跨肺压能干什么

跨肺压能干什么？Outline•跨肺压的定义•跨肺压的测定方法•跨肺压指导PEEP设定的临床实践和争议跨肺压：扩张肺组织的真正压力thepressurethatcounteractsalltheinwardactingtissueforcesdistributedatthepleuralsurface.JApplPhysiol1970;28:596-608跨肺压PL：兼顾肺、胸壁力学特征ELEcwPawPL=Pao*EL/(EL+Ecw)Pcw=Pao*Ecw/(EL+Ecw)AmJRespirCritCareMed2008;178.pp346–355跨肺压由气道内压、肺及胸壁弹性阻力决定呼吸系统弹性阻力（Ers）由肺弹性阻力（EL）与胸壁弹性阻力（EW）组成Ers=EL+EWPL=Palv–PplSouthMedJ.1991Jun;84(6):697-700CTscanofPL=Palv–PplJApplPhysiol108:515–522,2010.End-expiratoryEnd-inspiratoryRelationshipofPLandPalvAmJRespirCritCareMedVol178.pp346–355,2008•19healthypats,11medicalpatients•26patsALI,24patsARDS忽略胸壁呼吸力学改变无法实现合理的通气参数设置AmJRespirCritCareMed1997;156:1082–10919medicalARDSpats,9surgicalARDSpats•仅通过呼吸系统PV曲线设置通气参数有问题•导致内科ARDS患者PEEP设置过高•过度限制了外科ARDS患者潮气量胸壁弹性阻力的改变不能忽视CriticalCare2004,8:350-355呼吸系统弹性阻力（Ers）由肺组织弹性阻力（EL）与胸壁弹性阻力（EW）组成Outline•跨肺压的定义•跨肺压的测定方法•跨肺压指导PEEP设定的临床实践和争议跨肺压的测定•肺泡内压吸气屏气或呼吸屏气测得的气道内压•胸腔内压常用食道压力代替PL=Palv–Ppl(Pes)Pes与Ppl具有很好的相关性AmJRespirCritCareMed2001;164(1):122-130.食道压的测定在解剖关系上，食道与胸膜腔非常接近下三分之一处的食道压力近似于比邻的胸膜腔压力使用带有10cm长的气囊导管测定Pes食道压测定影响因素：气囊导管位置导管位置（呼气末气道阻断法确定）气囊充气量（0.5-1.0ml）患者体位食道管的放置RespirCare,2005,50:68–75.位置的确定•呼气屏气时气道压力的变化值等于食道压的变化值Pao=Pes食道压准确性的前提•食道气囊的压力可以准确反映食道压•食道的跨壁压为零•食道没有受到心脏或者其它胸腔组织的压迫•食道周围的纵隔压力等同于胸膜内压PL=Palv–PplNEnglJMed2008;359:2095-104.OurresultFactorsaffectingPesmeasurement•Structureoftheballon/catheter•Inflation/maintenancetechnique•Airvolumeintheballon•Toneofesophagealwall•Presenceofothercatheters•Heart/lungweigh•Positionofpatient•SpecificlocationofcatheterOutline•跨肺压的定义•跨肺压的测定方法•跨肺压指导PEEP设定的临床实践和争议ARDS的病理生理学改变•肺容积明显降低•肺顺应性明显降低•通气/血流比例失调AmJRespirCritCareMed2001;164:1701HEARTSPLungprotectivestrategy1.Limitedtidalvolume/plateaupressureeffective2.SufficientPEEPnotyetMethodstoselectPEEP•BestPEEP(Suter,NEJM,1975)•SuperPEEP(Kirby,Chest,1975)•Pflex(Amato,AmJRespirCritCareMed,1995)•Oxygenationscale(ARDSnet,NEJM,2000)•Stressindex(Ranieri,Anesthesiology,2000)•Pmc(Goddon,Anesthesiology,2001)•FRC+Cst(Lambermont,CriticalCare,2008)•Pes(Talmor,NEJM,2008)•Increasedrecruitmentstrategy(Mercat,JAMA,2008)•EIT(Meier,ICM,2008)•…Weneedabestpeep！跨肺压大于零有利于肺开放PLexp=-0.3cmH20PLexp=5.6cmH20汤睿，邱海波等，俯卧位通气改善ARDS肺组织病变不均一性的力学机制研究，未发表跨肺压指导PEEP的设定•Object：UseesophagealballooncatheterstoestimatedtranspulmonarypressureforfindingaPEEP.•Design：Prospective,single-centertrial,RCT•Methods:PatientswithALI/ARDSesophageal-pressure–guidedgroup(30)ARDSNetgroup(31)•Primaryendpoint：oxygenation•Secondaryendpoints:patientoutcomesNEnglJMed2008;359:2095-104.VentilatorSettingsAccordingtotheProtocolNEnglJMed2008;359:2095-104.BaselineofthePatientsNEnglJMed2008;359:2095-104.MeasurementsNEnglJMed2008;359:2095-104.跨肺压滴定的PEEP总体较高NEnglJMed2008;359:2095-104.ResultNEnglJMed2008;359:2095-104.Primaryendpoint：improveoxygenationNEnglJMed2008;359:2095-104.Secondaryendpoints:improvecomplianceNEnglJMed2008;359:2095-104.Secondaryendpoints:patientoutcomesNEnglJMed2008;359:2095-104.Kaplan-MeiercurveP=0.13由于主要观察终点为氧合改善，阳性结果得出后便被迫停止试验，是未改善病死率的原因之一···CurrentOpinioninCriticalCare2010,16:39–44呼吸系统弹性阻力（Ers）=肺组织弹性阻力（EL）+胸壁弹性阻力（EW）PEEP的设定受胸壁及肺组织力学影响ELEcwPL=Pao*EL/(EL+Ecw)Pcw=Pao*Ecw/(EL+Ecw)PEEP促进塌陷肺泡复张避免肺泡过度膨胀CriticalCare2004,8:350-355AmJRespirCritCareMed1998;158:3–11肺内外源性ARDS中Ecw和EL有显著性差异腹腔高压可导致膈肌上抬—胸壁顺应性下降呼气末膈肌处于平衡位ThoraciccavityEnterocoelia腹腔压力增高时膈肌向胸腔移动，导致胸腔内容积减少IAH导致跨膈压（IAP-Ppl）升高膈肌向胸腔移动JApplPhysiol108:515–522,2010.腹腔高压肥胖胸水胸廓畸形……AmJRespirCritCareMed1998;158:3–11.腹高压导致胸壁弹性阻力增加IAH导致呼吸系统顺应性下降IAP20mmHgNormalIAHIAH+ALIJTrauma.2010;69:375–383ALIIAH需要更高的开放压IAHPressureTotleLungcapacity(100%)AmJRespirCritCareMed2001,164.131–140IAHneedahigherpressure胸壁力学异常时需根据跨肺压滴定PEEPCritCareMed.2012May4.[Epubaheadofprint]PEEPcounteractIAPIAHIAHNormalPEEPIAH+ALI(n=7)ALI(n=8)p值性别(男/女)2/55/3NS年龄(年)59+1867+15NSBMI(kg/m2)25+423+1NS身高(cm)164+7170+5NS体重(kg)68+1567+6NSAPACHEⅡ27+1026+4NSLIS2.7+0.92.4+0.5NS28天病死率43%25%NSIAP(mmHg)16+210+20.0001ARDS类型ARDSexp20NSARDSp25NSARDSmix33NS跨肺压滴定呼气末正压对IAH+ALI患者呼吸力学影响的临床研究李洋、邱海波等东南大学附属中大医院*#△0510152025ARDSnetPTPPEEP(cmH2O)IAH+ALIALI对于IAH+ALI患者跨肺压法选择的PEEP明显高于ARDSnet法注：IAH：腹腔高压；ALI：急性肺损伤；ARDSnet：ARDSnetPEEP选择法；PTP：跨肺压PEEP选择法与IAH+ALI组ARDSnet法相比，*p0.05；与ALI组ARDSnet法相比，#p0.05；与ALI组PTP法相比，△p0.05。李洋、邱海波等东南大学附属中大医院跨肺压法选择的PEEP使ALI患者跨肺压增加注：IAH：腹腔高压；ALI：急性肺损伤；ARDSnet：ARDSnetPEEP选择法；PTP：跨肺压PEEP选择法与IAH+ALI组ARDSnet法相比，*p0.05；*012345678910ARDSnetPTPPtrans-ins(cmH2O)IAH+ALIALI*-7-6-5-4-3-2-101234ARDSnetPTPPtrans-exp(cmH2O)IAH+ALIALI跨肺压法选择PEEP改善IAH+ALI患者呼吸系统顺应性*&△0102030405060708090100ARDSnetPTPCrs(ml/cmH2O)IAH+ALIALI&△050100150200250ARDSnetPTPCw(ml/cmH2O)IAH+ALIALI*&020406080100120140160180200ARDSnetPTPCL(ml/cmH2O)IAH+ALIALI注：IAH：腹腔高压；ALI：急性肺损伤；ARDSnet：ARDSnetPEEP选择法；PTP：跨肺压PEEP选择法与IAH+ALI组ARDSnet法相比，*p0.05；与ALI组ARDSnet法相比，&p0.05；与ALI组PTP法相比，△p0.05。跨肺压滴定PEEP增加ALI+IAH患者肺复张容积注：IAH：腹腔高压；ALI：急性肺损伤；ARDSnet：ARDSnetPEEP选择法；PTP：跨肺压PEEP选择法与ALI组相比，*p0.05；-200-1000100200300400500Recruitvolume（ml）RecruitvolumeoftwogroupsALIIAH+ALI*PL滴定的PEEP水平较低0246810121416OL-PEEPPLPEEP050100150200250300350400450500OL-PEEPPLP/F与CT法OL-PEEP相比，PL-PEEP较低，氧合改善较差黄英姿，汤睿，邱海波等，东南大学附属中大医院PL滴定的PEEP未使肺泡充分复张0501001