Lab Tests

– See Rx of UTI  – Routine cultures will fail to dx: Chlamydia, GC, and TB; – LE & Nitrite  – In and Out Cath: any growth is considered UTI;  – Clean Catch Urine:  – about 85% accurate in women and uncirc’ed men;  – positive culture is > 100,000 bacteria/ml… or  – positive culture is … Read more

– Discussion:  – Urine pH less than 6 is common in pre-renal azotemia and unusual in acute tubular necrosis;  – Acid:  – High Protein, Ammonium Chloride, Mandelic Acid & Chlorothiazide Acidosis, ketoacidosis (Starvation, DKA), COPD;  – Uric acid, cyytine and calcium oxalate stones precipitate in acid urines;  – Meats and cranberry juice makes the urine … Read more

Positive: Diabetes mellitus. Pancreatitis, Pancreatitic ca Pheochromocytoma, Cushing’s dz Shock Burns Pain Steroids, Hyperthyroidism Renal Tubular dz Iatrogenic causes; Common after heavy meals Ascorbic acid overdose  – Misc:  – large amount of ketones will give False Negatives;  – precise timing is essential or dipstick color change is meaningless, & over timing by only 1-3 seconds … Read more

– Detects primarily Acetone & AcetoAcetic Acid, not Beta-Hydroxybutyric acid;  – Positive: Starvation, High Fat Diet, DKA (See Hyperglycemia) Vomiting Diarrhea Hyperthyroidism, Pregnancy, Fever  – Misc:  – precise timing is essential or dipstick color change is meaningless & over timing by only 1-3 seconds will cause false elevation;  – carbohydrate free diets as well as … Read more

– Discussion:  – Persistent proteinuria by dipsick should be quantified by 24hr;  – Positive: pyelonephritis, glomerulonephritis, Kimmelstiel-Wilson dz Nephrotic syndrome, Myeloma, Postural causes, Pre-eclampsia, Inflammation and Malignancies of Lower Urinary Tract, Functional causes (Fever, Stress, Heavy Exercise, Malignant Hypertension)

– See: Urine Culture – Conversion of nitrates to nitrite;  – Positive: infection (negative test does not rule out infection since some organisms such as Strep faecalis & other gram positive cocci will not produce nitrite, & note that urine must also be retained in bladder for several hours to allow the reaction to take … Read more

    Diagnostic Indexes in Acute Renal Failure                    PreRenal     PostRenal      Renal     Acute GN ————— U/P osm              >  1.5      1.0 – 1.5    1.0 – 1.5   1.0 – 1.5 Urine Na, mEq/l … Read more