微循环与血管活性药.ppt

Sepsis微循环与血管活性药,2011年2月,引言,Sepsis：疑问：临床上血流动力学稳定、氧传递指标等均可，但依然进展、乳酸升高？早期亦已存在微循环功能障碍！,引言,微循环：如此重要、关键应成为危重患者复苏中的一个关键指标但：传统的评价指标难以准确评价微循环！,主要问题：,1.有什么新的方法监测微循环？2.现有血管活性药物微循环的影响如何？,微循环的结构,直径500m2组成：微动脉，后微动脉，毛细血管前括约肌，真毛细血管、通血毛细血管、动静脉交通支、微静脉,微循环的功能及分类,1.迂回通路：物质交换，交替开放（又称营养通路）2.直捷通路：不进行物质交换，血液快速回流，骨骼肌多见3.动静脉短路：不进行物质交换，皮肤多见,Sepsis时微循环的改变,1994年，LamC等对血压稳定的鼠sepsis微循环活体显微镜在体观察，发现sepsis时：1.灌注毛细血管密度减少，血流停止的毛细血管数增加；2.灌注毛细血管空间分布不均，平均毛细血管间距增加2002年，DeBacker等利用OPS成像观察sepsis舌下微循环，发现：1.微血管密度显著减少，血流停滞和血流灌注间断的小血管比例增加；2.各区域间灌注血管的变异系数明显大于健康志愿者DeBackerD,CreteurJ,PreiserJC,etal.Microvascularbloodflowisalteredinpatientswithsepsis.AMJRespirCritCareMed,2002,166:98-104,OPS图像,Sepsis时微循环的改变,特征：1.adecreaseincapillarydensity2.anincreaseinheterogeneityofperfusionwithnon-perfusedinclosevicinitytowell-perfusedcapillaries后果？,Tissuestoleratebetterahomogeneousdecreaseinbloodflowbetterthanaheterogeneousone,DanielDeBacker，GustavoOspina-Tascon，etal.IntensiveCareMed(2010)36:18131825.,Howtoevaluatethemicrocirculation,IntensiveCareMed(2010)36:18131825.,Nailfoldvideocapillaroscopy,Thefirstmethodusedatthebedsidethenailfoldareaisverysensitivetochangesintemperature:onecancontrolambientbutnotbodytemperature.PeripheralvasoconstrictioncanalsooccurduringchillsandacutecirculatoryfailureOflimiteduseincriticallyillpatients.,LaserDoppler,Mainlimitation：measuresflowinavariablevolumeoftissue，unabletodetectitinindividualvesselsSamplingvolume:0.5and1mm3,about50vesselsCannotshowtheheterogeneity,SvO2,VenousO2saturationcanbehighorlowforthesamedegreeofmicrovascularshuntingcanbemisleadingSeveralstudieshaveshownthatmeasuringSvO2doesnotprovidemuchinformationaboutmicrovascularalterations-PodbregarM,MozinaH.Skeletalmuscleoxygensaturationdoesnotestimatemixedvenousoxygensaturationinpatientswithsevereleftheartfailureandadditionalseveresepsisorsepticshock.CritCare2007,11:R6MarikPE,BankovA,Sublingualcapnometryversustraditionalmarkersoftissueoxygenationincriticallyillpatients.CritCareMed2003,31:818822,Gastrictonometry,AgastricPCO2gapabove20mmHgdiscriminatedsurvivorsfromnon-survivors-LevyB,GawalkiewiczP.CritCareMed2003,31:47448GastricPCO2gap-mostlyreflectsgutmucosalmicrocirculation-Insepsis,nocorrelationbetweenthegastricPCO2gapandtotalsplanchnicperfusionDuodeno-gastricrefluxandfeedingcaninterfere,Lactate,Timelag-Cannotdetectalterationsinmicrovascularperfusionbeforetheyareassociatedwithcellularhypoxia,OPS/SDF,OPS成像：正交偏振光谱成像orthogonalpolarizationspectralimaging原理：利用血细胞对偏振入射绿光产生消偏振光散射和对正偏振光的成像特征，能在皮下0.5mm深度内产生高清晰度和高分辨率的成像。局限性：敏感性偏差；需具备高能光源，难以应用到临床。,OPS/SDF,SDF成像：旁流暗场成像，sidestreamdark-field，2007年开始应用于临床优点：更加清晰所需能量小，可以方便的使用电池床边操作,SDFimage,OPS/SDF,Advantage:1.visible2.differentvariablescanbeobservedandbemeasured-vasculardensity,heterogeneityofperfusion,microvascularbloodflowTheconsensusadvisesreportingofPVD,PPV,MFIandheterogeneityindex,inordertodescribethefunctionalperfusionofthemicrocirculation.-Howtoevaluatethemicrocirculation:reportofaroundtableconference,CriticalCare2007,11:R101,血管活性药物对微循环的影响,Vasopressors:Norepinephrine,Epinephrine,VasopressinInotropes:Dopamine,Dobutamine,Vasodilators:Nitroglycerin,Prostacyclin,NEdoesnotimprovemicrocirculatorybloodflow,20septicshockpatientsBasalmeasurementofMAP65mmHg,NEwastitratedtoreachaMAPof75mmHg,then85mmHgSublingualmicrocirculationwasevaluatedbySDFimagingDubinA,PozoMO,etal.Increasingarterialbloodpressurewithnorepinephrinedoesnotimprovemicrocirculatorybloodflow:aprospectivestudy.Critcare,2009,13(3):R92,NEdoesnotimprovemicrocirculatorybloodflow,NEdoesnotimprovemicrocirculatorybloodflow,NEdoesnotimprovemicrocirculatorybloodflow,1.NEdoesnotimprovemicrocirculataryperfusionfurtherincreaseMAPfrom65mmHg.2.ReductionsintheperfusedcapillarydensitiesfurtherincreaseMAPfrom65mmHg.结论：使用去甲升高MAP并不是改善感染性休克患者微循环的一个恰当方法，反而可能对患者有害。,TheeffectofincreasingdosesofNEontissueoxygenationandmicrovascularflowinpatientswithsepticshock,16septicshockpatientsNEfrom0.18to0.25,0.35,0.41ug/kg.minMAPfrom60-70-80-90mmHgSDFimagingShamanJhanji,etal.CritcareMed2009;37:1961-1966,TheeffectofincreasingdosesofNEontissueoxygenationandmicrovascularflowinpatientswithsepticshock,MAP高于60-65mmHg不能改善感染性休克患者微循环增加NE对感染性休克患者微循环无明显影响ShamanJhanji,etal.CritcareMed2009;37:1961-1966,多巴胺对微循环的影响,1.1Meier-HellmannA,BredleDL,SpechtM,SpiesC,HannemannL,ReinhartK(1997)Theeffectsoflow-dosedopamineonsplanchnicbloodflowandoxygenuptakeinpatientswithsepticshock.IntensiveCareMed23:31371.2OlsonD,PohlmanA,HallJB(1996)Administrationoflow-dosedopaminetononoliguricpatientswithsepsissyndromedoesnotraiseintramucosalgastricpHnorimprovecreatinineclearance.AmJRespirCritCareMed154:166416702.MarikPE,MohedinM(1994)Thecontrastingeffectsofdopamineandnorepinephrineonsystemicandsplanchnicoxygenutilizationinhyperdynamicsepsis.JAMA272:13541357,NG对微循环的影响,NGinsepticshockafterintravascularvolumeresuscitation,8septicshockpatientsMAPwasgreaterthan60mmHgandCVPgreaterthan12mmHgafterinfusionofcrystalloidsandcolloids,andthelowestpossibledoseofdopamineNG：anintravenousloadingdoseof05mg,thensubsequentcontinuousinfusionof2mg/hOPS：usedtoproduceimagesofsublingualmicrocirculationLancet2002;360:1395-1396,NGinsepticshockafterintravascularvolumeresuscitation,OPSimages,70个Severesepsis和septicshock患者充分复苏后给予硝酸甘油或安慰剂SDF评估舌下微循环主要终点：sublingualmicrocirculatorybloodflowofsmallvesselsCritCareMed2010;38:93-100,Microvascularvariablesovertime,TakeHomeMessage,1.重视微循环检测2.sepsis微循环功能障碍：异质性3.传统指标不足以反映微循环4.OPS/SDF有较好临床应用前景5.血管活性药对微循环的作用？,谢谢捧场！,谢谢捧场！,2.LeDouxD,AstizME,CarpatiCM,RackowEC(2000)Effectsofperfusionpressureontissueperfusioninsepticshock.CritCareMed28:272927323.BourgoinA,LeoneM,DelmasA,GarnierF,AlbaneseJ,MartinC(2005)Increasingmeanarterialpressureinpatientswithsepticshock:effectsonoxy