Office-Based Urinalysis: A Comprehensive Review

Comprehensive urinalysis involves inspection of the urine, dipstick chemical analysis, and microscopy and can be performed in the office setting. When testing for urinary tract infection, midstream urine should be collected using the clean-catch technique. A urine collection bag specimen can be used for clinically stable febrile infants with suspected urinary tract infection; however, the presence of leukocyte esterase or nitrites warrants more invasive urine collection. Urine specific gravity shows hydration status. Urinary pH levels can indicate diet, metabolism, or the presence of stones. Bilirubin and urobilinogen may suggest hepatobiliary disease or hemolysis. Glucosuria often indicates uncontrolled diabetes mellitus, and ketones suggest illness and inadequate nutrition. Hematuria on dipstick testing can be confirmed in the office using a spun urine sample. Proteinuria on dipstick testing should be followed by a quantitative test such as a spot urine albumin/creatinine ratio. In patients with symptoms of a urinary tract infection, the presence of nitrites is more specific for bacterial infection, and a positive leukocyte esterase result may occur from inflammation and infection. Asymptomatic bacteriuria is often unnecessarily treated in older patients. Without symptoms of urinary tract infection, urine culture is useful only in pregnancy and preparation for endoscopic urologic procedures.