医药-临床-护理肾功能检验ppt课件

1、欢迎进入学习 课堂Laboratory tests of renal functionJunfu HuangSouthwestern HospitalTMMUAnatomy of KidneyFunctions of the kidneyExcretion of Metabolite Waste: urea, uric acid, creatinineUrine Production, regulation of homeostasis, water, acid base balanceEndocrine Function: renin, erythropoietin, 1,25 -dihyd

2、roxycholecalciferolRenal function testsDetect renal damageMonitor functional damageDistinguish between impairment and failureKidney FunctionA plumbers viewHow do you know its broken?NO Urine!Clinical symptomsTestsWhere can it break?Pre-renalRenalPost-renalLaboratory tests of renal functionGlomerular

3、 Function TestsRenal Tubular Function TestsSection 1 Investigation of Glomerular FunctionRenal Blood Flow: 1200-1400ml/minRenal Plasma : 600-800ml/min20% of plasma: glomerular filtration GFR:Glomerular Filtrtion Rate Concept Renal CleranceConcept Virtual volume of plasma from which the substance in

4、question has been completely removed during a given time interval. C=UV/P U:urine concentrtion P:plasma con. V:urine flow rateUsefulness of Renal CleranceFreely filtrated, neither secreted, nor reabsorbed: Inulin: GFR DeterminationFreely Filtrated, small amounts secreted, without reabsorption: Creti

5、nine:GFRFree filtrated, completely reabsorption: Glucose Tubular Maxima Reabsorption RateInulin ClerancePolymer of fructoseMW:5500Free filtration, without secretion and reabsorptionGFRMethod Reference Interval: 2.0-2.3ml/minEndogenous Creatinine Clearance100g,98% stored in musle,MW:113Cretine phosph

6、ate-cretinecretinineFreely filtration, small mounts: secretionExogenous and Endogenous CreatinineGrossly Investigate the GFRMethod 24h urine collection method modified 4h urine collection method Clerance Correction： Ccr x SBSA/IBSAPlasma ureaSecreted and reabsorbed by tubules, freely filtratedquick,

7、 simple measurementwide reference range 3 - 8 mmol/Lsensitive but non-specific index of illnessUrea excretionfiltered at glomerulusabout 40% filtered urea is reabsorbed by renal tubules in healthmore urea is reabsorbed if rate of tubular flow is slowtubular flow rate is slow when there is renal hypo

8、perfusionIncreased plasma ureaGI bleedtraumarenal hypoperfusiondecreased RBFdecreased ECFVacute renal impairmentchronic renal diseasepost-renal obstructioncalculustumourUreaUseful test but must be interpreted with great careAlways consider input, output and patients fluid volumePlasma creatinine50 -

9、 140 umol/Lincreases in concentration as GFR decreasesanalytical interferences (acetoacetate - DKA)NOT proportional to renal damagePlasma CreatinineGFRpCreat140 mL/min0 mL/minChange within an individual patient is usually more important than the absolute valuePlasma creatinine in chronic renal disea

10、se May increase to 1000 umol/LPlot of recipricol of plasma creatinine concentration predicts when intervention is required in end stage renal failureTime1/ pCreatPlasma Uric Acid20%:foods;80%:purine metabolismSmall amounts: conjugated with albuminFree Filtrated,98%-100%:reabsorbedPlasma UA concentra

11、tion: depend on glomerular filtration and tubular reabsorptionProgression of chronic renal diseasePlasma Cystatin CCysteine proteinase inhibitorProduced by nucleated cellsMW:13000, free filtration,reabsorbed and metabolized by tubulesPlasma CysC concentrtion: depend on glomerular filtrationCarbamyla

12、ted hemoglobinUreabloodcyanateHb carbamylatedCarHbARF：no changes(1 weeks)CRF: increaseLaboratory tests of renal functionglomerular filtration rate impracticalcreatinine clearance unreliableplasma creatinine specific but insensitiveplasma urea subject to problemsurine volume often forgotten!Section 2

13、 Investigation of Tubular FunctionDistal nephron Function tests 1. Mosenthal test Concentration dilution test 8 AM :Voiding and Discarded 10,12,14,16,18,20:00 and 8:00 next day: collecting urine samples Determing the urine volume and gravity2.Urine Osmolarity3.Acute Oliguria Prenal? Renal?Proximal t

14、ubular Function tests 1.Low MW proteins in urine 2.Tubular maximal glucose reabsorption 3.Tubular maximal PAH secretion 4.Amino acide in urine Fanconi SyndromeSection 3 Effective Renal Blood FlowIsotope Method:131I-OIHPAH Clearance: 20%:filtrated,80%:secreted by tubulesSection 4 Investigation of renal tubular acidosisTubular Acidosis:I,II,III.IVI:distal formII:proximal formNH4Cl Loading TestOral administration of NH4ClArtificial Metabolic AcidosisUrine Sample CollectionpH determinationFraction of HCO3- excretionHCO