ICU中的血液净化指南之我见

ICU中的血液净化指南之我见ContentsIntroduction1Typeoftherapy2TimingofCRRT3DoseofCRRT4Conclusions56IntroductionMethodsofextracorporealrenalreplacementtherapy(RRT)havebeenusedforthesupportivetreatmentofAKIforover60years.CRRTforthecriticallyillpatientwithARFwasintroducedin1977byKrameretal.Sincethen,manystudieshavereportedonCRRTinthecriticallyill.KlinWochenschr1977;55:1121-1122.IntroductionButforseveralreasonscomparisonamongstudiesisdifficult:Varioustreatmentmodalitieshavebeenappliedinheterogeneouspopulations.DifferencesinclinicalsettingandunderlyingmolecularbiologicalmechanismsthatinitiateandmaintainARF.Furthermore,morethan35definitionsofARF.Practicepatternsvarywidelybetweenindividualcenters.Uptonow,therearenostandardguidelinesfortheapplicationofCRRTincriticallyillpatients.CurrOpinCritCare2002;8:509-514.IntroductionTheRIFLEClassificationforacuterenalfailureCritCare2004;8:R204-R212.IntroductionConclusions:Morethen200differentdefinitionsofARFandabout90RRTstartcriteriawerereported.OliguriaandRIFLEwerethemostfrequentcriteriausedtodefineARF.RIFLEcriteriamightshowaclinicalimpactonfuturedailypracticeandresearch.DifferentRRTtechniquesareavailableinmostcenters,butagenerallackoftreatmentdosestandardizationisnotedbyoursurvey.Non-renalindicationstoRRTstillneedtofindadefinitiveroleinroutinepractice.NephrolDialTransplant(2006)21:690–696Inthepast,theinteractionbetweennephrologyandintensivecarewasminimal.Today,thereiscontinuousinteractionwithseveralmomentsofhighinteractionduetocommonpatientsandcomplexsyndromes,andmuchofthetreatmentofAKIhasmovedfromtherenalwardintoICUs.IntroductionContribNephrol.Basel,Karger,2010(166):1–3ContentsIntroduction1Typeoftherapy2TimingofCRRT3DoseorintensityofCRRT4Conclusions56TypeoftherapyClassificationofbloodpurificationincriticalcare(BPCC)technologyPMX=polymyxin-Bimmobilizedfiber;PMMA=polymethylmethacrylate;PAN=polyacrylonitrile;PEPA=polyetherpolymeralloyContribNephrol.Basel,Karger,2010(166):11–20TypeoftherapyAsacontinuoustherapy,CRRTcanberapidlytailoredtochangesinapatient’sclinicalconditionduringcriticalillnessBloodpurificationincriticalcareContribNephrol.Basel,Karger,2010(166):11–20HDF=hemodiafiltrationTypeoftherapyTheseadvantageshavecontributedtothewidespreaduptakeofCRRTasthefirst-choiceRRTinICUsthroughoutAustralia,JapanandEurope.Intheseregions,CRRTisusuallyinitiatedandmanagedwithintheICU,withRRTbeingintegratedwithotheraspectsofthemanagementofcriticalillnessNat.Rev.Nephrol.2010:6:521–529.TypeoftherapyInnorthAmerica,however,traditionalstructuresofICUmanagementfavoran‘open-ICU’approach:Withinthismodel,RRTisusuallyprescribedbyanephrologistintheICUandisinitiatedbyadialysisnurseInthisenvironment,IHDhastheadvantageofrequiringonlydailyoralternate-dayattendancebytherenalteamConversely,therelativelaborcostsofprovidingCRRTareincreased,aneffectthatiscompoundedbythelargerfixedcostsandhigherconsumablerequirementsofCRRTTheselogisticfactorshaveledtoapreferenceforIHDoverCRRTbeingmaintainedinICUsthatusethenorthAmerican.Nat.Rev.Nephrol.2010:6:521–529.TypeoftherapyClinicalstudiesofCRRTintheICUThediversityofclinicalapproachestothetreatmentofAKIintheICUisillustratedbytheresultsoftheBESTKidneystudy,ThemultinationalepidemiologicalstudyofRRTpracticeintheICUStudydocumentedthetreatmentofAKIin1,738patientsin54ICUsonfivecontinentsNat.Rev.Nephrol.2010:6:521–529.TypeoftherapyBESTstudyresultsCRRTwasthemostcommonchoiceofinitialRRTtreatment,with80%ofpatientsonCRRT;IHDusewasmostlyrestrictedtoICUsinnorthandsouthAmerica,whereitwasusedasinitialtherapyin30–40%ofpatients,while,bycontrast,CRRTisusedfirstin100%ofICUsinAustralia.AmongpatientsreceivingCRRT,however,markedvariationinthemodality,intensity,timingwasobservedMakingitdifficulttocompareoutcomesbetweenpatientsonCRRTandthoseonIHDNat.Rev.Nephrol.2010:6:521–529.TypeoftherapyNat.Rev.Nephrol.2010:6:521–529.有些研究表明在ICU不稳定的患者中应用IHD也不会存在明显的问题,

有RCTs并没有显示出CRRT优于IHDTypeoftherapyKidneyInt2009,76:422-427.BMCNephrol2010,11:32.NephrolDialTransplant2009,24:512-518.Lancet2006,368:379-385.

对于依赖血管活性药物的AKI患者，CRRT才是最适合的；依赖血管活性药物的AKI患者将来接受长期透析的几率CRRT<间断性治疗；AKI的急性期推荐应用CRRT，尤其是对于严重血流动力学不稳定、需大量清除液体以便于进行更有效药物治疗的患者。CritCareMed2008,36:610-617.KidneyInt2009,76:422-427.NatRevNephrol2010,9:521-529.ClinPharmacolTher2009,86:562-565.目前共识：ContentsIntroduction1Typeoftherapy2TimingofCRRT3DoseofCRRT4Conclusions56TimingofCRRTTherighttimetostartRRTisstillatopicofdebate.主要的原因的是：没有一个明确的、协商一致的AKI定义能够根据肾损伤程度对患者进行分级研究时很难获得同种类相同特征的患者组人群RIFLE和AKIN分级标准使对于AKI的研究向前迈进了一大步两种分级标准均能使临床医生警惕AKI的出现，进行早期干预CritCare2009,13:211.TimingofCRRTThereissignificantvariationinthetimingofinitiationofRRT,withuptotwo-folddifferencesinthereportedvaluesofBUN,creatinine,orurineoutputatRRTinitiation.ClinicalstudiesevaluatingthetimingofinitiationofCRRTincriticallyillpatientsTimingofCRRTIntheabove-mentionedstudiesthereisacleartrendtowardabetteroutcomewithearliertimingofRRT.IntheabsenceoflargeRCTscomparingearlytolateinitiationofRRT,nofirmoverallrecommendationsfortimingofRRTcanbemade.TimingofCRRT目前广为接受的SepticAKI开始RRT时机，尤其是在septicshock时：RIFLEinjurystage(orAKINstage2)butconsensusonthistopicawaitsresultsfromlarge-scaleRCTs.TimingofCRRT除AKI外，患者的一些其他情况也需要行早期RRT治疗：mainlypediatric,treatedbyECMOforsevereARDS.Fluidoverloaddefinitelyplaysaroleintiming,becauseCRRTprovedsuccessfulinpatientswithoutAKIbutrefractorytodiuretics.治疗时机的标准在不断发展，包括：severityoforgandysfunction(SOFAscore)；severityofAKI(RIFLEorAKINstage)；fluidoverloadstatus；

timefromadmission；biomarkeruse,etc.但他们在日常临床实践中的应用价值仍然需要评估KidneyInt2010,77:469-470.KidneyInt2009,76:1289-1292JAmSocNephrol2011,22:810-820.TimingofCRRTWheninitiationofRRTisconsidered,itisimportanttorealizethat:theconsequencesofureamictoxicity,metabolicacidosisand/orfluidoverloadarelikelytobemoresevereinthecriticallyillpatient.Moreover,renalfunctionisunlikelytorecoverwithinashortperiodduringpersistentandseverefailureofotherorgans.Furthermore,variousinflammatorymediatorsareclearedbythekidney.TimingofCRRT最近的一项前瞻性研究和两项meta-analysis明确地支持earlytimingThefindingsofthesestudiessupportearlierinitiationofacuteRRTIntheabsenceofnewevidencefromsuitably-designedrandomisedtrials,adefinitivetreatmentrecommendationcannotbemadeContentsIntroduction1Typeoftherapy2TimingofCRRT3DoseofCRRT4Conclusions56DoseorintensityofCRRTDoseorintensityofCRRTDoseorintensityofCRRTBoththeATNandRENALstudiesfailedtodetectanysurvivalbenefitfrommore-intensiveRRTAndnosignificantdifferencesinmortalityrateswereobservedbetweenhigh-intensityandlow-intensitytreatmentinsubgroupsineitherstudy.TheseresultsprovidedefinitiveevidencetorecommendthatescalationofCRRTintensitytobeyondconventionaldosesof25ml/kg/hisnotbeneficialforunselectedICUpatientswithAKI.PossiblerelationshipbetweendelivereddoseofCRRTandsurvival,withresultsfromtheATNandRENALtrialsillustrated.DoseorintensityofCRRT而关于non-septicAKI的治疗剂量，RENAL研究得到了一个明确的答案:RandomizedEvaluationofNormalversusAugmentedLevels(RENAL)study:nobeneficialeffectofCVVHDFat40ml/kg/hcomparedwith25ml/kg/h.Therefore,currentconsensussuggestsahemofiltrationdoseof25ml/kg/hinnon-septicAKIwithnoadditionalbenefitfromadoseincrease.NEnglJMed2009,361:1627-1638.DoseorintensityofCRRT然而，需要强调的是：专家的意见是患者治疗剂量要足够，至少25ml/kg/h。但实际中由于存在可预测的（bagschange,nursing...）和不可预测的（surgery,clotting...）治疗中断，意味着剂量要在30-35ml/kg/h；SepticAKI患者的治疗剂量目前仍存在争议，一些小的前瞻随机研究表明高剂量的血液滤过是有益的。多中心的“IVOIREstudy”(hIghVolumeinIntensivecare)，在sepsis引起的AKI，休克和多脏衰患者中，比较35ml/kg/h

vs.70ml/kg/h

，不久后，可能会对治疗剂量的争论有所定论。Joannes-BoyauO,HonorePM:HemofiltrationStudy:IVOIREStudy:IDNCT00241228.,lastAccessedinJune2011.CritCare2009,13:R57.JNephrol2011,24:165-176.DoseorintensityofCRRT“IVOIREstudy”(hIghVolumeinIntensivecare)初步结果：Althoughpatientsincludedweremoreseverelyill,overallmortalityintheIVOIREstudyremainsverylow(39%at28daysand52%at90days)comparedwiththeRENALstudy.Thismaybeduetotheearlierstartoftreatmentattherenalinjurylevel.Awaitingresultsfromthisimportanttrial,35ml/kg/hshouldremainthestandarddoseinsepticAKI,particularlyinthepresenceofshock.Joannes-BoyauO,HonorePM:HemofiltrationStudy:IVOIREStudy:IDNCT00241228.,lastAccessedinJune2011.ContentsIntroduction1Typeoftherapy2TimingofCRRT3DoseofCRRT4Conclusions56RRTinICU:PreferenceDecisionaboutwhichtechniquetousedependson:1.WhatwewanttoremovefromtheplasmaRRTinICU:Preference2.Thepatient`scardiovascularstatusCRRTcauseslessrapidfluidshiftsandisthepreferredoptionifthereisanydegreeofcardiovascularinstability.3.TheavailabilityofresourcesCRRTismorelabourintensiveandmoreexpensivethanIHDAvailabilityofequipmentmaydictatetheformofRRTRRTinICU:Preference4.Theclinician`sexperienceItiswisetouseaformofRRTthatisfamiliartoallthestaffinvolved5.

OtherspecificclinicalconsiderationsConvectivemodesofRRTmaybebeneficialifthepatienthassepticshockCRRTcanaidfeedingregimesbyimprovingfluidmanagementCRRTmaybeassociatedwithbettercerebralperfusioninpatientswithanacutebraininjuryorfulminanthepaticfailure许多问题悬而未决标准与个体化Youareunique!Standard!KeyPointsItisrecommendedtodefineARFaccordingtotheRIFLEclassificationsystemintoARFrisk,ARFinjuryandARFfailure.ItisrecommendedtobasethedecisionwhentostartRRTnotonlyontheseverityofARF,butalsoontheseverityofotherorganfailure.InitiationofRRTistobeconsideredinoliguricpatients(RIFLErisk-oliguriao