gasman應(yīng)用在吸入麻醉教學(xué)中體會(huì)

gasman應(yīng)用在吸入麻醉教學(xué)中體會(huì)第1頁/共31頁Exercises第2頁/共31頁Wash-inofasinglecompartmentWash-inofasinglecompartmentproducesanexponentialcurve第3頁/共31頁Wash-inofasinglecompartmentτ=t0.63τequalsthetimerequiredforthecurvetoreach1-e-1,or63%ofitsfinalvalueAttheendof1,2,3,4,5timeconstants,thecircuittensionequals63%,87%,95%and99%ofthedeliveredfromthevaporizer第4頁/共31頁Wash-inofasinglecompartmentτ=V/FThetimeconstantsforwash-inofasinglecompartmentequalseffectivevolumedividedbyeffectiveinflowrate第5頁/共31頁Wash-inofasinglecompartmentτ=V/FCircuitvolumeis8litersτ=V/F=8/4=2minInspiredtensionreached63%ofdelivered第6頁/共31頁第7頁/共31頁TwoSequentialCompartmentsBreathingcircuitpatient’slungsLung’sτ=FRC/VAFRC:functionalresidualcapacityVA:alveolarventilation第8頁/共31頁TwoSequentialCompartmentsLung’sτ=FRC/VAFRC:functionalresidualcapacityVA:alveolarventilationAlveolartensioncurve(ALV)looksidenticaltotheinspiredtensioncurve(CKT)第9頁/共31頁TwoSequentialCompartmentsOverpressurecanspeedtheriseinanesthetictensiontowcompartmentsawayObjective:achieve70%alveolartensionsmoothlyandquickly第10頁/共31頁第11頁/共31頁AlveolarTensionCurveOpencircuitalveolartensioncurveisthealveolarresponsetoastepchangeininspiredtension,representingpatientwash-in第12頁/共31頁AlveolarTensionCurve第13頁/共31頁AlveolarTensionCurveInitialriseinthealveolartensioncurveisresultsfromalveolarwash-inresponsivetoastepchangeininspiredtension第14頁/共31頁AlveolarTensionCurve第15頁/共31頁AlveolarTensionCurveLowerventilationslowsinitialriseinalveolartension第16頁/共31頁AlveolarTensionCurveVA：7.5----1.25τ

：0.33-----2AlveolartensionreachafinalvalueequaltoinspiredtensionundertheconditionofCO=0第17頁/共31頁AlveolarTensionCurveUptakeproducesakneeandplateauinalveolartensionDisablereturn:emptyvenousanesthetictensionbar(VEN)3minpause第18頁/共31頁AlveolarTensionCurveIncreasingalveolarventilationraisesthekneeandplateau6minpause第19頁/共31頁AlveolarTensionCurveIncreasingcardiacoutputlowersthekneeandplateau9minpause7.5第20頁/共31頁AlveolarTensionCurve第21頁/共31頁AlveolarTensionCurveKneeorplateauheightdeterminedbytheratioofalveolarventilationtocardiacoutput?第22頁/共31頁AlveolarTensionCurve第23頁/共31頁AtconstantCO,increasingVAinastepwisefashioncauseastepwiseriseinalveolarplateauheightSetbreakpointsateveryminuteupto10and15Ateachminute,increaseVAbyoneAlveolarTensionCurve第24頁/共31頁AtconstantVA,decreasingCOinastepwisefashioncauseastepwiseriseinalveolarplateauheightSetbreakpointsateveryminuteupto10and15Ateachminute,reduceCOby1L/minuntil0AlveolarTensionCurve105第25頁/共31頁AlveolarTensionCurveKneeandplateauheightisdeterminedbytheratioofalveolarventilationtoeffectivecardiacoutput第26頁/共31頁AlveolarTensionCurveAnestheticreturnedtothelungsinvenousbloodconvertsthealveolartensioncurveplateauintoagently-risingtailSetabookmarkat2minutesDeselectdisablereturncontinue第27頁/共31頁AlveolarTensionCurveAscendingtailproducedbytheadditionofanestheticreturninginvenousbloodVenousanesthetictensionisdeterminedbythearterialbloodanesthetictension,tissuebloodflowandtissuecapacity第28頁/共31頁第29頁/共31頁BloodGasSolubilityBlood/