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Ask the Expert

Barry Craig


Sometimes when I run CBCs on my hematology analyzer, the results look weird. I always check to see that my controls were within range, but the patient results will sometimes look strange. What could be the problem?

If the controls and calibration for the analyzer look good, but your patient results are bad, it is usually a specimen collection problem. Recollecting a fresh specimen and rerunning will usually fix the problem. Here are a few things to watch for that indicate a collection error:

  • Low platelet counts or strange WBC counts – If your specimen is clotted, the platelets will clump and cause low platelet counts or erroneous WBC counts on the report. The WBC counts will show error codes as the analyzer tries to read the clumped platelets as white cells.

  • High hemoglobin values – If the specimen is hemolyzed due to collection problems, red blood cells are damaged and release their hemoglobin, causing the hemoglobin to read falsely elevated

  • Major changes to the patient history – If there is a sudden shift in the patient’s results that do not match their previous results, this can indicate a problem as well. For instance if a patient had a 38.6 hematocrit last month and the current result reads 27.7, it could be a sample problem.

What steps can you take when these weird results pop up?

First, check the specimen for clots. Using two wooden applicator sticks, move them around in the specimen and then pull them free, looking for clots or “strings” on the sticks.

Second, if no clots are present, rerun the specimen. If the same results are achieved, recollect and run a fresh specimen. If you still get similar results, you do not have a specimen problem.

Always remember to rerun all patients that show critical results and to document your actions. Notify the ordering physician of the critical value and document the date, time, and result.

My office tests for urine alcohol as part of a drug screen panel. I am constantly having problems with calibration, controls and patient results. I use a lot of reagents up constantly recalibrating, etc. What can I do? We are at the point of dropping the test.

Urine alcohol testing is one of the more frustrating tests to perform (It is enough to drive you to drinking). Here are some tips to help you keep your sanity and sobriety.

  • Keep the lid tight on the specimen until you are ready to test. The alcohol will evaporate off of the specimen if the lid is not tightened securely.

  • The specimen only has a limited shelf life. Check your product insert sheet to see how long the specimen can be stored before testing.

  • Do not wear perfume or use breath sprays in the same area as the testing. Either of these things can set off your calibration, controls or patients and cause false positives.

  • Do not use alcohol-based hand cleaners or aerosol cleaners such as Lysol, etc. These should not be anywhere near the lab area or the adjacent hallway. These will contaminate your reagents, controls, calibrators and patient specimens.

  • Post notices around the office warning to keep the above mentioned items away from the lab.

If your laboratory area becomes contaminated:

  1. Remove the contamination source.

  2. Wipe down the entire area with a non-spray, non-alcohol based cleaner.

  3. Discard and replace your alcohol reagent.

  4. Open fresh calibrators and recalibrate.

  5. Open fresh controls and rerun

These steps should eliminate your alcohol related problems. Remember that your office has a central air system and circulates air from throughout the building. You could pull contaminants in from any area of your building.