ARDS呼吸功能监测与通气策略抉择

内容提要

PhysiopathologiccourseofARDSandthedilemmainMechanicalventilationOxygenation

andShuntRespiratorymechanicsCompliance(Elastance)andResistanceStressindexEsophagealPressureVd/Vt第二页，共六十六页。TherapeutictargetofMVinARDSBecomeevidentoverthepasttwodecadesMVitselfcanaugmentorcausepulmonarydamageShiftoftherapeutictargetofMVinARDS

1970sNormalgasexchange1980-1990ProtectionofthelungfromVILINEnglJMed1972;287:799-806.Lancet1980;2:292-4.AmRevRespirDis1987;135:312-5.IntensiveCareMed1990;16:372-7.第三页，共六十六页。Thelung-protectionstrategyLungrecruitment-openthelungUseofhigherPEEP---keeplungopen(avoidcollapse/recruitment)Lowtidalvolumes(Pplat<30cmH2O)---avoidoverdistensionPreventregionalandglobalstressandstrainonthelungparenchymaAmJRespirCritCareMed.2008,178:346–355.第四页，共六十六页。SameMVstrategysutiableforeveryARDSpat??MaybeNo.PhysiologicaleffectsofRMandPEEPassociatedwithpatient’sindividualcharacteristicsInflamattionspreadingfromcorediseasePercentageofpotentiallyrecruitablelungDifferentstagesofARDSNEnglJMed.2006,354;1775-86.JAMA.1994,271,1772-79.

第五页，共六十六页。InflamattionspreadingfromcorediseasePossiblemodelLowerHigherHigherseveritymortalityCoredisease24%Inflammationspreading1Lowerseveritymortality第六页，共六十六页。PotentiallyrecruitablelungLowerpercentageofpotentiallyrecruitablelungHigherpercentageofpotentiallyrecruitablelungNEnglJMed.2006,354;1775-86第七页，共六十六页。MortalityinRelationtothePercentageofpotentiallyRecruitableLung(PanelA)

PulmonaryanatomyaccordingtoCTFindingsinpatientswithHealthyLungs,PatientswithUnilateralPneumonia,andPatientswithAcuteLungInjuryorARDS(PanelB).NEnglJMed.2006,354;1775-86第八页，共六十六页。LowerVSHigherpercentageofpotentiallyrecruitablelungHigherpercentageofpotentiallyrecruitablelungGreatertotallungweightsPooreroxygenationRespiratory-systemcomplianceHigherlevelsofdeadspaceHigherratesofdeathNEnglJMed.2006,354;1775-86第九页，共六十六页。DifferentstagesofARDSPathologicstagesEarlyexudativephaseedema,bleeding,atelactasis,PMNandpltembolus,andmicroembolusProliferativephaseproliferationoftiveIIepitheliumcellFibroticphaseProliferationoffibroblastHeterogeneity：location,timecourseVersatility:Pathologicchanges第十页，共六十六页。DifficulttoassessGattinoniL(1994)EarlyARDS(MVupto1week):prevalentedemaIntermediateARDS(between1~2weeks):atransitionperiodduringedemabeginstobereabsorbedandproliferativeprocessesbegintooccurLateARDS(morethan2weeks):fibrousprocessesClinicalstagesofARDSJAMA.1994,271,1772-79.

第十一页，共六十六页。EarlyVSLateARDS

84severARDSforunderwentextracoreslsupport(1979-1992)JAMA.1994,271,1772-79.

第十二页，共六十六页。EarlyVSLateARDS

JAMA.1994,271,1772-79.

第十三页，共六十六页。CTscan,earlyVSlateARDSGattinoniLType1EarlyARDSWeek1IntermediateARDSWeek2LateARDSWeek<=3第十四页，共六十六页。Type2Day1EarlyDay5Day12InterDay17Latediffusegroundglassopacification,rightgreaterthanleftinhomogeneousdiseaseandboththecraniocaudalandsternovertebralPartialclearingofboththediffusegroundglassopacificationandthegravity-dependentatelectasisgroundglassopacificationhasamorereticularpattern.apneumatoceleintheleftmidlungandincreasingatelectasisadjacenttoitAmJRespirCritCareMed.2001,164:1701–1711.第十五页，共六十六页。EarlyandLate--RecruitabilityN=17ARDSwithalungprotectiveventEarlyARDS(n=9)vsLateARDS(n=8,>7d)RM:PCV2minatPIP50cmH2O/PEEP>PUIPAmJRespirCritCareMed,2002,165:165–170第十六页，共六十六页。Summary-EarlyandLateARDSEarlyARDSischaracterizedbyedemaandintactlungstructureRecruitabilityisfunctionoftheextentofedemaWithtimelungstructureisalteredassociatedwithincreaseddeadspaceandPCO2第十七页，共六十六页。PrognosisofARDSInflammationspreadingPotentiallyrecruitablelungLowerLowerseveritymortalityRMandhigherPEEPmaybeharmfulHigherHigherseveritymortalityRMandhigherPEEPareneededCorediseaseAggravatedImprovedEarlyARDSLateARDSEffectofRMandhigherPEEP?第十八页，共六十六页。QuestionsHowtoknowwhowillgetbenefitfromRMandPEEPHowtosetasuitablePEEPinARDSpatientCTscanmaybeonechoiceButnotatbedsidePaO2(P/F)maybeanotherchoiceButourgoalisnotbettergasexchangeHowaboutbedsiderespiratorymechanicalmonitoring

ReduceVILI第十九页，共六十六页。内容提要

PhysiopathologiccourseofARDSandthedilemmainMechanicalventilationOxygenation

andShuntRespiratorymechanicsCompliance(Elastance)andResistanceStressindexEsophagealPressureVd/Vt第二十页，共六十六页。ShuntisthefundamentalcauseofhypoxemiainARDSRMandPEEP—

Improveoxygenation

(P/F)

ReducedShunt

AmJRespirCritCareMed,2001,164:1701-1711第二十一页，共六十六页。肺泡完全复张的临床标准----P/FPaO2/FiO2>400PaO2+PaCO2>400

2.PaO2/FiO2

降低>5%第二十二页，共六十六页。PaO2+PaCO2>400(at100%oxygen):维持肺开放的可靠指标达到PaO2+PaCO2>400时：CT显示只有5%的肺泡塌陷PaO2+PaCO2>400对塌陷肺泡的预测：ROC曲线下面积0.943BorgesJB,…,AmatoMBP.AmJRespirCritCareMedVol174.pp1–11,2006肺泡完全复张的临床标准--CT第二十三页，共六十六页。肺泡完全复张的临床标准---CTBorgesJB,…,AmatoMBP.AmJRespirCritCareMedVol174.pp1–11,2006动脉氧合与塌陷肺组织重量明显呈负相关(R=0.91)第二十四页，共六十六页。MethodsofQs/QtcalculationQc:经肺毛细血管回心的血量(已气体交换)Qs:经短路回心的血量(未经体交换)Qt=Qc+Qs总回心血量计算公式：太复杂但比较准确正常肺Qs/Qt4-5%ARDSQs/Qt常>30%第二十五页，共六十六页。简化公式吸空气时：吸纯氧时：应用条件吸纯氧10-20min(最大限度纠正相对分流)PaO2>150-200mmHg第二十六页，共六十六页。P/FandQs/Qtchangewithlungrecruitment

Case63YwomanGuillain-BarreSyndrome,Pneumonia,ALIPEEPPEEP第二十七页，共六十六页。内容提要PhysiopathologiccourseofARDSandthedilemmainMechanicalventilationOxygenation

andShuntRespiratorymechanicsCompliance(Elastance)andResistanceStressindexEsophagealPressureVd/Vt第二十八页，共六十六页。

Respiratorymechanics

---Compliance(Elastance)

andResistance第二十九页，共六十六页。ConceptsandFormulaE=P/VolC=Vol/PCst=Vt/(Pplat-PEEPtot)Cdyn=Vt/(PIP-PEEPtot)R=P/V’C=1/E第三十页，共六十六页。ComplianceandResistancechangesinARDSCompliancedecreasedsignificantlyResistancemayincreaseslightlyCompliancedecreasedDuetoalveolarcollapseResistanceincreased第三十一页，共六十六页。Compliancedecreased

P-Vcurve

Reducedrangeofvolumeexcursion:LowcomplianceFlatteningatlowandhighvolumes:LowerandupperinflectionpointsVolumePressureNORMALARDS顺应性曲线明显向右下移位第三十二页，共六十六页。sixpigletsvenousinfusionofoleicacidPEEPtitration(from26to0cmH2OwithaVtof6to7ml/kg)performed,followingaRMCriticalCare2007,11:R86.第三十三页，共六十六页。RonitoringrespiratorymechanicsduringaPEEPtitrationproceduremaybeausefuladjuncttooptimizelungaerationCriticalCare2007,11:R86.PEEPatminErscorrespondedtothegreatestamountofnormallyaeratedareas

第三十四页，共六十六页。%E2:PercentageofvolumedependentelastancePercentageofnon-linearityoftheelastanceoftheErs%E2<0%:tidalrecruitment%E2>30%:tidaloverdistensionIntensiveCareMed.2008,34:2291–2299Innon-injuredanimals第三十五页，共六十六页。Stressindexand%E2areusefulinnon-injuredlungsonlyErscanbesuperiortothestressindexand%E2toguidePEEPtitrationinfocallossoflungaerationErsseemstobeusefulforguidingPEEPtitrationinnon-injuredandinjuredlungs第三十六页，共六十六页。FemalepigsLunglavageCrs:computedusingtheocclusiontechniqueRM:45cmH2Ofor40sPeep10cmH2OProandPostRM(CTscan)GasexchangeLungmechanicsAmountandthechangesinaeratedandCriticalCare.

2005,9:R471-R482第三十七页，共六十六页。Vpoor:volumeofpoorlyaeratedlung;Vhap:volumeofhyperinflatedlungPmcd:pressureofmaximumcompliancedecreaseoninflationcurve

第三十八页，共六十六页。CrsmaybeusefulforguidingPEEPtitrationChangesinaeratedandnonaeratedlungvolumeswereadequatelyrepresentedbyCrsNotbychangesinoxygenationorshuntCriticalCare.

2005,9:R471-R482第三十九页，共六十六页。Case79y,man,75kgPneumonia,ARDS,APACHII27SedationandnerveblockBaiseline:VcV,Vt500ml,PEEP6cmH2O,RR20b/min,P/FCrs56,Pplat16cmH2O,PaCO235mmHg,P/F121RM:SI40cmH2O30s(P/F≥400mmHgorchange<10%)SetPEEP20cmH2OReducePEEP2cmH2OstepbystepCrs:computedusingtheocclusiontechnique第四十页，共六十六页。NotroutinelyRM?;PEEP10or8cmH2O?;VT500mlPEEPPEEP第四十一页，共六十六页。Respiratorymechanics

---Stressindex第四十二页，共六十六页。StressindexP=a*tb+cVCVConstancyflowSlutskyAS,Aneathiology,2000,93:1320-8GrassoS,CritCareMed,2004,32:1018–27第四十三页，共六十六页。第四十四页，共六十六页。CritCareMed,2004,32:1018–27第四十五页，共六十六页。PreconditionRMConstancyflowCritCareMed,2004,32:1018–27第四十六页，共六十六页。Howtodoitatthebedside

ChangetoVCV(Constancyflow)Sedation(ifnecessary)RMSetahigherPEEP(eg20cmH2O)ReducePEEPstepbystep(2-3cmH2O)andeye-measurementbRecordthePEEPsinb>1---b=1---b<1RMagainsetthePEEPinb=1第四十七页，共六十六页。Case64y,man,70kgMultipletrauma,ARDSBaiselineMVset:SIMV+PS(autoflow),Vt420ml,PEEP10cmH2O,FiO250%,RR20b/minPplat26cmH2O,PaCO247mmHg,P/F155ChangetoVCV:VT420ml,RR20b/minRM:SI40cmH2O30s(P/F≥400orchange<10%)

SetPEEP18cmH2OReducePEEP3cmH2OstepbystepEye-measurementb第四十八页，共六十六页。RMSIMV+PS(autoflow),Vt400ml,PEEP14cmH2O,FiO250%,RR24b/minPplat28cmH2O,PaCO245mmHg,P/F339Suitable??

PEEPBPplat18>13415≈1316<122第四十九页，共六十六页。Respiratorymechanics

---MVGuidedbyEsophagealPressure

第五十页，共六十六页。MVGuidedbyEsophagealPressure

inALI

Esophagealpressure≈pleuralpressurepressureTranspulmonarypressure=pulmonaryalveolarpressure-Esophagealpressure61ARDSpatsMVControloresophagealpressure–guidedgroupPrimaryendpointimprovementinoxygenationSecondaryendpoints:Respiratory-systemcompliancePatientoutcomesNEnglJMed.2008,359;2095第五十一页，共六十六页。第五十二页，共六十六页。第五十三页，共六十六页。第五十四页，共六十六页。AscomparedwiththecurrentstandardofcareSignificantlyimprovesoxygenationandcomplianceNEnglJMed.2008,359;2095MVGuidedbyEsophagealPressure

第五十五页，共六十六页。内容提要

PhysiopathologiccourseofARDSandthedilemmainMechanicalventilationOxygenation

andShuntRespiratorymechanicsCo