Urinary System - Diagnostic Studies

Description & Purpose
Urinalysis is a general examination of urine to establish baseline information or provide data to establish a tentative diagnosis and determine whether further studies are to be ordered
Nursing Responsibility
Try to obtain first urinated morning specimen. Ensure that specimen is examined within 1 her of urinating. Wash perineal area if soiled with menses or fecal material.

Description & Purpose
Creatinine is a waste product of protein breakdown (primarily body muscle mass). Clearance of creatinine by the kidney approximates the GFR.
Normal finding: 85-135 ml/min
Nursing Responsibility
Collect 24-hr urine specimen. Discard first urination when test is started. Save urine from all subsequent urinations for 24 hr. Instruct patient to urinate at end of 24 hr and add specimen to collection. Ensure that serum creatinine is determined during 24-hr period.

Description & Purpose
The purpose of a composite specimen is to examine or measure specific compents, such as eletrolytes, glucose, protein, 17-ketosteroids, catecholamines, creatinine, and minerals. Composite urine specimens are collected over a period that may range from 2-24 hr.
Nursing Responsibility
Instruct the patient to urinate and discard this first urine specimen. This time is noted as the start of the test. All urine from subsequent urinations is saved in a container for the designated period. Finally, at the end of the period, the patient is asked to urinate, and this urine is added to the container. Reminding the patient to save all urine during the study period is critical. Specimens may have to be refrigerated, or preservatives may have to be added to the container used for collecting urine.

Description & Purpose
Urine culture is done to confirm suspected urinary tract infection and identify causative organisms.
Normally, bladder is sterile, but urethra contains bacteria and a few WBCs. If properly collected, stored, and handled <10,000 organisms/ml usually indicates no infection; 10,000-100,000/ml is usually not diagnostic, and test may have to be repeated; >100,000/ml indicates infection.
Nursing Responsibility
Use sterile container for collection of urine. Touch only outside of container. For women, separate labia with one hand and clean meatus with other hand, using at least three sponges (saturated with cleansing solution) in a front-to-back motion. For men, retract foreskin (if present) and cleanse glans with at least three cleansing sponges. After cleaning, instruct patient to start urinating and then continue voiding in sterile container. (The initial voided urine flushes out most contaminants in the urethra and perineal area.) Catheterization may be needed if patient is unable to cooperate with this procedure.

Description & Purpose
Study evaluates renal concentration ability. Concentration is measured by specific gravity readings.
Normal finding: 1.020-1.035
Nursing Responsibility
Instruct patient to fast after given time in evening (in usual procedure). Collect three urine specimens at hourly intervals in morning.

Description & Purpose
Study determines amount of urine left in bladder after urinating. Finding may be abnormal in problems with bladder innervation, sphincter impairment, BPH, or urethral strictures. Normal finding: ≤50 ml urine (increases with age).
Nursing Responsibility
If residual urine test is ordered, catheterize patient immediately after urinating or use bladder ultrasound equipment. If a large amount of residual urine is obtained, health care provider may want catheter left in bladder.

Description & Purpose
-Dipstick (albustix, Combistix): Dispstick test detects protein (primarily albumin) in urine. Normal finding: 0-trace
-Quantitative test for protein: A 12- or 24-hr collection gives a more accurate indication of the amount of protein in urine. Persistent proteinuria usually indicates glomerular renal disease. Normal finding: <150 mg/24hr (<0.15 g/24hr), consisting mainly of albumin.
Nursing Responsibility
-Dipstick: Dip end of stick in urine and read result by comparison with color chart on label as directed. Grading is from 0 to 4+. Interpret with caution. A positive result may not indicate significant proteinuria; some medications may give false-positive readings.
-Quantitative test for protein: Perform 12- or 24-hr urine collection.

Description & Purpose
Urine can be analyzed to identify abnormal cellular structures that occur with bladder caner and to follow the progress of bladder cancer.
Nursing Responsibility
Specimens may be obtained by voiding, catheterization, or bladder irrigation (bladder washing). The first morning's voided specimen should not be used because epithelial cells may change in appearance in urine held in the bladder overnight. As with urinalysis, the specimen should be fresh or brought to the lab within the hour. An alcohol-based fixative is then added to preserve the cellular structure.