腎功能檢驗的學習課件

腎功能檢驗的學習課件第1頁/共34頁FunctionsofthekidneyExcretionof

MetaboliteWaste:urea,uricacid,creatinineUrineProduction,regulationofhomeostasis,water,acidbasebalanceEndocrineFunction:renin,erythropoietin,

1,25-dihydroxycholecalciferol第2頁/共34頁RenalfunctiontestsDetectrenaldamageMonitorfunctionaldamageDistinguishbetweenimpairmentandfailure第3頁/共34頁KidneyFunctionAplumbersview第4頁/共34頁Howdoyouknowit’sbroken?NOUrine!ClinicalsymptomsTests第5頁/共34頁Wherecanitbreak?Pre-renalRenalPost-renal第6頁/共34頁LaboratorytestsofrenalfunctionGlomerularFunctionTestsRenalTubularFunctionTests第7頁/共34頁Section1InvestigationofGlomerularFunctionRenalBloodFlow:1200-1400ml/minRenalPlasma:600-800ml/min20%ofplasma:glomerularfiltrationGFR:GlomerularFiltrtionRateConcept

第8頁/共34頁RenalCleranceConceptVirtualvolumeofplasmafromwhichthesubstanceinquestionhasbeencompletelyremovedduringagiventimeinterval.C=UV/PU:urineconcentrtionP:plasmacon.

V:urineflowrate第9頁/共34頁UsefulnessofRenalCleranceFreelyfiltrated,neithersecreted,norreabsorbed:Inulin:GFRDeterminationFreelyFiltrated,smallamountssecreted,withoutreabsorption:Cretinine:GFRFreefiltrated,completelyreabsorption:GlucoseTubularMaximaReabsorptionRate第10頁/共34頁InulinClerancePolymeroffructoseMW:5500Freefiltration,withoutsecretionandreabsorptionGFRMethodReferenceInterval:2.0-2.3ml/min第11頁/共34頁EndogenousCreatinineClearance

100g,98%storedinmusle,MW:113Cretinephosphate---cretine—cretinineFreelyfiltration,smallmounts:secretionExogenousandEndogenousCreatinineGrosslyInvestigatetheGFR第12頁/共34頁Method24hurinecollectionmethodmodified4hurinecollectionmethodCleranceCorrection：CcrxSBSA/IBSA第13頁/共34頁PlasmaureaSecretedandreabsorbedbytubules,freelyfiltratedquick,simplemeasurementwidereferencerange3-8mmol/Lsensitivebutnon-specificindexofillness第14頁/共34頁第15頁/共34頁Ureaexcretionfilteredatglomerulusabout40%filteredureaisreabsorbedbyrenaltubulesinhealthmoreureaisreabsorbedifrateoftubularflowisslowtubularflowrateisslowwhenthereisrenalhypoperfusion第16頁/共34頁IncreasedplasmaureaGIbleedtraumarenalhypoperfusion

decreasedRBF

decreasedECFVacuterenalimpairmentchronicrenaldisease

post-renalobstruction

calculus

tumour第17頁/共34頁UreaUsefultestbutmustbeinterpretedwithgreatcareAlwaysconsiderinput,outputandpatient’sfluidvolume第18頁/共34頁Plasmacreatinine50-140umol/LincreasesinconcentrationasGFRdecreasesanalyticalinterferences(acetoacetate-DKA)NOTproportionaltorenaldamage第19頁/共34頁PlasmaCreatinineGFR[pCreat]140mL/min0mL/minChangewithinanindividualpatientisusuallymoreimportantthantheabsolutevalue第20頁/共34頁PlasmacreatinineinchronicrenaldiseaseMayincreaseto1000umol/LPlotofrecipricolofplasmacreatinineconcentrationpredictswheninterventionisrequiredinendstagerenalfailureTime1/[pCreat]第21頁/共34頁PlasmaUricAcid20%:foods;80%:purinemetabolismSmallamounts:conjugatedwithalbuminFreeFiltrated,98%-100%:reabsorbedPlasmaUAconcentration:dependonglomerularfiltrationandtubularreabsorption第22頁/共34頁Progressionofchronicrenaldisease第23頁/共34頁PlasmaCystatinCCysteineproteinaseinhibitorProducedbynucleatedcellsMW:13000,freefiltration,reabsorbedandmetabolizedbytubulesPlasmaCysCconcentrtion:dependonglomerularfiltration第24頁/共34頁Carbamylatedhemoglobin

Urea—blood—cyanate—Hbcarbamylated—CarHbARF：nochanges(1weeks)CRF:increase第25頁/共34頁Laboratorytestsofrenalfunctionglomerularfiltrationrateimpracticalcreatinineclearanceunreliableplasmacreatininespecificbutinsensitiveplasmaureasubjecttoproblemsurinevolumeoftenforgotten!第26頁/共34頁Section2InvestigationofTubularFunctionDistalnephronFunctiontests1.MosenthaltestConcentrationdilutiontest8AM:VoidingandDiscarded10,12,14,16,18,20:00and8:00nextday:collectingurinesamplesDetermingtheurinevolumeandgravity第27頁/共34頁2.UrineOsmolarity3.AcuteOliguriaPrenal?Renal?第28頁/共34頁ProximaltubularFunctiontests1.LowMWproteinsinurine2.Tubularmaximalglucosereabsorption3.TubularmaximalPAHsecretion4.AminoacideinurineFanconiSyndrome第29頁/共34頁Section3EffectiveRenalBloodFlowIsotopeMethod:131I-OIHPAHClearance:20%:filtrated,80%:secretedbytubules第30頁/共34頁Section4InvestigationofrenaltubularacidosisTubularAcidosis:I,II,III.IVI:distalformII:proximalform第31頁/共34頁NH4ClLoadingTestOraladministrationofNH4ClArtificialMetabolicAcidosisUrineSampleCollectionpHdetermination第32頁/共34頁FractionofHCO3-excretion