Download PTY4CAP EXAM NOTES

PTY4CAP NOTES
MONICA VOONG
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TableofContents
LECTURENOTES.................................................................................................................5
RESPIRATORYPHYSIOLOGYANDPATHOPHYSIOLOGICALCAUSESTORESPIRATORYPROBLEMS.6
INCREASEDWORKOFBREATHING............................................................................................14
REDUCEDVENTILATIONANDLUNGVOLUMES.........................................................................20
NONINVASIVEVENTILATION(NIV)...........................................................................................26
ARTERIALBLOODGASES(ABGs)...............................................................................................33
SPUTUMRETENTION&AIRWAYCLEARANCE...........................................................................36
ASTHMA...................................................................................................................................42
PNEUMONIA............................................................................................................................47
OBSTRUCTIVERESPIRATORYDISEASES.....................................................................................51
PULMONARYFUNCTIONTESTS(PFTs)......................................................................................56
RESTRICTIVELUNGDISEASES....................................................................................................61
CYSTICFIBROSIS&BRONCHIECTASIS........................................................................................67
CARDIACDISEASEANDFAILURE...............................................................................................71
ELECTROCARDIOGRAPHY(ECGs)...............................................................................................81
THORACICTRAUMA.................................................................................................................88
SURGERY(PRE&PERIOPERATIVE)...........................................................................................95
SURGERY(POSTOPERATIVE)...................................................................................................101
CARDIACSURGERY.................................................................................................................109
PULMONARYREHABILITATION...............................................................................................115
PRACTICALTECHNIQUES................................................................................................123
VitalSignNorms.....................................................................................................................124
ArterialBloodGasesNorms....................................................................................................124
SubjectiveAssessment...........................................................................................................125
ObjectiveAssessment............................................................................................................126
Intervention...........................................................................................................................127
ProblemList...........................................................................................................................128
Positioning.............................................................................................................................129
BreathingExercises/Interventions..........................................................................................131
RelaxedControlledBreathing(RCB)..........................................................................................131
PursedLipBreathing..................................................................................................................131
ThoracicExpansionExercises(TEEs)..........................................................................................131
AdjunctstoBreathingExercises................................................................................................132
OxygenTherapy.....................................................................................................................133
VariablePerformanceDevices...................................................................................................135
FixedVariableDevices...............................................................................................................137
Non-InvasiveVentilation(NIV)...............................................................................................139
ContinuousPositiveAirwayPressure(CPAP)............................................................................139
Bi-LevelPositiveAirwaysPressure(BiPAP)................................................................................140
AerosolandNebuliserTherapy..............................................................................................142
Relievers....................................................................................................................................142
Non-steroidalPreventers..........................................................................................................142
CorticosteroidPreventers–MUSTRINSEMOUTHAFTERUSE..................................................142
Long-actingBeta2Agonists(LABA)............................................................................................142
Combination(corticosteroid&LABA)–MUSTRINSEMOUTHAFTERUSE................................142
COPDonlymedication...............................................................................................................142
MeteredDoseInhaler(With/WithoutSpacer)..........................................................................142
Turbuhaler.................................................................................................................................143
Accuhaler...................................................................................................................................143
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HandiHaler.................................................................................................................................143
Nebuliser...................................................................................................................................144
AirwayClearanceTechniques.................................................................................................145
Cough.........................................................................................................................................145
Huff............................................................................................................................................145
ForcedExpiratoryTechnique(FET)............................................................................................145
ActiveCycleofBreathingTechnique(ACBT).............................................................................145
Percussion&Vibrations.............................................................................................................145
PositiveExpiratoryPressure(PEP).............................................................................................146
Positioning.................................................................................................................................149
Spirometry.............................................................................................................................150
FVC&FEV1.................................................................................................................................150
FlowVolumeLoop(FVL)............................................................................................................150
VitalCapacity.............................................................................................................................151
ResponsetoBronchodilators.....................................................................................................151
Peakexpiratoryflowrate(PEFR)measurement......................................................................152
UnderwaterSealDrainage(UWSD)........................................................................................153
Pre-OperativeAssessment.....................................................................................................154
Post-OperativeAssessment....................................................................................................154
PrioritisingPatients................................................................................................................155
DischargePlanning.................................................................................................................155
ShuttleWalkTest...................................................................................................................156
6MinuteWalkTest................................................................................................................158
BORGSOB&RPEScale...........................................................................................................160
Cardiac&PulmonaryRehabilitationPrograms.......................................................................161
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LECTURENOTES
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RESPIRATORYPHYSIOLOGYANDPATHOPHYSIOLOGICALCAUSESTORESPIRATORY
PROBLEMS
LEARNINGOUTCOMES
• Tobefamiliarwiththeanatomicalstructureswhichcomprisethethoraxandit’scontents
• Tounderstandrespiratoryphysiologyandthemechanicsofrespiration
• Tounderstandhowtherespiratorysystemandthoraxchangeswithage
• Tounderstandhowdiseasewillaffectthefunctionoftherespiratorysystem
RELATIONSHIPOFTHELUNGSTOTHETHORACICWALL
• Thorax=chestwall(closedcompartment)
• Thelungssitinthethorax–thelungsaretwoseparatelungs
o Areonlyjoinedwheretheairwaysbranch(primarybronchus)
• Eachlungissurroundedbypleura–thetwopleuraaretwoseparatestructures
o Visceralpleura(immediatelyontopofthelungs)
o Parietalpleura(‘outerlayer’)
o Separatedbyintrapleuralfluid
BONYTHORAX
• Bonesthatmakeupthethorax:
o Vertebralcolumn(12)
o Ribs(12)
o Sternum
• Jointsinvolved:
o Intervertebral
o Costovertebral
o Costochondral
o Sternocostal
o Manubriosternal
o Allowsformovementofthethoraxduringrespiration
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CHANGINGDIMENSIONSOFTHETHORAX
• Thethoraxisnotafixedstructure
• Vertically
o Diaphragmcontractsandflattens
o Ribselevate
• Anterior-posterior(Pumphandle)
o Sternumispulledupandforward
o Upperribselevate
• Transverse(Buckethandle)
o Lowerribsswingoutwardsandup
• APandtransversemovementreducedby
o Burns–scartissueformation&tightening
o Bonythoraxchanges/trauma
§ Sternaldeformities
§ Kyphosis
§ Ribfractures
§ Sternalfractures
o COPD
§ Hyperinflation(higherrestingvolume)leadingtobarrelchest
• Verticalmovementreducedwith
o COPD
§ Lowflatdiaphragm,furthercontractionwillpullthelowerribsinwards–‘Hoovers
sign’
o Obesity–increasedweightoftissue
o Abdominaldistension–increasedweightoftissue
o Pregnancy–increasedweightoftissue
o Diaphragmaticweakness
§ Accessorymusclesandshoulderswillbeusedtocompensate
RIBCAGEACROSSTHELIFESPAN
• Childhood
o Whenababyisborn,theyarebornwithhorizontalribs–whichhaveverylittleroomfor
elevation
o Circularribcagecomparedtotheellipticalshapeinanadultribcage
o Cartilagechestwall–softer(untilossificationoccurswhichproducethebonyribcagein
adults)–effectsmechanicsofbreathing)
o Theadultchestshapeisachievedby3yearsold
o Highlycompliantchestwall(notossifiedtill25yearsold)
• Adulthood
o Ribsareusuallyanobliqueangle
o Upperandlowerchestmovementsinmen,femaleusuallyhavemovementinupperthorax
o TheAP:Transversediameteris2:1diameter
o Ossificationiscomplete–givingafirmbutflexibleribcage
o NormalRR=12-16breaths/min
• Oldage
o Increaseinupperthoraciccurvature
o Stiffeningofthoracicspineandcostovertebraljoints
o Costalcartilageossifies
§ Decreasestheabilitytomovetheribcage
§ Upperthoracicvertebrasarestiffresultingininsufficientbreathing
o Ligamentsweakenallowingribstodrop
o Lossoftoneinabdominalmuscles
o Lessmovementinupperthoracicthorax
o Bonythoraxisstiffer=lesscompliant
o NormalRR=16-22breaths/min
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MUSCLESOFRESPIRATION
QuietInspiration
• Diaphragm
o Thin,dome-shapedmuscle
o Primarymuscleofinspiration
o Innervatedbyphrenicnerve(C3,4,5keepsyourdiaphragmalive)
o Pushesabdominalcontentdownandforwards
o Liftslowerribsmarginsupandout
• Externalintercostalmusclesassistinelevatingtheribs
• Importanttonote:
o Childrendependmuchmoreonactionofdiaphragmthereforeabdominaldistensionthat
interfereswithdiaphragmaticexcursionwillrestrictinspiration.
o Thisisbecauseofthehorizontalorientationoftheirribsandtheweakenmusclesinthe
intercostals
o Theyareunabletoeffectivelyincreaserespiratoryvolume,thuswillincreaserespiratoryrate
formoreeffectiverespiration,butwillfatigueeasily
Quietexpiration
• Passiveprocess
• Naturalelasticrecoilofthelungsandribcage
Forcedinspiration
• Diaphragm
• Externalintercostal
• Accessorymuscles–Musclesthatstemfromneckorbackandinsertintoribcage-whichwillhelpby
stabilisingormovingtheribs
o Sternocleidomastoid(SCM)
o Scalenes
o Pectoralismajorandminor
o Latissimusdorsi
o Serratusanterior
Forcedexpiration
• Abdominalwall
o Rectusabdominus
o Internalandexternalobliques
o Transversusabdominis
• Internalintercostals
CAUSESFORRESPIRATORYMUSCLEPROBLEMS
• Respiratorymuscleweakness
o Lowermotorneurondisease(neurologicalconditions)
o Musculardystrophy
• Nervedamage
o Phrenicnerve
o Spinalcordinjury
• Altereduse
o Chronicobstructivepulmonarydiseases(COPD)
• Overuse
o Obstructivelungdiseases
o Occupationallungdiseases(Restrictivelungdiseases)
o Acutelungpathology–e.g.asthma,pneumonia
o Hyperventilation–painoranxiety(peoplewillbreatherapidly)
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ORGANISATIONOFTHERESPIRATORYSYSTEM
ConductingZone
• Extendsfromtracheatoterminalbronchioles
• Noalveoli
• Nogasexchangewiththeblood
RespiratoryZone
• Extendsfromrespiratorybronchiolesondown
• Containsalveoli
• Gasexchangeoccurswiththeblood
DEADSPACE
• Anatomicaldeadspace
o Airinconductingzone~150Ml
o Doesnotparticipateingasexchange
o Insufficientbloodsupplytothisarea
• Alveolardeadspace
o Airinalveolithatisnotusedforgasexchangeduetolittle/nobloodsupply
• Physiologicaldeadspace=anatomicaldeadspace+alveolardeadspace
o Increaseswithageandlungdisease
ALVEOLI–SITEOFGASEXCHANGE
• 300-500milliontinyhollowsacs,each0.3mmindiameter
• Linedbyliquidcreatinghighsurfacetension–liquidhasahighattractiveforce
• Inherentlyunstablestructureatriskofcollapse
• Surfactant
o Reducessurfacetension
o Increasesstability
o Improvescompliance
o Keepslungdry
o Improvesinterdependencewithlungparenchyma
• Prematurebabieshavereducedsurfactantswhichmakethempronetolungcollapse
o Surfactantisonlyproduced>34weeksgestation
o Lungproblemsusuallycarryonthroughoutlife
PROTECTIONOFTHELUNG
o Large particles filtered by nose
o Cough and sneeze reflex – if body detects
particle, the body will expel air to get rid of
it
o Muscociliary escalator
§ Cilia beat within watery fluid or ‘sol’
layer on top of which mucus layers
moves
§ Smoking, use of anesthetics and
drugs can reduce cilia movements
o Macrophages engulf inhaled particles and
bacteria making them harmless
§ Smoking can injure macrophages
LUNGPROTECTION–COUGH
• Protectivereflextoclearsecretionsorforeignbodiesinairways
o Deepinspiration
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•
o Glottisclosesandvocalcordscontracttoshutthelarynx
o Abdominalmusclescontractwithotherexpiratorymuscles
o Vocalcordsrelaxandglottisopens
o Airisreleaseatover160km/h
Causesofcoughreduction
o Significantbraindamage
o Respiratorymuscleweakness
o Obstructedairways
o Pain
§ Decreasescoughstrength,decreaseeffectivenessofcough,increasessecretion
retention
o Weaknessinabdominalmuscles
DEFINITIONS
• Ventilation:Exchangeofairbetweenatmosphereandalveoli(movementofairwithinairways)
• Alveolarpressure:Gaspressureinthealveoli
• Atmosphericpressure:Thepressureofairsurroundingthebody–doesn’tchangeunlessyouchange
altitude
• Intrapleuralpressure:Thepressurewithinthepleuralcavity.Atrest,intrapleuralpressureissubatmospheric.Thisisduetotherecoilofthechestandlungsawayfromeachother(intrathoracic
pressure)
• Transpulmonarypressure:Differencebetweenthealveolarpressureandtheintrapleuralpressurein
thelungs.Duringventilation,airflowsbecauseofpressuregradients.
• Intrapulmonarypressuredecreasesduringinspiration
• Thedecreaseinpressureisgreaterintheintrapleuraincomparisontotheintrapulmonarypressure
PROPERTIESOFTHELUNG&CHESTWALLELASTICRECOIL
• “Thetendencyofanelasticstructuretoopposestretchingordistortion”
• Chestwallwantstospringoutwards
• Thelungswanttoretractinwards
o Duetoelasticfibresininteralveoliseptum
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•
•
Createsansubatmosphericintrapleuralpressure
Bringsthelungsbacktorestingstate(FRC)
LUNGCOMPLIANCE
• Definedasthemagnitudeofthechangeinlungvolumeproducedbyagivenchangein
transpulmonarypressure.
• Howdistensiblethelungsare
• Determinedby
o Stretchabilityofthelungtissue
o Surfacetensionattheairwaterinterfaceswithinthealveoli
• Totalpulmonarycompliance=complianceofboththoraxandlung
• Infantshaveahighlycompliantribcagesandstifflungs
• Adultshavelesscompliantribscages(buttheyareflexible)andcompliantlungs
• Olderadultshavelesscompliantribcages(theybecomestiffer)
• Reducedby
o Oedema–AcuteRespiratoryDistressSyndrome(ARDS)
o Scartissue–Pulmonaryfibrosis
o Deformity–Kyphoscoliosis
o Muscleparalysis–Polio
o Restrictivelungdiseases
• Increasedby
o Initiallyinemphysemabutashyperinflationincreasescompliancedecreases
o Innormalaginglung
• Lungcompliance≠thoraciccompliance(howeasyitisforthebonythoraxtostretch)
GASFLOWANDAIRWAYSRESISTANCE
• Nosetoterminalbronchioles=bulkflow
• Terminalbronchiolestoalveoli=gasdiffusion
o Lowvelocitycancauseinhaleddusttosettleinterminalbronchioles
• Volumeofgasflowin/outofalveoliis:
o Directlyproportionaltopressuredifferencebetweenatmosphereandalveoli
o Inverselyproportionaltoairwaysresistance
• Duringaforcedexpirationdynamiccompressionofairwayslimitstheairflowinanormalsubject
• However,theregetsapointwhereflowisindependentofeffort–thatis,itisdeterminedbythe
staticrecoilpressure
AIRWAYRESISTANCE
• Airwaysareheldopenbytranspulmonarypressureandradialtraction
• Airwayresistancetoairflowisnormallyverysmall
o Verysmallpressuredifferencesbetweenalveolarandintrapleuralwillproducelargevolumes
ofairflow
• Airwayresistancecanbealteredby
o Sizeofairwaye.g.bronchoconstriction
o Obstructioninairway
§ Sputum
§ Oedema
§ Tumours
§ Bronchospasm
Ventilationdistribution–Theyarenotdistributedequally(ADULTSONLY)
• Howairflowsintothelungs
• Thelungsdon’texpandatthesamerateindifferentareasofthelungs
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•
Lowerregionsofthelungventilatebetterthanupperzones
o Duetotheweightofthelungs
o Theapexofthelunghaslargeexpandingpressure,abigrestingvolumeandsmallchanges
oninspiration–UPPERREGIONS
o Bycontrast,theexpandingpressureofthebaseofthelungissmall,thereisasmallresting
volumeandlargechangesoninspiration.–LOWERREGIONS
o Dependentregionoflungs=wheregravitypulls
Pulmonaryvascularresistanceanddistributionofbloodflow(perfusion)
• Perfusion=thebloodflowthatgoestothelungs
• Pressureswithinpulmonarybloodflowareextremelylow
• Perfusionofthelungisbestinthemostgravitydependentportionofthelung
• Inarestingadult
o Upright–Highperfusioninbasecomparedtoapex
o Supine–Bloodflowinposteriorlung(dependent)exceedsflowintheanteriorparts
• Causesaffectingperfusion
o Pulmonaryarterypressureisfrequentlyincreased(hypertension)inpatientswithCOPDas
theirdiseasesadvances
§ Largeportionsofcapillarybedsaredestroyed
§ Hypoxiacanleadtopulmonaryvasoconstriction
§ Acidosismayexaggeratehypoxicvasoconstriction
§ Inadvanceddiseasetherearehistolicchangesinthewallsofthesmallerarteries
§ Patientsmaydeveloppolycythemia–increasedbloodviscosity
§ Mayleadtorightsidedventricularhypertrophy–CorPulmonale
Ventilationandperfusion(V/Q)matching
• Adulthood:
o Ventilationandperfusionarebestmatchedinthedependentportionsofthelungs
o Atthebasisofthelungswhenupright
• Childhood:
o Ventilationisbestinnon-dependentwhilstperfusionisbestinthedependentportions,this
changestothesamematchingasadultsat~8yearsofage
o Effectongravityonventilationisminimal
o Effectofcompressionofthechestwalloverridesanygravitationaleffectonventilation
V/Qmismatch
• LowV/Qratio:
o Reducedventilationrelativetoperfusion
o ¯PaO2(­PaCO2)
o E.g.pneumonia,COPD,fibrosis,asthma
• HighV/Qratio:
o Highventilationrelativetoperfusion
o EffectiveCO2elimination,relativelysmall­PaO2
o E.g.pulmonaryembolus(PE)
§ PaitentswithPEareoftenhypoxaemicasthereisincreasedperfusiontootherparts
ofthelung(=lowV/Qratio)
CONTROLOFBREATHING
• Respirationachievesabalancebetweenarterialoxygenandcarbondioxide
• Controlisneuralandchemical
• Neuralcontrol:
o Responseinfractionsofseconds
o Changesthesizeanddurationofindividualbreaths
• Chemicalcontrol:
o Slowerchanging–overminutes
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o Changesminuteventilation
Innervationofairwaysofthelungs
• Innervationoftheairwaysofthelungsisseparatetothatwhichbringsaboutbreathing
• Efferent(motor)systemsproducebrochomotortone
• Sympatheticandparasympatheticsupply
o Parasympatheticefferentismostimportant(producesbronchoconstriction)
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