急诊医学教学课件：Mechanical Ventilation

TheSecondAffiliatedHospitalofNanjingMedicalUniversityTheSecondClinicalMedicalSchoolofNanjingMedicalUniversityMechanicalVentilationWhatismechanicalventilation？Mechanicalventilationisamethodtomechanicallyassistorreplacespontaneousbreathing.Homemadeventilator

2013年01月30日

新华每日电讯5版

fromXinhuanews18/min1080/hour25,920/dayTragicallydied?/05/0111/06/19Q0RUCP0001124T.htmlchangedoxygenunskillfully2000-8-23Nursechangedoxygenunskillfully,patientdied８月２３日，因值班护士给呼吸机更换氧气不熟练，造成供氧暂停，患者后来因呼吸循环功能衰竭死亡。鉴定认为“医务人员在某些专业性技术操作中尚有不足之处”。ventilatorleaked2001-5-8ventilatorleaked,patientdied.５月８日因呼吸机严重漏气，郭玉芳抢救无效死亡。西安医学会认为，医方的过失构成一级甲等医疗事故。tracheatubeunmatchedwithventilator2004-01-28tracheatubeunmatchedwithventilator,patientdied.２００４年１月２８日，１７岁的商洛少年林强入住交大第一医院内分泌科，２月８日，医院决定对林强实行气管切开呼吸机辅助呼吸手术。林强的气管被切开后，主治医师发现气管套管和呼吸机连接口不能对接，林强抢救无效死亡。1600yearsago

塞两鼻孔，以芦管纳其口中至咽，令人嘘之。有倾，其中砻砻转，或是通气也…Plugtwonostrils,insertareedintothemouthtothepharynx,thenblowairintoit,afterawhile,therespirationwillcomebackagain…葛洪GeHong《肘后救卒方》(adoctor,alchemist,regardasaimmortalinJindynasty)(284～364)400yearsago“…anopeningmustbeattemptedinthetrunkofthetrachea,intowhichatubeofreedorcaneshouldbeput;youwillthenblowintothis,sothatthelungmayriseagain…andtheheartbecomesstrong…”--AndreasVesalius(1555)aanatomist,physician,andauthorofoneofthemostinfluentialbooksonhumananatomy,Dehumanicorporisfabrica(OntheStructureoftheHumanBody).80yearsagoTheironlungwascreatedbyPhilipDrinkerandLouisAgassizShaw,twoHarvardUniversityresearchers.ThefirstironlungwasinstalledatBellvueHospitalinNewYorkCityin1927.Polioepidemicof1955negative-pressuretankventilators(IronLungs).Decreasingmortalityfrommorethan80%toapproximately40%《协和医院病中即事》1937年烧电线似有因，电灯倏灭仅三分。医师护士都失色，吓煞邻厢铁肺人。(美国富豪史奈特之子在铁肺中疗治数年，邻余病室。)岭南画派”名家高剑父，当时住在协和医院倏shuWhatcantheydoonaventilator?Blinky,LessLight,

achildren'sbookusingavoiceactivatedcomputer,32pagestook10yearsabout100,000copiesofthebookhavebeensold.DianneOdelldiedafter61yearbattleDianneOdell(February13,1947–May28,2008)

polio

atage3in1950OdelldiedonMay28,2008atage61.Apowerfailureandthefailureofanemergencygeneratorcutoffherbreathingdevice'sfunctions.Familymembersattemptedtousetheemergencyhandpumpattachedtotheironlungtokeepherbreathing,buttheireffortswereunsuccessfulNoninvasiveventilation(NIV)Apump？Theventilatorsimulatesfourstagesofbreathing:1.Theventilatororthepatienttriggerstheinitiationofinspiration.2.Theventilatorprovidesabreath,determinedbypresetvariables(eg,pressure,volume,andflowrate).3.Theventilatorhaltsinspirationwhenapresetparameter,suchastidalvolume,inspiratorytime,orairwaypressure,isreached.4.Theventilatorswitchestoexpirationandthebreathiscompleted.Outline1.Principles2.ModesandFunctions3.Methodsofconnection4.Options5.Alarms6.Dyssynchrony7.WeaningOutline1.Principles2.ModesandFunctions3.Methodsofconnection4.Options5.Alarms6.Dyssynchrony7.WeaningOutline1.Principles2.ModesandFunctions3.Methodsofconnection4.Options5.Alarms6.Dyssynchrony7.WeaningOutline1.Principles2.ModesandFunctions3.Methodsofconnection4.Options5.Alarms6.Dyssynchrony7.WeaningOutline1.Principles2.ModesandFunctions3.Methodsofconnection4.Options5.Alarms6.Dyssynchrony7.WeaningOutline1.Principles2.ModesandFunctions3.Methodsofconnection4.Options5.Alarms6.Dyssynchrony7.WeaningOutline1.Principles2.ModesandFunctions3.Methodsofconnection4.Options5.Alarms6.Dyssynchrony7.Weaning1.Principles1.1ObjectivesandIndications***1.2Contraindication*1.3Classification1.4

Ventilator-InducedLungInjury1.5PhysiologiceffectsofPositivePressureventilation1.1Objectivesandindications***WhenandwhydoweuseMV？1.1.1Reversehypoxemia1.1.2Reverserespiratoryacidosis1.1.3PreventAtelectasis,keeplungvolume.1.1.4Decreasetheworkofbreathing1.1.5Stabilizechestcavity1.1.6Respirationbackupfordruguse(sedation,musclerelaxant….)

1.1.1ReversehypoxiaHypoxia=Cyanosis？NO！Cyanosisisnotaccurate!Ithappenwhenthereducedhemoglobin>40g/L.WhataboutCOPDpatients?Whataboutanemiapatients?1.1.2ReverserespiratoryacidosisSymptomsandSignsofHypercarbia1.1.3PreventAtelectasis,keeplungvolume.

(functionalresidualcapacity)Earlyopenlung–thebest!ReisMiranda,D.,etal.(2005)."Openlungventilationimprovesfunctionalresidualcapacityafterextubationincardiacsurgery."CritCareMed

33(10):2253-22Decreasetheworkofbreathing(normal5%WOB/total)Tachypnea,Dyspnea,Useofaccessorymuscles,Nasalflaring,Sweating,Tachycardia1.1.5Stabilizechestcavity

(forparadoxicalrespiratorymovementinmultiplyribfracture,flailchest)1.1.6RespirationbackupfordruguseDr.ConradMurray,theinfamousdocwho'scriminallychargedinMichaelJackson'sdeathWhenyouusesedation,musclerelaxant….1.2Contraindication*Noabsolutecontraindication!1.2Contraindication*1.2.1PneumothoraxDonotMVBeforethoracocentesisalarge-bore(16or18gauge)catheterisintroducedinthemidclavicularlineatthesecondorthirdintercostalspace.

1.2.2bullaeoflung1.2.3Hemoptysis1.2.4HypovolemicShockWhy?1.3Classification1.3.1Controlmechanicalventilation(CMV)versusassistantmechanicalventilation(AMV)1.3.2Negative-(Theironlungandchestcuirass)versusPositive-pressureventilation

AudreyKing;1958polio1.3.3Useapproach:pressurecontrol,volumecontrol,Timecontrol1.3.4Frequency:highfrequencyventilationversusnormalfrequencyventilation1.3.5InvasiveversusnoninvasiveAgirlwhohaveSpinalMuscularAtrophy1.4Ventilator-InducedLungInjuryNormalRatLungafterreceivingHigh-PressureMechanicalVentilation

Peakairwaypressure45cmH2OAtulMalhotra,M.D.,NEJM357;11,p.1114,2007mechanicalventilationforeightweekstidalvolumesof12to15mlperkilogramofbodyweight,peakairwaypressuresof50to70cmofwater,positiveend-expiratorypressuresof10to15cmofwater,fractionalinspiredoxygenconcentrationof0.80to1.00paramediastinalpneumatoceleintherightlung(PanelA,arrowheads)numerousintraparenchymalpseudocystsintheleftlung(PanelB,blackarrow,opencircle,andasterisk)Tobin,MartinJ."AdvancesinMechanicalVentilation."NewEnglandJournalofMedicine344,no.26(2001):1986-1996.PathogenesisofVILIAtelectrauma:repetitiverecruitmentandde-recruitmentBarotrauma:overdistention,airleakBiotrauma:orbiochemicaltrauma,possiblyinducedbyphysicaldamage,isaninflammatoryprocesswithsystemicconsequencesProtectiveventilationMalhotraA,etal.NEnglJMed2007Protectiveventilation*

Lowtidevolume:6ml/kg（4-8ml/kg）(vsnomal6-10ml/kg)(decreaseventilator-InducedLungInjury)HighPEEP(PreventionofAlveolarCollapse)Pplate<30-35cmH2OPermissivehypercapniaMalhotraA,etal.NEnglJMed20071.5PhysiologiceffectsofPositivePressureventilationOutline1.Principles2.ModesandFunctions3.Methodsofconnection4.Options5.Alarms6.Dyssynchrony7.Weaning2.1ModeModereferstothemannerinwhichventilatorbreathsaretriggered,cycled,andlimited.Thetrigger,eitheraninspiratoryeffortoratime-basedsignal,defineswhattheventilatorsensestoinitiateanassistedbreath.Cyclereferstothefactorsthatdeterminetheendofinspiration.IPPVCPAPIMV/SIMVBiPAPPSV2.1.1Intermittentpositivepressureventilation(IPPV)Intermittentpositivepressureventilation(IPPV)**•GenerictermforalltypesofpositivepressureventilationControlledmandatoryventilation(CMV)MostbasicclassicformofventilationPre-setrateandtidalvolumeDoesnotallowspontaneousbreathsAppropriateforinitialcontrolofpatientswithlittlerespiratorydrive,severelunginjuryorcirculatoryinstability****2.1.2Pressurecontrolledventilation(PCV)Pressurecontrolledventilation(PCV)Pre-setrate;pre-setinspiratorypressureTidalvolumedependsonpre-setpressure,lungcomplianceandairwaysresistanceUsedinmanagementofsevereacuterespiratoryfailuretoavoidhighairwaypressure2.1.3Synchronizedintermittentmandatoryventilation(SIMV)Synchronizedintermittentmandatoryventilation(SIMV)Pre-setrateofmandatorybreathswithpre-settidalvolumeAllowsspontaneousbreathsbetweenmandatorybreathsSpontaneousbreathsmaybepressure-supported(PS)Allowspatienttosettleonventilatorwithlesssedation2.1.4Pressuresupportventilation(PSV)Pressuresupportventilation(PSV)BreathsaretriggeredbypatientProvidespositivepressuretoaugmentpatient'sbreathsUsefulforweaningMaybecombinedwithSIMVPressuresupportistitratedagainsttidalvolumeandrespiratoryrate2.1.5Continuouspositiveairwayspressure(CPAP)Continuouspositiveairwayspressure(CPAP)Positiveairwaypressureappliedthroughouttherespiratorycycle(viaeitheranendotrachealtubeoratight-fittingfacemask)Freshgasflowmustexceedpatient'speakinspiratoryflowImprovesoxygenationbyrecruitmentofatelectaticoredematouslungMaskCPAPdiscouragescoughingandclearanceoflungsecretions;mayincreasetheriskofaspiration2.1.6Bi-levelpositiveairwaypressure(BiPAP/BIPAP)Bi-levelpositiveairwaypressure(BiPAP/BIPAP)Infullyventilatedpatients,BiPAPisessentiallythesameasPCVwithPEEPInpartiallyventilatedpatients,andespeciallyifusednon-invasively,BiPAPisessentiallyPSVwithCPAP2.2FunctionPositiveEnd-ExpiratoryPressure(PEEP)SighInverseratioventilationAutotubecompensation2.2.1PositiveEnd-ExpiratoryPressure(PEEP)ForQs/Qt(shunt/total)hypoxia,especiallyARDSPEEP***4.6.1PEEPincreasesend-expiredlungvolumeandreducesairspaceclosureattheendofexpiration.4.6.2PEEPat5cmH2Otolimittheatelectasis4.6.3HigherlevelsofPEEPimproveoxygenationindisorderssuchascardiogenicpulmonaryedemaandARDS.PEEPvsAuto-peepSetPEEP=80%auto-PEEPForCOPDandasthma2.2.2Sigh1.5-2timesofnormalVt1-3in50-100respirationLikeyawnforusRecrument2.2.3Inverseratioventilation2.2.4AutotubecompensationWithoutATC(top),ThePatienthastoGenerate

PtubeWithATC(bottom),theventilatorproducesexactlythisPtubeandrelievesthepatientoftheextrawork.2.3HowtoselectModeandfunction1.Oxygen2.CO23.respiratorymusclestrength4.airwayresistance5.weaning6.chronicpulmonarydiseaseOutline1.Principles2.ModesandFunctions3.Methodsofconnection4.Options5.Alarms6.Dyssynchrony7.Weaning3.MethodsofconnectionFaceMaskNasalmasklaryngealmaskEndotrachealintubation(oral,nasal)tracheostomytube3.1FacemaskNon-invasiveStomachoverextensionSkinulcer(Tootight),leak(tooloose)3.2NasalmaskMorecomfortableNotimpactdrink,eat,expectoration3.3laryngealmaskLessgasdistensionNon-invasive3.4Endotrachealintubation(oral,nasal)Oral:MostcommonNasal:moreVAP(ventilatorassociatedPneumonia)3.5TracheostomytubeLongtermventilationMoreComfortableMoreinvasiveOutline1.Principles2.ModesandFunctions3.Methodsofconnection4.Options5.Alarms6.Dyssynchrony7.Weaning4.OptionsFrequency(F)Tidalvolume(Vt)andminuteventilation(MV)Inspiratory:expiratory(I:E)ratioSensitivityPEEPFIO24.1Frequency4.1.1.Therespiratoryrateandtidalvolumedetermineminuteventilation.4.1.2.Settherateat12to25/mintoachieveaminuteventilationof8to12L/min.4.1.3.AdjusttheratetoachievethedesiredpHandPaCO2.4.2VtandMVAtidalvolumetargetof6to10mL/kgpredictedbodyweightisused.Idealbodyweightisdeterminedbytheheightandthesexofthepatient.Pleasematch5mL/kg(Low，4-8mL/kg)6to8mL/kgwith.8to10mL/kg（high）ARDS.neuromusculardiseaseorpostoperativeventilatorysupport.obstructivelungdisease4.3Inspiratory:expiratory(I:E)ratio

Whichisright？4.3.1.Theexpiratorytimegenerallyshouldbe(shorterorlonger)

thantheinspiratorytime.4.3.2.Theexpiratorytimeshouldbe(shortenedorlengthened)ifthebloodpressuredropsinresponsetopositive-pressureventilationorifauto-PEEPispresent.4.3.3.Longerinspiratorytimes(increaseordecrease)meanairwaypressureandmayimprovearterialpartialpressureofoxygen(PaO2)insomepatients.Answer:1.longer

(I:E1:1.5-1:2),2.lengthened,3.increase4.4Sensitivity4.4.1Sensitivityadjuststhelevelofnegativepressurerequiredtotriggertheventilator.4.4.2Atypicalsetting1–3L/min(quantitative)or-1–

-2cmH2O(pressure).4.4.3Toohighasettingcausesweakpatientstobeunabletotriggerabreath.4.4.4Toolowasettingmayleadtooverventilationbycausingthemachinetoauto-cycle.4.5FractionofinspirationO2Doeslifelikeoxygen？HyperoxiaincreasemortalityKilgannon,J.H.etal.JAMA2010;303:2165-2171Figure.In-HospitalDeathBetweenHyperoxiaandNormoxiaKilgannon,J.H.etal.JAMA2010;303:2165-2171Rincon,F.,J.Kang,M.Maltenfort,M.Vibbert,J.Urtecho,M.K.Athar,J.Jallo,C.C.Pineda,D.Tzeng,W.McBrideandR.Bell."AssociationbetweenHyperoxiaandMortalityafterStroke:AMulticenterCohortStudy."CritCareMed42,no.2(2014):387-96.FiO24.5.1.

InitiatemechanicalventilationwithanFiO2

of.2.

TitratetheFiO2

usingpulseoximetry.4.5.3.

InabilitytoreducetheFiO2tolessthan0.6indicatesthepresenceofshunt(intrapulmonaryorintracardiac).Outline1.Principles2.ModesandFunctions3.Methodsofconnection4.Options5.Alarms6.Dyssynchrony7.WeaningAlarm5.1.VtorMValarm5.2.Pressurealarm(highandlow)5.3.FIO2alarmOutline1.Principles2.ModesandFunctions3.Methodsofconnection4.Options5.Alarms6.Dyssynchrony7.Weaning6.Dyssynchrony6.1Causeofpatient:hypoxiadidnotcorrectedAcuteleftheartfailureCentralnervoussystemdiseaseChough,obstructionNervousAcidosisIncreaseofoxygendemand:fever,epilepsy

Dyssynchrony6.2Causeofventilator:synchronizationfunctionofthemachineTriggerLeak6.3ManagementofDyssynchrony

VentilatorPatient:Sedation

musclerelaxantOutline1.Principles2.ModesandFunctions3.Methodsofconnection4.Options5.Alarms6.Dyssynchrony7.WeaningWeaning21:0021:1221:347.1Screenforweaning7.1.1Lunginjuryisstable/resolving,7.1.2GasexchangeisadequatewithlowPEEP

andFIO2(PEEP<8cmH2OandFIO2<0.5),7.1.3Hemodynamicvariablesarestable(patientoffvasopressors),7.1.4Patientiscapableofinitiatingspontaneousbreaths.This"screen"shouldbedoneatleastdaily.7.2Spontaneousbreathingtrial(SBT)10cmH2OPSV30minor2hour7.3Removaloftheartificialairway7.3.1Theabilitytoprotecttheairway,tocoughandclearsecretions,andisalertenoughtofollowcommands.7.3.2Otherfactorsmustbetakenintoaccount,suchasthepossibledifficultyinreplacingthetube.7.3.3~10–15%ofextubatedpatientsr