Dipstick Urinalysis Slides - Murdoch University

CHI335 Urinary system Urinalysis The dipstick test Test reading guide The dipstick test – Glucosuria aka glycosuria Glucose is not normally present in the urine Glycosuria should always be followed up Causes: Elevated blood glucose levels e.g. DM Reduced tubular reabsorption e.g...

CHI335 Urinary system Urinalysis The dipstick test Test reading guide The dipstick test – Glucosuria aka glycosuria Glucose is not normally present in the urine Glycosuria should always be followed up Causes: Elevated blood glucose levels e.g. DM Reduced tubular reabsorption e.g. ATN The dipstick test – Bilirubinuria Is indicative of hepatic or biliary disease May be the first sign in an anicteric (not jaundiced yet) patient The dipstick test – Ketonuria Ketones are the breakdown products of fatty acid metabolism Acetone, acetoacetic acid, and B-hydroxybutyric acid (FYI) Ketones in the urine are abnormal Causes: Starvation or uncontrolled diabetes If diabetes mellitus is suspected – urgent action is required to prevent coma The dipstick test – Specific gravity Quick test of kidneys’ concentrating power Aids interpretation of other results If increased Dehydration Glucosuria SIADH If decreased Damage to kidney tubules, Kidney failure Diabetes insipidus Over hydration Severe kidney infection (pyelonephritis) The dipstick test – Haematuria Rule out food/Meds-related red-coloured urine (refer to the lecture slide) Causes: Refer to haematuria DDx in the lecture slide False +ve: menstruation, after vigorous exercise RBC Cast on microscopic examination The dipstick test – Proteinuria Normally urine may contain small amounts of proteins (< 150 mg/day) This (microalbuminuria) is undetectable using a dipstick The dipstick only detects the presence of albumin and no other proteins Positive test needs confirmation GN, Renal tubular disease, HTN, DM, pre-eclampsia, UTI The dipstick test - pH Urine is normally slightly acidic (normal range: 4.5-8) High urine pH kidney tubular disease, Kidney failure Urinary tract infection Vomiting Stale urine Low urine pH Fasting, starvation After meals Diabetic ketoacidosis Diarrhoea Metabolic acidosis, diabetic ketoacidosis The dipstick test - Urobilinogen Normally present If elevated Haemolysis Possible liver abnormalities Not reliable on its own The dipstick test – Nitrites Not normally present in the urine Produced when some (Gr-) bacteria convert dietary nitrates to nitrites The test is specific but not sensitive A positive result indicates UTI A negative result does not rule out a UTI The dipstick test – Leucocytes Aka Pyuria Pyuria may indicate infections of the urinary tract Dipstick only detects leukocyte esterase False-negative results are common Could be due to the contamination during collecting the sample