract form. Provide all au- ( 1 ) an ori}»inal study. (2) the eval- (3) a ma> ha\ e been abstract . —but not nation- meeting and should not have been published previously in a national journal. The abstract will be the only evidence by which the reviewers can decide whether the author should be invited to present a poster the abstract w case or case series. report nolog} or health-care delivery. The presented previously at a local or regional — encouraged but must he accompanied by is a hard copy. Identifiers habilitation, perinatology/pediatrics, cardiopulmonary tech- al authors (in- aspects of adult acute care, continuing care/re- ma\ may be all one paragraph. Data may be submitted in table form, (uul simple figures may be included provided rliev fit within the space allotted. No figures, illustrations, or uation of a method or device, or Topics with names of presenter" s Make An fust line of capital letters. Title should cluding credentials), institution(s). and location. Underiine sion on diskette SPECIFICATIONS— READ CAREFULLY! The will be photographed. the abstract should be the San Diego. California. No\ ember .^-6 1996. Accepted abstracts will be published in the October 1996 issue Annual Meeting Accepted abstracts will be in- must provide at the all OPEN FORUM. Therefore. important data, findings, and conclusions. Gise specific infomiation. Do not write such general statements as ""Results will be presented"" or "Significance will be discussed." the abstract all thor information requested at the bottom of abstract form. clear photocopy of the abstract may abbreviations A fonn may be used. Standard be employed without explanation. A new or infrequently used abbreviation should be preceded by the spelled-out term the first time it is used. Any recurring phrase or expression may the abstract for ( 1 be abbreviated, ) enors ures; (2) clarity of language; specifications. An if and is first it in spelling, explained. grammar, (3) facts, conformance abstract not prepared as requested Check and fig- to these may not be re\ie\\ed. Questions about abstract preparation ma> be telephoned to the editorial staff of RESPIRATORY CARE at (214) 243-2272. Essential Content Elements Deadline Allowing Revision Original study. Abstract must include ( 1 ) Background: statement of research problem, question, or hypothesis; (2) Method: description of research design and conduct in sufficient detail to pennit judgment of \alidity: (3) Results: statement of research findings with quantitative data and statistical analysis: (4) Conclusions: inteipretation of the meaning Authors may choose to submit abstracts early. Abstracts postmarked b\ February 11. 1996 will be re\iewed and the authors notified by letter only to be mailed by March 22, 1996. Rejected abstracts will be accompanied by a written critique that should, in of the results. Method/device evaluation. Abstract must include ground: identification of the method or de\ ice and ( 1 ) its ity; (3) Back- judgment of its 28, 1996). Final Deadline objectivity and valid- Results: findings of the evaluation; (4) Experience: of the author" s practical experience or a lack of ex- summary cases, enable authors to revise intended function; (2) Methitd: description of the evaluation in sufficient detail to permit many their abstracts and resubmit them by the final deadline (April perience; (5) Conclusions: inteipretation of the e\aluation and The mandatoi7 Final Deadline is April 28 (postmark). Au- thors will be notified of acceptance or rejection by letter only. These letters will be mailed bv July 15. 1996. experience. Cost comparisons should be included where possible Mailing Instructions and appropriate. Case report. Abstract must report a case that mon or of exceptional is uncom- educational value and must include ( I Introduction: Relevant basic information important to understanding the case. (2) Case Summary: Patient data details of interventions. 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Express measurements of length, height, weight, and \olume istry ( Mail three copies of the manuscript, figures, diskette, and the Cover used to prepare documents; and filcname(s). ters I Submitting the Manuscript ures. Receipt of use of laboratory animals was followed. Methods not human experimenta- informed consent was obtained. that names, patient's ( accordance with the ethical in standards of the institution's committee on tion. Hg (not sec). Spo, (pulse-oximetry saturation). reporting experiments on liunian subjects, indicate procedures were conducted that mm s is given by the author and orig- Please consult the Editor before submitting such work. 198S;.\Vl()|;X6l-87.^(Oct l98S)and I989;.U(2): 145 (Feb 1989). Authorship. All persons Conflict of Interest. Authors are asked to disclose any liaison or financial arrangement they tor who.se product is have with a manufacturer or distribu- part of the submitted manu.script or with the manufacturer or distributor of arrangements do not disqualify competing product. (Such paper from consideration and a a are not disclosed to reviewers.) A statement to this effect is included on the cover-letter page. listed as pated in the reported work and authors should ha\e partici- in the symbols. .Xvoid creating new abbreviations. Avoid and unusual abbreviations title abbreviation only if Write out the term the Drst time abbreviation alone. in it parentheses. Thereafter, Use an appears, followed by the employ the abbreviation 15 torr, 2..1 it. responsible for the article. Authorship is not justified solely on the basis of solicitation of funding, collection or analysis of data, may who provide be recognized u.se Standard 1), L/min (not an Permissions. The manuscript must be accompanied by copies of permissions to reproduce previously published material (figures or tables); to use illustrations of. or report sensitive personal intormation about, identifiable persons; and to the Acknow name persons in ledgmeiits section. abbrexiateil without explanation RevicHcrs. Please kPa), cm HiO (not cmH20), f LPM. l/min. or Ipni). inL (not the following forms: bpm). L (not in .'\cknowledgments section. su|ipl\ the names, credentials, affiliations, addresses, and phone/la\ numbers of three professionals Please A abbrevia- the term occurs several times in the paper. measurement can be lOL/min, all the abstract. Never use an abbreviation without delining units of (eg. full in should paper with corporate authorship must specify the key persons pnnision of advice, or similar services. Persons Abbreviations and Symbols. Use standard abbreviations and all be able to publicly discuss and defend the paper's content. such ancillary services exclusively tions in the shaping of the manuscript; must have proofread the submitted manuscript; and all (not \(iu ml). may be sent Editorial Olllce: Respiraior'i Care 11030 Abies Lane Dallas TX 75229-4593 (214) 243-2272 (telephone) (214) 484-6010 (fax) RESPIRATOR'^ whom consider expert on the topic of your paper. Your manuscript Care ti) one or more of them for blind peer review. Cover Letter & Checklist A copy Title of of this completed form must accompany all manuscripts submitted for publication. Paper: Publication Category; Authors: FAX: Phone: Author to be Contacted: Mailing Address of Contact Author: D Rephnts: Yes No ; approve its "We, the undersigned, have all participated in the work reported, proofread the accompanying manuscript, and and state. If city appointments, academic institution, title, credentials, include print and submission for publication." (Please form.) of this another copy use please authors, that 4 more Author Name: Author Signature/Date Author Name: Author Signature/Date Author Name: Author Signature/Date Author Name: Author Signature/Date Has If yes, where, Has If research been presented this this in a public forum? '^, Yes U No when and by whom? research received awards? D Yes D No yes, please describe, Do any D Yes of the authors D No If have a financial interest in the products mentioned in this paper or competing products? yes, please disclose: Checklist: U C D n D C D D n n D Is double-spacing used throughout entire manuscript? all pages numbered in upper-right corners? Are all references, figures, and tables cited in the text? Has the accuracy of the references been checked, and are they Have SI values been provided? Has all arithmetic been checked? Have generic names of drugs been provided? Have necessary written permissions been provided? Have authors' names been omitted from text and figure labels? Have copies of 'in press' references been provided? Has the manuscript been proofread by all the authors? Are correctly formatted? Respiratory Care — New Products News & Services releases about these listings. new produels and services will be considered for pubiication Send descriptive Products and Services Dept. sor has a 1 1 in this section. There is no charge release and glossy black and white photographs to Ri^.spir.xtory Cari^ Journal, 1()3U Abies Lane. Dallas TX 75229-459.1. -year wairanty. For a complete cross-reference listing, call VTI for New at (8(X)) cure'", a new holder for nasogastric tubes, nasal feeding tubes, and According oxygen can- company, 550-0856. please mention RH.SPIR.AI()RY nulas. CarE; or write to Vascular Technolo- holder feauires a moisture-resistant foam Ave, cushion to reduce pressure to the patient's gy Inc. Dept RC. 25 Chelmsford MA Industrial 01824. (508) 250-0856. nostnls and up|X'r to the the The hvpoalleigenic lip. holder attaches to the dry area of a patient's cheeks and helps eliminate the need for constant retaping by securely holding the tube with a resealable For details, contact at 2037 J &C tlap. M C Johnson Co Inc Blvd. Naples FL 33942Remem- Nebilizer Compressor System. 6213. or Medical Industries .America Inc intro- ber to mention Re.SPIRATORY Cari- duces the AertiMax Nebulizer Com- when you The AeroMax akiminum compressor pressor System. a die-cast sembly and a 3-prong call (800) 553-8483. call. features a strong grounded ABS as- plastic case, electrical cord, and removable nebuli/cr tubing. According to the manufacturer, the AeroMax also features a unique benefit for children the Max Pax. The Max Pax contains stickers for the and AeroMax compressor an activity/instruction booklet de- Generic Inhalation Aerosol. signed to familiarize children with the DEY use ol the nebulizer compiesse)r. For Inhalation Aerosol metered-dose inhaler, information call (800) 759-3038. Don^t forsiet to mention Rr.Sl'lR.ATORY CARE. Laboratories now offers Albuterol a generic alternative to Proventil " and Ventolin". According to the company, albuterol and is relief indicated for the prevention of bronchospasm in patients with reversible obstructive airway disease and acute attacks ot bronchospasm. For infomiation about indications, contraindications, Laboratories and side at effects, call DEY (800) 755-5560. Don't foraet to mention Ri:sPlR,\T()RV CARli. MEI ABOLIC MEASI REMENT SYSTEM. Par\iiMedics introduces MMS2400 Metabolic Measurement System, a compact integrated system for maximal Oi consumption sures Vo,, Vc().. Oxy(;en Sensor. Vascular Technology Inc vanic ( VTI 1 Oxygen the sensor is variables. the releases the VTI-.58() Gal- Sensor. VTI suggests that designed as a direct ic and placement for the oxygen sensors used MiniOx tion, the oxygen sensor can be used I. II, a replacement for factured 15: and III. by several companies. F.acii call as sen- to ParvoMedics, includes paramagnet- CO: g''^ analyzers, mix- printer. Bike ergometer and tread- mill options are available. In addi- equipment manu- indi- ing-chamber, pneumotach, computer, re- with the O:. infrared and RQ. REE. and other According MMS-240() testing assessment that mea- rect calorinietry Na.sogastric Tube Holder. .lohnson C(>mpanv Inc offers NG For Consentius Technologies details, at (800) MC 942-7255. Please mention Re.SPIR.'XTORY Se- Care when vou Respiratory Care • call. February "96 Vol 41 No 2 . New Products & Services mising performance. In addition, the monitor displays on-line help on a high visibility screen. The SC-210 may be used for intubated and noninmbated patients. For infonnation contact the company at N93 W 14575 Whittaker Way, Menomonee Falls WI 53051. Please mention Respir.ATORY Care when voucall(8()0)PRYONCO. analysis and trending, and b\ improving the accuracy of billing information, reports, and logs. LabManager dows-based application Microsoft's that is Win- a works with Windows', Windows 95®, NT* and Windows The program can operating systems. retrieve data from up 4 different brands of analyzers simultaneously and can exchange data to w ith hospital mainframe and other comHIS puter systems via a real-time terface. For details, write to LM in- Soft- ware. Dept RC. 4140 Oceanside Blvd #159-410, Oceanside forget to mention when you Cost-Rediction Medical-Gas call CA 92056. Don't RESPIRATORY CARE (619) 631-1343. Nellcor Puritan Bennett releas- Plan. es a program designed to help health- care institutions control the costs, in\ entor\ maintenance, and uses of ical gases. According med- company, to the the brochure, "Providing Services Tai- lored to Address Needs," will help Your Gas Product reduce the total cost Infant \L\NNEQIIIN. Laerdal Medical of buying and using medical gases. For Coiporation announces the a copy of the brtichure. contact Nellcor Anne' Puiitan Bennett Gas Products. Dept 9101 Bond. Overland Park KS 66214. or phone (913) 49.^-3610. Please tion RC. men- Respiratory Care when \ou call. ing '. mannequin with conect head rise new Baby an infantlike, low-cost tilt luid a CPR train- mo\able jaw chin lift, for natural chest during ventilation, and a realistic mouth and nose. Tl:e mannequin also includes a removable face that can be in- HOLTER Recorder. new Del Miu A\ ics releases and a disposable airway for easy clean- recorder that accurately captures ing. is According a\ ailable for as quadruplets to Laerdal, Baby Anne classroom or group use — four mannequins in a a recordings. According to the facturer, the it>n- digital Holler patient terchimged with Laerdal's Resusci' Baby ECG manu- Model 483 DigiCorderT"^ incorporates a unique digital memory con\ enient cany ing bag with a separate and advanced electronics that eliminate storage compartment for faces, con- data compression, which nectors, jaws details, call imd disposable Laerdal Please mention at aiivsa\ s. For (800) 649-185 1 RESPIRATORY Care. may intiodtice en'or into arrhythmia and ST-segment analysis. In addition, the be used with other Del and DigiCorder can Mar scanners features set-up instaictions in 5 lan- guages, a cairying pouch, an event but- SiDESTREAM CO2 MONITOR. Pryon Laboratory Management Soft- Corporation introduces the SC-21() \\ sidestream CO2 the monitor tle.xible. is monitor. Pryon claims easy to use, portable and and reaches full specifications in seconds. laboratory management software, LabABG for Windows. The Manager^"^ company claims the software The moni- signed to improve quality control in the and withstands excessive patient secretions or moisture w ithout compro- • LM Software announces a new operating tor features continuous self-calibration RESPIRATORY Care ARE. February "96 is de- ton to identify specific medical episodes, and an aku-m are included. For details, write to Del Mar Avionics. Dept RC. 1621 Alton Ave. Irvine storage of historical calibration data for TORY Care. 41 No 2 of a low trode extension cables and electrodes blood gas lab by providing comprehensive data management, retrieval, and Vol to alert the patient battery or a ct>mponent failure. Elec- CA 92714. or call (714) 250-3200. Please mention RESPIRA- 153 omm Now. Introducing a new high-tech benefit AARC mem- for It's Easy To Get Onto bers that allows you to share information with your AARC Online: e-mail, Member Benefit. tion about particular timely topics, ing download documents and search and managed care. You can concerns on onhne message boards and conferences. Members And Professional AARC Get Immediate Access To Infomiation like Hie find them out. or AARC Clinical Practice When You more YES! Send my 1 currentK ha\e a S9. 95 modem: Yes - dow nload them 24 hours available. to _\ them l No: VISA pay choose a month!} charge of Si 4. ^).\ which includes 3 at $9.95 per hour.)* It! you need, online, print them documents and ow) no monthly minimum S9.95 per hour, Fax or mail the reply form $14.95 per month (includes 3 hours) S P EXP ^£ W .5 MC U AMEX D Spaci:Works. Inc. Fax: 301-738-9284 DISCOVER 51 Monroe 1995 Sp,\ci Works. Inc. ille. Or SKtNATLRE: f Street. Plaza D.^TE: Rock\ arc billed at a hieher rale, s »: ._ L . FAX: k to: = NAME ON CARD: _ IS. to a dav. seven davs a week! CREDIT CARD oiiisijo ihe continental You can choose hour with no monthly minimum, or you can Preferred [filling Method: (select COMPANY: . the economi- our ow n computer. Miu also AARC MEMBER TEL: are two SpkeU ORhS Sofhvare Kit For AARC Online! TITLE: CITY STATi: ZIP payment plans SQ.Q.^ per in "'real-time" for the guidelines yourself, then read u D ADDRESS: modem, and AARC Clinical Pnuiice You can search NA.MI;: •Areas JSeed iia\e access to newsletters, articles, Guidelines. 3.1. a SpaceWorks software. There pro\ ides 24-hour access to important information, like the Guidelines. cal AARC Online is a PC hours of connect time, (Additional hours are billed Information Colleagues. $9.4.^ such as restructur- AARC Heodquorlers, for informa- also share ideas and Communicate Online With you need running Microsoft Windows respiratory care colleagues, send and receixe Internet AARC's Newest Critical All AARC Online. to access Spacf.Works i.s a sen ice inark of Sp.ace Works. In One MD ZOS.'Ô call: I-800-5-SP.4CE-5, Ext. 2170 . . . American Association for Please read the eligibility requirements for each of the classifiin the nght-hand column, then complete the applicable section. All information requested below must be provided, except where indicated as optional. See other side for more information and fee schedule. Please sign and date application on reverse side and type or pnnt clearly. Processing of application takes approximately 15 days. cations D Respiratory Care Membership Application FOR ACTIVE MEMBER An individual pnor to eligible is moving outside mandates such. care. OR Member he/she its lives in the US, or its terntories or vi/as borders or territones, and meets OR (2) is ONE of good standing on December membership remains in if an Active Member the following critena: employed in a graduate of an accredited educational program holds a credential issued by the (3) in if credentialed as a respiratory care professional (1) IS legally Place Active . , good NBRC, An 1994 8, will who individual is an a slate in that respiratory AARC Active continue as such provided hislier standing. Employment of Associate ^ Foreign Address D Physician City " D D Last Name First Name Industrial Zip. State Special Phone No. Student J ( Medical Director/Medical Sponsor FOR ASSOCIATE OR SPECIAL MEMBER Middle _ hold a position related to respiratory care but do not meet the who Individuals Social Security No. quirements of Active Member shall be Associate Members They have all of the rights re- and benefits of the Association except to hold office, vote, or serve as chair of a standing Home Address committee. The following subclasses of Associate Membership are available: Foreign, Physician, City devoted Special -Zip. State Phone No. and to the Industrial (individuals whose primary occupation is directly or indirectly manufacture, sale, or distnbution of respiratory care equipment or supplies) Members are those not working a respiratory care-related in field. PLEASE USE THE ADDRESS OF THE LOCATION WHERE YOU PERFORM YOUR JOB. NOT THE CORPORATE HEADQUARTERS IF IT IS LOCATED ELSEWHERE (. Place Employment of Primary Job Responsibility (check one only) Technical Director D Assistant Technical Director D Pulmonary Function Specialist D Instructor/Educator D Supervisor n Staff Therapist Address n staff Technician D Rehabilitation/Home FOR STUDENT MEMBER City Phone No. Care Individuals n Medical Director n Sales n Student D Other, specify be classified as Student Members accredited by, or in all the requirements for in respiratory care AARC-recognized not receive Continuing Respiratory Upon completion of your may be pursued upon your transcnpts. continuing education credits Care respiratory care education, reclassification to Active or Associate Member. Skilled Nursing Facility School/RC Program Educational Institution Address Manufacturer or supplier City _ specify Sex of Birth (optional) U.S. Citizen? Yes (optional) Zip. Phone No. Lj when? From Preferred mailing address: American Association .) (_ Length of Program No Have you ever been a member so, they meet the process of seeking accreditation from, an State If if an educational program — Student Members do SPECIAL IÔTICE Education (CRCE) Hospital n Other, Date in agency. n DME/HME D Home Health Agency D D will (_ Associate Membership and are enrolled Type of Business „ D -Zip. State of the AARC? for Respiratory year i; 4 years Z Other, specify. Expected Date of Graduation (required information) to Home 1 n 2 years Care '11030 Abies Lane Year Month Business • Dallas, TX 75229-4593 • (214) 243-2272 • FAX W^^" ' American Association for Membership Fees Demographic Questions Payment must accompany your We request that you answer these questions us design services and programs to in order to help meet your needs. Fees are High School Associate Degree n D Master's Degree Number S80.00 D D D D n Graduate Technician Bachelor's Degree for Active S77.50 Associate (Industrial or Physician) $77.50 Associate (Foreign) $92.50 Special $77.50 Student $35.00 D n 0-2 years 3-5 years 1 1 - 1 5 years Established to recognize the specialty areas of respiratory 6-10 years care. Job Status Full The sections Time Part national n RRT D LVN/LPN D CPFT D RPFT D Perinatal/Pediatric CRTT Physician D CRNA D RN Salary Less than $10,000 $10,001-820,000 $20,001-330.000 $30,001 -$40,000 $40,001 or more PLEASE SIGN hereby apply for membership in the American Association for Respiratory Care and have enclosed my dues, approved for membership in the AARC, will abide by its bylaws and professional code of ethics authonze investigation of all statements contained herein and understand that misrepresentations or omissions of facts called for is cause for rejection or expulsion I if I I yearly subscription to Respiratory includes an allocation of $6.50 from Contributions or gilts to Care AARC the and AARC Times magazine each of these publications. journal my dues for are not tax deductible as charitable income tax purposes. However, they may be lax deductible as ordinary and necessary business expenses subject to restrictions imposed as a result of association lobbying activities. The AARC estimates that the nondeductible portion of your dues the portion which is allocable to lobbying contributions for - is 26'.' Signature Date of specific concern AARC meetings. Time ^1 D D D D D publish a newsletter four times a year that to that specialty. The sections also design the specialty programming at the Credentials NOTE: $ Specialty Sections 16 years or more focuses on issues ^ for Doctorate Degree TOTAL D AARC. Associate-Foreign status: and $35.00 of Years in Respiratory Care D n n A application to the 12 months. (NOTE: Renewal fees are $65.00 Student status.) Check the Highest Degree Earned „ for Active, Associate-Industrial or Associate-Physician, or Special status; RC I Respiratory Care Membership Application - Adult Acute Care Section MECJ^TCH m IHh \ M KUIHK MUl IS Kt I'llK I I PKdl.K ^t. V M Patient identifier ' Age at Sex 3 or I I I I Date 4 Weight Name 1 Triage unit sequence # igive labeled strength & mfr labeler, kgs 3 Dose, frequency & route used 2 B. Adverse event or product problem Outcomes 2 (check Q all and or Product problem I I I I #1 permanent impairment/damage hospitalization - °^^^' LD or prolonged Lot # Date of Dgggfy"' known) 7 Exp. date known) (if #1 «2nyesn"o Dgg^Py"'' Event reappeared after 8 reinlroduction 1*2 Describe event or problem 5 (if #1 this report event Dyes Dho #1 6 4 3 Date of Event abated after use stopped or dose reduced 5 (indication) #1 required intervention lo prevent life-lhrealening initial Diagnosis for use 4 congenital anomaly death I unknown, give duration) (if best eslimale) tt2 disability I {ot defects/malfunctions) attributed to adverse event thai apply) I [ le g Therapy dates trom 10 #1 Ad-Iverse event known) it #1 female male of birth: confidence 0910-0291 Expires: 1/3V96 0MB statement on reverse C. Suspect medication(s) time of event: In See FDA Use Only (RESP CARE) Page A. Patient information 1 0MB No Form Approved VOLUNTARY reporting For bv health professionals of adverse events and product problems Dyes Dno Dt°pf,ff ssDyesDno Dggfy"'' #1 NDC 9 # (for product problems onlyi Concomitant medical products and Iheiapy dates (exclude treatment 10 of event) Suspect medical device D. Brand name 2 Type 3 lUlanufacturer of device name & address Operator of device 4 I I I I I I health professional lay user/patient other 5 Expiration date 7 If 6 model # _ 6 Relevant tests/laboratory data, including dates catalog # implanted, give date Imo dav v serial # If lot# explanted. give date jmo.day.'yr) other # 9 (Do not send Device available for evaluation? I n yes I Q no FDA) to relurned to manufacturer on Concomitant medical products and therapy dales (exclude treatment 7 of event) Other relevant history, including preexisting medical conditions (eg, allergies, race, pregnancy, smoking and alcohol use, hepaticrenal dysfunction, etc) Reporter E. ) 2 Mail to: MIhWaKH or 5600 Fishers Lane Rockville, MD 20852-9787 FDA Form 3500 (6/93) FAX 1 5 8. (see confidentiality section on back) phone address Health professional? D to: -800-FDA-01 78 Name yes D 3 # Occupation manufacturer you do I I I I no user facility NOT want your identity disclosed to X in this box. the manufacturer, place an If Also reported to 4 " distributor ' I j [ | Submission of 3 report does not constitute an admission that medical personnel or the product caused or contrit-uted to the event. ADVICE ABOUT VOLUNTARY REPORTING How to Report experiences with: • medications (drugs or biologies) • medical devices (including • special nutritional products (dietary supplements, medical foods, infant formulas) • other products regulated by Report is SERIOUS adverse in-vitro diagnostics) FDA death • life-threatening (real risk of dying) • hospitalization • disability (significant, persistent or (initial or prolonged) permanent) • attach additional blank • use a separate form • report either to in fill all FDA products except pages needed each patient if for or the manufacturer (or both) to FAX report modem • 1-800-FDA-7737 to report by • 1-800-FDA-1088 to report by phone or for more information congenital anomaly • required intervention to prevent permanent Report even use section C for medical devices Important numbers: • 1-800-FDA-0178 • impairment or • An event outcome is: • the sections that apply to your report just events. serious wlien the patient report: • • fora VAERSform for vaccines 1-800-822-7967 damage If your report involves a serious adverse event with a device and occurred m a facility outside a doctor's office, that facility may be legally required if: it • you're not certain the product caused the event • to report to you don't have all the person the details Report product problems - quality, performance or safety concerns such as: FDA Confidentiality: The patient's confidence by FDA and protected • suspected contamination the law. • questionable self-reporter, • defective components poor packaging or labeling • therapeutic failures The identity The public reporting burden tor this collection of information has been estimated to average 30 minutes per response, including the time tor reviewing mstructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of informationSend your comments regarding this burden estimate or any other aspect of this collection of information, including suggestions lor reducing this burden to; held in strict reporter's identity, including the identity of a may be shared Reports Clearance Officer, PHS Hubert H. Humphrey Building, Room 721-B 200 Independence Avenue, S.W. Washington, DC 20201 and ATTN PRA Washington. DC 20503 Please do to: and Budget Paperwork Reduction Project Office of lyianagement return U S Please Use Address Provided Below - Just Fold In DEPARTMENT OF HEALTH AND HUMAN SERVICES Thirds, Tape • Food and Drug Adminislfalton and Mail NO POSTAGE NECESSARY IF MAILED IN THE UNITED STATES Public Health Service Food and Drug Administration MD 20857 Official Business Penalty for Pnvate Use $300 form these addresses. Department of Health and Human Services Rockville, NOT tfiis to eitfier of (0910-02911 Public Heaitii Service FDA Form 3500-back is to the fullest extent of with the manufacturer unless requested otherwise. However, FDA will not disclose the reporter's identity in response to a request from the public, pursuant to the Freedom of Information Act. stability • and/or the manufacturer. Please notify who would handle such reporting. in that facility OR APO FPO BUSINESS REPLY MAIL FIRST CLASS MAIL PERMIT NO. 946 ROCKVILLE, MD POSTAGE WILL BE PAID BY FOOD AND DRUG ADMINISTRA TION lEI^TCH The FDA Medical Products Reporting Program Food and Drug Administration 5600 Fishers Lane Rockville, MD 20852-9787 ||||,|||,Mlllllllllllllllllliili.lllMMllilllllll Nol-for-profil organizations are offered a free adverliscmenl of up to eight lines lo appear, Respiratory Care Ads months preceding 1 the for other meetings are priced at $5,50 per line month 1030 Abies Lane, Dallas basis, in is Calendar of Exents the 20th of the hich you wish the ad to run. Submit copy and insertion orders to Calendar of Events. in v, TX on a space-available and require an insertion order. Deadline Calendar of Events in month two RESPIRATORY CARE. 75229-4593. AARC & AFFILIATES Health Law and Organizational Behavior) of the Management Training Institute (MTl) Independent Study Program February 20-23 in Reno, Nevada. The NSRC and the American Lung Association of Nevada host the 15th Annual High at the Peppermill Hotel and Sierra Critical Care Conference Casino. The conference covers critical care topics of Nevada. PO NV 895 . MTI versity. is an 8-module program of the Sign up now to earn the MTI Certificate Development. Call Barbara Hakes April is AARC and Indiana Uni- at Management in (317) 274-4475. in adult, pediatric, and neonatal medicine. Contact Sherry Landis, Box 7036. Reno I ALA OTHER MEETINGS 10. Baltimore, Maryland. The Johns Hopkins Southshore Lake Tahoe, California. Chapter 9 of the CSRC presents the KSlh Annual Tahoe Conference. "Setting the Sails into the Winds of Change," at the Em- March 13-14 in bassy Suites. CRCE credit has been requested. Call Johns Hopkins University School of Medicine's Turner Auditorium. Topics include sleep-disordered breathing, pulmonary March LV-15 lego. (510) in Kathy Gal- 947-5375 or George Rice. (510) 947-5292. Hospital Department of Respiratoi-y Ciue presents a 2-day seminar, "Lectures in Adult and Pediatric Respiratory Care," management of acute lung April 18-19 in Palm Springs, CSRC presents "Bright California. Chapter 2 of the Horizons in Respiratory Care." Hyatt Regency Suites. Presentations include at the New Modes of injury, nitric oxide. Joint at Com- mission preparation, and liquid ventilation. The seminar approved for at 1 2 hours of CRCE credit. Contact Debora is Brown (410) 955-9276. Mechanical Ventilation, Invasive Pulmonology. and Clinical Application of Metabolic Monitoring. been requested. Contact CRCE credit has Tom Taylor at the following phone/fax number: (909) 777-3214. March tact the May 24 New Hampshire Society in Weirs Beach, New Hampshire. The for Respiratory Vermont- Care presents its . Mount Washington. tact Bill Hay at ALA of Montana, 825 Helena Ave, Helena MT 59601, (406) 442-6556. fax (406) 442-2346. "CE (Continuing Education) Cruise. .IV" aboard the Motor Vessel 28-30, 1996 at Big Sky, Montana. The American Lung Association of Montana announces the 15th Annual Big Sky Pulmonary & Critical Care Medicine Conference. Con- CRCE credit has been requested. Con- (603) 267-7406. April 9-15, 1996 in Miami, Florida. The Ventilation Assisted Children's Center (VACC) of Miami Children's Hospital Division of Pulmonology announces its free camp for ventilation-assisted children and their families. Activities conjunction with the University of Texas Health Science swimming, games, arts, and crafts. The application deadline for overnight campers was January 5, San Antonio, and Wilford Hall Medical Center, an- 1996. Contact Director Moises Simpser or Coordinator Cathy May 24 in San Antonio, Texas. The TSRC (Alamo District), in Center at nounce the at the 1st Annual Riverwalk Respiratory Symposium Marriott Riverwalk. Topics include the future of res- piratoi7 care, the impact of managed protocols, and sleep studies. ed. care, implementing RC include field Klein, trips, VACC, Hospital. Division of Pulmonology, 3200 SW 60th Ct, Suite 203. Miami Children's Miami FL 33155- 4076, (305) 662- VACC, fax (305) 663-8417. CRCE credit has been request- Contact the University of Texas Health Science Center San Antonio. Department of Respiratory Care, 7703 Floyd Cud Dr., San Antonio TX 78284-7784, (210) 567-3706. at May 10-15 in New Orleans, Louisiana. The American Lung Association/American Thoracic Society hosts ternational Conference. The its annual In- conference features informa- on the prevention, control, and management of lung disease. For more information, write to the 1996 Internationtion May 1-June 30 — Management Training deadline to enroll in Module Managerial Accounting Part Respiratory Care • 2 1 ) Institute. The (Communication Skills and and Module 6 (Business and February '96 Vol 41 No 2 al Conference, ALA/ ATS, 1740 Broadway. New York, NY 10019-4374. 159 Authors in This Issue Anderson, Wayne C 142 Mathewson, Hugh S R 123 Meliones. Jon 100 Palmisano. John M 1.^4 Ravenscrat't. .Sue A Black. Donald Chatburn. Comroe Roben L Jr. Julius H Haines. -Stephanie Kall.strom, Thomas Kern, Frank J H Trant. Charles 113 Volsko. Teresa To advenise RESPIRATORY Carf, in RESPIRATORY CaRK's Marketing RHSPIRATORY CarF's Marketing 19 Call (800) 962-1266 Circle Reader Service No. 155 Call (800) 2.s.S-ft773 1 Inc. Rcptoduetion Caki-. photocopy material in this in part is granted. without permission, quote up to .SOO words of material in vided the quotation is for Golclshury. 20 Tradcwinds Circle. Tcqutrsla is h> without the Bmkle>. Anyone may. this journal pro- Cark is publisher. .Single reprints are available only from the authors. Reprints lor commercial use may be purchased from Dacd. litis Enlerprises Inc. made payable I 10.30 e.xpiessed in any article or editorial are those Care (AARC). or Daedalus Neither are the Editors, the AARC (407) 745-6793. al is S9 Call (8(X)) 3.'56-8874 Cover 4 to Call (800) 325-7472 RKSPIRAToRV Cark and Si liSCRIITlON K.vil.s TX sent to the subscription office at 75229-4503, reduced lOR .VSSOCIAUONS. All RESPIRATORY Cark rate. The members; $5.50 rates based on membership for .501-1.500 are: members: $5 may members association subscriptions of individual to its $6 per year for for 1.501-10.000 a members: at (214)243-2272. \N(;k of label ) .\1)[)RKSS. Notity in Rfspira iokn Carf and your name, old address, change. To as soon as possible of number (from the mailing and new address. Allow 6 weeks tor the address. Note the subscription avoid charges for replacement copies of missed issues, requests must be made w ithin 60 days in the US and 90 days in other countries. or the Publisher The .lournal publishes clinical studies, method/device Manfscrii'IS. methods or devices described evaluations, reviews, and other materials related to cardiopulmonary any at 101-500 responsible for the consequences of the clinical applications or use of any in otter $4 for more than 10.000 members. For information, contact Ray Masferrer C'll of the author and do not necessarily retlect the views of the Editors, the Respiratory .13469 (2141243-2272. Fax (2141484-6010. Dale Grilfilhs ,il Abies Lane. Dallas any change for FL For recruitnicni/classified advertising contact kits. For information and prices call (214) 243-2272. American Association and media prohibited. noncommercial use and Rhspiratorv The opinions rates Sherwood Medical Longer quotation requires written approval by the author and Inc. 123 Nonin Medical. Inc Journal for noncomtnercial purposes of scientific or educational advancement Enterprises 100 12. 1 Circle Reader .Service No. 104 ctipyrighicJ is whole or in express written permission of Daedalus Enterprises Inc Dl.si 1..M.M1-.R. A G Director. 82 Coi'^Kii.HT Information. Rispiratok'i credited. 98 113 Circle Reader Service No. 99 Nellcor Puritan Bennett Daedalus Enterprises Tim Assistant. Belh 87 HealthScan Products hic Circle Reader .Service No. contacl Fax (407) 74.^-6795. email: timo2 [email protected]. for This Issue to 12 105 142 Advertisers Permission 1 Wilson. Barbara 98 Kittredge, Phil in Sloller, 100 33 112. 113. 123 K A James 142 Lucy Kester. 1 N article or advertisement. med- and research. Manuscripts may be submitted to the Editorial Office. RliSPIR.vroRY CakF. 110.^0 Abies Lane. Dallas TX 75229-4593. icine St H.S( UIIMION R.\rKS. Individual subscription issues), $125 for 2 years, and $185 rales are for 3 years in the $6? per year (12 US and Puerto Rico. Rates are S80 per year. SI 55 for 2 years, and $230 for 3 years in countries (add S84 per year for air mail). Single copies when $5; add $7 lor air mail postage to overseas countries. 160 all other Instructions for authors are printed in every issue. the Instructions is An expanded version of available from the editorial office. available cost Checks should he Ciipyhghl RESPIRATORY Care © • ]995. by DaaUitiis Eiueri>rises Inc. February "96 Vol 41 No 2 5 . RE/PIRATORy CARE Expires 5/31/96 February 1996 Reader Service Reply Card Phone. Name Institution Street City/State/Zip , For faster service, FAX to (609) 786-441 : NO POSTAGE NECESSARY IF Authors in This Is Anderson, Wayne C R MAILED IN THE UNITED STATES BUSINESS REPLY MAIL .. Black. 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Single reprints comnieicial use inforniali<in may and prices be _ | call CII.WCK Ol (214) 243-2272. UlstT,.\lMER. The opinions expressed in any article or editorial arc those of the author and do not necessarily rellect the views of the Editors, the American Association for Respiratory Care (AARCl, or Daedalus Enterprises hic. Neither are the Editors, the AARC in any $125 for 2 years, and $185 for 3 years in the US S{i5 per year when $5; add $7 tor air mail postage to overseas countries. 160 ( I 2 and Puerto Rico. Rates are $80 per year, $155 for 2 years, and $230 for 3 years countries (add S84 per year for air mail). Single copies as .soon as possible of musi be made « ithin 60 days in the US and QO days in other countries. M..\M SCRIPTS. The Journal publishes clinical studies, inelhod/device and other materials related to cardiopulmonary medicine and research. Manuscripts may be submilled to the Editorial Olhce. RESPIRATORY Cark. 11030 Abies Lane. Dallas TX 75229-4593. ev ablations, reviews, article or advertisement, SllSSCRlI'llON K.VIKS. Individual subscription rates are issues), CarH in address. or ihc Publisher responsible for the consequences of the clinical applications or use of any methods or devices described RliSPIR.MOR'i .\l)l)Rt.ss. Noilly Note the subscription number (from the mailing label) and your name, old address, and new address. .<\llow 6 weeks for the change. To avoid charges for replacement copies of missed issues, requests any change in all other Instructions for authors are printed in every issue. (he Instructions is An expanded version ol available from the editorial office. available cost Checks should be Cojnrighl RESPIRATORY CARE © • 1995. by Daedalus Enterprises Im. FEBRUAR'i '96 VOL 41 NO 2 fo SciN Ol%q9^ €nllhml9 San Diego, Califomia...a picture-perfect vacation destination where you can explore the ocean depths of Sea Worldf go wild at the world famous San Diego Zoo, head south of the border to Tijuana, kick back and enjoy the sun-bleached beaches of Mission Bay, and partake of the exciting AARC Annual Meeting. To picture yourself in this exciting vacation package, circle number 84 on the reader service card in this issue, request any other material you might like to receive, complete the requested information, and mail the card. / Your picture-perfect vacation includes: Round-trip air transportation to San Diego for two, 4 nights hotel accommodations, including room San Diego hotel, November 2-5, 1996 November tax, at 2-6, 1996 a selected Admission to the AARC Annual Meeting, November 3-6, 1996 (Sunday-Wednesday) circle number 84 on the reader service request any other material you might like to receive, then complete your name, address, telephone number, and other information requested. Mail the postage-paid card to AARC Publications, P.O. Box 11605, Riverton, NJ 08076-7205. Entries must be received no later than midnight September 1 1996. Prize is valid for travel only November 2-6, 1996. Entrants must be at least 1 8 years of age. Illegible entries will be disqualified. AARC Tunes and Resperatory Care* are not responsible for late, lost, damaged, or misdirected mail. The winner will be selected in a random drawing at Daedalus Enterprises, 11030 Abies Lane, Dallas, TX 75229-4593 on or about September 5, 1996. Federal, state, and local taxes are not included in prize package. Meals, gratuities, and all other expenses not specified herein are the responsibilities of the winner. Void where prohibited by law. and all federal, state, and local laws apply. NO substitution for prizes. Prizes are not transferable and are not redeemable in cash. The winner will be notified by mail or telephone. Official Rules: card No purchase necessary. To enter, in this issue, , Circle 84 on reader service card INTRODUCING NEW Technologies 3 in Arterial Blood Sampling Arterial Blood NEW, Advanced ASPIR-PULSE Patented design improves filling for Gas Svst Syringe both Aspiration and Pu/sation techniques NEW, Purge Guard^ One-Handed Needle Venting System Safety Patent-pending design allows to immediately Guard other Purge the needle point hand NEW, OneHanded Air Bubbles, and immediately to apply pressure at the Total operation immediately free the puncture site Ca++ LyteTM Precision Heparin A breakthrough patented heparin to maximize the precision of test results obtained from the care blood gas and critical new critical- analyte analyzers See your Sherwood Medical OR /Critical Care Sales Representative or call 1-800-325-7472 for a complete Arterial Blood Gas Kits. listing of ASPIR-/'i//xe'" O ' 994 Sherwood Medico) Company A Sheriuaad MEDICRI ^^ MO ST tnuiS. 63103 USA. Circle 104 on reader service card

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