Tainted Blood Sample - Additional Info

[Mishie14]

Did not anticipate another blood sample error yesterday using hematology clinic lab with the personal touch specifically to avoid errors. Finding the positive, it is good to know that it is not only potassium that can be skewed greatly from a bad/coagulated sample but also protein and liver AST (aspartate) values. In addition to a call from my hematology nurse, the blood test report was posted to my chart with a note for these 3: 'sample is hemolyzed - results maybe falsely increased.' Bravo lab person for reporting the warning! That's a first. Without that disclaimer, seeing significant increases in two more values as in 30% higher would cause significant angst. Previously only potassium was skewed and we know why. Out of caution as before, I had to return to the clinic lab for a retest which results showed no cause for alarm. While I was en route home, the clinic lab reported to hematology that they had a problem transferring the sample vial that was to be used for CMP tests (comprehensive metabolic panel) that caused the sample to coagulate. I don't understand why heparin in the special vial used for the draw apparently didn't work but more to come. FYI for those of you who have yet to experience potassium testing issues, in the US there are two blood draw tubes that are supposed to be used when testing potassium stand alone or when in a panel like CMP that includes potassium. The tubes are pre- coated with heparin to prevent the blood from coagulating which platelet cells are apt to do when disturbed. These tubes have medium green and dark green color rubber caps. The color cap difference is to distinguish sodium heparin and lithium heparin coatings. I told the nurse to check the expiration date on the green cap vials they use. Thank fully she laughed as I intended. Life is good. Stay safe!

[hunter5582]

Very interesting and useful information. Thanks for posting.

Regarding the potassium testing, there is more than one type of test. One of the labs, I do not remember which, is apparently less prone to reading with pseudohyperkalemia.

Always more to learn when managing a MPN. .

[ritaandscooter1]

Thank you for this very useful information that I will bring to my Doctor as I get high readings as well.

[Mishie14 in reply to ritaandscooter1]

The high values reported multiple times in the range of 5.9 to 6.1. Thanks to an ER doctor who pointed out incorrect potassium level is a common issue he sees every week. He said using an IV draw makes all the difference for not disturbing red blood cells. That proved correct for me. There are a few articles online and referred to on this site about pseudohyperkalemia—false high potassium. They are helpful. My hematology doctor said they would do the draw via large needle and different technique until my platelet volume came down. Second time they did it there was a 6.1 value but their lab reported in the test results that the sample coagulated before testing. I still had to go back in immediately for a retest. Added to the draw technique was warming the area of the draw. The nurse applied a very warm heat pack for 10 minutes. The recheck had value of 4.5. A second serious outcome of high potassium test is I cannot get interferon vial for injections for treating my ET. Releasing it requires a good blood test within 3 days prior of receiving interferon. I should add that my platelets are slowly coming down from 1.1 million, a very high real level due to problems taking other ET drugs. When that level is well below 1 million, I expect the testing issue to go away. Hope this helps you get some answers to your situation. Stay safe!