URISYS 1100 ANALYZER

I.    PRINCIPLE OF OPERATION:

The Urisys 1100 Urine Analyzer is a reflectance photometer. It reads the urine test strips under standardized conditions, saves the results to memory and outputs them via its own built-in printer and/or serial interface.

The Urisys 1100 Urine Analyzer standardizes urine test strip results by eliminating factors known to affect visual evaluation of urine test strips, such as; variable lighting conditions at the workplace, individual skill levels at matching test strip pad colors, failure to keep the prescribed testing times, and clerical errors.

The LED emits light of a defined wavelength onto the surface of the test pad at an optimum angle. The light hitting the test zone is reflected proportionally to the color produced on the test pad and is picked up by the detector, a phototransistor positioned directly above the test zone. The phototransistor sends an analog electrical signal to an A/D converter, which changes it to digital form. The microprocessor then converts this digital reading to a relative reflectance value by referring it to a calibration standard.

The following is a list of test principles specific to each parameter. Please reference the most recent Chemstrip urine test strip package insert for modifications in test principles.

• Specific Gravity: In the presence of cations, protons are released by a complexing agent in the test pad. The indicator bromthymol blue changes from blue via blue-green to yellow.

• pH Test: The test pad contains the indicators methyl red and bromthymol blue. These indicators give clearly distinguishable colors over the pH range of 5 to 9. Colors range from orange through yellow and green to blue.

• Leukocyte Test: Granulocytic leukocytes contain esterases which catalyze the hydrolysis of an indoxylcarbonic acid ester to indoxyl. The indoxyl formed reacts with a diazonium salt to produce a purple color.

• Nitrite Test: Nitrite, if present, reacts with an aromatic amine to give a diazonium salt, which, by coupling with a further compound, yields a red-violet azo dye.

• Protein Test: The test is based on the color change of the indicator 3’, 3”, 5’, 5”-tetrachlorophenol-3, 4, 5, 6-tetrabromosulfophthalein in the presence of protein. A positive reaction is indicated by a color change from yellow to light green/green.

• Glucose Test: Glucose detection is based on the enzymatic glucose oxidase/peroxidase (GOD/POD) method. The reaction utilizes the enzyme glucose oxidase to catalyze the formation of gluconic acid and hydrogen peroxide from the oxidation of glucose. In turn, a second enzyme, peroxidase, catalyzes the reaction of hydrogen peroxide with the chromogen tetramethylbenzidine to form a green dye complex. A positive reaction is indicated by a color change from yellow to green.

• Ketone Test: Based on the principle of Legal’s Test, sodium nitroprusside and glycine react with acetoacetate and acetone in an alkaline medium to form a violet dye complex. A positive result is indicated by a color change from beige to violet.

• Urobilinogen Test: Urobilinogen is coupled with 4-methoxybenzene-diazonium-tetrafluoroborate in an acid medium to form a red azo dye.

• Bilirubin Test: The detection of bilirubin is based on the coupling reaction of a diazonium salt with bilirubin in an acid medium. The reaction yields a pink to red-violet color proportional to the total bilirubin concentration.14 (Some users may describe this as a cream to peach color.)

• Blood Test: Hemoglobin and myoglobin, if present, catalyze the oxidation of the indicator by the organic peroxide contained in the test pad. Intact erythrocytes hemolyze on the test pad and liberate hemoglobin, which produces a green dot. Since the test pad absorbs several microliters of urine, more erythrocytes become visible than would correspond to 1μL. Separate sets of color blocks are representative of erythrocytes and hemoglobin. A uniform green coloration of the test is indicative of free hemoglobin, myoglobin, or hemolyxed erythrocytes in the urine. Scattered or compacted green dots on the yellow test pad are indicative of intact erythrocytes, or myoglobin.

• Compensation Pad: The compensation area is not impregnated with reagent. This pad allows the instrument to compensate for the intrinsic color of urine, which may affect test results.

II.   INTENDED USE:

To establish safe, accurate urine test results to be used for screening and monitoring patient status.

The Roche Diagnostics Urisys 1100 Urine Analyzer is a semi-automated analyzer intended for in vitro semi-quantitative determination of urine analytes. The analyzer is designed to read and evaluate the results of Chemstrip 10MD*, Chemstrip 7, and Chemstrip 5 OB Urine Test Strips. These urine test strips are multiparameter strips used for the determination of specific gravity, pH, leukocytes, nitrite, protein, glucose, ketones, urobilinogen, bilirubin and blood in urine.

III.  REAGENT :

ROCHE CHEMSTRIP 10 UA is stored at room temperature.  Do not store in direct sunlight.  Do not introduce moisture into product. Keep lid tightly capped. Strips are stable until expiration date on bottle if storage recommendations are followed.

IV.  CONTROL:  KOVA Liqua-Trol

1. The urine Dipstick control reagent is Kova Liqua-Trol.  There are two levels: normal and abnormal.  This reagent is stable until the expiration date on the label and when stored between 2-8 degrees C. Do not freeze.  Handle as biological. Run both normal and abnormal controls daily. Record the control result on the control Log. If controls are not within limits note so on the Log and do not perform patient testing.  Controls are tested in the same manner as patient testing.  Allow controls to come to room temperature. Mix gently by inversion to assure homogeneity of the contents. Remove cap and invert bottle.
2. Apply Kova Liqua-Trol directly onto the reagent strips. Hold the reagent strip horizontally, ensure good pad saturation and remove excess control by tilting the reagent strip on the edge on a paper towel. Read the urine dipstick as described for patient testing below.

V.   SPECIMEN:

Specimen Requirements: The routine urinalysis should be done on a fairly concentrated specimen, preferably the first morning voiding or post-prandial urine specimen. Specimens should be collected in a sterile container so if a culture is required it may be done from this specimen.  The urine specimen should be tested as soon as possible, preferably within two hours, but no more than four hours.  If specimen is not tested within one hour the specimen must be kept refrigerated at 2 - 8ºC.  When testing the urine specimens every precaution must be taken to avoid contamination of the specimen and the operator. Instructions for collection of a clean-catch midstream urine specimen may be found in Appendix I.

 VI.  IMPLEMENTATION:

1. Only a certified operator may perform a urine test with the Urisys 1100 Urine Analyzer.
2. Because of the potentially hazardous nature of handling urine and the possibility of its contamination with blood, use universal precaution when performing test procedures.
3. Outdated Chemstrip urine test strips are discarded.

VII.  INTERPRETATION:  NORMAL VALUES

1. Expected results for glucose, bilirubin, ketone, protein, nitrite, blood/hemoglobin and leukocytes are negative.
2. Expected results for specific gravity ranges from 1.001 to 1.025
3. Expected results for urobilinogen is 0.2-1.0 mg/dL
4. Expected results for pH  is 5-8

Please refer to the most recent Chemstrip urine test strip package insert for any changes to the expected values information.

•      Specific Gravity: Random urine specimens vary from 1.001 to 1.035.

•       pH: Urine pH values generally range from 5 to 9. The most frequent pH values for first-morning specimens in healthy subjects are between 5 and 6.

•      Leukocytes: Normal urine should produce no color reaction. “Trace” indicates a possible borderline situation.

•      Nitrite: A nitrite concentration as low as 0.05 mg/dL will produce a slightly pink coloration of the test pad. This indicates a positive result.

•     Protein: A color change from yellow to light green/green will occur if protein is present in urine. The concentrations given on the vial label correspond with the albumin concentration in urine. Pathological proteinuria usually will produce persistent values above 30 mg/dL. Clinical significance of the trace result should be determined by additional testing.

•     Glucose: Due to the test’s sensitivity, glucose should not be detectable in normal urine. Therefore, any positive reaction should be followed by further diagnostic evaluation of the patient.

•      Ketones: Ketone bodies should not be detected in normal urine with this test. Fasting or starvation diets may cause positive results. In known pathological conditions such as diabetes, the presence of ketones may be useful as an index of metabolic status. Therefore, any positive reaction should be followed by further diagnostic evaluation of the patient.

•     Urobilinogen: Concentrations are usually greater in the afternoon than during the remainder of the day. Values up to 1 mg/dL are usually considered normal.

•     Bilirubin: In normal urine, bilirubin should not be detectable with this test. However, the test is very sensitive to bilirubin (0.5 mg/dL will produce positive results), and any positive reaction indicates that further diagnostic evaluation of the patient is needed.

•     Blood: Erythrocyte excretion up to 5 Ery/μL may be expected in normal urine.  Levels above this may require further evaluation of the patient.

VIII.  SPECIAL CONSIDERATIONS: Precautions:

1. Only a certified operator may perform a urine test with the Urisys 1100 Urine Analyzer.
2. Because of the potentially hazardous nature of handling urine and the possibility of its contamination with blood, use universal precaution when performing test procedures.
3. Outdated Chemstrip urine test strips are discarded.
4. If a spill should occur, disinfect the area with a 1:10 bleach solution (1 part bleach plus 9 parts water)
5. Bilirubin and urobilinogen in urine are unstable at room temperature and exposed to light, thus it is important to use freshly collected urine to preserve the integrity of the test results.
6. Bring refrigerated specimen to room temperature before testing. Mix thoroughly before testing.
7. All orange urine samples should be sent to St. Peter’s Laboratory for Urinalysis testing. Do not perform a urine dipstick testing on the Urisys 1100 or manual dipstick testing on orange colored urine. Urine dipstick testing done on patients who have been given Pyridium and their urine is dark orange will be falsely elevated on many of the tests of the test strip. It is important to perform microscopic testing on all dark orange urine because Pyridium reduces pain but is not an antibiotic. These urine samples should be sent to St. Peter’s Laboratory for urinanalysis testing.
8. Leukocytes in urine are detected by the action of esterase, present in granulocytic leukocytes. Monocytes and Lymphocytes are not detected by this method. Patients on immunosuppressant drugs may have a microscopic urine test with a positive result for leucocytes, and a dipstick leukocyte test with a negative result due to the fact that Lymphocytes and/or Monocytes are present and not granulocytes. Therefore patients on immunosuppressant drugs should not be tested with a dipstick only urinanlysis test. These urine samples should be sent to St. Peter’s Hospital Laboratory for urinanalysis testing.

IX.   REAGENTS STORAGE AND STABILITY:

CHEMSTRIP 10 UA Urine Test Strips are stored at room temperature 15-30º C.  Strips must not be frozen. Opened CHEMSTRIP 10 Strips are stable until the expiration date on the vial label when stored in the original capped vial.  The vial must be closed tightly and immediately after use, using the original cap.

X.    CALIBRATION: 

1. Calibration is required if using the Chemstrip 10UA Test Strips.
2. The Urisys 1100 Urine Analyzer must be calibrated every seven days or when indicated by the analyzer.
3. The Chemstrip Urine Analyzer Calibration Strips (Catalog Number 418007) should remain in the vial until just before use. Do not touch the elevated gray areas on the strips.
4. The calibration strips should be used only once.
5. If you do not obtain a successful calibration, the analyzer will not process samples.
6. Calibration should be documented on the Maintenance Log.

XI.   QUALITY CONTROL:

Use KOVA Normal and KOVA abnormal controls. Both levels of KOVA controls are used daily and when a new vial of strips is opened. The controls are run exactly like patients.

1. The urine Dipstick control reagent is Kova Liqua-Trol.  There are two levels: normal and abnormal.  This reagent is stable until the expiration date on the label and when stored between 2-8 degrees C. Do not freeze.  Handle as biological. Run both normal and abnormal controls daily. Record the control result on the control Log. If controls are not within limits note so on the Log and do not perform patient testing.  Controls are tested in the same manner as patient testing.  Allow controls to come to room temperature. Mix gently by inversion to assure homogeneity of the contents. Remove cap and invert bottle.
2. Apply Kova Liqua-Trol directly onto the reagent strips. Hold the reagent strip horizontally, ensure good pad saturation and remove excess control by tilting the reagent strip on the edge on a paper towel. Read the urine dipstick as described for patient testing below.
3. Verify that quality control results are inside the acceptable control range. Initial test printout.
4. Place control test printout in control book.  Quality control records are retained for a minimum of two years.
5. If quality control result falls outside the acceptable control range, repeat the control test. If control test still fails then retest using a new control bottle. If problem still exists do not perform patient testing. Notify Point-of-Care-Testing coordinator of problem. Record any corrective action in the Urinalysis Quality Control Log

XII.   MAINTENANE

Cleaning the Analyzer

1. Clean and disinfect the exterior of the Urisys 1100 Urine Analyzer by using a cloth dampened with a suitable disinfectant such as 10% bleach or isopropyl alcohol. Be sure that no liquid enters the analyzer.
2. Clean the test strip tray every day.

Replacing Printer Paper

Replace the printer paper as soon as it runs out or when low.

XIII. TROUBLE SHOOTING:

1. If a reprint of the test result is required at the time of testing then:  Press Menu, Memory, Print, Last one. The printer will now print a second copy of the last test result.
2. Mechanical problems are evident when the analyzer displays an error message. A chemistry problem may become evident with an unexpected result. Abnormal results are flagged with an asterisk. If you obtain an unexpected result on any chemistry, refer to the Limitations and Performance Characteristics sections of the Chemstrip urine test strip package insert.

If you are comparing the analyzer values against the visual strip values and the deviation is more than one concentration block, one of the following may have occurred:

• Test strip is not positioned correctly in the test strip tray
• Power supply failure or high frequency interference by other devices
• Visual strip is deteriorated
• Improper testing technique

If one of the above situations has occurred, repeat the measurement with a new test strip, being very careful to properly position the test strip. Remove any external source of interferences. If problem persists contact Point-of-Care-Testing Coordinator.

The following is a list of error messages and suggestions on how to eliminate the problem:

XIII.  DOCUMENTATION:

Record: appearance, color of urine, and type of specimen on result log. Record the test results in Meditech. Place the printout from Urisys analyzer in the result box.

• Test requisitions, test authorizations, and test results are retained for a minimum of two years.
• An audit trail exists, linking the patient test with the Chemstrip test strip lot number and control lot number used.

 PLACED INTO SERVICE: January 20, 2009

SUPERSEDES PREVIOUS PRACTICES.