Chemical-Examination-of-Urine：尿液化学检验课件

ChemicalExaminationofUrine：尿液化学检验1、战鼓一响，法律无声。——英国2、任何法律的根本；不，不成文法本身就是讲道理……法律，也即明示道理。——爱·科克3、法律是最保险的头盔。——爱·科克4、一个国家如果纲纪不正，其国风一定颓败。——塞内加5、法律不能使人人平等，但是在法律面前人人是平等的。——波洛克ChemicalExaminationofUrine：尿液化学检验ChemicalExaminationofUrine：尿液化学检验1、战鼓一响，法律无声。——英国2、任何法律的根本；不，不成文法本身就是讲道理……法律，也即明示道理。——爱·科克3、法律是最保险的头盔。——爱·科克4、一个国家如果纲纪不正，其国风一定颓败。——塞内加5、法律不能使人人平等，但是在法律面前人人是平等的。——波洛克ChemicalExaminationofUrineRickiOttenMT(ASCP)SC2Objectives:Reviewtheobjectivesonpage1and2 ofthelecturehandoutObjectivesmarkedwith‘*’willnotbetestedoverduringstudentlabrotation3HistoricalPerspectiveMicroscopicexaminationofurineNotuntilinventionofthemicroscopeThenclinicalusefulnessrealized6ReagentStripTestingTechnologyandnecessityChemicalreactions‘miniaturized’RequiredlessurineTestresultswithinminutesEasytoperformIncreasedtestutilizationBrunzel,2ndEd,page1247ReagentStripTestingIdealqualitativescreeningtoolSensitive:Lowconcentrationofsubstances Negativeresult=normalSpecific:Reactswithonlyonesubstance FalsenegativeandfalsepositiveCosteffective:Relativelyinexpensivetoolthat providesinformationaboutthehealthstatus ofthepatient8ReagentStripTestingChemicallyimpregnatedabsorbent padsattachedtoaninertplasticstripEachpadisaspecificchemicalreactionthat takesplaceuponcontactwithurineChemicalreactioncausesthecolorofthepadto changeColorcomparedtoacolorchartforinterpretation9ReagentStripTestingQualitativeorsemi-quantitativeresultsConcentrationunits(mg/dl)Negative,small,moderatelargeNegative,1+,2+,3+,4+TimingofchemicalreactionsisCRITICALShortesttimerequirementononeendofstrip:30secLongesttimerequirementontheother:2min10ReagentStripTestingPrincipleofchemicalreactionsFalsenegativereactionsFalsepositivereactionsColorinterferencesAlternativetesting:usedtoconfirmresultsthatyoumaythinkareinvalidduetoInterferingsubstanceColorinterference(calledcolormasking)11CareandStorage(pg4)ConfirmatoryTesting(pg6)Readingassignment:Textbook,chapter713012ConfirmatoryTestingAlternativetestingestablishesthecorrectnessoraccuracyofanotherprocedureOftenusedwhenurineishighlypigmentedBilirubinreagentstripictotest13ConfirmatoryTestingCharacteristics:DifferinsensitivityIctotestvsBilirubinreagentstripDifferinspecificitySSAvsProteinreagentstripClinitestvsGlucosereagentstripDifferinmethodology/reactionIdeallywantall314DifferinSpecificityClinitestreactswithallreducing substancesGlucosereagentstripreactswithonlyonereducingsubstance:glucose1510reagentstriptestsSpecificgravitypHProteinGlucoseKetonesBloodBilirubinUrobilinogenNitriteLeukocyteEsterasePurposeofthetestWhatisnormalWhatisabnormalReactionCausesofinvalidresults16SpecificGravity:PurposeEvaluatestheconcentratinganddiluting abilityofthekidneyDensityisrelatedtotheamountofsubstances(solutes)insolutionIncreaseddensity~increasedsoluteinsolution~hypertonicurine~concentratedurineDecreaseddensity~decreasedsoluteinsolution~hypotonicurine~diluteurine17SpecificGravity:NormalNormal:1.002–1.035Majorityofurines:1.010–1.025Physiologicallyimpossible: 1.000 >1.040Dependentuponhydrationstatus18SpecificGravity:TermsIsosthenuriaFixedat1.010RenaltubuleslostabsorptionandsecretingcapabilityHypersthenuriaIncreasedspecificgravityConcentratedurineHyposthenuriaDecreasedspecificgravityDiluteurineSensitivityissues:PregnancytestingUrinarytractinfection19SpecificGravity:MethodsMethodsofmeasurementReagentstriptest:indicatesionicsolutesRefractometer:indicatesamountoftotalsolutesTwofunctionsofthekidneyMaintainwaterbalanceMaintainelectrolytehomeostasisPerformedbyrenaltubulesthroughconcentratinganddiluting;reabsorbingandsecretingwaterandelectrolytes(ionic)20SpecificGravity:Reaction

BasedonachangeinthepKaofapolyelectrolyteonthereagentpadIncreasedionsinsolutioncausesthepolyelectrolyteonthepadtoproducefreeH+FreeH+causeachangeinpHonthereagentpadChangeinpH:bromthymolblueindicator21SpecificGravity:Reaction22SpecificGravitySensitivity:1.000Specificity:detectsonlyionicsubstancesRadiographicdyeMannitolGlucoseDoesnotinterfere23pH:PurposeKidneysregulatebody’sacid-base balancebyselectivehandlingofH+andHCO3-UrinepHreflectsacid-basestatusofbodyTreatmentprotocolmayrequireurinepHbemaintainedataspecificpH (Aidsinidentificationofcrystals(microscope))24pH:NormalNormal:rangesfrom4.5–8.0Firstmorningvoid:acidicPhysiologicallyimpossible: <4.5 >8.0UrinenothandledproperlyOldurineTreatmentinduced25pH:InterpretationMadeinconjunctionwithAcid-basestatusRenalfunctionPresenceofinfectioninurinarytractDiet:highprotein,lowproteinMedicationsAgeofurinesample26pH:AbnormalAcidRespiratoryacidosisHighproteindietStarvationUTIAlkalineRespiratoryalkalosisVegetariandietRenaltubularacidosisUTI27pH:ReactionDoubleindicatorsystemMethylredBromthymolblueAmountoffreeH+influencesacidityofurineandcausepHindicatortochangecolorNeededtomeasurethewidepHrange:acidtoalkaline28pH:Invalidtestresultsdueto:ImproperhandlingofurinesampleContaminationofurinevesselpriortocollection‘Run-over’phenomenon29Protein:PurposeNormalkidneyssecreteLITTLEprotein<15mg/dl (or<150mg/24hours)TheproteinthatisfoundinurinecomesfromBloodstreamUrinarytractProteinuriaisanindicatorofearlyrenaldiseaseProteinuriaalsocausedbynon-renaldisease

30RenalCauseofProteinuria:Glomerulardamage:MostseriouscauseofproteinuriaMostcommoncauseofproteinuriaGlomerulonephritisNephroticSyndromeTubulardysfunction:ReabsorptioncapabilitydecreasedToxinexposure,inheriteddisorderFancon’ssyndrome:heavymetalpoisoning31ClassificationofProteinuriaFunctionalOrthostatic(postural)TransientPathologicPre-renal(overflow)Renal:glomerularRenal:tubularPost-renal32Protein:MethodsReagentstriptestSSAtestFoamtestMicro-albumintest33Protein:ReagentStripThereagentpadisheldata constantpHof3byabufferProteins(anions)insolutioncausean indicatordyetoreleaseH+causingacolor change‘Proteinerrorofindicators’34Protein:ReagentStripSensitivity:~10-25mg/dlSpecificity:reactswithalbuminFalsepositive:highlyalkalineurine(pH>8.0)Falsenegative: Diluteurine Presenceofotherproteins (Tamm-Horsfall,globulins,myoglobin, freelightchains,hemoglobin)35Protein:SSA(Exton’sTest)SulfosalicylicAcid(SSA)PrecipitationTestAcidwillprecipitateproteinsoutofsolutioncausingthesolutiontobecomecloudyAmountofcloudinessisrelatedtotheamountofproteinpresent36Protein:SSA(Exton’sTest)Amountofcloudinessisevaluated,thusmustusecentrifugedurineSensitivity:5-10mg/dlSpecificity:detectsallprotein37Protein:SSA(Exton’sTest)Falsepositiveresults:RadiographicdyesTurbidurineUncentrifugedurineFalsenegativeresults:HighlyalkalineurineDiluteurine38Protein:FoamtestShakealiquotofurineandobservecolorofresultingfoamWhitefoam:proteinpresent39Protein:Micro-albumintestMeasuresverylowconcentrationofalbumin(bettersensitivitythanreagentstriptestforalbumin)ManagementofdiabeticpatientMethodsvary:reagentstriptest, immunochemicalreaction40Glucose:PurposeHealthynormalurinedoesnotcontainglucoseNormally,glucoseisfilteredbytheglomerulusandisreabsorbedbackintothebloodstreamthroughactivetransportmechanismGlucoseinurineispathologic41Glucose:PurposeGlucosuria GlycosuriaCausedbyrenalandnon-renaldiseasePre-renalglycosuria:plasmaglucoselevelexceedsrenalthreshold(diabetesmellitus)Renalglycosuria:plasmaglucoselevelbelowrenalthreshold,buttubulescannotreabsorbglucosebackintobloodstreamTermsusedinterchangeably42ReducingSubstances:PurposeReducingSubstances:GlucoseOthersugars:galactosemia(inheritedmetabolicdisorder)43Glucose,ReducingSubstancesNormal:negativeAbnormal:Diabetesmellitus:glucoseImpairedrenaltubularreabsorption:glucoseInbornerrorofmetabolism:galactosemia44MethodsReagentstrip:detectsonlyglucoseCopperReduction:detectsreducingsubstances45Glucose:ReagentStripDetectsonlyglucoseDoublesequentialenzymereaction46Glucose:ReagentStripSensitivity:~30mg/dlSpecificity:ReactsonlywithglucoseFalsepositive:Strongoxidizingagents(bleach)PeroxidesFalsenegative:Ascorbicacid(reducingagent)Improperlystoredurine:glycolysis47ClinitestReactionCopperReductionTest:ReducingsubstancesareabletoreducecoppersulfatetocuprousoxidePass-throughphenomenonAllchildren<2years:metabolicdisorder (galactosemia)

48ClinitestReactionSensitivity:~250mg/dlSpecificity:ReactswithallreducingsubstancesReducingsugars:glucose,galactose,fructose,lactose,maltose(NOTSUCROSE)Falsepositive:anyreducingsubstance (Ascorbicacid)Falsenegative:radiographicdye

49Ketones:PurposeKetonesareintermediaryproductsoffatmetabolism50KetonesThreeketonebodiesAcetone 2%Acetoaceticacid 20%Beta-hydroxybutyricacid 78%Characteristic‘fruitybreath’~acetone51Ketones:NormalNormal:negativeAbnormal:InabilitytoutilizecarbohydratesExcessivelossofcarbohydratesInadequateintakeofcarbohydrates52Ketones:MethodsReagentstripAcetest:tablettest53Ketones:MethodGlycine:alsomeasuresacetoneReagentstrip:checkpackageinsertAcetesttablets:containglycine54KetonesReagentstripSensitivity:5-10mg/dlSpecificity:acetoaceticacidand/oracetoneFalsepositive:highlypigmentedurineFalsenegative:improperspecimenhandlingAcetestSpecificity:acetoaceticacidandacetoneFalsepositive:highlypigmentedurienFalsenegative:improperspecimenhandling55Blood:PurposeBloodinurineindicatespathologyTwoformsfoundinurineIntactRBCHemolyzedRBC56Blood:TermsHematuriaHemoglobinuriaMyoglobinuriaAllwillgiveapositivebloodreaction57Blood:ReagentstripTestcandetecthemolyzedRBCHememoietyimpartsperoxidaseactivityandcatalyzesthereaction58BloodSensitivitySpecificityIntactRBCHemolyzedRBC(hemoglobin)MyoglobinFalsepositives:myoglobin,oxidizingagentsFalsenegatives:ascorbicacid59Blood:CorrelatereagentstripresultsMicroscopicfindingsColorandclarity60BilirubinandUrobilinogenBilirubininurineisalwayspathologic: liverdiseaseUrobilinogeninurine:normaltohaveasmallamount: 0.2–1.0mg/dl61ThreemechanismsPre-hepatic:liverishealthyHepatic:liverdiseasePost-hepatic:liverishealthy,obstructionindicated62Bilirubin:MethodsReagentstripIctotest:tablettestFoamtest63Bilirubin:MethodsReagentstripIctotest:tablettestSamereactionSamespecificity:conjugatedbilirubinFalsepositive:urinecolorFalsenegative:lowconcentration,ascorbicacid,improperspecimenhandling64Bilirubin:MethodsReagentstripIctotest:tablettestSensitivitydiffers

Reagentstrip:~0.5mg/dl Ictotest: 0.05–0.1mg/dl 65Bilirubin:MethodsPossibletohaveanegativereagentstriptestandpositiveictotestDifferenceinsensitivitylevelsAlwaysperformIctotestwhenUrinebilirubintestspecificallyorderedUrineappearanceisamber:evenifbilirubin reagentstriptestisnegativePositivereagentstriptest66Bilirubin:FoamTestShakeurineandobserveresultingfoamYellowfoam=bilirubin67Urobilinogen:MethodsReagentstriptestTworeactionsdependentuponmanufacturerPara-dimethylaminobenzaldehydeDiazoniumsaltCannotdetermineabsenceofUBGWatson-Schwartzassay68Urobilinogen:MethodsPara-dimethylaminobenzaldehydeSensitivity:0.2mg/dlSpecificity:Falsepositive:any‘Ehrlichreactivecompound’;colormasking;urineatbodytempFalsenegative:improperspecimenhandlingDiazoniumsaltSensitivity:0.4mg/dlSpecificity:reactsonlywithUBGFalsepositive:colormaskingFalsenegative:improperspecimenhandling69Urobilinogen:WatsonSchwartzClassicmethodusedtodifferentiate urobilinogenfromporphobilinogenusinga differentialextractionmethodPara-dimethylaminobenzaldehyde70Nitrite:PurposeBacteriathatcontainaspecificenzymecanreducedietarynitratestonitritesRapidscreeningtestforUTI71Nitrite:NormalNormal:negativeAbnormal:Cystitis:bladderPyelonephritis:kidney72Nitrite:MethodReagentstri