URINE ANALYSIS

Urine dipstick

• Screening for disease • Fresh urine is collected into clean dry

container• Reagent strip immersed in the urine specimen,

ensure all the reagent blocks are covered.• Errors in results

• Three urine samples are shown. The one at the left shows a red, cloudy appearance. The one in the center is red but clear. The one on the right is yellow, but cloudy.

Parameters in urine dipstick test• Glucose• Bilirubin• Urobilinogen• Ketones• Specific gravity• pH • Protein• Blood• Nitrite• Leucocytes

Physical examination of urine

• Volumea) physiological factor-increase intake of water-temperature-physical activity

-others due to diuretic drugs, coffee and alcohol-normal adult urine volume : 600-1200ml/hour-difference in urine volume due to: polyuria, oliguria, anuria and nocturia

• Colour- normal : pale yellowish- urochrom pigment- abnormal : due to food intake and drugs

Red : beets, rhubarb (alkaline urine)Orange-yellowish : carrot, antibioticGreen, blue-green : drugs eg: amitryplineDark brown : drugs eg: methyldopa, metronidazole

- abnormal : due to pathologicalRed/maroon : rbc, hemoglobin, myoglobin‘wine-red’ : porphyrinDark brown : melanin, homogentisic acidYellowish-brown or greenish-brown : bilirubin, bile pigment

• Odour normal: aromatic odour - Food and drugs causes characteristic odour

e.g: methyl salicylic, asparagus- Ketosis : fruity/sweet- Congenital metabolism disorder : e.g:

phenylketonuria ‘mousy’

• Appearance/ transparencyNormal: -Slight turbidity: mucus (in women), squamous epithelial cell-Turbidity: calcium oxalate, uric acid, amorphous phosphate, amorphous urates

Abnormal:-turbid-red : rbc-turbid : bacterial or yeast infection -milky: lipid

Normal urine composition

• Urea- End product of protein metabolism- 50% from urine composition- 25-30 g/24hr• Uric acid- End product of purine metabolism- 0.5-1 g/24hr• Creatinine- Skeletal muscle tissue

• Creatine- Can be found in muscle tissues in form of

phosphocreatin• Sulphur- Protein intake• Indican- Triptophan katabolism in intestine• Ammonia- Final product of protein metabolism

• Chloride- Second largest composition found in urine- Excreted in form of NaCl : 10-15g/24hr urine• Phosphate- Protein intake- 1.1g/24hr urine

Pathological urine composition• Glucose• Protein• Ketones• Pus cells• Red blood cells• Lipid• Amino acid• Bile pigment• Calculi

Microscopic sediment of urine• Cells -rbc, wbc, squamous epithelial cells, urethral epithelial cells• Casts- Represent a collection of protein and cellular debris in a

kidney tubule- Eg: hyaline : occasionally found in normal urine but their

number is increased in renal diseases. - Cellular cast: one or more type of cells are trapped during

their formation. Eg; pus cell casts, red cell casts, epithelial casts, and mixed cellular casts.

- Granular casts : fine granules appear in glomerular and tubular renal disease.

Cyrstals• Uric asid• Amorphous urates• Amourphous phosphate• Calcium oxalate• Triple phosphate• Calcium carbonate• Tyrosine• Leucine• Cystine• Cholesterol

• Red blood cells in urine appear as refractile disks. With hypertonicity of the urine, the RBC's begin to have a crenated appearance

• These white blood cells in urine have lobed nuclei and refractile cytoplasmic granules.

• Large polygonal squamous epithelial cells with small nuclei are seen here.

• Oval fat bodies consist of degenerated tubular cells containing abundant lipid, which appears refractile.

broad (Figure 3).

Urinary casts. (A) Hyaline cast (200 X); (B) erythrocyte cast (100 X); (C) leukocyte cast (100 X); (D) granular cast (100 X).

Urinary crystals. (A) Calcium oxalate crystals (arrows; 100 X); (B) uric acid crystals (100 X); (C) triple phosphate crystals with amorphous phosphates (400 X); (D) cystine crystals (100 X).

Type of Urine Sample & CollectionSample Sampling Purpose

Morning sample First urine in the morning

Pregnancy test, microscopic test

Random sample No specific time Routine screening, chemical & FEME

Postprandial 2 hours after meal Determine glucose in diabetic monitoring

Midstream/clean match

Discard first few ml, collect the rest

Culture

2 hours Within 2 hours period Determine urobilinogen

24 hours Within 24 hours period Determine renal function