Module 2: Point of Care Testing

Section 1: AccuChek fingerstick glucose

The accurate testing of patients at the bedside depends upon the proper usage of the equipment by the operator.  The AccuChek is capable of producing highly accurate results if given a good specimen to test.

Testing Protocol (condensed) AccuChek Inform system

  1. Testing Protocol (condensed)  AccuChek Inform system

  2. Power up the unit.

  3. Input Operator ID (full 9 digit EID)

  4. Select test type; ie Patient Test

  5. Input Patient ID (full Medical Record # from ID wrist band)

  6. Verify Code Numbers match on both instrument and test strip

  7. Insert a test strip into the instrument.

  8. Load test strip by touching the curved side of the strip to the sample. Do not over fill.  If the result is critical (adults <50 or >500; neonates >200), then repeat the test.  If needed, obtain a tube of blood and send to the lab for a stat glucose verification.

  9. Record the result in the patient's medical record.

  10. Turn instrument off before placing into the re-charger base.

 General Considerations

  • The test strips are sensitive to heat, moisture and light.  Always keep the vial tightly capped when not in use.  If an un-capped vial is found, discard all the strips.

  • Ensure that the instrument has the proper Coding Chip by replacing it with the new one found in each box of test strips every time.  Test the High and Low controls before testing patients with the new vial of strips.

  • The daily control solution bottles must be dated when first opened.  They have a 90-day life or the date printed on the bottle, which ever is sooner.

  • Over or underfilling of the test strip can lead to erroneous results.  Ensure that the yellow target area is filled.

  • If the controls fail during testing, try repeat testing immediately; if still out of range, verify that the control solutions are not expired.  Next, try a new vial of strips and if this still fails, report this to Clinical Engineering and call Medical Stores to obtain a replacement. Do not test patients with a meter that fails the QC checks.

Section 2: Occult blood (Guiac) tests Fecal and Gastric

This screening test relies on the guaiac reaction wherein hemoglobin acts as a catalyst in the oxidation of a-guaiaconic acid by hydrogen peroxide.  The test is affected by the diet and medication status of the patient. Potential causes for false positive reactions include: oral iron supplements, rare or undercooked meat, fruits and vegetables high in peroxidase activity such as radishes, turnips, broccoli or cantaloupes.  Vitamin C in excess of 250mg/day may mask a positive reaction and appear to be negative.

Testing Protocol (condensed)

1.   Apply a thin smear of the sample into each test window.

2.   Turn card over and open back.

3.   Dispense two drops of the appropriate developer onto each test site.  Do not interchange the Gastroccult and Seraccult developers, Gastroccult is formulated to work in the acidic conditions of gastric content.  Seraccult developer will not react properly in low pH conditions.

4.   Interpret results within 60 seconds, the color may fade after 2-4 minutes.  Blue or any shade of blue is considered positive.

5.   Dispense a drop of developer on to the built-in QC.  Seraccult; Performance Control Line

      Gastrocult; Pos. Neg. dots.

      Do not report patient results if QC fails.

6.   Record the result in the patient's medical record.

 General Considerations

·Diet and medication status can affect the result.

·Use the correct developer with the correct card for the specimen to be tested.  Do not interchange.

·Always test the on-slide QC to demonstrate proper reactivity.

·Weekly QC requirements; record lot numbers and expiration dates for both slides and developers on the QC log sheet.

Record the reactions from the built-in QC on the test cards as either QC reactive or QC non-reactive on the patient's medical record, avoid using the terms Positive or Negative to describe the QC to prevent confusion with the patient's test results. 

Section 3: HemoCue fingerstick hemoglobin

 This screening test measures the hemoglobin released from erythrocytes by measuring the absorbance of azidemethemoglobin at both 570 and 880nm to compensate for turbidity.  Proper filling of the test cuvette is essential for producing accurate results.

 Testing Protocol (condensed)

1.   Power up the unit.

2.   Input Operator ID (full 9 digit EID)

3.   Input Patient ID (full Medical Record # from ID wrist band)

4.   Verify Code Numbers match on both instrument and test curettes.

5.   Fill the test cuvette in one motion, do not double dip.  If bubbles are present, do not use for testing.

HemoCue recommended fingerstick technique:

·Avoid fingers with rings. Clean the puncture site with disinfectant and allow to dry.

·Warm patient's hands if necessary to improve blood circulation.

·Using your thumb, lightly press the patient's finger from the top of the knuckle to the tip. This will stimulate the blood flow.

·With your thumb, apply gentle pressure at the tip of the patient's finger, prick at the side of the fingertip.

·Wipe away the first two or three drops. This will also stimulate the blood flow. If necessary, apply light pressure again, until another drop of blood appears.  Avoid "milking".

6.   Record the result in the patient's medical record.

 General Considerations

·        The bottle of cuvettes must be capped when not in use.  The cuvettes are affected by heat and humidity.  If a bottle is found without a cap, discard all cuvettes, do not use for patient testing purposes.

·        The cuvette's outer surface is an optical field. Wipe off all blood before placing cuvette into the analyzer.

·        If bubbles are present in the circular area of the cuvette, do not use for testing.

·        The cuvettes have a shelf life of ninety days or the printed expiration date at room temperature whichever is sooner after being opened for the first time. Always date the bottle.

·        The control solutions are to be stored in the refrigerator and brought up to room temperature before testing.  They are good for thirty  days or the printed expiration date whichever is sooner after initial opening.

·        Multiply the hemoglobin result by 3 to obtain an approximate hematocrit value.

Section 4a : Activated Clotting Time Measurement (Anesthesia Only)

This is a quantitative assay for the monitoring of heparin anticoagulation during various medical procedures.  Fresh whole blood should be used for testing.  Any specimen contaminated with tissue thromboplastin, in-dwelling i.v. solution, alcohol cleansing solution or visible clotting and/or debris accumulation should be discarded immediately. 

Testing Protocol (condensed); Hemochron FTCA510 tube method

  1. Depress the SELECT button to begin pre-warming the test well.

  2. Collect a fresh whole blood sample in a syringe.

  3. Dispense exactly 2 cc of blood into the FTCA510 test tube, at the same time, press the START button on the instrument.

  4. Close the flip-top and agitate vigorously 10 times to disperse the activator.

  5. Insert test tube into test well, rotate the tube clockwise until green DETECTOR light is lit.  Turn 1 more revolution to ensure that the green light remains on.

  6. Instrument will beep and the display will flash when a clot is detected.

  7. Record result in Patient's medical record.

  • 2 levels of the Electronic System Verification (ESV) tubes must be tested each shift when patients are tested.

  • 2 levels of liquid QC material must be tested each time a new box of FTCA510 tubes are open for usage.

  • Once a month, use the HE1001 Temperature Verification Tube to check the temperature of the test wells. 

  • All Quality control activities should be documented on the QC log sheet.

 Quality Control Considerations

Section 4b: Outline the protocol for performing an Activated Clotting Time measurement. (Critical Care Units, Radiology, MIPS)

This is a quantitative assay for the monitoring of heparin anticoagulation during various medical procedures.  Fresh whole blood should be used for testing.  Any specimen contaminated with tissue thromboplastin, in-dwelling i.v. solution, alcohol cleansing solution or visible clotting and/or debris accumulation should be discarded immediately. 

Testing Protocol (condensed); Hemochron Jr. Signature + method

  1. Press "START" key or insert a cuvette with the label facing up. Push it all the way in until it stops.

  2. Enter the Operator ID (OID) and then the Patient ID (PID) by using the numeric keys and press "ENTER".

  3. When the test cuvette reaches 37.0°C ±1.0°C, the instrument will beep.

  4. Once the "Add Sample" "Press Start" messages are displayed you have a 5-minute window to: a) Acquire the sample, b) Fill the sample well and c) Press "START"

  5. Do not obtain the blood sample until the instrument displays the message "Add Sample" and "Press Start" or the fresh whole blood sample will begin to clot.

  6. Fill the sample well from the bottom up.  Add enough blood so that the lower wall of the center sample well is completely filled.  If the blood sample extends above the lower wall, push the excess blood into the overflow area.

  7. Press the "START" key, the elapsed time is displayed in seconds until the sample clots. When a clot is detected, the instrument beeps and final results of the test are displayed.

  8. Record results in the patient's medical records.

Quality control considerations

  • 2 levels of the Electronic Verification Cartridges (EVC) and the Temperature Verification Cartridge (TVC) must be tested each shift when patients are tested. If the temperature check is within limits, document this by attaching NOTE #1 Temp Check OK to one of the results of the EVC at the end of that test.

  • 2 levels of liquid QC material must be tested each time a new box of test cuvettes  is opened for usage and once each month.

  • Unopened pouches of test cuvettes may be stored at room temperature for up to four weeks.  These pouches must be re-dated to indicated the new expiration date.  In no case shall the expiration date exceed that printed on the pouch by the manufacturer.

Section 5: Urine Dipstick

This screening test is used to detect a number of analytes useful as an indicator of health or disease especially in the areas of metabolic or renal disorder.

Testing Protocol

1.   Collect patient sample into a clean specimen container. 

2.   Remove a single dipstick from the bottle.  Recap the bottle immediately.

3.   Insert dipstick into urine sample and begin timing.

4.   Withdraw dipstick and drain excess urine from stick to avoid spill over effects.

5.   Compare the color reaction for each pad to the color chart on the bottle at the time specified for each test. 

6.   Document patient results in the patient's medical records.

General Considerations

·        For best results use a clean, fresh first-morning specimen.

·        Any conditions that mask or alter the color development of the test pad will interfere with the visual interpretation of the test.  Unusually colored urine should be sent to the lab for testing.

·        The dipsticks are vulnerable to heat, moisture and light.  Uncapped bottles of dipsticks should be discarded.

·        Accurate timing is essential for best results.  Do not read beyond the time limits.

·        Record lot numbers and expiration dates of dipsticks on the QC log sheet once a week.

Objective 6: Urine Specific Gravity using a Refractometer

Specific gravity is an assessment of the amount of dissolved solids in a fluid.  The refractometer measures specific gravity indirectly by measuring the angle of refraction (light bending) caused by the solutes (such as glucose and protein) in a beam of light.

Testing Protocol

1.   Place a few drops of urine on to the glass platen.

2.   Gently lower the plastic cover.

3.   Hold the refractometer towards a light source.

4.   Look through the eyepiece and determine where the line of demarcation crosses the specific gravity scale.

5.   Record patient's result in the medical record.

6.   Clean and dry the refractometer after each use.

 General Considerations

·        The refractometer is temperature compensated to read optimally between 15.6°-37.0° C.  Allow refrigerated samples to warm to room temperature before testing.

·        Do not aim the refractometer up towards a ceiling light fixture, any excess urine can roll towards your eye and contaminate you.

·        The eyepiece is adjustable for focus.

·        Inadequate sample volume will produce a hazy or indistinct line of demarcation.

·        Do not use harsh chemicals or alcohols for cleaning.

·        Two levels of QC solutions must be tested and the results recorded on the QC log sheet once a week.

Section 7: Urine Drug Abuse Screen (Emergency Dept Only)

Syvaâ RapidTest 10 

The Syva urine drug abuse screen provides qualitiative detection of methamphetamine, opiates, cocaine, THC (cannabinoids), phencyclidine (PCP), benzodiazepines, barbiturates, methadone, tricyclic antidepressants, and amphetamines. 

The staff member opens the pouch kit, and labels the testing device. Using the enclosed dropper, he/she places 3 drops of urine each in the 2 test wells on the device. The urine wicks up the chambers.  A line forms to note a negative result. There are 10 drug indicators, plus 2 control indicators. A negative urine tox screen would be 12 lined results. A faint line is still considered a negative result. 

The device should be read between 5 to 10 minutes. If at 5 minutes, there are several blanks, the device should be allowed to develop a couple more minutes. Beyond 10 minutes, the accuracy of the result is decreased. 

The reporting form should be filled out completely, with the patient's name, hospital number, and date.  This includes documenting the MD/HCS ordering the test, the staff person performing the test, the lot number and expiration date.  Document the appearance of the control lines, as well as the "lined" (negative) and "no-lined" (positive) results. 

The form also notes the most common causes of false positives of test indicators:

  • a urine specimen containing multiple drugs
  • medications that contain the test indicator (i.e. an opiate-containing drug, testing positive for opiates)
  • poppy seeds (positive for opiates)
  • phenytoin (positive for barbiturates)
  • ibuprofen exceeding 200mg/dose (positive for PCP)
  • ranitidne, ibuprofen, carbamazepine, acetaminophen, sertaline, and promethazine (positive for tricyclic antidepressants).  

QA Controls and Tips 

Do not use the test device after the expiration date. 

There are 2 internal controls on each device.  The first control is a line that must form for each "C" (Control) indicator.  The second control is the color change from white to purple as the urine wicks up each chamber, and back to white. If the background remains purple, the test is invalid. 

Positive and negative liquid controls are done on monthly, and on each new shipment.  CAP proficiency samples are done periodically to ensure procedural integrity.

Need to compete the test?
Send mail to:
Last modified: 7/31/2008 12:39 PM