Urinalysis Hematuria Proteinuria - Division of …

1 UrinalysisUrinalysis Clean-catch midstream collection Single straight catheterization Suprapubic aspiration Foley s catheter High osmolarity and low pH Cellular preservation First voided morning urine*Routine urinalysisGross examDipstickMicroscopic Color pH Cells Turbidity Sp gr Casts Odor Protein Bacteria Blood Yeast Glucose Parasites Ketones Crystals Leukocytes Artifacts Nitrites UrobilibogenUrinalysis: Odor Ammonia: bacterial contamination Fruity: ketones (diabetes, starvation) Maple syrup: maple syrup urine disease Musty: phenylketonuria Ingested foods: asparagus Excreted drugs: antibioticsUrine: physical properties Yellow (urochrome) Clear Specific gravity Inaccurate surrogate for osmolarity ~ 50-1000 mOsm/kg ~ Isosthenuria Used to determine concentrating abilityUrine: chemical properties Dipstick methodology pH: Protein: Trace = 5-20 mg/dL1+ = 30 mg/dL2+ = 100 mg/dL3+ = 300 mg/dL4+ = >2000 mg/dL Blood: peroxidase activity of HgbUrine pH Normal range pH > : taking bicarbonate, alkali suppl pH 8-9.

2 Urea-splitting bacteria Acidosis with urine pH > , suggests RTA Amorphous crystal type depends on pH pH : urates pH > : phosphates pH can rise in open container (CO2 loss)Urine: chemical properties Glucose: Ketones: Acetoacetate (++), acetone (+)NOT -hydroxybutyrate Urobilinogen: Ehrlich reaction Bilirubin: Only conjugated obstructive Nitrite: Gm(-)bacteria convert Nitrate Leukocytes: Leukocyte esterase False Positive Vaginal contamination False Negative High glucose Albumin Ascorbic acid Tetracycline Cephalexin Oxalic acidNitrite False negative Inadequate bladder retention time (it may take up to 4 hrs to convert nitrate to nitrite) Prolonged storage of sample Several uropathogens do notconvert nitrate to nitrite Streptococcus faecalis, other gram positiveMicroscopic examination Spun urine sediment Centrifuge @ 1500-2000 rpm x 5 minsErythrocytes Sources.

3 Glomerulus urethra >2-3 rbc/HPF = pathologic Crenated in hypertonic urine Dysmorphic rbc s ~ glomerular pathologyLeukocytes Larger than rbc Nucleated cells/granules Glitter cells (granules brownian motions)Leukocytes R/O contamination Mostly PMN s, but also look for Eosinophils Staining for eosinophils Wright stain Hansel stain (improves the sensitivity and PPV)Diseases Associated with EosinophiluriaUrine StainNHanselWrightAIN11102 RPGN104 4 Postinfectious6 11 ATN3000 Acute pyelo1000 Acute prostatitis1062 Nolan III RC et al: NEJM 1986.

4 315:1516-19 Renal tubular epithelial cells Larger than PMN s Few cells can be found in normal urine Indicate tubular damage or inflammation from ATN or interstitial glycoprotein Uromodulin RBC cast formationGranular casts Finegranular casts Serum proteins Coarsegranular casts Degeneration of embedded cells Non-specific but pathologic CrystalsAcid Urine (pH<6)Alkaline Urine (pH>6) Uric acid PhosphatesRhombic prism formTriple phosphatesSodium urateCalcium phosphatesAmorphous urateAmorphous phosphates Calcium oxalate Ammonium urates Cystine Leucine Tyrosine Cholesterol SulfaOxalate crystals Envelope-shaped Dumbbell-shapedTriple phosphate crystalsCoffin lid-shapedCystine crystalsCrystals due to drugsBoth are birefringent (strongly in Indinavir)E