Urinalysis

Panita Limpawattana 4 April 2010

Urinalysis

•  pH •  Sp.gr •  Dip strip

– Protein – Glucose – Bile – Urobilinogen

•  Microscopic – WBC – RBC – Cast – Epithelial cell – Oval fat body – Crystal

Urinalysis

•  Gross : color, turbidity – Colorless: diabetes insipidus – Orange: drug (rifampicin) – Red : hematuria, hemoglobinuria, drug – Deep green: obstructive jaundice – Blue: methylene blue – Brown black: hemoglobinuria, myoglobinuria

pH

•  Normal : 4.6-8 (average = 6)

•  Aciduria : starvation, high protein diet,

acidosis

•  Alkaliuria : sodamint, alkalosis, UTI

(Proteus), high veggie intake

Urine specific gravity

•  Normal urine spec: 1.003-1.030 •  Low specific gravity:

–  Chronic nephritis –  Diabetes insipidus

•  High specific gravity: – Dehydration – Glucosuria – Contrast media

Glucosuria

•  Renal threshold 180 mg/dl

•  Glucosuria without hyperglycemia

–  Renal glucosuria (Fanconi’s syndrome or proximal tubule

disease)

–  Pregnancy

–  Inborn error of metabolism

–  Nephrotoxic substance : CO, Pb, Mercury

Urine strip for protein

•  1/3= albumin

•  Normal protein excretion = 150 mg/d

•  Positive urine strip: 300-500 mg/d

•  Not sensitive for diabetic nephropathy

Positive urine strip for protein

Protein from glomerular, tubulointerstitial •  Albumin •  B2 immunoglobulin: tubulointerstitial

disease •  Immunoglobulin light chain: MM

Causes of proteinuria

•  Functional- < 500mg/d – Exercise, pregnancy, orthostatic proteinuria

•  Organic – renal and systemic disease – Prerenal- fever, venous congestion (CHF),

relative anoxia (shock, severe acidosis, severe anemia)

– Renal- glomerulonephritis, NS – Postrenal- infection beyond renal pelvis

Nephrotic syndrome: criteria

• Urine dipstick 3+, 3 gm/d

• Serum albumin < 3 gm/dL

• Serum cholesterol > 300 mg/dL

Ketone

•  DKA

- serum ketone (dilute 1:2)

•  Non DKA

-  Fever

-  High fat diet

-  Starvations

-  Dehydration

Approach to red urine Urine centrifuge

Supernatant red Sediment red

Hematuria Dipstick heme

Negative Positive

Beet root Porphyria

Plasma

Clear myoglobinuria

Red hemoglobinuria

Cell in urine

•  RBC: 0-2/hpf – Renal diseases

– Lower uri. Tract

– ExtraMenstrual

– Drugs- ASA, anticoagulant

– Physiologic- heavy exercise

•  Dysmorphic RBC

Cell in urine

•  WBC: 0-5/hpf –  Infection

– Nephritis (+WBC cast)

Urine cast RBC cast

WBC cast

Hyaline cast

Granular cast

Broad cast

WBC cast

Epithelial cell Calcium oxalate

Oval fat body Uric acid crystal

Telescopic urine sediment?

•  Lupus nephritis •  NS (late stage)