血管外肺水的定量评估.

血管外肺水的定量评估安徽省立医院重症医学科杨田军血管外肺水的定义Pulmonaryedemaischaracterizedbyexcessaccumulationoffluidintheextravascularspaceofthelungs,namelyextravascularlungwater(EVLW).肺水肿是指过多的液体聚集于肺血管外，也就是血管外肺水Thepathologicalconditionofpulmonaryedemadevelopsbytwomechanisms:Anincreaseinthepulmonarycapillaryhydrostaticpressure(hydrostaticorcardiogenicpulmonaryedema)andanincreaseinpulmonarycapillarypermeability(acuterespiratorydistresssyndrome[ARDS]).However,itisoftendifficulttodiscriminatebetweenedemacausedbyincreasedhydrostaticpressureinthecourseofcardiacdisease,orbyincreasedpermeabilityassociatedwithARDS肺水肿的发生机制有两种：1.肺毛细血管的静水压增高（静水压或者心源性肺水肿）。2.毛细血管通透性增高（ARDS）。然而临床上有时很难区别这两种病因。前者进入肺间质和肺泡的主要是水分，而后者除了水分外还有大量蛋白等组织成分AECC和柏林标准诊断ARDS存在的问题对影像学的评估主要是主观的，缺少客观指标基础有慢性心脏疾病的患者，在罹患ARDS时会合并心脏功能不全，即使既往五心脏疾病，脓毒症本身等因素本身也会导致心脏功能受损对病理与临床关系的研究显示，临床诊断为ARDS是患者，仅有一半左右表现为ARDS的特征病理学变化：弥漫性肺泡损伤AmJRespirCritCareMed.2013,187(7):761-7.Ifwearetorequirepositivepressureventilationinourdefinition,whynotconsiderlungwater–isitnottimetomoveforward？IfnotEVLWthenperhapsdeadspacefraction,orthedistributionofinjuryand/orlungweightbyCatScan,oradirectmeasureofpermeability–somemoredirectmeasureofinjuryspecifictoARDS.Conclusions:AdefinitecorrelationexistsbetweenEVLWmeasuredbythesingle-indicatortranspulmonarythermodilutiontechniqueandpost-mortemlungweightinhumansTagamietal.CriticalCare2010,14:R162CritCareMed.2013Sep;41(9):2144-50.EVLWI与ARDS发病前状态及ARDS的关系Annualupdateinintensivecareandemergenctmedicine2014,p258弹丸注射肺PiCCO导管如：股动脉经肺热稀释技术需要在中心静脉注射冷盐水(8°C)或室温盐水(24°C)A.热稀释参数左心右心RAPBVEVLWLALVEVLWRV11全心舒张末期容积（GlobalEnddiastolicVolume，GEDV）是舒张末时心脏4个腔室的容积之和全心舒张末期容积PTVRAEDVLAEDVLVEDVRVEDVGEDVGEDV=ITTV-PTVITTVGEDV是ITTV与PTV之差12血管外肺水EVLWEVLWRAEDVRVEDVLAEDVLVEDVPTVEVLWITBVITTVRAEDVRVEDVLAEDVLVEDVPBV血管外肺水（ExtravascularLungWater，EVLW）反映肺间质内含有的水量，通过ITTV与ITBV之差得到血管外肺水与血管外肺水指数单纯讨论血管外肺水无意义，必须评估血管外肺水指数血管外肺水指数的计算方法为：血管外肺水/体重此体重为哪种体重？实际体重？预计体重？CritCareMed.2008June;36(6):1803–1809CritCareMed.2008Jan;36(1):69-73.CritCareMed.2008Jan;36(1):69-73.预计体重的计算公式ThePBWiscalculatedasfollows:men,PBW(kg)=50+0.91×(heightincentimeters-152.4);women,PBW(kg)=45.5+0.91×(heightincentimeters-152.4].CritCareMed.2012March;40(3):847–854CritCareMed.2012March;40(3):847–854问题IntheBerlindefinition,themeasurementofEVLWwasconsideredbutnotincludedinthecurrentcriteria.Theauthorsstatedthat“EVLWdoesnotdistinguishbetweenhydrostaticandinflammatorypulmonaryedema”,andforthisreasonitwasnotincluded21肺血管通透性指数肺血管通透性指数（PulmonaryVascularPermeabilityIndex，PVPI）是血管外肺水（EVLW）与肺血容积（PBV），反映了肺水肿的类型PulmonarvBloodVolume静水压肺水肿通透性肺水肿PVPI=PBVEVLW正常升高升高PVPI=PBVEVLW升高升高正常PVPI=PBVEVLW正常正常正常PBVPBVPBV正常ExtraVascularLungWaterAnnualupdateinintensivecareandemergenctmedicine2014,p259Kushimotoetal.CriticalCare2012,16:R232Annualupdateinintensivecareandemergenctmedicine2014,p263Examples:InterpretationofEVLWandPVPIValuesApatientadmitted2daysearlierwithbacterialpneumoniaandbilateralconsolidationsonaCTscanwasventilatedwithanFiO2of60%,aPEEPof10cmH2O,thePo2is70mmHgDiagnoses:Severepneumonia？ModeratetosevereARDS？HehadanEVLWof17ml/kg,andaPVPIof1.5Examples:InterpretationofEVLWandPVPIValuesEarlyaggressiveintervention,inadditiontolung-protectiveventilation,mayberequired.Ontheotherhand,despitea2-dayhistoryofsepsiswithfluidoverload,‘whitelungs’onportableradiograph,andventilationwithanFiO2of60%andaPEEPlevelof10cmH2O,anEVLWof8ml/kgandaPVPIof1.0couldindicateclinicalconditionsotherthanpulmonaryedema,Examples:InterpretationofEVLWandPVPIValuesHeacceptedlungCTscan,theresultrevealedatelectasisBronchoscopywasprescribedforhim.2dayslatehissymptomreleasedandweanedfromventilation总结目前ARDS诊断标准存在问题，如果要提高诊断的准确率需要评估血管外肺水指数及肺血管通透性血管外肺水指数应该根据预测体重来计算，而不应该根据实际值计算对于罹患ARDS的高危患者，根据血管外肺水指数提前2天左右干预能改善患者预后PVPI大于3能诊断ARDS，而小于1.7可排除ARDS的诊断谢谢各位老师的聆听