LABORATORY 6: The Complete Urinalysis with Automation
PreLab Preparation:
1. Review YouTube videos on Clinitek Status
Principle & Operation / http://www.youtube.com/watch?v=j-8loszD-U8&feature=relatedhttp://www.youtube.com/watch?v=S1tpQqh9M88&feature=endscreen&NR=1
Performing a UA / http://www.youtube.com/watch?v=6TCIOB1vUvI
Cleaning the reference strip / http://www.youtube.com/watch?v=tRZn6BPP5EA
Note: do not attempt this procedure without instructor’s permission and supervision!
2. Review the corresponding information in the course textbook(s) as well as the classroom notes in preparation for this lab and to aid in answering the study questions.
Points Points are awarded for prelab assessments, skills, as well as successful and timely completion of study questions.
Objectives
According to the standards set by the instructor and following appropriate demonstrations, the student will:
1. observe the instructor’s demonstrations of care, handling, operation and quality control procedures of the urine analyzer.
2. ‘mentor’ and evaluate one or more classmates on the operation of the Siemens Clinitek Status+.
3. perform routine maintenance and quality control on an automated urine analyzer as directed.
4. analyze assigned urine samples to obtain dipstick results within ± 1 pad reading of the instructor’s results and matching microscopic results ± 20% as outlined in the Microscopic Lab.
5. record results accurately.
6. analyze quality control results to determine quality control acceptability. (One set of controls per instrument will be performed and all students who use that instrument will record and utilize the information.)
7. recognize abnormal dipstick and microscopic results as have been outlined in previous lab exercises.
Equipment and Supplies
1. Siemens Clinitek Status+ urine chemistry analyzer
2. Urine specimens (5 or more), appropriate urine controls with expected results sheet.
3. Multistix 10 SG reagent strips
4. Centrifuge, microscope, centrifuge tubes, Sharpie marker, Kim-wipes, microscope slides and cover glasses.
5. Clinitest, Acetest, and Ictotest supplies, reagent tablets and product inserts.
6. Color reference pictures of urinary sediment.
Urinalysis Instrumentation & Related Information
The biggest preventable variable in urinalysis results comes from the mis-reading/mis-interpreting of the dipstick results. The solution to this problem is utilization of an automated urine dipsick reading instrument. Advantages to use of such instrumentation includes: increased efficiency, improved precision, accuracy and reproducibility.
Inside the urinalysis dipstick reader, a filtered focused light is directed to the dipstick pad where, depending on the depth of pad’s reacted color, some of it is absorbed and the remainder is bounced/reflected to a photocell - detector. The signal created in the photocell detector is sent to the instrument’s on-board computer which compares the amount of reflected light detected to that of known concentrations of the analyte/substance being measured and displays the appropriate concentration for the amount of light detected from this analysis.
Urinalysis dipstick reading instruments vary greatly in size, cost and the tasks they perform, but all strip readers evaluate the reactions on the dipstick at specified times. Their accuracy depends on the operator’s skill and accuracy in appropriately identifying the sample, mixing, dipping, blotting, getting the strip onto the tray and activating the timer appropriately. Higher end instruments add the urine to the strip and automatically activate the timing mechanism. There are also instruments capable of performing the complete UA from evaluating the physical and chemical properties through the microscopic.
See reference listings for sources of additional/general information on automated urinalysis.
Laboratory informatics
Where the Clinitek Status Analyzer is a suitable instrument for low volume clinics, educational settings and doctor’s offices; the larger and more automated urinalysis analyzers with on-board computers capable of interfacing with the laboratory mainframe computer is standard equipment in the modern hospital laboratory.
In today’s modern laboratory a system of computers and software programs exchange data about patients, test requests and test results. This is known as a Laboratory Information System or LIS. The LIS is interfaced with the Hospital Information System. This system enables the hospital and lab to order the correct test requests for each patient, keep track of individual patient or specimen histories, and help guarantee a better quality of results as well as printing hard copies of the results for patient charts and apply appropriate billing.
Siemans Clinitek Status+ Analyzer
The Siemans Clinitek Status+ Analyzer is a semi-automated, benchtop instrument designed to read the Siemans Multistix 10 SG Reagent Strip. Like most urine dipstick readers, this analyzer works on the principle of reflectance photometry. The instrument’s optical system consists of six light emitting diodes, a light guide, a mirror, a lens and a detector. Light from the LEDs travels along the light guide and is reflected off the calibration bar, strip or cassette onto the mirror. It is then directed through an aperture on the lens, from where it is focused onto the detector. The light intensity detected is converted into electrical impulses, which are processed by the instrument’s microprocessor and converted into clinically meaningful results. The programming module for the Multistix 10 SG Reagent Strips contains programming information necessary to read the reagent strip areas for testing of glucose, bilirubin, ketone (acetoacetic acid), blood, pH, protein, urobilinogen, nitrite, and leukocytes.
The instrument is programmed with such information as wavelengths, error messages, operating sequence, and algorithms needed to convert reflectance into clinically meaningful results. A white plastic strip located at the end of the feed table insert, provides a reflectance surface for the internal calibration of the instrument’s optical system. Calibration is accomplished automatically by the measurement of reflected light from the calibration strip surface. The calibration strip (aka - the white bar) must be kept clean for proper instrument calibration.
Equipment Maintenance: The Siemens Clinitek Status+
Students working with these instruments must, under the direction of their instructor(s), follow the manufacturer’s written directions for maintenance and operation. Any information presented in this lab is subject modification based on manufacturer’s directions.
Though students will work in pairs, each student must independently perform the instrument’s basic maintenance (tray cleaning) as follows.
1. Tray cleaning - The tray should be cleaned daily or more often if buildup is seen/suspected.
a. Remove table by simply pulling it out; be careful that the white bar at the top of the tray does not become in the process.
b. Clean strip area using a cotton-tipped applicator wetted with distilled water. Rinse both sides of table.
c. Dry carefully and thoroughly.
2. Disinfect the table. If the table is in need of disinfection, one of several solutions is safe to use: Cidex®, Theracide®, Amphyl®, 5% household bleach and Isopropyl alcohol (70-80%). Most area laboratories use 5% household bleach or 70% Isopropyl alcohol. Rinse the table with distilled water; dry thoroughly.
Again, do not touch the white bar as it is used by the instrument for calibration. Periodically, check the white bar to insure that it is free of dust, scratches or other marks. If it is scratched or has other marks on it, bring it to the attention of the course instructor. Damaged white bars must be replaced.
3. Changing the paper roll (discussed, not performed unless needed)
a. Pull out the remainder of the paper from the existing roll
b. Open cover and remove the paper core.
c. Insert new paper roll so that paper unrolls from underneath
d. Trim insert end to resemble a large “V” shape.
e. Insert paper under printer roller until the paper comes through other side of roller. Pull paper towards the back. Do not pull paper up or to the front as it may damage the printer.
f. Feed paper through printer cover and snap cover into position.
Basic Reactions and Expected Results
Note: A complete explanation of reaction principles is found in the Multistix 10 SG product insert.
Constituents analyzed are as follows:
Analyte / Expected reactionGlucose: Glucose Oxidase-peroxidase method. / Negative for normal samples
Bilirubin: Diazotized dichloroaniline method. / Negative for normal samples
Ketone: Nitroprusside test. / Negative for normal samples
Specific gravity: By indicator dye. / Range: 1.015-1.025 Test indicates how dilute or concentrated the urine.
Blood: Peroxidase like activity of hemoglobin. / Negative for normal samples
pH: By double indicator. / Dipstick range: 5 to 9; normal patient 4.5 - 8.0
Protein: Protein-error-of-indicators principle. / Negative for normal samples
Urobilinogen: A modified Ehrlich reaction. / 0.2 - 1 mg/dL reported as *“Normal”. Higher levels are reported as a number representing an amount in mg/dL.
Nitrite: Reaction of nitrite with p-arsanilic acid. / Negative for normal samples
Leucocytes: Detection of leucocyte esterase enzyme. / Negative for normal samples
*Note: In the normal urine sample, the constituents/tests are reported as being “Negative” with the following exceptions: specific gravity, pH and urobilinogen.
Quality Control
Review specific manufacturer’s recommendations.
1. Instrument calibration is performed internally by the instrument before each strip. Error codes are displayed on the screen.
2. Store controls at 2-8C. Do not freeze. If properly handled, the controls are stable until the expiration date stated on the label.
3. On initial use, the controls must be labeled date, time, and initials of medical laboratory technician. Expiration date must be noted on the control bottle when it is opened.
4. After removing the controls from the refrigerator, they must be allowed to come to room temperature (25 - 25 C); about 15 to 30 minutes. All specimens; control and patient samples, must be tested at room temperature to obtain accurate results.
5. Control (and patient samples) should be protected from direct sunlight and never subjected to a heat source.
6. Positive and negative controls will be analyzed during each laboratory.
7. Control results must be placed on the student report sheet. Any discrepancies must be brought to the instructor’s attention.
Reference
Siemens Clinitek Status+ users guide (http://www.medical.siemens.com/siemens/en_GLOBAL/gg_diag_FBAs/files/POC/Urinalysis/Clinitek_Status_Brochure_update_Rev02.pdf) .
Procedures and Sample Analysis
1. Review instrument routine maintenance, quality control and operation procedures outlined in this document. Observe demonstration(s) / PowerPoint presentation.
2. Students will work in pairs, coaching and monitoring these procedures. Each student pair must equally participate in the performance of these activities.
3. Obtain and organize supplies and specimens. All control and patient urine samples must be at room temperature and well mixed prior to testing.
4. If needed, turn analyzer on by depressing button located on right side of top surface. Instrument requires a short warm-up period; when complete, the tray table will be opened. Take care not to bump or jar the tray table.
5. Basic maintenance: Clean tray table on initial startup and upon completion of the shift. (See procedure for cleaning tray table under Equipment Maintenance.) When students are working in pairs, one member will clean tray table before sample analysis and other student will clean it after the lab activities are completed.
6. Sample testing procedure. (applies to quality control and patient samples)
a. Remove a Siemans Multistix 10 SG Reagent Strip from its bottle and place it on a clean dry paper towel. Reclose bottle to prevent moisture from contaminating unused strips.
b. Select “STRIP TEST” on the Clinitek Status+ instrument’s main screen.
c. Mix well, by inversion, the room temperature control or patient sample to be tested.
d. Using appropriate dipstick technique, completely immerse all reagent areas of the dipstick into the specimen (either control or patient sample). Immediately remove the strip while running the edge along the specimen container’s side.
e. With your free hand, immediately touch “START” on the instrument screen – thereby * activating the instrument’s timing mechanism.
f. Keeping the strip horizontal, touch its side (2X) to a clean paper towel to remove excess specimen.
g. Immediately place the strip into the notched area of the instrument table, pad’s side up and as far forward as possible. Be sure the strip is lying flat in the strip holder.
NOTE: The strip must be in correct position on the holder within 8 seconds of activation of the instrument’s timing mechanism.
7. Instrument will move the strip into the reading area automatically. Do not interfere with the instrument including the dipstick holder during this time.
8. After the strip is in the instrument, you can change the description of the color and clarity, if needed. The process is outlined in the YouTube video; consult operator’s manual for specifics.
9. At the end of the incubation period, the instrument will display the results and provide a printed copy. Abnormal results will be marked with an asterisk (*) symbol.
10. Record the results using the format presented.
11. If the patient info has not been printed on the results paper, you must write it on the paper. Staple the instrument results to your report sheet.
12. Record results according to facility policy. See Below.
URINALYSIS REPORT SHEET
XYZ Medical Clinic
2243 Round Rock Road
Austin, Texas 78701
Name ______Date ______/10 points
Control 1 Lot # ______Control 1 Exp Date______
Control 2 Lot # ______
Control 2 Exp Date______ / Control 1 / Control 1
expected results / Control 2 / Control 2 expected results / Within Range?
Yes or No
(If No, must bring to instructor’s attention and add a comment - as to course of action.)
Whether yes or no, you must include your initials!
Multistix:
Lot#:
Exp Date: / Glucose / Negative / 100-1000 mg/dL
Trace – 3+
Bilirubin / Negative / Small – Large
Ketones / Negative / 5 – 160 mg/dL
Trace – Large
Sp. Gravity / 1.010-1.025 / 1.005 – 1.020
Blood / Negative / 10 – 200 cells/uL
Trace – Large
pH / 5.0-6.5 / 7.0 – 9.0
Protein / Negative / Trace ->= 300 mg/dL
Trace – 3+
Urobilinogen / 0.2 mg/dL / 2 – 8 mg/dL
Nitrite / Negative / Positive
Leukocyte Esterase / Negative / Trace - Large
Microscopic – only if indicated by manufacturer AND directed by instructor
ADDITIONAL TESTING Perform the following tests as directed by the instructor.
*Reminders: 1. In the ‘Comments’ box, you must state ‘Yes’ or ‘No’ whether or not the controls have given expected results and include your initials. 2. ‘If at any time, a control sample does not give the expected result, you must note it under ‘Comments’ and bring it to the instructor’s attention.Back-up / Confirmatory Tests / Control 1 / Control 1
Expected results / Control 2 / Control 2 expected results / *Comments:
Within Range?
Yes or No?
3% SSA (for protein)
Acetest
(ketones)
Ictotest
(bilirubin)
Clinitest
(reducing substances)
Controls performed by: / Date:
2