肺保护性通气病因病理病程BP70/50,HR170,cvp8.NE5+PHE5FiO270%,PEEP12Ph24SaO290%ARDS常见的临床综合征EndothelialandepithelialinjuryPathophysiologyofARDS•MOF,death•IncreasedLungInjury,ScarringSepsis,TraumaARDSRecoveryUncontrolledSystemicInflammationOngoingalveolarandsystemicinflammationResolutionARDS病理生理特点1肺容积减小2肺顺应性降低3通气/血流比例失调LungProtectiveVentilationStrategiesHEARTSPPEEPKeepTheLungOpenLowTidalVolumeRMOpenLungVentilationinducedlunginjuryCMAJ2008;178(9):1174-1176肺保护性通气——小潮气量小潮气量降低ARDS病死率n=53Protective:6ml/kgConventional:12ml/kgProtective:improvedsurvivalat28dNEnglJMed1998;338:347-541998-AmatoProtective:VT6ml/kgplat<30cmH2OConventional:12ml/kgPplat<50cmH2ONEnglJMed2000;342:1301-8LowTV:DecreasedmortalityIncreasesthenumberofdayswithoutventilatoruse小潮气量通气降低ARDS病死率2000-ARDSnetRCTn=8616ml/kg通气仍然存在肺泡过度膨胀N=30VT6ml/kgMoreprotected:withalargernormallyaeratedcompartmentPplat25-28cmH2OLessprotected:withalargernonaeratedcompartmentPplat28-30cmH2OAJRCCM,2007,175:160–166TidalVolumeLowerthan6ml/kgEnhancesLungProtectionAnesthesiology2009;111:826–3525
3•Refractoryhypoxemia:PaO2of<90mmHgfor1h(FiO2>0.8)•Refractoryacidosis:pH<7.10for1hr•PersistentlyelevatedPplat>35-40cmH2O:VT4-6ml/kg小潮气量通气•在原发病的基础上积极应用小潮气量通气•4ml/kg潮气量可能具有更好的肺保护能力•潮气量的选择需根据肺顺应性•目标:肺保护,避免肺泡过度膨胀导致VILIInitialVtsettings(ml/kgPBW)from2000to2008AmJRespirCritCareMed.2011;183(1):59-66ARDS重力依赖区大量肺泡塌陷•小潮气量通气仅能避免部分肺泡过度膨胀•并不能使塌陷肺泡复张AmJRespirCritCareMed2001;164:1701–1711Openthelung(RM-PEEP)控制性肺膨胀法(SI)压力控制法(PCV)PEEP递增法常用肺复张手法RM可促进塌陷肺泡开放CritCareMed2003;31[Suppl.]:S265–S271AmJRespirCritCareMedVol178.pp1156–1163,2008•Fortystudies(1,185patients)metinclusioncriteria.LackofRMinformationontheirinfluenceonclinicaloutcomes,theroutineuseofRMscannotberecommendedordiscouragedatthistime.RMsshouldbeconsideredforuseonanindividualizedbasisinpatientswithALIwhohavelife-threateninghypoxemia.ARDS患者肺可复张性差异大NEnglJMed2006;354:1775-86.多种因素影响肺复张多种因素影响肺复张•ARDS病因学分类•ARDS病程的早晚•肺可复张性•患者血压及容量状态RM是压力依赖性过程AmJRespirCritCareMed2001;164:1701–1711RM是时间依赖性过程Anesthesiology2003;99:71–80肺开放:病因不同,反应性不同28mixed-breedpigsModelsofARDS:OAVILIPneumonia(PNM)RMSIIncreasedPEEPPCVCCM,2004,32:2371-2377RM-RM-改善氧合:改善氧合:OAOA对对RMRM反应最好,反应最好,PNMPNM最最差差肺开放:病因不同,血流动力学影响不同CCM,2004,32:2371-2377血流动力学:血流动力学:PNMPNM影响最大影响最大CCM,2004,32:2378-8428mixed-breedpigsModelsofARDS:OAVILIPneumonia(PNM)RMSIIncreasedPEEPPCVLungProtectiveVentilationStrategiesHEARTSPPEEPKeepTheLungOpenLowTidalVolumeRMOpenLungPost-RM-PEEP可维持肺开放PEEP0cmH2OVT4ml/kgFio2100%PEEP19cmH2OPflex2afterCPAP40cmH2OVT4ml/kgFio2100%CritCareMed2003;31[Suppl.]:S265–S271Post-RM-PEEP—keepthelungopenCritCareMed2004;32:2371–2377RM-PEEP促进并维持肺泡开放,减少潮汐性肺泡塌陷复张导致的VILIALVOELI-ARDSnet•1999-200223hospitalsn=549pats•VT6ml/kgPplat<30cmH2ONEnglJMed2004;351:327-36ClinicaloutcomesaresimilarbetweenlowerandhigherPEEPlevels•Lowerpeep:8.3±3.2cmH2O•Higherpeep:13.2±3.5cmH2ONEnglJMed2004;351:327-36PEEP水平是否合适?PEEP选择目标:促进肺泡开放,避免肺泡过度膨胀•Control:VT6ml/kgPEEP5-9cmH2O•Interventional:VT6ml/kgPplat28-30cmH2O(highestPEEP)RCT37ICU(767Pats)2002-2005JAMA.2008;299(6):646-655LVT-PEEP减少抢救措施的应用JAMA.2008;299(6):646-655Intervention:VT6ml/kgPplat<40cmH2Ohighpeep(14.6cmH2O)Control:VT6ml/kgPplat<30cmH2Onormalpeep(9.8cmH2O)RCT983PatsLVT-RM-HPEEPJAMA.2008;299(6):637-645高/低PEEP不减少ALI/ARDS病死率和机械通气时间LVT-RM-HPEEP改善氧合,减少顽固性低氧血症的发生率和病死率JAMA.2008;299(6):637-645RM-PEEP的应用•在小潮气量的基础上联合使用RM-HPEEP•权衡RM-HPEEP的益处与风险,及时评估在血流动力学不稳定、肺可复张性低需谨慎使用Thankyou