Urine examination: Urine Dipstick testing
Dipstick testing Analysis for pH, blood, protein, glucose, and white cells can be done with dipstick testing. pH Urinary pH varies between 4.5 to 8, averaging between 5.5 and 6.5. Blood Normal urine contains <3 RBCs per high-powered field (~1000 erythrocytes/ml of urine; upper limit of 5000 to 8000 erythrocytes/ml). +ve dipstick for blood indicates the presence of haemoglobin in the urine. Haemoglobin has a peroxidase-like activity and causes oxidation of a chromogen indicator, which changes colour when oxidized. Sensitivity of urine dipsticks for identifying haematuria (>3 RBCs/HPF is >90%); specificity is lower (i.e. a higher false +ve rate with the dipstick, due to contamination with menstrual blood, dehydration (concentrates what rbcs are normally present in urine)). Protein Normal, healthy adults excrete about 80 to 150mg of protein per day in their urine (normal protein concentration <20mg/dL). Proteinuria suggests the presence of renal disease (g