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117 Resident Handbook Updated January 2001 Pediatric Anesthesia RESIDENT HANDBOOK Written, Compiled, and Edited by Michael L. Schmitz, M.D. Copyright Resident Survival Handbook © 2000 The University of Arkansas for Medical Sciences Arkansas Children’s Hospital April, 2000 Resident Handbook 116 TABLE OF CONTENTS Page # I. II. III. IV. V. VI. VII. VIII. IX. Introduction Preoperative Evaluation & Management A. Gather Information Verbal & recorded history Optimize medical therapy Recognize stress on family B. NPO How long and for what? Timing Infants & neonates Transpyloric feeding tubes C. Premedication Premed or not to premed? Mode of administration Uncooperative patients Behavioral intervention Informed Consent Method of interaction What to tell the child Special Techniques Reassurance The Operating Room & Monitoring Induction & Maintenance of Anesthesia A. Clinical monitoring B. Airway & ventilation C. Fluids D. Conduct of the anesthesia team PACU Postoperative Visit Pain Management Conclusion i. 1 1 1 2 3 3 4 4 5 5 5 6 6 7 7 7 7 7 8 9 10 12 13 14 15 16 17 115 Resident Handbook X. Page # Appendices: Appendix A--Common Drug Dosages Appendix B--Fluid Replacement Appendix C--Airway Equipment Appendix D--Blood Components Appendix E--Pain Management Guidelines Appendix F--QI Chart Requirements Appendix G-- Outline of Preop Note Appendix H--Machine/Room Preparation Appendix I--Inhaled Anesth Characteristics Appendix J--Normal Vital Signs 31 Appendix K--Adrenocorticosteroids Appendix L--Laboratory Values 36 Appendix M--Malignant Hyperthermia Appendix N-- Preparation Protocol For MH Sensitive Cases Appendix O--Dermatomes Appendix P--CV Drug Infusions Appendix Q--Pulmonary Gas Exchange Appendix R--Compressed Gas Characteristics Appendix S--Resuscitation Appendix T--SBOS for Pediatric Patients Appendix U--Body Surface Area Nomogram Appendix V--Initial Fluid Therapy/Burns Appendix W--ASC NPO Instructions Appendix X--Policy/Lower RT Infections Appendix Y--Caudal Handout Appendix Z--Breaks and Lunch Relief Appendix AA--Sickle Cell Transfusion Protocol 61 Appendix BB--Endocarditis Prophylaxis 62 Appendix CC--ACH Staff Appendix DD--Miscellaneous Phone Numbers Appendix EE--Formulary Appendix FF--Regional Anesthesia ii. 18 20 21 22 23 26 27 28 30 34 42 44 45 46 46 51 52 53 55 55 57 58 59 60 66 67 68 74 1 Resident Handbook I. INTRODUCTION This manual is intended to serve as a guide for residents who are rotating in pediatric anesthesia at Arkansas Children’s Hospital. It is my intention that the information contained in this manual will reduce the stress associated with being a new resident on this rotation. It is by no means meant to be a comprehensive reading of all one needs to know about pediatric anesthesia. Contained in it are nuts and bolts information assembled to facilitate getting the usual work of the day finished. Remember, if you are ever unsure of the manner in which to proceed, talk to an attending, especially for activities outside the OR. “It is my belief that the attending anesthesiologist should be apprised of all procedures done by residents while at Arkansas Children’s Hospital. This certainly includes procedures in the operating room, as well as significant procedures out of the operating room, such as intubating patients in the intensive care unit, the burn unit, or the neonatal intensive care unit. If there is any question in your mind about whether or not you should call your attending, please err on the side of making them aware of what is going on in the hospital.” Raeford E. Brown, Jr., M.D. December 14, 1994 II. PREOPERATIVE EVALUATION & MANAGEMENT A. THE GATHERING OF INFORMATION VERBAL HISTORY: The resident must play an active role in gathering all the pertinent information in an organized manner that is essential for the preoperative evaluation. The best circumstance occurs when the resident during the preoperative evaluation will also be the resident performing Resident Handbook 114 113 Resident Handbook Resident Handbook 2 the anesthesia. The work-up consists of a medical history which includes: history of present illness, past medical history, past surgical and anesthesia history, allergies, medications, a brief review of systems, such as has the child had a recent URI or other acute illness on top of the present illness. A family history of anesthetic complications, a social history which includes use of alcohol, recreational drugs, and sexual activity. Often the tendency is to forget that when one is at a children’s hospital there are teenagers who engage in recreational drug activities or who smoke, drink, or are sexually active. Usually a urine or serum beta HCG screen is obtained for any postmenarchal female patient. This is more reliable than taking an accurate sexual history from a teenaged person. RECORDED HISTORY: Also important in gathering information is the review of old medical records. These records may be requested to the anesthesia work room or to the floor where the child is admitted. A brief scan of these records will reveal whether that child had any anesthetic difficulties during previous surgical procedures. Information may also be obtained from the hospital computer system. Information such as echo cardiogram reports, dictation’s from prior chest x-ray’s, CT scans, or MRI scans may be available there also. All residents will have a password to access the hospital system for this information. The information may be printed in hard-copy form by specifying “OR2.2” behind the command “print on.” This information will then be printed on the OR work room printer. OPTIMIZE MEDICAL THERAPY: In addition to gathering and organizing information, it is also essential to optimize the patient’s medical therapy. This may include prophylactic nebulizer treatments for an asthmatic, SBE prophylaxis, or stress-dose steroid administration. Depending on the medical therapy, the anesthesia resident may chose not to write for this alone, but may consult with 3 Resident Handbook the attending anesthesiologist and/or the staff of the service to which the patient belongs. ESTABLISH RAPPORT: It is essential that the preoperative visit be used to establish rapport between the child and the anesthesiologist, as well as between the family and the anesthesiologist. It is best when the child has a sense of trust when they separate from their family and enter a room full of strangers. This may be facilitated with an established relationship with the anesthesiologist, who may be the only person in the OR they have met previously. Active resistance to the anesthesia process by the child due to behavioral distress can be hazardous to the child as well as the anesthesiologist. The child needs to be reassured that they will be taken care of and be given medicine for pain and for anxiety. They also need to be reassured they will be able to see their parents again soon. RECOGNIZE STRESS ON FAMILY: Often times, the patient and the family are very anxious during the preoperative period. It is during the preoperative visit that reassurance and information may be relayed to the patient and family to allay anxiety. It is unfair to the family for them to miss out on the preoperative evaluation. Families that are extremely stressed may also require a very patient and empathetic approach to their situation. B. NPO How long a child is made NPO is dependent upon many considerations. The age of the patient is important because metabolic rates are different, and the frequency in which they eat is markedly different. For example, a neonate may breast feed every 2-3 hours whereas a 7 month-old child take formula every 4-6 hours. What kinds of food or fluids are being taken in is also important to gastric emptying. Solid food tends to stay in the stomach longer than noncarbonated, clear liquids. Our present guidelines are as follows: Resident Handbook 112 111 Resident Handbook Resident Handbook 4 Inpatients ASC Patients Infants 0-6 mon formula/food 4 hr clear liquids 2 hr See Appendix Children 6 mon-2 yr food 6 hours clear liquids 2 hr Children > 2 yr food8 hr clear liquids 2 hr V Clear liquids are acceptable in quantities of 8 ounces within the 2 or 3 hours prior to surgery. TIMING: It is important to note that the OR schedule is extremely variable and just because a patient is scheduled at 4:00 pm does not mean that they will not be advanced on the schedule. They may actually go to the OR at noon or even 7:30 a.m. If it is unclear exactly when the patient will come to the operating room, as it usually is, then the resident should either consult with their staff about when to make the child NPO or make the child NPO for the earliest possible OR time. Feeding orders can always be changed the morning of the surgery if it looks like the case will go later in the day. All Dr. Bower’s inpatients for ENT surgery should be NPO for solids and nonclear liquids after midnight. INFANTS & NEONATES: Infants and neonates have limited glycogen stores and require more frequent feeding. Certainly, newborn infants and babies that are small for gestational age or premature may require an IV glucose source. These babies could possibly become hypoglycemic during an NPO period of even a few hours. For these instances, consultation with the attending anesthesiologist would be appropriate. This may also be applicable to children with certain types of metabolic disorders characterized by impaired glucose homeostasis mechanisms. 5 Resident Handbook TRANSPYLORIC FEEDINGS: In general, patients with transpyloric feeding tubes have had the feedings discontinued for 2 hours prior to surgery. This is meant to minimize accumulation of fluids in the stomach that may reflux back through the pylorus from the duodenum. When evaluating a patient with a transpyloric feeding tube, it is important to document that the tube indeed still is in the duodenum and is transpyloric. This may be done by checking a recent (ie, within 24-48 hours) chest x-ray or KUB. When minimal interruption of feeding is essential, such as with burn patients, it is acceptable to order a film to confirm that the feeding tube is still beyond the pyloric sphincter. C. PREMEDICATION TO PREMED OR NOT TO PREMED?: When assessing children preoperatively, one must decide first of all if they need premedication or not. Teenagers who have been to the operating room on a number of occasions, may feel entirely comfortable entering the OR without any premedication at all. However, the majority of teenagers and children, just as with adults, do require some type of anxiolysis prior to entering the operating room environment. Anxiolysis need not always be pharmacological. (See Behavioral Intervention, below) MODE OF ADMINISTRATION: The mode of administration of premedication is important for both reasons of cost and stress to the patient. Medications which are given PO require larger dosages due to the first pass effect of hepatic extraction and are therefore, more expensive. Medications given IV, IM, or SC require lower doses and are less expensive, but frequently are more stressful to the patient since they need a “shot.” In appropriate patients, we typically give midazolam PO at a dose of 0.5 mg/kg (up to a maximum of 15 mg) 15-30 minutes prior to entering the operating room. If the patient already has an IV in place, we typically use midazolam by the intravenous route. Resident Handbook 110 Cook, D. Ryan and Peter J. Davis: "Pharmacology of Pediatric Anesthesia" SMITH'S ANESTHESIA FOR INFANTS AND CHILDREN Fifth Edition, Mosby 1988 Fisher, Quentin A., et. al. Postoperative Voiding Interval and Duration of Analgesia Following Peripheral or Caudal Nerve Blocks in Children. Anesthesia and Analgesia 1993;76:173-177 Gunter, Jowl B., et. al. Optimum Concentration of Bupivacaine for Combined Caudal-General Anesthesia in Children. Anesthesiology 1991;75:57-61. Rice, Linda Jo and Raafat S. Hannallah: "Pediatric Regional Anesthesia" SMITH'S ANESTHESIA FOR INFANTS AND CHILDREN Fifth Edition, Mosby 1988 Sartorelli, Kennith H., et. al. Improved outcome Utilizing Spinal Anesthesia in High-Risk Infants. Journal of Pediatric Surgery 1992;27:no.8 1022-1025 Sethna, Navil F. and Charles B. Berde: "Pediatric Regional Anesthesia" GREGORY'S PEDIATRIC ANESTHESIA Second Edition, Churchill-Livingston 1989 Sethna, Navil F. and Charles B. Berde: "Pediatric Regional Anesthesia" GREGORY'S PEDIATRIC ANESTHESIA Third Edition, Churchill-Livingston 1994 Small, George A. Brachial Plexus Block Anesthesia in Children. Journal of the American Medical Association 1951;147:17 16481651. Verghese, M. D., et. al. Pediatric Caudal Anesthesia: Volume vs. Concentration As Determinants Of The Level Of Blockade. Anesthesiology ASA Abstracts 1992,77:3A A1157. 109 Resident Handbook any other block to cause toxicity. Being careful to not exceed the recommended safe total doses of anesthetics, and utilizing epinephrine containing solutions should attenuate the chances of this occurring. subarachnoid/total spinal block this is more likely with the paravertebral approach, as the dura invests the rib heavily, especially in children. This can be avoided by not injecting too close to the vertebral bodies. infection hematoma INFILTRATION ANESTHESIA The use of either pre-incisional or post-incisional infusion of local anesthetics greatly decreases the requirements in the immediate post operative period for narcotics and other analgesics. The concept of pre-emptive analgesia is too broad to cover here, but may indicate that infusion prior to incision may also decrease the long term narcotic/analgesic requirements by ablating the development of pain pathways. Most surgeons are happy to inject local anesthetics to help with their patients postoperative pain control. Remember to assist the surgeon with maximum dose recommendations and note the total doses administered to avoid toxic reactions. Regional anesthesia is one of the most satisfying techniques to the patient, surgeon (they like happy patients) and anesthesiologists, and once mastered are easy and safe to perform. Happy "blocking", but always be safe first for the patient's sake. REFERENCES: Alifimoff, James K. and Charles J. Cote: "Pediatric Regional Anesthesia" in Cote, Ryan, Todres, and Goudsouzian's A PRACTICE OF ANESTHESIA FOR INFANTS AND CHILDREN Second Edition, Saunders 1992 Arnett, Robert M., et. al. Effectiveness of 1% lidocaine dorsal penile nerve block in infant circumcision. American Journal of Obstetrics and Gynecology 1990;163:3 1074-1078. Broadman, Lynn M. Pediatric Regional Anesthesia Clinical Anesthesia Updates 1992;3:2 1-14. Resident Handbook 6 Dosages vary and are dependent upon what other drugs the patient has on board and if the patient has a history of adverse reaction to benzodiazepines. An intravenous dose of midazolam of 0.075 to 0.15 mg/kg may be considered for a healthy patient who has received no respiratory depressant medications. UNCOOPERATIVE PATIENTS: There will be circumstances such as with mentally retarded young adults or teenagers where administration of an oral premed or placement of an IV is impossible. Sometimes premedication to these patients may be given via the SC or IM route utilizing midazolam or another drug such as ketamine in a dose of 2 - 4 mg/kg. The attending anesthesiologist should be notified of these instances so that a plan of action can be formulated. BEHAVIORAL INTERVENTION: Something that the resident will experience at Children’s Hospital is a concept known as behavioral intervention. Children are very distractible and may have considerably less anxiety when they are busy with an activity. The Division of Pediatric Anesthesia has purchased a number of behavioral intervention tools (which the child sees as toys) to be used in distracting children during times in which they need an IV placed or need to be separated from parents or taken into a strange environment. Such behavioral intervention tools include toys that make music, storybooks, bubble blowers, head phones, etc. Behavioral intervention is not a substitute for premedication, but an adjunct. However, some children may not require premedication if provided with behavioral intervention. Selection of premedication and behavioral intervention is an art to be learned by the anesthesiologist who provides for pediatric patients. We encourage residents to learn as much about it as they can during this rotation. Resident Handbook 108 7 Resident Handbook Technique III. INFORMED CONSENT METHOD OF INTERACTION: When speaking with families and patients about the risks and benefits of anesthesia, it is important to use the appropriate tone. By this, I mean taking care not to sound cold and calculating speaking with an already frightened patient and family. One’s approach to explanations of risks and benefits needs to be modified to the level of anxiety and educational background of the parent and child. WHAT TO TELL THE CHILD: It is best to involve the child in the discussion about the anesthesia and in the description of exactly what will happen to them when they come down to the operating room area. Children of school age should be asked if they have any questions or fears about the anesthesia since they feel they are part of the decision making process. It is especially important to reassure the child that they will not “wake up” during the procedure, and that they will awaken at the end of the procedure. Children are most afraid of pain when presenting for a procedure. It is important that accurate explanations of what will be done both when the child is awake and asleep be given to the family. For instance, the knowledge that the IV will be placed when the child is asleep is especially comforting to the child. SPECIAL TECHNIQUES: Discussion of invasive monitoring and regional anesthetic techniques as well as postoperative pain control measures that may be instituted by the Pain Management Service should be discussed. Parents’ opinions about postoperative pain management should be sought. REASSURANCE: Most importantly, the family needs to be assured that good care will be taken of their child in the operating room. Frequently, this is the only time during their child’s illness that the parent is not allowed to be with them. Parents also need to be assured that an attending pediatric anesthesiologist will be present during their child’s anesthetic. Technique of posterior intercostal nerve block. Either a paravertebral or mid axillary block can be performed. Perpendicular to the middle of the rib wall, insert the needle and advance until the rib is contacted. Walk the needle inferiorly and carefully advance until the needle is walked off the rib. Further advancement of the needle by 2-3 mm should be met with a distinct pop. Aspirate and inject the local anesthetic. Medications Each intercostal nerve block anesthetizes 1-3 dermatomes on either side. Use 0.08 ccs of epinephrine containing local anesthetic for each block, being careful not to exceed the total safe amount of local anesthetic. Complications pneumothorax is more likely with the midaxillary approach than the paravertebral, but it is usually small and does not often require treatment. A post-block chest film is indicated in all patients who receive intercostal nerve blocks. systemic toxicity for reasons mentioned above, this procedure is more likely than Resident Handbook 8 107 Resident Handbook All attempts will be made to answer the parents’ questions about the anesthesia prior to coming to the operating room. TABLE.: Recommended Doses for Penile Block in Infants and Children Study Soliman & Tremblay Bacon Kirya & Werthmann Carlsson & Svenssor 104 Lau a Plain Anesthetic Solution Age 4 months-8 years 3-12 months 1-5 years 6-12 years 13-40 years 2-3 days 1-15 years 2-5 years 6-10 years Bupivacaine 0.25% Bupivacaine 0.5% Bupivacaine 0.5% Bupivacaine 0.5% Bupivacaine 0.5% Lidocaine 1% Bupivacaine 0.25% Bupivacaine 0.5% Bupivacaine 0.5% Duration of Analgesia Dose 0.54 mg/kg (mean) 1 ml 3 ml 4 ml 5-7 ml 0.5 ml 0.38 mg/kg (mean) 2.5 ml 5 ml a 6 hr 6 hr 6 hr 6 hr 6 hr 30 min 4-24 hr 6-12 hr 6-12 hr Maximum of 12.5 mg. Complications There has never been a serious complication reported from performing the subcutaneous ring block to date. The following are potential or reported complications with both techniques; pressure induced compression of the dorsal penile vessels infection hematoma intravascular injection gangrene of the tip of the glans very rare INTERCOSTAL NERVE BLOCKS These blocks are ideal for postoperative analgesia for thoracotomy patients, patients who have had upper abdominal procedures, and patients with rib fractures. Intercostal nerve blocks optimizes postoperative pulmonary function superiorly to narcotics alone, but there is a higher and more rapid resorption of local anesthetic than with any other nerve block. The plasma concentration rate of rise of local anesthetic is even more rapid in children than adults, so addition of vasoconstrictors is imperative, as well as limiting the total dose of local medication. Anatomy The intercostal nerves traverse on the inferior aspect of the rib in a neurovascular bundle with the intercostal artery and vein. The rib is invested with both dura posteriorly and pleura antero-posteriorly. IV. THE OPERATING ROOM AND MONITORING When the patient comes to the holding area, it is important that the chart be checked for new information about the patient that may be pertinent to the anesthetic. It is also very important that the patient’s identification bracelet be checked and confirmed, especially if the anesthesiologist providing the anesthetic is not the same person as did the preoperative examination. The anesthesiologist taking care of the child will have personally checked the equipment needed for induction and maintenance of anesthesia. This includes suction, monitoring devices, and all other equipment. The degree of monitoring is modified based on the child’s clinical condition and the surgical procedure. For all cases, basic monitoring is essential and includes: observation of patient’s color and chest movements auscultation of heart tone and breath sounds palpation of the arterial pulse (occasionally) a precordial stethoscope continuous ECG temperature inspired or expired oxygen concentration and alarms intermittent blood pressure monitoring exhaled carbon dioxide monitor In addition, all children except for those having the briefest of procedures should have an intravenous line placed which allows replacement of the fluid deficit and allows for rapid and reliable drug administration. Arterial cannulation may be beneficial under circumstances where one anticipates extensive or sudden blood loss or fluid shifting. It is also important for patients who are medically unstable and require continuous rather than intermittent Resident Handbook 106 9 Resident Handbook penile nerve block measurement of blood pressure. It is also useful in patients that require frequent blood sampling during the surgical procedure especially for those patients with difficult vascular access. Central venous pressure monitoring is used less often but may be quite useful in cases involving extensive blood loss and fluid repletion. Pulmonary artery occlusion pressures obtained with the Swan-Ganz catheter are rarely used at this hospital. However, they are indicated in cases where the dynamics of the heart cannot be predicted merely by measurement of preload (CVP) and afterload (systemic blood pressure). The urinary catheter can provide good data regarding the intervascular volume status of the patient. It also allows some prediction regarding organ perfusion since it is a measurement of kidney perfusion. It is quite useful for procedures that are very long which would otherwise result in a full and distended bladder or procedures in which blood loss is extensive and verification of fluid repletion may be obtained by measuring urine output. Most importantly the focus of monitoring should be on the appearance of the child. Frequently residents in training spend too much time looking at the monitors and trying to interpret the monitors rather than looking across the screen directly at the patient. V. INDUCTION AND MAINTENANCE OF ANESTHESIA Penile block. A 23- to 25-gauge needle is inserted in the midline, 1 cm above the symphysis pubis at an angle of 30º and directed caudad. After piercing the penile fascia (0.5-1.0 cm) and negative aspiration for blood, 1 to 4 ml of local anesthetic without epinephrine is injected. Using a 22 gauge short bevel needle, the needle is inserted perpendicular to the skin above the symphysis pubis and walked inferiorly and directing the tip of the needle 2-3 mm laterally in a sagittal plane until off the bone and a pop is felt. Inject one-half of the medication. Then perform the same block directing the needle to the other side using the same needle hole. Alternatively, give one injection in the midline in the same manner. Although a fascial plane separates the two penile nerves, this technique is as effective as the two injection technique. A. CLINICAL MONITORING The cliché statement, “the child is not merely a small adult,” is based on significant differences that are found in the physiology and behavior of the child when compared to the adult. This is especially true of the newborn. Many of the differences that are seen in the physiology of the infant and child are based on the much higher metabolic rate of the child in comparison with the adult. As a result, anesthesia Medications *DO NOT USE EPINEPHRINE CONTAINING SOLUTIONS!!!* Bupivacaine 0.5% without epinephrine 0.1 ml/kg/side OR Lidocaine 1.0% without epinephrine 0.1 ml/kg/side 105 Resident Handbook Resident Handbook 10 induction and maintenance vary considerably from what is seen in adult patients. Also, behavioral differences in children may require a change in the plan of induction of anesthesia at the last minute. PENILE NERVE BLOCK The penile nerve block has many of the same benefits of the ilioinguinal/iliohypogastric nerve blocks in comparison to the caudal block. It is an ideal block to supplement general anesthesia for circumcision and hypospadius repair with benefits being a decreased requirement for general anesthetics, quicker emergence time, decreased recovery time, earlier discharge from the hospital, decreased requirements for postoperative pain medications, no delayed mobility or micturition, decreased total dose of local anesthetic in comparison to a caudal, and decreased nausea and vomiting. It is often used as the sole anesthetic for circumcisions done in newborns. The most important clinical monitors during the induction period are the senses of the anesthesiologist. During induction, the pediatric anesthesiologist is constantly observing the depth and symmetry of chest excursion, the color of the lips, oral mucosa and nail beds, as well as sometimes capillary refill. This provides information regarding ventilation and perfusion. In addition, the anesthesiologist is listening to the quality of the heart tones and the breath sounds through a precordial stethoscope which provides immediate information about heart rate and rhythm. The intensity of heart sounds gives some indication of cardiac output and changes in the intensity of heart sounds relate changes in cardiac output. In a similar manner, ventilation may be assessed. As a result arrhythmia’s, hypovolemia, anesthetic overdose, and airway obstruction may immediately be detected. When blood pressure monitoring devices fail, palpation of an arterial pulse can provide information confirming adequacy of cardiac output and heart rate. Peripheral temperature may also be assessed by merely touching the patient. Anatomy The 2 dorsal penile nerves are branches of the pudendal nerve (S2-4) that emerge from the pelvis covered by Buck's fascia under the symphysis pubis. They run alongside the dorsal penile arteries and veins deep to Buck's fascia. They provide sensory innervation to the glans and most of the shaft of the penis except the most proximal and scrotal portions (which are innervated by branches of the genitofemoral and ilioinguinal nerves). Technique There are two techniques to block the penile nerves: subcutaneous ring block - local anesthetic is injected circumferentially around the shaft of the penis with a small (27 or 30 gauge needle) Penile nerve block via the subpubic space approach in children. B. AIRWAY AND VENTILATION Infants and children have many unique characteristics regarding their airway in comparison with the adult. The infant and child’s airways are more prone to obstruction. A pediatric anesthesiologist is attuned to this propensity for obstruction and is adept at relieving causes of obstruction. Most morbidity and mortality in pediatric anesthesia is related to inadequacy of ventilation. A comparison between the neonatal and the adult airway reveals five areas of major difference. 11 Resident Handbook Resident Handbook 104 1) The tongue. The tongue of the infant is relatively large in proportion to the oral cavity. This results in two problems. The first is that the tongue more easily obstructs the airway in the neonate, and the second is that the tongue is more difficult to manipulate and displace to the side with a laryngoscope blade. 2) The position of the larynx. The adults larynx is located anterior to C4-5. However, the infant’s larynx is higher in the neck at approximately C3-4. This rostral displacement of the larynx in infants results in the tongue being closer to the roof of the mouth. The more superior location of the larynx and tongue creates more difficulty in visualization of the glottis. A straight laryngoscope blade allows better visualization of the glottis in neonates. 3) The epiglottis. In the adult, the epiglottis is broad and it’s axis is parallel to that of the trachea. When looking at the infant’s epiglottis, one finds that it is narrower, shorter, and is angled away from the axis of the trachea. This angulation causes the epiglottis to fold down posteriorly over the glottic opening when visualized through the laryngoscope. As a result, it is beneficial to lift the epiglottis with the laryngoscope blade in order to view the glottic opening. 4) Vocal folds. In the adult, the axis of the vocal folds is perpendicular to that of the trachea. This means basically that the vocal folds sit flat on top of the trachea at a right angle. In the infant, the vocal folds are angulated such that they slant inferiorly at the anterior attachment. This angulation often results in the tip of the endotracheal tube becoming caught at the anterior commissure of the vocal fold. 5) The subglottic area. The most narrow portion of the adult airway is the rimaglottidis. This means that any endotracheal tube that is able to pass through the glottis will pass into the trachea easily since the trachea has a larger diameter than the rimaglottidis. However, in the Ilioinguinal and iliohypogastric nerve blocks. The anterior superior iliac spine is palpated and a point 1.0 to 1.5 cm cephalad and toward the midline is located. A 22-gauge needle is passed through the external and internal oblique muscles, and 1 to 5 ml of local anesthetic is deposited in a fanlike fashion cephalad toward the umbilicus, medially, and caudad toward the groin. Just before removal from the skin, another 0.5 to 1.0 ml of local anesthetic is injected subcutaneously to block the iliohypogastric nerve. Using a 22 gauge short bevel needle, place it one of the patient’s width of their 5th finger medial and inferior to the anterior superior iliac crest perpendicular to the skin and advance until either a pop is felt or bone is met. If bone is met, withdraw 1-2 mm, aspirate and inject in a column to the skin about 2/3 of the local. Next, inject the remainder in a subcutaneous cuff towards the umbilicus using the same needle hole. Medications Each set of nerves can be consistently and successfully blocked with bupivacaine 0.5% with epinephrine in a dose of 1 mg/kg/side. Complications infection rare, transient paresis of the quadriceps muscles manifested as difficulty walking from femoral nerve blockade. This adverse affect can be decreased or abolished by using 0.25% instead of 0.5% bupivacaine. rare, transient paresthesia in the cutaneous distribution of the femoral nerve 103 Resident Handbook need for postoperative narcotics), earlier ambulation without the risk of motor blockade from a caudal, and lower doses of local anesthetic than a caudal thus decreasing the risk of systemic toxicity. In addition, there is practically no risk of intravascular injection. Anatomy The ilioinguinal (L1) supplies cutaneous sensory innervation to the scrotum and inner thigh. The iliohypogastric (T12-L1) supplies cutaneous innervation above the inguinal ligament. The sensory area supplied by these nerves receives a small contribution from the genital branch of the genitofemoral nerve. Both nerves pass in a plane between the transversus abdominus and the internal oblique muscles. The ilioinguinal becomes superficial at the inguinal ring and the iliohypogastric nerve becomes superficial earlier in its course and is located subcutaneously in the abdominal wall just lateral to the anterior superior iliac spine. Technique Resident Handbook 12 child, this is not the case. The narrowest portion of the child’s airway is the cricoid cartilage which is a nondistendible structure. This means that although an endotracheal tube may pass easily through the cords, it may fit tightly at the level of the cricoid cartilage. A tight fitting endotracheal tube may result in subglottic edema and narrowing of the airway. One mm of edema in an adult subglottic area may narrow the airway by 44%. However, in an infant 1 mm of edema, given the narrow diameter of the airway at this point, may reduce the cross sectional area by 75%. 6) Obligate nasal breathing. Another peculiarity pertinent to breathing in infants is that infants are obligate nasal breathers. This means that the infant preferentially breaths through its nose during periods of quiet respiration. At these times, the tongue actually rests against the roof of the mouth resulting or oral airway obstruction. Coordination of respiratory and oral function continues to develop in the infant for the first 3 - 5 months of life. After 3 - 5 months of age, the infant is able to coordinate breathing adequately through the mouth. This is why young infants with nasal obstruction due to URIs may have difficulty sleeping. If the nasal passages are obstructed, the only way they can breath is by opening their mouth and crying. C. FLUIDS Diagram showing the course of ilioinguinal and iliohypogastric nerve, the landmarks, and the needle insertion site. Fluid management is especially important in the infant and child. Infants and children have a relatively large surface area given their blood volume. As a result, insensible losses of fluids are relatively greater. As a result, the increase in venous capacitance that occurs from vasodilatation and the losses of blood during the surgical procedure may be more significant in a dehydrated infant or child. Repletion of fluid deficits must be done carefully. Occasionally, the liter of IV fluid that is hung above the OR table is actually greater in mass than the entire patient. 13 Resident Handbook Resident Handbook 102 Needless to say, fluid overload may occur easily from unregulated intravenous fluid infusion. For this reason, children who come to the operating room routinely, have their IV fluids placed and run through a Travenol® pump. of local from the lateral malleolus to the extensor hallucis longus tendon anteriorly and medially. Replacement of fluid deficits should be done in a carefully measured and planned manner. Deficit fluids are given in addition to maintenance fluids, fluids to accommodate the increase in venous capacitance, and fluids for evaporative, “third space,” and blood losses. Typically, in the first hour of anesthesia care, 1/2 of the fluid deficit is administered, plus the maintenance fluid rate plus replacement for blood loss. In the second and third hour of anesthesia care, 1/4 of the fluid deficit is given per hour. This results in replenishment of the fluid deficit within a three hour period. Certainly if upon induction of anesthesia, the child appears to be tachycardic due to dehydration, a fluid bolus may be given. Frequently lactated Ringer’s or normal saline is given in boluses of 10-20 cc/kg over 20-30 minutes. Laparotomy may require 4-10 cc/kg/hr of crystalloid solution beyond maintenance fluid to replace third space losses into manipulated viscera and evaporative losses. Many different local anesthetics can be used. Two suggested dose regimens are: Calculation of fluid deficit is used for periods of time up to 8 hours. I do not believe it is worth while calculating fluid deficits for periods greater than 8 hours since most of our patients have endogenous antidiuretic hormone (ADH). If more fluid replenishment is needed beyond the 8 hour deficit, this is done based on clinical observation of the patient’s vital signs in the operating room. D. CONDUCT OF THE ANESTHESIA TEAM During the surgical procedure, communication must be open between the anesthesiologist and the surgeon in order to anticipate changes in the child’s physiological status that may be induced by the surgical procedure. Cooperation between the anesthesiologist and the surgeon is essential to best care for the patient. Medications; Lidocaine 1.0% or 1.5% with/without epinephrine 6 mg/kg total dose (approximately 1 mg/kg/nerve) Bupivacaine 0.25% or 0.5% with/without epinephrine 3 mg/kg total dose (approximately 0.5 mg/kg/nerve) Complications pressure ischemia a theoretical complication from injecting large amounts of local anesthetic into fascial planes with limited space for diffusion. Compartment syndromes with severe muscle loss have been described in adults, but not children as of yet. hematoma infection neuropathy OTHER PERIPHERAL NERVE BLOCKS ilioinguinal and iliohypogastric nerve blocks This block was reported first by Shandling and Steward in children in 1980. These nerves are major branches of the lumber plexus. These blocks are good for analgesia for procedures such as inguinal hernia repair, varicocele repair, testicular biopsy, and orchiopexy. These blocks do not abolish the visceral pain from peritoneal traction or exploration and manipulation of the spermatic cord and testicles. Nevertheless, they allow for a decreased MAC during the surgery, excellent postoperative analgesia with few complications, markedly decreased postoperative analgesic requirements, a decreased incidence of postoperative nausea and vomiting (most likely from decreased requirements for intraoperative narcotics and the decreased 101 Resident Handbook deep peroneal nerve (anterior tibial nerve) A branch of the sciatic nerve (contributions from L4-S2), it is found deep to the extensor retinaculum, next to anterior tibial artery on the anterior surface of the distal end of the tibia between the tibialis anterior and the extensor hallucis longus tendons at the level of the medial malleolus. It innervates the adjacent joints and skin between the first and second toes. It is blocked by placing the needle lateral to the extensor hallucis longus until contact with the tibia is made. Alternatively, the needle can be placed just lateral to the extensor hallucis longus tendon on the dorsal aspect of the foot just medial to the dorsalis pedis until bone contact is made. The needle is withdrawn 1-2 mm, aspiration is performed and the injection made if no blood is returned. posterior tibial nerve Another branch of the sciatic nerve, it is found deep under the flexor retinaculum posterior to the pulsation of the posterior tibial artery at the upper level of the medial malleolus. It innervates the skin and muscles of the plantar surface of the foot. It is blocked by injection posterior to the pulsation of the posterior tibial artery and advanced until a pop is felt or contact with bone is made. After negative aspiration for blood, injection of the local anesthetic is done. sural nerve A branch of the sciatic nerve, it is a cutaneous nerve that supplies sensation to the lateral side of the foot and lateral side of the little toe, as well as the heel. It is blocked by injecting a subcutaneous cuff of local from the lateral malleolus to the Achilles tendon. superficial peroneal nerve Also a branch of the sciatic nerve, it supplies sensory innervation to the dorsum of the foot. It is blocked by injecting a subcutaneous cuff Resident Handbook 14 Based on the high metabolic rate of infants and children, rapid response times are needed by the anesthesiologist. This is what makes pediatric anesthesia such a challenging subspecialty since not only does the anesthesiologist need to know exactly what to do, but must make decisions and act in an immediate fashion. Most often the actions concern airway management. When residents experience difficulty in the operating room the call needs to go out immediately to the attending anesthesiologist for help if the attending anesthesiologist is not present in the room. When transferring the care of the patient to a colleague, it is essential that information be relayed in an efficient and clear manner regarding the nature of the surgery, the child’s underlying disease conditions, the anesthetic management and plan, and the tabulations of fluid and blood replacement. All drugs should be labeled clearly by name and concentration before turning the case over to another anesthesiologist. If the child’s condition warrants close attention by the anesthesiologist during the procedure, it is acceptable to forego documentation on the anesthetic record until a later, more pertinent time. There is no need to risk patient endangerment for purposes of documentation. VI. THE PACU Transport of the child to the PACU is done with care and attention to patency of the airway, adequacy of ventilation, and perfusion. Appropriate monitoring is utilized during this transport. Frequently, this monitoring amounts to observation of the child utilizing the anesthesiologist’s own senses of sight, hearing, and touch. Pediatric patients are frequently placed on their side for transport so that if emesis occurs, it will likely exit the mouth and be less likely to enter the lungs. A hand is usually placed over the patient’s mouth and nose, frequently while providing a small amount of chin lift for airway support 15 Resident Handbook during transport. This allows the anesthesiologist to feel air movement in and out of the patient’s airway. On arrival in the PACU, the PACU nurse is given a clear and concise summary of the patient’s medical problems and the surgical procedure that has occurred. It is also important to relay specific information regarding the adequacy of the patient’s airway and the expectations for needs for pain control. Orders are written for fluid management and pain control, but also may include other drug administration, blood tests, or oxygen administration. Resident Handbook 100 Complications systemic toxicity sciatic nerve injury or dysesthesia delayed neuropathy hematoma formation infection ANKLE BLOCK For patients not going to the PACU, but rather directly to the PICU or NICU, observe the following.* 1. Patients that are taken directly to the PICU are taken there at the discretion of the attending anesthesiologist. It is that person’s responsibility to ensure that at least twenty minutes warning is given to the medical and nursing staff so that equipment and personnel can be coordinated. 2. It is often in the best interest of patient care that direct communication between the attending anesthesiologist and the attending intensivist take place to resolve issues of medical management. 3. Morbidity associated with transport is high. Communication between the parties concerned is necessary to reduce the risk of injury to the patient. * Raeford E. Brown, Jr., M.D. March 3, 1995 VII. THE POSTOPERATIVE VISIT It is essential that the resident visit the child and family in the postop period (within 48 hours) to assess the child’s experience of the anesthesia procedure and to note any postoperative complications that may have occurred. It is not adequate to Ankle block. Block of the ankle generally requires five separate nerves to be blocked. Three nerves can be blocked from the dorsal aspect of the foot (A) and two on either side of the Achilles tendon (B). (Sites of injection are indicated by the circles with dots). The ankle block is indicated for procedures on the plantar and dorsal aspects of the foot. Discomfort associated with multiple injections make this procedure objectionable to most awake pediatric patients. It can be safely and easily be performed on anesthetized patients, though. Block of the ankle requires anesthetizing five nerves: saphenous nerve The only branch of the femoral nerve distal to knee, it is found subcutaneously and innervates the medial calf, proximal medial half of the foot, and the metatarsophalangeal joint of the great toe. It is blocked by a subcutaneous injection of anesthetic around the saphenous vein anterior to the medial malleolus. 99 Resident Handbook Anterior Approach Resident Handbook 16 merely review the patient’s chart without speaking to the family or the child since not all information is recorded on the chart. A note needs to be placed in the child’s chart about the postoperative visit. If no postoperative visit is performed, and the child has had postoperative difficulties, the family may assume that no one from the anesthesia department cares about what happened to their child since the anesthetic was over. Given that anesthesiologists have very little limited contact with patients and their families it is important to utilize every opportunity to establish rapport and communication with families and patients so that the anesthesiologist is recognized as a physician in their eyes. This is the only way the public will ever come to know the important role that the anesthesiologist plays as a physician, not technician, in the care of patients in the operating room. VIII. PAIN MANAGEMENT (A and B) Sciatic nerve block (anterior approach). With the patient in a supine position, a line is drawn from the anterior iliac spine to the pubic tuberosity (line 1). The greater trochanter is located, and another line is drawn parallel to the first (line 2). A perpendicular line is dropped from line 1 at a point one third the distance laterally from the pubic tuberosity to the anterior iliac spine (broken line 3). (C and D) A needle is inserted at the intersection of line 2 and the perpendicular line (in A, circle with dot) until bone is encountered. The needle is redirected off the edge of the femur to the approximate posterior margin of the femur (A), and after negative aspiration for blood, ease of injection is ascertained. Resistance to injection indicates that the needle is within muscle or fascial bundle; the needle should be advanced until there is minimal resistance to injection or until a paresthesia is elicited. With the patient supine and the lower extremity in a neutral position, draw a line from the anterior superior iliac crest to the pubic tuberosity and a parallel line from the greater trochanter medially. One-third from the median upper line, draw a perpendicular line connecting the two parallel lines. The point of injection is on the cross point on the line drawn from the greater trochanter. Insert a 22 gauge short bevel needle until the bone is contacted. Withdraw the needle slightly and direct it medially and posteriorly until the posterior margin of the femur in contacted. With a nerve stimulator you may elicit motor activity identical to the above approach. After aspiration, injection of medication should not meet any resistance. If resistance is felt, the injection is either in the fascial plane or the body of the muscle. While on call, you will be responsible for carrying the pain beeper (#405-6079) and responding to all calls. Most of these calls will be from in-house sources regarding needs of patients on the pain service or notification of new consults. Occasionally, a parent of an outpatient with a chronic pain syndrome may call for advice. It is imperative that the staff person on pain call be notified immediately of all interactions and interventions that have to do with management of pain patients. Inpatients should be assessed and examined prior to contacting the on-call staff for the pain service. All patients should be seen prior to alterations in therapy. Please Inform The Pain Attending Of Any Pain Management Regimen Changes Made Regarding A Patient While On ACH Rotation. Michael L. Schmitz, M.D., Director Pediatric Pain Management 17 Resident Handbook Guidelines for pain control modalities such as epidural infusions and patient-controlled analgesia (PCA) pumps are outlined in Appendix E. Resident Handbook 98 Posterior Approach IX. CONCLUSION Once again, this manual is meant to be a guide, not a definitive reading of essentials for pediatric anesthesiology. I appreciate all comments for subsequent revision and improvement of this manual which may make it more useful to the anesthesia residents and fellows rotating at Arkansas Children’s Hospital in Pediatric Anesthesia. (A) Static nerve block (approach of Labat). The patient is placed in a lateral position with the lower leg extended and the upper leg, the one to be blocked, flexed; a line is drawn from the greater trochanter of the femur to the posterior superior iliac spine (line 1). A second line is drawn from the greater trochanter to the coccyx (line 2). Line 1 is bisected, and a perpendicular line is drawn from that point to line 2 (broken line 3); the point at which the perpendicular broken line intersects line 2 (circle with dot) is the point of needle insertion. (B and C) A 22-gauge needle is advanced perpendicular to the skin until it strikes bone, or if the patient is awake, a paresthesia is elicited. Place the patient in the lateral decubitus position with the leg to be blocked uppermost and flexed so the foot is at the popliteal fossae of the dependent leg. This stretches the nerve so that it does not roll. Make a mark on the greater trochanter of the femur and the posterior superior iliac crest and connect the dots. Next make a line from the greater trochanter to the sacral hiatus. From the midpoint of the first line draw a perpendicular line to the second line. This is the point of injection. Using a 22 gauge short bevel or a 3 1/2 inch 22 gauge spinal needle (depending on the size of the patient) with a nerve stimulator, advance the needle perpendicular to the skin until dorsiflexion of the foot is seen. Aspirate and incrementally inject the medications. 97 Resident Handbook Complications accidental intravascular injection aspiration for blood during incremental injections is strongly indicated. hematoma formation temporary or permanent nerve injury infection sparing of the obturator and/or LFCN SCIATIC NERVE BLOCK The sciatic nerve is made from branches from L4-S3 and supplies motor innervation to the extensor muscles of the hip and to flexors of the knee and ankle. It supplies sensory innervation to the skin over the back of the thigh and leg, extending from the sacrum to the dorsum of the foot. It is often performed in conjunction with the saphenous nerve block for anesthesia for the foot, or in conjunction with the femoral, obturator, and/or the lateral femoral cutaneous nerve for anesthesia for the lower extremity. Resident Handbook 18 X. APPENDICES APPENDIX A: COMMON DRUG DOSAGES BENZODIAZEPINES INDUCTION AGENTS Medications This nerve block is not well studied in children, but those that have done a number of these suggest have used of 0.6-1.0 ml/kg of 0.5% bupivacaine with/without epinephrine and have not observed toxic levels of bupivacaine. pentothal 3-6 mg/kg IV propofol (Diprivan) 2-2.5 mg/kg IV etomidate (Amidate) 0.2-0.3 mg/kg IV ketamine (Ketalar) 1-2 mg/kg IV MUSCLE RELAXANTS Induction Doses: Anatomy The sciatic nerve emerges from the anterior aspect of the sacrum through the great sciatic foramen and passes anterior to the piriform muscle and through the sciatic notch posterior to the quadriceps femoris muscle. midazolam (Versed) 0.5 mg/kg po (max 15 mg) 15-30 minutes prior to entering operating room, or 0.075 to 0.15 mg/kg IV/IM up to 5 mg maximum. lorazepam (Ativan) 0.1 mg/kg po/IV up to 1-2 mg total. diazepam (Valium) 0.3-0.5 mg/kg po 30 min. prior to anesthesia succinylcholine 1-1.5 mg/kg IV for > 6 months of age - 2 mg/kg IV for < than 6 months of age - 5 mg/kg IM rapacuronium (Raplon) 2 mg/kg for children, 1.5 mg/kg for adults mivacurium (Mivacron) 0.3 mg/kg IV in two divided doses of 0.15mg/kg rocuronium (Zemuron) 0.6-0.9 mg/kg IV cisatricurium (Nimbex) - 0.1mg/kg (child) - 0.2 mg/kg (adult) atracurium (Tracrium) 0.5 mg/kg IV vecuronium 0.1 mg/kg IV pancuronium 0.1 mg/kg IV ANTICHOLINERGICS Technique There are several techniques of placing the sciatic nerve block, of which the two most common ones are described below: atropine 20 mcg/kg IV/IM, maximum 1.0 mg glycopyrrolate (Robinul) 8-10 mcg/kg IV up to 0.6 mg per dose 19 Resident Handbook ANTICHOLINESTERASE edrophonium 1 mg/kg IV neostigmine 70 mcg/kg IV up to 5 mg maximum per dose NARCOTICS morphine 0.1 mg/kg IV usually divided into about 3 doses every 5-10 minutes PRN in the PACU fentanyl 1 mcg/kg IV per dose for pain control. For anesthesia: - 1-2 mcg/kg IV - Low dose - 5 mcg/kg IV - Moderate dose - 7-10 mcg/kg IV - High dose hydromorphone (Dilaudid) 20 mcg/kg IV usually divided into 3 doses in the PACU for pain control and given every 5-10 minutes PRN meperidine (Demerol) 1-1.5 mg/kg IM/IV codeine 0.5-1.0 mg/kg PO every 4 hours PRN pain oxycodone 0.05-0.10 mg/kg PO every 4 hours PRN pain NSAIDS acetaminophen (Tylenol) 15 mg/kg PO/PR q4H or 20 mg/kg PO/PR q6H. ketorolac (Toradol) 0.9-1.0 mg/kg IV/IM loading dose, then 0.5 mg/kg - IV/IM every 6 hours up to no more than 5 days of treatment - 10 mg PO every 6 hours up to no more than 5 days of treatment REVERSAL AGENTS flumazenil (Mazicon) 0.1-0.3 mg IV every 1-2 minutes to effect. Reassess etiology of sedation after 0.5 mg administered. naloxone (Narcan) 1 mcg/kg IV/IM per dose. Titrate dose to effect. ANTIEMETICS metoclopramide 0.15-0.25 mg/kg PO/IV up to 10 mg q6H. droperidol 20-75 mcg/kg IV up to 1.25 mg qH6 ondansetron (Zofran) 0.05 mg/kg IV up to 4.0 mg total q6-8H phenergan 0.25-0.5 mg/kg IM/PR q6H Resident Handbook 96 caudad and 2 cm lateral to the anterior superior iliac crest. Advance the needle perpendicular fashion through the skin until a pop is felt. Inject the local in a fan fashion in a sagittal plane. Note that there is no motor innervation of this nerve, so a peripheral nerve stimulator is not useful. Medications Use of 0.25 mg/kg of 0.25% bupivacaine or 1 mg/kg of 1% lidocaine without epinephrine will usually provide an adequate block. Complications This block is one of the safer blocks to perform in terms of having a low incidence of complications. Since no major arteries travel with the nerve at this location, risk of hematoma formation or intravascular injection is remote. The two greatest risks are: temporary or permanent nerve injury infection INGUINAL PARAVASCULAR NERVE BLOCK This is an excellent block for analgesia for surgical procedures on the anterior surface of the thigh. It has not been evaluated in children, and is rarely used. It blocks the femoral, lateral femoral cutaneous, and obturator nerves (L1-5). Technique and Medications Similar to a femoral nerve block (see above) but after the second pop is felt, instead of directing the needle in a perpendicular plane, direct the needle cephalad at a 30-45 degree angle up the femoral sheath, applying distal pressure during the injection of medication to promote cephalad flow. Although not established in children, use of 0.5 ml/kg of 0.5% bupivacaine with/without epinephrine has been successfully performed and shown to provide 2-4 hours of analgesia. 95 Resident Handbook bupivacaine lidocaine 0.5% with/without epinephrine 0.2-0.3 ml/kg (1-1.5 mg/kg) maximum 10 ccs. onset 15-20 minutes, duration 2-4 hours 1.0% with/without epinephrine 0.2 ml/kg (2 mg/kg) onset 10-15 minutes, duration 30-40 minutes Complications accidental intravascular injection aspiration for blood during incremental injections is imperative Hematoma formation Temporary or permanent nerve injury infection pseudoaneurysm formation a delayed and unusual complication LATERAL FEMORAL CUTANEOUS NERVE BLOCK The lateral femoral cutaneous nerve (LFCN) supplies sensory innervation to the skin on the anterolateral side of the thigh to the knee. This nerve block is mainly used to supplement femoral and sciatic nerve blocks, to relieve tourniquet pain, or for analgesia for skin donor graft sites. In combination with the femoral nerve block it is ideal for muscle biopsy for patients with suspected malignant hyperthermia susceptibility, muscular dystrophy, and other neuromuscular disorders--and may allow one to avoid general anesthetic agents. Anatomy The LFCN is formed from branches from L2 and L3. It emerges from the lateral border of the psoas muscle and passes obliquely under the fascia iliaca to enter the thigh 1 - 2 cm medial to the anterior superior iliac spine. Technique After a sterile preparation, place a 22 gauge short bevel needle 2 cm Resident Handbook 20 MISCELLANEOUS caffeine benzoate 20 mg/kg IV q24H Hespan maximum 20 cc/kg per 24 hours cefazolin (Ancef Kefzol) 20 mg/kg IV q8H CAUDAL NERVE BLOCK bupivacaine maximum 2.5 mg/kg. Concentrations used 0.125 0.5% bupivacaine with 1:200,000 epinephrine. Volume 0.5 cc/kg for an extremity, 1 cc/kg for surgical site below umbilicus. 1.4 cc/kg for a T4 level. Note for higher levels, lower concentrations of bupivacaine are used and will result in less total analgesia. For most surgical procedures, 0.75-1.0 cc/kg up to 20 cc maximum of 0.25% bupivacaine with 1:200,000 epinephrine. Bupivacaine caudals generally provide 4-6 hours of analgesia. butorphanol 30 mcg/kg ED up to 1.0 mg. Note: butorphanol usually provides for 8-12 hours of analgesia. It usually is added to a bupivacaine solution for caudal administration. APPENDIX B: FLUID REPLACEMENT MAINTENANCE FLUIDS First 10 kg Second 10 kg For 20-50 kg > 50 kg 4cc/kg/hr 2 cc/kg/hr 1cc/kg/hr 0.5 cc/kg/hr Deficit = Maintenance fluid rate x # of hours NPO (max 8 hours) DEFICIT REPLACEMENT First hour Second hour Third hour 1/2 of fluid deficit plus maintenance 1/4 of fluid deficit plus maintenance 1/4 of fluid deficit plus maintenance 21 Resident Handbook Resident Handbook 94 Fourth hour and beyond maintenance fluid Replacement of blood loss with crystalloid solutions. crystalloid = 3 x blood loss Femoral nerve block. Note that the femoral nerve lies lateral to the femoral artery. The appropriate dose of local anesthetic is administered while maintaining pressure on the nerve sheath distal to the site of injection just below the inguinal ligament; local anesthetic is thus forced proximally and all three femoral nerve branches can often be blocked with a single injection. Replacement of blood loss with colloid solutions colloid solution = 1 x blood loss Fluid boluses for mild to moderate hypovolemia crystalloid 10-20 cc/kg over 20 minutes colloid 10 cc/kg over 20 minutes APPENDIX C: AIRWAY EQUIPMENT INTERNAL DIAMETER OF ENDOTRACHEAL TUBES AGE Premature Infant 1000 gm 1000-2500 gm SIZE Neonate to 6 mo 3.0-3.5 mm 6 mo to 1 yr 3.5-4.0 mm 1-2 yr 4.0-4.5 mm Beyond 2 yr Age (yrs) + 16 4 2.5 mm 3.0 mm Technique THE SIZE OF LARYNGOSCOPE BLADES AGE Premature Neonate Neonate-2 yr 2-6 yr 6-12 yr Over 12 yr Miller 0 0 1 2 3 Wis-Hippel 1.5 McIntosh 2 3 After sterile preparation, identify the femoral artery pulse 1 - 1.5 cm below the inguinal ligament. Using a 22 gauge short bevel needle, enter the skin in a perpendicular fashion just lateral to the pulsation (remember the order in from the genitalia laterally vein, artery, nerve [VAN]). Advance the needle until two distinct pops are felt. If using a nerve stimulator, watch for quadriceps contractions (but not sartorius contractions, which indicate the needle has not been advanced far enough). Aspirate and inject the medication in 0.5 - 2 cc increments, depending on the size of the patient. Medications There are at least two safe medication schemes for femoral nerve blocks: 93 Resident Handbook Femoral Nerve Block The femoral nerve block is indicated for relief of quadriceps muscle spasm, pain free manipulation of middle third femoral shaft fractures, and to augment other lower extremity blocks. This block can be performed as either a single shot or continuous block. Anatomy The femoral nerve is made of contributions from L2, 3, and 4 and supplies motor innervation to the quadriceps and sartorius muscles, sensory to the medial ligament of the knee joint, overlying skin of the anterior aspect of the thigh, and to the periosteum of the femoral shaft. The saphenous nerve is the only continuation of the femoral nerve below the knee and supplies sensory innervation to the medial aspect of the calf, the proximal medial half of the foot, and the metatarsophalangeal joint of the great toe. The femoral nerve passes in the groove between the psoas major and the iliac muscles and enters the thigh under the inguinal ligament lying anterior to the iliopsoas muscle and immediately lateral to the femoral artery. Resident Handbook 22 FORMULAS FOR DEPTH OF INSERTION OF ENDOTRACHEAL TUBE 1. Age (years) 2 + 12 2. Weight (kg) 5 + 12 APPENDIX D. BLOOD COMPONENTS COMPONENT DOSE REFERENCE SHEET NEONATES: Maintenance Transfusions: RBC: 10 cc/kg (body weight) (should raise Hct by 3%) FFP: 10 cc/kg (contains 1 international unit of Coag Factor activity per cc) PLT: 10 cc/kg (should raise Plt ct by 60,000) PP: 10 cc/kg (should raise Plt ct by 200,000) Cryo: 0.5 bags/kg (should raise fibrinogen by 150 mg/dl AND raise Factor VIII activity by 75%) For Surgery: 50-100 cc in aliquot bag If order is placed for 1 unit, aliquot into 2 bags before issue NON-NEONATES: Therapeutic Transfusions: RBC: 10-15 cc/kg (should raise Hct by 3%) FFP: 10 cc/kg (contains 1 international unit of Coag Factor activity per cc) PLT: 10 cc/kg or 1 unit/10 kg (should raise Plt count by 60,000) PP: 10 cc/kg (should raise Plt ct by 200,000) Cryo: 0.5 bags/kg (should raise fibrinogen by 150 mg/dl AND raise Factor VIII activity by 75%) Hemophilia A or von Willebrand patients should receive the appropriate pharmacy product ... NOT Cryo. Femoral nerve block. Diagram showing the course of the needle piercing fascia lata and iliaca. 23 Resident Handbook HEM/ONC patients 1 or 2 pp usually - may need to Reduce Volume if pt is volume sensitive or because of ABO incompatible units. Trauma: (Emergency Released 0 negs) Age: 0-5 years 1-2 units in transport box 5-10 years 2-4 units in transport box >10 years > 4 units in transport box Burns: Pediatrics: as above Adults: as many units as are ordered ...Verify use of FFP before thawing, many times it is only to be on hold. APPENDIX E: PAIN MANAGEMENT GUIDELINES A. EPIDURAL REGIMENS Epidural Medications (Most Commonly Used) Bupivacaine Butorphanol (Stadol) Fentanyl Morphine Resident Handbook 92 decrease the risk of CNS toxicity from intravascular injection but not cardiac toxicity. Complications; convulsions more likely when using the transarterial approach. Must carefully aspirate every 1-3 ccs prior to injecting the next volume of anesthetic. dysrhythmias usually related to systemic absorption of epinephrine containing solutions or intravascular injection of either local alone or local containing epinephrine. hematoma direct nerve injury intravascular injection pneumothorax more likely with the supraclavicular and interscalene approaches than the axillary approach. infection LOWER EXTREMITY PERIPHERAL NERVE BLOCKS Most Common Combination Infusion Combinations & Concentrations Fentanyl 0.0005% (5 mcg/ml) + Bupivacaine 0.075% (750 mcg/ml) Morphine 0.005% (50 mcg/ml) + Butorphanol 0.001% (10 mcg/ml) Morphine 0.005% (50 mcg/ml) + Butorphanol 0.001% (10 mcg/ml) + Bupivacaine 0.075% (750 mcg/ml) Morphine 0.005% (50 mcg/ml) + Butorphanol 0.001% (10 mcg/ml) (Bupivacaine and Fentanyl are used when the end of the epidural catheter is near the affected dermatomes.) The sensory innervation of the lower extremity is presented. Note that anesthesia of the lower extremity requires block of the femoral nerve (A) (and its branches) as well as the sciatic nerve (B). 91 Resident Handbook Characteristic movements of the fingers, wrist, and elbow in response to nerve stimulation. (Cousins MJ, Bridenbaugh PO (eds); Neural Blockade in Clinical Anesthesia and Management of Pain, 2nd ed, p. 406. Philadelphia, JB Lippincott, 1988) Technique Resident Handbook 24 Dosages for boluses (usually to precede infusions) Bupivacaine: 1cc/kg (up to 10 cc, usually) of 0.25% Bupivacaine with 1/200,000 epinephrine for pain control in the conscious patient. Morphine 50-60 mcg/kg (up to 5 mg, maximum) in combination with Butorphanol 10-12 mcg/kg (up to 1 mg, maximum), respectively. A combination of the above two regimens. Fentanyl 0.5-1.0 mcg/kg--only if the patient is under your direct observation for the next hour. Dosages for Infusion Bupivacaine 7.5-15 mcg/kg/hr Butorphanol 1-1.2 mcg/kg/hr Fentanyl 1 mcg/kg/hr Morphine 5 mcg/kg/hr (Simplified: 2 cc/10 kg/hr for the Fentanyl/Bupivacaine solution listed above, and 1 cc/10 kg/hr for any of the Morphine/Butorphanol±Bupivacaine solutions listed above) As in axillary blocks in adults, one can use the transarterial, intrasheath, or nerve stimulator techniques to perform this block. Since the block in children is usually performed after the child has received a general anesthetic, the nerve paresthesia approach is not useful. Often the axillary sheath can be palpated in children. B. PCA REGIMENS (Usual starting doses for patients pushing their own PCA buttons) Medications Morphine: Several dosing regimens have been suggested for use in brachial plexus anesthesia. The most important factor appears to be the volume of anesthetic injected, rather than the concentration. The three most commonly used agents are lidocaine, mepivacaine, and bupivacaine. When using 1% mepivacaine or lidocaine the suggested volume is 0.7 cc/kg; for 0.5% bupivacaine it is slightly lower at 0.6 ml/kg. Campbell and colleagues showed that using 2-3 mg/kg of bupivacaine in a total volume of 0.6 ml/kg allowed an adequate block without producing toxic levels. The addition of 1:200,000 epinephrine may decrease the rate of vascular absorption and potential for toxicity. Some believe that bupivacaine should be avoided for brachial plexus anesthesia given in the axilla because of a higher risk of intravascular injection. The administration of benzodiazepines pre- or intra-operatively may also Background: Bolus: Lockout: Max. boluses/hr: Hydromorphone (Dilaudid) Background: Bolus: Lockout: Max boluses/hr: 15 mcg/kg/hr (maximum 1.0 mg) 15 mcg/kg (maximum 1.0 mg/hr) 8-10 minutes 4-6 3 mcg/kg/hr (maximum 0.2 mg) 3 mcg/kg (maximum 0.2 mg/hr) 8-10 minutes 4-6 25 Resident Handbook Fentanyl Resident Handbook 90 Background: Bolus: Lockout: Max boluses/hr: Meperidine (Demerol) 6-8 Background: Bolus: Lockout: Max boluses/hr: 0.2 mcg/kg/hr (maximum 10 mcg) 0.3 mcg/kg (maximum 15 mcg) 5 minutes 110 mcg/kg/hr (maximum 7.5 mg/hr) 110 mcg/kg (maximum 7.5 mg) 8-10 minutes 4 (Consult with staff always since normeperidine toxicity is an issue). C. NARCOTIC INTERCONVERSION TABLE Narcotic Morphine Hydromorphone Meperidine Methadone Fentanyl Sufentanil Alfentanil Nalbuphine Buprenorphine Codeine phosphate Oxycodone Anileridine Levorphanol tartrate Oxymorphone Diamorphine Pentazocine IM/IV Dose 10 mg 2 mg 75 mg 10 mg 750-1,250 mcg 150-250 mcg 5,000 mcg 10-15 mg 0.3 mg 25 mg 2 mg 1.5 mg 5-8 mg 60 mg PO Dose 20-30 mg 7.5 mg 300 mg 20 mg 130 mg 10-15 mg 75 mg 4 mg 10-15 mg 180 mg UPPER EXTREMITY PERIPHERAL NERVE BLOCKS brachial plexus block; There are three techniques of blocking the brachial plexus in adults (axillary, supraclavicular, and interscalene), but the axillary approach is the most used and safest in smaller patients because it is easier to perform, does not require an awake patient, and has less risk of blocking the phrenic or recurrent laryngeal nerves (as these are much more proximal to the injection site with supraclavicular and interscalene blocks), or causing a pneumothorax. Block of the phrenic nerve in small patients can lead to postoperative respiratory failure as infants and small children are heavily reliant on the diaphragm for normal respiration. This block has to date not been extensively used or studied in the pediatric population. Anatomy The brachial plexus is made of nerve contributions from C5-T1. The nerve sheath for the brachial plexus in the axilla contains the median nerve anteriorly, the ulnar nerve posteriorly, and the radial nerve posterolaterally in relation to the axillary artery. In addition, blockade of the musculocutaneous nerve (in the belly of the coracobrachialis muscle that supplies the sensation to the medial forearm) and the inter-costobrachial nerve (subcutaneously) must be done as these nerves are frequently not located in the axillary sheath at this level. The anatomic relationships of the brachial plexus are presented. Note that the fascial sheath envelops the nerves and the axillary artery and vein; the musculocutaneous nerve lies within the body of the coracobrachialis muscle. Local anesthetic injected within the sheath (on either side of the axillary artery) produces a satisfactory block. 89 Resident Handbook Resident Handbook 26 sympathetic blockade in infants and children, sympathetic blockade is not usually associated with significant hypotension or bradycardia Lumbar and Thoracic Epidurals Lumbar and thoracic epidural anesthesia are not as well studied in children, but are easy to do and with good outcomes. The benefits and complications are similar to those for caudal epidural blockade. While many pediatric anesthesiologists will place a lumbar epidural in patients after they have received a general anesthetic, most recommend only doing thoracic epidurals in awake patients to elicit signs of neural stimulation. Also remember the anatomy of the spinal cord and where it terminates in the infant compared to the adult. Below are listed two dosing regimens for lumbar epidural blockade: TABLE: Equations for Determining Doses of Local Anesthetic Solution for Lumbar Epidural Blockade Study a b Patient Age (years) Ruston 0-10 Bromage 4-20 Equation 0.5 + (weight in lb) 2 Anesthetic Solution Lidocaine 1% + epinephrine 1:200,000 a 0.106 + (years x 0.075) b Lidocaine 2% + epinephrine 1:200,000 Dose in total milliliters Dose in milliliters per spinal segment Despite the above table, no formula or dose schedule predictably ensures the desired level of lumbar or thoracic epidural block for infants or children. As in adults, neither height, age, nor weight is a reliable predictor of anesthetic level. A study by Schulte and Rahlfs seems to correlate best between the age of the child and dermatomal effects of local anesthesia. Their formula is: Volume per spinal segment = 0.1 X age (in years) Also, in children under the age of 5 years, the epidural fat is compliant enough to pass a styletted caudal catheter to the appropriate lumbar or thoracic level, thus avoiding the risks of placing thoracic catheters in small patients. Although lumbar and thoracic epidurals can be placed safely in small children and infants, hey should only be performed by those expert in the technique, as the risks are much greater in children. D. Other Control Measures for Pain Tens unit Relaxation therapy Distraction techniques or introduced coping mechanisms NSAID's (see Appendix A). codeine 0.5-1.0 mg/kg PO Q4° PRN pain. oxycodone 0.05-0.10 mg/kg PO Q4° PRN pain. MS Contin, methadone, other PO narcotics--consult staff amitriptyline (Elavil) or other TCA's--consult staff fluoxetine (Prozac) or other SSRI's--consult staff anticonvulsants (phenytoin, carbamazepine, valproate, etc.)-consult staff clonidine (alpha-2 agonist)--consult staff APPENDIX F: QI CHART REQUIREMENTS I. PRE-ANESTHETIC EVALUATION: 1. Complete medical and surgical history, including ASA status 2. Complete physical exam, including vital signs (HR, RR, BP, Temp, Weight) 3. Appropriate lab data recorded (if no labs, put "NR") 4. Anesthetic plan is recorded 5. Your signature II. INTRA-OP RECORD: 1. Reevaluation 2. Equipment check 3. ID and consent checked 4. Monitors recorded 5. ECG at least every 15 min 6. SpO2 at least every 15 min 7. ETCO2 at least every 15 min 8. Temperature at least every 15 min 9. Anesthetic drugs and dosage recorded 10. BP recorded at least every 5 min 11. Type and amount of fluids and blood recorded 12. IV site recorded 13. IV size recorded 14. Pt reassessed at end of case and given PAR score 27 Resident Handbook III. POST-OP NOTE/CONSULT: EVERY patient must have a post-op note written, after leaving the recovery room but before 48 hours post-op. This should involve more than circling "NONE" for complications. Essentially all out-patients get a post-op note because they can't be discharged without it. However, many inpatients never have a documented post-op visit, especially emergency cases done at night and on weekends, burn unit patients, and patients who return directly to an ICU bed post-op. APPENDIX G: OUTLINE OF PREOP NOTE A preop note should fulfill these functions: 1. It carries the heading “Anesthesia Preop Note” 2. It reviews the important problems presented by the patient. This can be done by a series of numbered paragraphs. With very complex patients, it may help to organize problems by organ system (ie Cardiovascular, Pulmonary, Neuro, etc.) This outline should include the expected or feared consequences of each of these problems. It should tell how each problem will be handled. 3. List allergies and medications 4. Physical exam: height / weight / vital signs Evaluation should be directed toward: a) Airway: dentition; range of motion of TMJ and cervical spine, mouth opening, ability to see the uvula; distance between thyroid cartilage and chin; position of trachea (midline or deviated) b) Heart and lungs; rales; wheezing, rhonchi, murmurs, S3, S4; bruits c) IV access, Allens test, needle insertion sites for regional anesthesia or invasive monitoring should be inspected for local infection, evidence of prior trauma or deformity 5. Pertinent laboratory values 6. Assignment of one of the ASA Physical Status Classes: Class I - healthy patient Class II - mild systemic disease Resident Handbook 88 bupivacaine. In fact, in children under the age of 5, 0.25% bupivacaine with epinephrine can give up to 22 hours of analgesia with minimal motor effects. A benefit of administering only narcotic or non-narcotic analgesics is the absence of motor or autonomic block, less morbidity associated with an inadvertent intravascular injection, and up to 36 hours of analgesia. Frequently 0.1-0.15 mg/kg of a 0.5 mg/kg solution of morphine is used. Higher doses than this greatly increases the incidence of delayed respiratory depression, and with all centrally administered narcotics, the patient should receive monitored continuous care for at least 24 hours post-administration. Complications The failure rates of caudal blockade range between 2-29%. The rate is usually attributed to inadequate volume or concentration of local anesthetic, inexperience of the performer, or abnormalities of the sacral anatomy. In experienced hands, the failure rate is very low. Other reasons for failure include: misplacement of local anesthetic into the bone marrow (which may present as an intravascular-type injection reaction) periosteal injection injection into the posterior sacral ligaments injection into a decoy hiatus injection into the anterior sacral wall or the pelvis injection into a lateral foramen (which may demonstrate itself as a partial block). lower extremity muscle weakness the inability to walk for up to 6 hours is seen in up to 31% of patients when 0.5% bupivacaine is used urinary retention intravascular injection subarachnoid injection infection meningitis, cellulitis, arachnoiditis, epidural abscess, hematoma temporary or permanent neurologic injury while this is a risk, I have never read of or heard of an infant or child with this complication. In addition, many colleagues I have questioned have not either. 87 Resident Handbook Resident Handbook 28 the needle is in the caudal canal. Aspirate, administer a test dose, and if negative inject in small increments (as described above.) Medications TABLE: Equations for Determining Doses of Local Anesthetics for Pediatric Caudal Anesthesia Study Spiegel Patient Age 41 2 days-14 years Fortuna & Santos 56 Schulte-Steinberg & 54 Rahlfs Lourey & 51 McDonald Takasaki et al 53 0-10 years 7 weeks - 12 years 8 months-10 years 0-7 years <8 kg Dose Lidocaine or tetracaine b (ml) & procaine variable % and combination 10 mg/kg Lidocaine 0.5-2.0% 12.5 mg/kg Lidocaine 0.5-2.0% 0.056 + (years x Lidocaine 1% with c 0.097) epinephrine 1:200,000 3-4 mg/kg Lidocaine 1% 4+ Da - 15 2 1 mg/kg c (kg x 0.078) - 0.17 >8 kg Satoyoshi & 42 Kamiyama 55 Melman et al. 28 days -11 years 0-4 years Local Anesthetic Solution (% weight in volume) b D - 13 (ml) 4 mg/kg or 1.6 ml/kg Level of Analgesia T4 - T 2 T12 T10 Not mentioned Bupivacaine 0.2% Lidocaine 1% with epinephrine 1:200,000 Lidocaine 1.5% with epinephrine 1:200,000 Bupivacaine 0.20.375% Bupivacaine 0.25% with epinephrine 1:200,000 T4-T5 T4-T5 a D = The distance from C 7 to the sacral hiatus, in centimeters. Total dose. c Dose in milliliters per spinal segment. b Three important variables determine the quality, duration and extent of a caudal block: volume, total dose, and concentration of local anesthetic. Usually local anesthetics are used in the caudal space, but narcotics and non-narcotic analgesics (ex. clonidine, Stadol) have also been used with good success in infants and children. Extensive literature exists reporting multiple successful formulas for determining the amount of local anesthetic to use to obtain certain dermatoma levels. There is no agreement whether the age, weight, or height is the best criteria for determining the dose of anesthetic to use though. A study by Schulte-Steinberg and Rahlfs states that using Lidocaine 1%, Mepivacaine 1%, or Bupivacaine 0.25% 0.1 ml/segment per year of life in prepubertal children is a reliable method for determining anesthetic dose. I usually use 0.25% bupivacaine with 1:100,000 or 1:200,000 epinephrine 0.5-0.75 cc/kg for sacral levels, 1 cc/kg for lumbar levels, and 1.25 cc/kg for thoracic levels with a maximum dose of 20 ccs. There is no additional benefit for analgesia in giving higher concentrations of Class III - severe systemic disease that limits activity but is not incapacitating Class IV - incapacitating systemic disease that is a constant threat to life Class V - moribund patient not expected to survive 24 hours with or without operation E - If the procedure is performed as an emergency 7. It may ask for further studies, therapy or consultation 8. It documents informed consent to the planned anesthetic 9. It is signed legibly by an anesthesiologist APPENDIX H: ANESTHESIA MACHINE CHECK-OUT AND IMMEDIATE PRE-ANESTHESIA PREPARATION: SHORT FORM Room 1. Table Trendelenburg and is locked 2. Suction and catheter or Yankauer, scavenger Machine 3. Battery test appropriate to machine: power on: machine attached to power outlet. 4. GASES - correct gases in correct yokes and tanks: hoses correct 5. All valves closed: ensure full range of flows without sticking or erratic behavior 6. O2 - adequate reserve in cylinders (If piped O2 to be used - 500 psi on one (If cylinder O2 to be used - 500 psi in one; 1500 psi in 2nd 7. N2O adequate reserve in cylinders - 740 psi in each cylinder 8. Turn off all cylinders; leave tank wrench on closed O2 cylinder 9. FAIL-SAFE/O2 RATIO: a) O2 1.5 LPM:N2O > 5 L/M. Check: charge In O2 flow alarm b) If not (a), check fail-safe:run N2O, disconnect O2 supply; bring O2 pressure to zero. Check N2O shut-off for alarm. 10. Vaporizers: labeled, not empty or full, caps closed, shut off when done 11. LOW PRESSURE SYSTEM - Check for leaks: (expect some OHIO machines): open the vaporizer to be used. Turn on O2 flow 300/min/min: route O2 flow through vaporizer; Resident Handbook 86 29 Resident Handbook Anatomy occlude gas delivery tubing; listen for leaks, ensure that rotameters fall slowly and then bounce back when occlusion is released. 12. Place anesthesia bag on circuit elbow; fill ventilator bellows; turn on ventilator to check ventilation function BREATHING CIRCUIT 13. OXYGEN ANALYZER: Turn on and calibrate. Connect to anesthesia circuit. 14. Soda lime is present and not exhausted. 15. Reservoir bag, corrugated tubing and Y-piece, elbow connector 16. Uni-directional valves competent and patent 17. Check circuit for leaks; 40 cm of H2O for 5 seconds; no inflow; no pressure decrease 18. Release pressure by pop-off. Proper sequence; no connections broken after leak test. AIRWAY 19. Masks of appropriate sizes: oral and nasal airway 20. LARYNGOSCOPE and spare 21. Endotracheal tube and spare - check cuff, proper size 22. Lubricant and stylette 23. Proper pillow for patient’s head MONITORING (Locate, turn on, calibrate, etc. as needed) 24. Precordial or esophageal stethoscope 25. EKG 26. Blood pressure cuff, Dinamap or equivalent 27. Temperature monitoring device 28. Pulse oximeter 29. CO2 analyzer DRUGS & IV’s 30. Thiopental or other IV hypnotic 31. Atropine, glycopyrrolate 32. Succinylcholine 33. Extra syringes and needles 34. IV Set, IV Supplies 35. Supplies specific for the case 36. Check availability of blood products as indicated The sacrum is a triangular bone formed by the fusion of five sacral vertebrae. Ossification is incomplete at birth and it continues to ossify until eight years of age. The sacral hiatus is an opening into the sacral canal formed by the failure of fusion of the fifth sacral vertebral arches. Remnants are prominent sacrally and are referred to the cornua on either side of the hiatus. The opening is covered by the sacrococcygeal membrane. The sacral hiatus is easily palpated in infants and prepubertal children. A prominent sacral fat pad develops during puberty that may obscure normally prominent cornua. There is a large variation in the anatomy secondary to the frequent occurrence of developmental defects which accounts for a portion of failed blocks. Because of the relative stability of the anatomical landmarks, this block can be easily performed in either the lateral decubitus or prone position. In small infants and neonates, recall that the dural sac may end as low as S3, and the sacrum is narrower and flatter, so advancement of the needle more than 2-5 mm may result in a total spinal anesthetic. Also, the epidural fat in newborns and children less than five years is gelatinous, spongy, and less compact. There is less resistance to the cephalad spread of local anesthetics, and a styletted catheter can easily be passed to the lumbar or low thoracic vertebrae in these patients. Technique The caudal block is performed in either the lateral decubitus or prone position. Identify the tip of the coccyx, then with the index finger move cephalad until locating the sacral hiatus, which is felt as a depression in the bone. Superior and on either side of the hiatus, the sacral cornua are palpable. Mark the cornua and the tip of the coccyx and draw a triangle. Draw a perpendicular line from the base of the triangle to the apex, and divide this line into thirds. The caudal most intersection marks where the needle is to be inserted, and the other is the center of the sacral hiatus. Advance the needle at a 25 degree angle to the skin with the bevel facing down (to avoid piercing the anterior sacral wall--which is the most common reason to aspirate blood) until a pop is felt. Then drop the hub of the needle to 15 degrees and advance 2 millimeters more to assure that the bevel of Resident Handbook 30 85 Resident Handbook total spinal usually demonstrated as apnea with no change in the blood pressure or heart rate. In neonates, the rate of administration of the local does affect the level, whereas in adults it does not. Several cases of total spinals have been reported following rapid administration of usually safe doses of anesthetics. epidermoid tumors none reported in anyone who has received a spinal as an infant, ... so far. Caudal block The caudal block is the most frequently utilized regional anesthetic in infants and children for lower abdominal, upper abdominal, and lower extremity procedures. There is available data on pharmacokinetics and pharmacodynamics in all age groups, so drug doses are known. Well defined landmarks, simplicity, safety, ease of performance, less postoperative agitation secondary to excellent analgesia, decreased incidence of nausea and vomiting, earlier resumption of activities, and more rapid emergence from general anesthesia from a decreased use of narcotics all make this a superb anesthetic adjunct to general anesthesia. Sites of misplacement of local anesthetics for caudal block anesthesia. Note that injection may be made into bone marrow (A), into subperiostium (B), into posterior sacral ligaments (C), into a false “decoy” hiatus (D), into the anterior sacral wall and possibly out into the pelvis (E), or into a lateral foramen, producing a limited block (F). (Cousins MJ, Bridenbaugh PO [eds]: Neural Blockade in Clinical Anesthesia and Management of Pain, 2nd ed. Philadelpia, JB Lippincott, p. 378. 1988) APPENDIX I. INHALED ANESTHESIA CHARACTERISTICS 31 Resident Handbook