Urinalysis

Urine Dipstick

Measurement Significance and uses

Specific gravity

estimate Uoim:each 0.001 above 1 -30 osm (SG 1.010 U,nm -300) S.G.and U«m useful in evaluating ARF, dysnatremias, polyuria heavy substances (glucose, contrast) increase SG more than Uovn

PH

range: 4.5-8.5; useful in evaluation of stones and RTAs

Protein

detects albumin (marker for glomerular dysfxn); see "Proteinuria"

RBC

see "Hematuria"; also 0 with myoglobinuria (rhabdomyolysis)

WBC

suggests inflammation (UTI. interstitial nephritis, GN)

Ketones

detects acetoacetate (ie, ketoacidosis), but not (J-hydroxybutyrate

Nitrite

suggests presence of Enterobocteriaccae

Bilirubin

t in biliary or hepatic disease

Glucose

® in hyperglycemia, pregnancy, Fanconi s syndrome

Urine Sediment (microscopic examination)

Method: centrifuge test tube x 3-5 min at 1500-3000 RPM; pour off supernatant in one motion; resuspend pellet by agitating base of tube: pour suspension onto slide, place cover-slip; view under "high • dry" power; phase contrast for RBC morphology.

Cells Casts

RBCs: assess amount & morphology (many dysmorphic -* glomerular) WBCs: PMNs (UTI) vs. eosinophils (AIN; may require special stain) Epithelial cells: tubular (ATN), transitional (bladder or ureters), squamous Proteins molded in lumen of renal tubule _ entrapped cellular elements RBC - GN

WBC - AIN. pyelonephritis. GN

Granular ("muddy brown"): degenerating cellular casts — ATN Tubular cell — ATN

Hyaline:Tamm-Horsfall protein (nonspecific) Waxy and broad - advanced renal failure

Crystals

Calcium oxalate monohydrate: spindle, oval, or dumbbell shaped Calcium oxalate dihydrate: envelope shaped or octahedral Uric acid: variable shape; polychromatic under polarized light Cystine: hexagon shaped

Struvite: coffin-lid shaped; seen in chronic UTI with urea-splitting organisms

Was this article helpful?

0 0

Post a comment