URINE AND STOOL EXAMINATION DR.S.K.BISWAS ASSOC. PROF. & ASST. MICROBIOLOGIST TATA MEMORIAL CENTRE, MUMBAI
Urinalysis : How the Test is Performed : • Urine sample is needed : Clean catch urine specimen A urinalysis may be done: • As part of a routine medical exam to screen for early signs of disease • If you have signs of diabetes or kidney disease, or to monitor if you are being treated for these conditions • To check for blood in the urine • To diagnose a urinary tract infection
Physical color and appearance : Chemical appearance: A special stick ("dipstick") tests for various substances in the urine. The stick contains little pads of chemicals that change color when they come in contact with the substances of interest. Specific Gravity pH Leukocytes Nitrite Protein Glucose Ketone bodies Urobilinogen Bilirubin Blood
Specific Gravity : Specific gravity test reveals how concentrated or dilute the urine is. Normal values are between 1.002 to 1.030. Increased urine specific gravity may be due to dehydration, diarrhea, glucosuria, heart failure, shock. Decreased urine specific gravity may be due to excessive fluid intake, diabetes insipidus, kidney failure.
Urine pH : • pH test measures the acidity of urine. • Normal values range from 4.6 to 8.0. • Acidic urine is associated with xanthine, cystine, uric acid, and calcium oxalate stones. • Alkaline urine is associated with calcium carbonate, calcium phosphate, and magnesium phosphate stones. • High pH may be due to gastric suction, kidney failure, UTI. • Low pH may be due to Diabetic ketoacidosis, diarrhea, starvation.
Normal Results : • Normal urine varies in color from almost colorless to dark yellow. Some foods (like beets and blackberries) may turn the urine a red color. • Usually, glucose, ketones , protein, and bilirubin are not detectable in urine. The following are not normally found in urine: Hemoglobin Nitrites Red blood cells White blood cells
Abnormal Results : • Bilirubin: to diagnose liver or gall bladder problems • Glucose : to test for diabetes • Protein : larger amounts of protein in the urine may be due to amyloidosis, bladder tumor, congestive heart failure, diabetic nephropathy, glomerulonephritis • Red blood cells : due to acute tubular necrosis, Cystitis, glomerulonephritis, Pyelonephritis, kidney trauma, kidney stones • Urine ketones: indicates anorexia, starvation, fasting, burns, fever
Microscopic appearance: The urine sample is examined under a microscope to look at cells, urine crystals, mucus, and other substances in the sample, and to identify any bacteria or other germs that might be present.
Visual observation of the faecal sample : • Observe the macroscopic appearance of the stool • Consistency; formed, unformed or liquid; • Colour and the presence or absence of the exudate • Presence of adult worms can also be seen in a freshly passed stool • Intestinal parasites : trophozoites and cysts, helminth eggs and larvae • Concentration method