URINALYSIS

Effective Date: 
Tue, 05/01/2007
Reviewed: 
Tue, 01/10/2017
Policy: 

MATERIALS AND EQUIPMENT:

  • Chemstrip 10-UA test strips
  • Kova LiquiTrol
  • Urisys 1100 Urine Analyzer
  • Plastic urine containers, sterile or unsterile
  • Conical centrifuge tube, 15 ml
  • Horizon miniE Centrifuge
  • Microscope slides and #1 coverslips

SPECIMEN: Freshly voided, clean-catch, midstream: first morning or random. Causes for rejection: unlabelled specimen, specimen at room temperature for longer than one hour; Containers and instructions are located in each restroom. (See following page for patient instructions). If specimen cannot be examined within one hour, it may be refrigerated up to eight hours and brought to room temperature before examination.

PRINCIPLE: Through chemical and microscopic analysis of the urine specimen, information about the body’s metabolic functions may be obtained. This aids in the evaluation of renal, urinary, and metabolic disorders.

Procedure: 

Routine urinalysis

  • Color: yellow, straw, or amber (observe well-mixed urine in centrifuge tube). Note: if urine color is orange, see note in Limitations section.
  • Appearance: clear, hazy, or cloudy (observe well-mixed urine in centrifuge tube).
  • Chemical examination (use Chemstrip 10-UA)

CAUTION: Chemstrip 10-UA contain toxic substances such as phenol, diazonium salt, and nitroferricyanide. Avoid contact with skin and mucous membranes; flush affected areas with copious amounts of water. Get immediate medical attention for exposure to eyes or if ingested.

  1. Before strip assay, verify the test strip tray of the Urisys 1100 urine analyzer is clean of any residue. Wipe with a Kimwipe if necessary.
  2. Press the button on the instrument until "INSERT REAGENT STRIP" status message is flashing. Wand the barcode from the patient's Harvest label to enter sample number into instrument.
  3. Briefly dip the Chemstrip 10-UA urine test strip into well-mixed urine specimen for no longer than one second. Ensure that the test strip pads are totally immersed.
  4. Gently touch (for one second) the long edge of the test strip on a piece of absorbent paper to remove any excess urine.
  5. The test strip tray and the retaining bar (upright) must be in the open position.  Place the test strip, with pads facing upward, onto the tray so that the end of the strip fits under the clip. IT IS IMPORTANT THAT THE STRIP IS CORRECTLY POSITIONED, AND THE START BUTTON PRESSED WITHIN 5 –10 SECONDS OF DIPPING THE STRIP.
  6. Press the START button. You will hear a beep and then the tray advances slightly and the retaining bar closes. The gray reference pad on the test strip tray is read first. If the test strip is not lined up straight in the tray, gently move it until it is properly lined up under the retaining bar. Be careful not to move the tray.
  7. Approximately 70 seconds after the START key is pressed, all test pads will be read. Results are printed out with the sample number, date and time. Abnormal results are flagged with an asterisk. Document color and clarity on printout (eg. Yellow and Clear). Place label on the printed copy of the test results.
  8. The test strip tray will return to the start position, and the retaining bar will open. Remove used test strip and wipe the tray as needed with a Kimwipe to remove any urine residue.
  9. Machine is now ready for the next test strip.
  10. All urines are saved and refrigerated until the next morning for possible culture or further testing.

TEST & INTERPRETATIONS

  • Specific Gravity: 1.000, 1.005, 1.010, 1.015, 1.020, 1.025, 1.030, 1.035
  • pH: 5, 6, 7, 8, 9
  • Leukocytes: Neg, trace, 1+, 2+
  • Nitrites: Neg, pos
  • Protein: Neg, trace, 1+ (30 mg/dL), 2+ (100), 3+ (500)
  • Glucose: Normal, trace (50 mg/dL), 1+ (100), 2+ (250), 3+ (500), 4+ (1000)
  • Ketones: Neg, 1+ (small), 2+ (moderate), 3+ (large)
  • Urobilinogen: Normal, 1+ (1 mg/dL), 2+ (4), 3+ (8), 4+ (12)
  • Bilirubin: Neg, 1+, 2+, 3+
  • Occult Blood/Hemoglobin: Neg, 1+ (about 10 rbc/ L), 2+ (about 50), 3+ (about 250)

Microscopic Examination

  1. Pour off a 12ml aliquot of well-mixed urine into a 15ml conical centrifuge tube.
  2. Spin for 5 minutes at 2000 RPM.
  3. Discard clear supernatant to volume of 0.05ml and resuspend sediment.
  4. Place a drop of well-mixed sediment on a microscope slide using a plastic bulb pipette and cover with a #1 coverslip.
  5. Scan slide under low power for examination of cellular elements. Switch to high power for enumeration and identification of elements found under low power.
  6. Scan at least 10 fields and average the number of elements seen. Report as follows:

ELEMENTS & ENUMERATIONS

  • RBC/HPF: 0-2, 3-10, 11-20, 21-50, >50, TNTC
  • WBC/HPF: 0-5, 6-10, 11-20, 21-50, >50, TNTC
  • Epithelial Cells/HPF: 0-5, 6-10, 11-20, 21-50, >50, TNTC Report type: squamous, transitional, renal etc.
  • Bacteria, yeast, mucus, crystals, Trichomonas: None, 1+, 2+, 3+, 4+; report crystal type
  • Casts/HPF: 0-5, 6-10, 11-20, 21-50, >50, TNTC; report type
  • Other formed elements i.e. sperm, talc: 1+, 2+, 3+, 4+ if present

.

SCUBA: Performed in-house. Only glucose and protein are reported. Use "SCUBA dip" test.

QUALITY CONTROL: CAUTION: Potentially biohazardous material. Use gloves when handling. Product contains sodium azide. Dispose by flushing with large volumes of water.

 

  1. Run QC daily on normal and high abnormal  in the morning after performing daily maintenance or when opening a new vial of dipsticks. Record all values in Harvest LIS. DO NOT REPORT PATIENT VALUES UNLESS CONTROL VALUES ARE WITHIN SPECIFIED RANGE.
  2. Allow each aliquot of control to warm to room temperature for 15 minutes before assay.
  3. Verify lot number matches assay sheet with known values.
  4. Remove dropper cap, invert bottle and apply control liquid directly across Chemstrip pads by gently squeezing bottle, blot long edge of strip, place strip in test strip tray and press START. EACH PAD MUST BE COMPLETELY SATURATED TO AVOID TEST ABORT.
  5. Record values on log. ALL VALUES MUST BE WITHIN ACCEPTABLE RANGE.
  6. Refrigerate controls after use.

LIMITATIONS: Review product insert for Chemstrip 10-UA test strips for information on individual tests:

  • NOTE: If patient has taken a medication containing a pyridium type substance, urine will be orange in color, and several parameters (nitrites, protein, urobilinogen, and bilirubin) may be false positive. Document these tests as "unable to analyze" and perform microscopic analysis (automatic reflex).

 

 LIMITATIONS

  • Specific Gravity: Glucose and urea concentrations>1% may cause a low specific gravity relative to other methods. In the presence of moderate amounts of protein (100-500mg/dL) or ketoacidosis, readings may be elevated.
  • Leukocytes: Interference from cephalexin and gentamicin; Nitrofurantoin colors the urine and interferes with visual interpretation. High levels of albumin (>500 mg/dL) may interfere with test results.
  • Nitrite: Large amounts of ascorbic acid may decrease sensitivity. Pyridium will cause false-positive results.
  • Protein: False positive results with strongly basic urine (pH>9). Pyridium will cause false-positive results.
  • Glucose: False-negative rarely with high concentration of ascorbic acid.
  • Ketones: None encountered with this population.
  • Urobilinogen: The total absence of urobilinogen cannot be
    detected. Most normal urines give a slight pink reaction. False-positive reaction with phenazopyridine.
    Nitrite concentrations above 5mg/dL may cause a decrease
    in the color reaction.
  • Bilirubin: Large amounts of ascorbic acid lower sensitivity.
    Increased nitrite, as in urinary tract infections, may
    result in lower bilirubin values. Pyridium will cause
    false-positive.
  • Blood: Menstruating females will occasionally yield a
    positive.

EXPECTED VALUES:
A. Specific Gravity: random urine = 1.001 - 1.035
B. Leukocytes: normal urine produces no color reaction.
C. Nitrite: normal urine is negative
D. pH: normal urine = 5-9, first morning specimen = 5-6
E. Protein: normal urine = negative. Clinical significance of trace result should be determined by additional testing (may be done at clinician’s discretion i.e. urine microalbumin sent to Quest Lab
F. Glucose: normal urine = negative. Any positive result should be followed up with blood testing.
F. Ketones: normal urine = negative. Fasting or starvation diets may produce positive reaction.
H. Bilirubin: normal urine = negative. Any positive reaction requires further diagnostic evaluation. If Icotest (bilirubin confirmatory test) is unavailable document positive test as "unable to analyze".
I. Blood: RBC excretion up to 5 RBC/l is expected in normal urine. If greater, further diagnostic evaluation is required.

Key Points: 

References:

  • Davidsohn, MD, Israel, Clinical Diagnosis by Laboratory Methods, 15th Edition, W.B. Saunders Co., Philadelphia, pp.18-45
  • Operator’s Manual, Urisys 1100 Urine Analyzer, Roche Diagnostics, 2005
  • Product Insert, Chemstrip 10-UA, Roche Diagnostics, 1999
  • Product inserts, qUAntify controls, BioRad, 2005