8.16全身麻醉与保护性肺通气策略

全身麻醉与保护性肺通气策略四川大学华西医院麻醉科喻洁晨课P.O.PVENTILATION

Peri-OperativePositivepressureventilationHowwecameallthewayhere?肺是外部环境与血液之间气体交换的媒介机械通气保证正常PO2、PCO2、PH值机械通气相关性肺损伤Ventilationinducedlunginjury(VILI)功能VS.状态只有当器官处于正常状态，才能持久稳定地发挥功能amulticenter,randomizedtrialTraditionaltidalvolumes:VT4-12ml/kg(PBW);plateaupressure≤50cmH2OLowertidalvolumes:VT4-6ml/kg(PBW);plateaupressure≤30cmH2OPrimaryoutcome:1deathbeforeapatientwasdischargedhomeandwasbreathingwithoutassistance2thenumberofdayswithoutventilatorusefromday1today28Thetrialwasstoppedaftertheenrollmentof861patientsInpatientswithacutelunginjuryandtheacuterespiratorydistresssyndrome,mechanicalventilationwithalowertidalvolumethanistraditionallyusedresultsindecreasedmortalityandincreasesthenumberofdayswithoutventilatorusePredictedBodyWeight(PBW)

PBWformales=50kg+2.3kg×(Height[in]−60)PBWforfemales=45.5kg+2.3kg×(Height[in]−60)(1inch=0.3937cm)PBWformales=50.0+0.91(height[cm]–152.4)PBWforfemales=45.5+0.91(height[cm]–152.4)PBW将潮气量按肺体积进行标准化处理肺体积主要由性别及身高决定例:52岁,女性,153cm,70KgVT=6ml/Kg则VT=420ml(ABW)PBW=46KgVT=276ml(PBW)Doesmechanicalventilationwillactuallycauselunginjury?VentilatorInducedLungInjury以45cmH2O的气道峰压机械通气5分钟后局灶性肺不张形成20分钟后肺明显充血、水肿、气管内可见水肿液ventilatorinducedlunginjury炎性细胞侵润透明膜形成血管通透性增加肺水肿Volutrauma大潮气量使肺泡过度充气导致的“牵张”损伤pneumothorax不张肺泡随呼吸运动周期性开放及塌陷，所致损伤含气肺泡和不张肺泡之间剪切力，导致肺实质进一步损伤Atelectrauma全身麻醉与肺不张Itisnowknownthatatelectasisoccursinthemostdependentpartsofthelungof90%ofpatientswhoareanesthetizedBiotraumaConventionalVentilation传统通气ProtectiveVentilation保护性通气通气策略VT10-15ml/ABW6-8ml/PBWPEEP<4cmH2O/0cmH2O6-8cmH2ORM无30min/次主要通气参数PaCO2normalpermissivehypercapniaPO2normalnormal目的保证足够通气，减少呼吸做功保证适当通气，预防肺损伤两种机械通气方式比较RMrecruitmentmaneuverRecruitmentManeuver(RM)aPAWof30cmH2Oisrequiredforinitialopening,and40cmH2OformorecompletereversalinflationwithaPAWof40cmH2Ofor7to8secondsappearstosuccessfullyopenalmostallanesthesia-inducedatelectasisvolutraumalimitoverdistentionlowtidalvolumeatelectraumapreventatelectasishigherPEEPbiotraumapreventvolutraumatelectrauma

保护性通气减少VILIConventionalVS.Protectiveventilation保护性通气的弊端小潮气量通气PaCO2增高、呼吸性酸中毒应谨慎用于合并颅内高压、肺动脉高压患者PEEP/RM静脉回流受阻导致循环波动气胸（罕见）lowtidalvolumesduringsurgerydecreasetheneedforpostoperativenon-invasiveandinvasiveventilatorysupportwefoundnoevidenceforadetrimentaleffectofroutineuseoflowintraoperativevolumesLowversushightidalvolume,Outcome1Mortalitywithin30daysthenumberofparticipantsincludedinthepresentmeta-analysisrepresentslessthan10%oftheoptimalinformationsizeforthisoutcomemoredatawillberequiredbeforeadefinitiveconclusioncanbedrawnontheeffectoflowtidalvolumeonperioperativedeathLowversushightidalvolume,Outcome2PneumoniaLowversushightidalvolume,Outcome3Needforpostoperativenon-invasiveventilationLowversushightidalvolume,Outcome4NeedforpostoperativeinvasiveventilationPreventisbetterthancure!ProtectiveVentilation参考文献1.

FutierE,MarretE,JaberS.Perioperativepositivepressureventilationanintegratedapproachtoimprovepulmonarycare.Anesthesiology2014;121:400-082.DugganM,KavanaghBP.Pulmonaryatelectasis:apathogenicperioperativeentity.

Anesthesiology2005;102:838-543.TheAcuteRespiratoryDistressSyndromeNetwork.etal.Ventilationwithlowertidalvolumesascomparedwithtraditionaltidalvolumesforacutelunginjuryandtheacuterespiratorydistresssyndrome.NEnglJMed2000;342:1301-84.MalhotraA.Low-tidal-volumeventilationintheacuterespiratorydistresssyndrome.NEnglJMed2007;357:1113-205.SlutskyAS,RanieriVM.Ventilator-inducedlunginjury.NEnglJMed2013;369:2126-21366.GuayJ,OchrochEA.Intraoperativeuseoflowvolumeventilationtodecreasepostoperativemortality,mechanicalventilation,lengthsofstayandlunginjuryinpat