【持续性肾脏替代治疗crrt英文精品课件】 arf

AcuteRenalFailure Rapidlossofglomerularfiltrationandtubularfunctionleadingtoabnormalwater electrolyteandsolutebalanceOccursoverhourstodaysUsuallyassociatedwitholiguria Somepatientsdevelopnon oliguricARFeg AfterradiocontrastmediaAcute onchronicrenalfailure AetiologyofARF Pre renalRenalGlomerularTubulointerstitialVascularPost renal AetiologyofARF GlomerularRPGNTubulointerstitialAcutetubularnecrosisAcutetubulointerstitialnephritisInfectionCastnephropathyVascularThromboticmicroangiopathyCholesterolemboliVasculitis Acutetubularnecrosis ProlongedhypoperfusionDrugs NSAIDs ACEinhibitorsDirecttoxicityDrugs eg Aminoglycosides cisplatinRadiocontrastagentsHaempigmentsSnakevenomHeavymetals lead mercuryAssociatedwithnephroticsyndrome ARFinICU ARFiscommonintheICUARFisanindependentfactorforprognosisintheICUTheincidenceofARFintheICU40 60 comparedto1 3 inthewardARFstillhasamortalityof50 sinceitoccursinverysickpatientswithmultiorganfailure ARFinICU PredisposingfactorstoARFincludeoldagesepsispreexistingrenaldiseaseheartdiseaseandchronicliverdiseaseMechanicalventilationhasanadverseeffectonrenalbloodflowandGFRandsubsequentrenalfunction ModeratedeclineinrenalfunctioncanaffecttheoutcomeEvenariseofcreatinineof 5mg dlcanaffecttheoutcome Acutetubularnecrosis TubulardilatationLossofbrushborderEpithelialcellvacuolationDetachmentofepithelialcellsGranularcastsHyperchromasiaoftubularnucleiMitosesCalcification InterstitialoedemaInterstitialinflammationNucleatedrbcsinvasarecta ARFPATHOGENSIS LossofintactornecrotictubularcellsOcclusionoftubularcellsbydebrisThedeclineinrenalfunctionisoftenmoreprominentthantheseverityofhistologicalchangesManynephronsdraintoasinglecollectingductthereforeobstructionoffewductscauseseverrenaldysfunction ARFPATHOGENSIS TheischemicdamageismostseverintheearlyproximaltubulesandthickascendinglobeMedullaryhypoxiaplaymajorroleinthesusceptibilitytoischemicdamagePooroxygenationleadtointracellularaccumulationofcalciumdepletionofATPandapoptosisleadingtocelldeathorsloughingofviablecells ARFPATHOGENESIS EnodotoxinsmaypromoterenalinjuryinmultiorganfailurepatientsCytokinesreleasedduringdialysismaypromotecellularinjuryIntratubularobstructionbycellsandcellulardebrisisanimportantcomponentofATN TherateofrecoveryofARFmaybeacceleratedandmortalityreducedwiththeuseofbiocompatiblemembranesifdialysisisrequiredthatlimitthedegreeofcytokinesactivation ARFPATHOGENESIS IntratubularobstructionbycellsanddebrisisanimportantcomponentofATNIntegrinreceptorscontributetothisprocessastheirtranslocationtothelumenpromotetheadhesionofsloughedmaterialtothetubularcells Complementactivation Complementactivationisanearlyprocessinischemicrenaldamagecausingdirectcellulartubulardamageaswellasendothelialdamage ARFprevention InanimalstudiestheuseofmannitolandloopdiureticminimizethedegreeofrenalinjuryifgivenatthetimeofischemicinjuryLoopdiureticsdecreasetheactiveNatransportinthethickascendingloopdecreasingtheenergyrequirement ARFprevention DopamineandANPhadbeentriedinexperimentalmodelswithoutanybenefitdespitetheirabilitytoincreaserenalbloodflowandNaexcretionCalciumchannelblockersdecreaseCainfluxtothecellsthatleadtocellinjury ARFprevention MosthumanstudiesweredoneonestablishedATNIncreasingtheurineoutputbyloopdiureticmakethemanagementeasierbutdoesnotaffectcellinjuryortheseverityoftherenaldamageLoopdiureticincreasetheurineoutputintheremainingnephronsandthereforehugedosesarerequiredthatmaycausedeafness ARFprevention UncontrolledstudiesshowedthatthosepatientswhorespondtodiureticsormannitolmayhavebetteroutcomebutthesepatientshaslessseverdiseaseControlledstudiesfailedtoshowanyevidencethatlowdosedopaminehaveanyprotectionofcellinjuryinischemicrenaldamage Thepatientisa62 year oldmalewithahistoryofperipheralandcerebrovasculardiseaseandhypertensionwithoutknownrenaldisease Hepresentedwithabdominalpainandfever Physicalexaminationandlaboratoryanalysiswerediagnosticofanacutepancreatitis Atthistime hewaseuvolemicwithabloodpressureof150 90mmHgandbloodureanitrogen BUN andserumcreatininelevelsof22and1 4mg dL respectively Becauseofadeteriorationinhiscondition heunderwentanexploratorylaparotomy Adiagnosisofacutehemorrhagicpancreatitiswasestablished andthepancreaswasdebridedandthegallbladderremoved Postoperativelythepatientrequiredpressoragents includingdopamine becauseofhemodynamicinstability healsoneededventilatorysupportbecauseofworseningpulmonaryedema Largequantitiesofintravenousfluidwererequiredbecauseof third spacing especiallyintotheabdominalcavity Bythesecondhospitalday rising BUNandserumcreatininevalues 48and5 4mg dL respectively oliguriaunresponsivetodiuretics andfluidoverloadnecessitatedhemodialysis Afterseveraldaysofdailyintermittenthemodialysis thepatientwasswitchedtocontinuousvenous venoushemofiltrationbecauseofhisworseninghemodynamicinstabilityandfluidoverload Thisformoftreatmentwascontinuedfortendays afterwhichintermittenthemodialysiswasreinstated Twomonthsaftertheonsetofacuterenalfailure thepatientshowedevidenceofrenalrecovery anddialysiswasdiscontinued Threemonthsafteradmission BUNandserumcreatininelevelsfellto22and1 8mg dL respectively Hiscourseinthehospitalhasbeenpunctuatedbyrecurrentsepsisandbytheneedforrepeateddebridementoftheperitonealcavity Healsodevelopedasmall bowelobstructionandasmall bowelfistula necessitatingsurgery Atthistimethepatientremainstheintensivecareunitwithrelativelygoodrenalfunction 58YoldYemenimaleDiabeticfor5yearswithnoobviousdiabeticcomplicationsparticularlynoretinopathyAdmittedwithfeverandpaininbothlegsfor4days HehadnoothersymptomsparticularlynodyspneacoughorchestpainHehadnoGIsymptomsandnourinarysymptoms CASEPRESENTATION P M HHypertensionfor5yearsonenalapril5mgoncedailyNohistoryofIHD Casepresentation SocialhistoryNonsmokermarried3children Casepresentation CellulitisbothlegsextendingfromanklestobothkneesNoobviouscollectionGoodperipheralpulsesNoevidenceofperipheralnueropathy Casepresentation OnexaminationHelookedwellBP135 80Temp38 5pulse90 minregularJVPnormalchestclearCVSnormalAbdomennormal Casepresentation LabworkWBC17MainlynuetrophilsHb13 1Na138K4 1urea18mmol lCr212umol lCa2 1mmol lP1 6mmol lUrinalysisproteinurianohemturianocastsLFTnormal Casepresentation LabdataU SnormalsizekidneysC3andC4normalANAnegativeHepatitisscreennegative Courseinhospital StartedonceftrixoneandclindamycinwithhisusualmedicationsHistempraturesubsidedandcellulitisimproved Courseinhospital Hisurineoutputhadbeenmaintainedwithinnormalrangebuthisrenalfunctiongotworseandfinallyhiscreatininereached1100umol landurea45mmol lK5 5butnofluidoverloadDialysiswasstarted Diffdiagnosis PostinfectiousGNDruginducedPreexistingdiabeticnephropathygotworsewithsepsis Kidneybiopsy NormalglomeruliNointerstilalinfeltrate Courseinhospital Hewasdialysedfor10daysthenhisrenalfunctionstatedtoimproveandcreatininedecreasedandreachednormalvaluetowweeksafterstoppingdialysisAtthattimehebecamepolyuricforoneweekHewassenthomeingoodmedicalcondition NSAIDHEMODYNAMICALLY MEDIATEDACUTERENALFAILURE Althoughrenalprostaglandinsareprimarilyvasodilators theydonotplayamajorroleintheregulationofrenalhemodynamicsinnormalsubjectsthereleaseofthesehormones particularlyprostacyclinandprostaglandinE2 isincreasedbyunderlyingglomerulardisease renalinsufficiency hypercalcemia andthevasoconstrictorsangiotensin NSAIDHEMODYNAMICALLY MEDIATEDACUTERENALFAILURE InhibitionofprostaglandinsynthesiswithanNSAIDinanyoftheabovesettingscanleadtoreversiblerenalischemia adeclineinglomerularhydraulicpressureandARF RenalfunctioninCHF CHFisacommondisorderandalterationinrenalfunctionaffectmortalityandmorbidityRenalimpairmentmaketreatmentmoredifficultsincetheresponsetodiureticsisdecreasedInCHFthereisNaretentioninspiteofextracellularvolumeexpantion RenalfunctioninCHF ThereisincreaseinthenuerohormonalvasoconstrictorsinCHF A2Aldosteroneandvasopressin ThisleadtoafferentarteriolarvasoconstrictionNaandKretentionandwaterretentionThereisincreaseinthehormonalvasodilatorsasANPandrenalprostaglandins ThekidneyinCHF ThenuerohormonalchangesleadtodecreaseinrenalbloodflowandGFRandmaygiveapictureofprerenalazotaemiaorleadtoworseningofapreexistingrenalimpairmenttothepointthatdialysismayberequiredDialysisandfluidremovalinthissituationmayimprovecardiacoutputandinducediuresis ARFINICU ReversetheunderlyingcauseAssessandcorrectvolumeandremovenephrotoxicdrugsCorrectseveracidosis HemodialysisisthestandardtherapyTheoreticallyitmayhaveadverseeffectsincludingdecreaserenalbloodflowGFRandurineoutputSeverhypotensionmaydelaytherecoveryofARF UsingnoncompatiblemembranesmayactivatecomplementandmoreinflammatoryprocessUsingmorecompatiblemembraneshadbeenassociatedwithbetteroutcomeItisbettertoavoidunnecessarydialysis SomestudieshadshownthatearlydialysisisassociatedwithbetteroutcomeThisismainlybecausethesewouldactuallyimprovewithoutdialysis Gillumetal foundthatintensivehemodialysis maintenanceofpredialysisserumcreatininebelow5mg dL providednoadvantageovernon intensivedialysis predialysisserumcreatininemaintai