Inflated potassium again

[Mishie14]

another blood test showing very high potassium that I am not accepting, however, the only way to combat it is to take another blood test. Irritates me that the process of drawing blood is not changing which means there is no feedback getting to the lab to help prevent this from recurring. . My question is if any of you have dealt with needle size? I can handle less tight tourniquet and no closed fist during the draw but I know nothing about needles, specifically what size needle larger than usual should be used so that we can rule out needles causing smooshed blood cells that release more potassium in the sample. Will be talking with hematology again tomorrow as they try to figure this out. Thanks for your comments. Knowledge is power. Stay safe.

[ainslie]

I can’t remember the science to this but us with MPN can have very high potassium readings which are not real, your Haem should know about that, maybe others on here who know more about it can chip in.

[Mishie14 in reply to ainslie]

Yes, very good point to remember. Thank you for adding this comment. I have been searching for info about hyperkalemia diagnosis I received for having potassium values weekly between 5.4 and 5.8, once at 5.9 and once at 6.1--all lab values and all inflated values I found out. In particular now because of unpleasant ER visits but getting great feedback from ER doctors, this triggered my interest in pseudohyperkalemia--falsely increased potassium most often caused by technique and process of blood collection, and predisposition to high potassium due to pathology such as high platelet counts associated with MPNs. There is a very interesting Pseudohyperkalemia article by Chris Higgins posted 2018 on acutecaretesting.org. He's from Gloucester, UK. He appears to very well understand the chemistry of blood and blood collection. He suggests that platelet counts over 500 'should have their potassium status assessed using plasma recovered from an anticoagulated blood sample or an anticoagulated whole-blood sample.' Once high platelet blood coagulates as a result of lab technique and testing methods, potassium released from damaged blood cells during that process causes inflated levels in the sample compared to bloodstream reality. Whew. always opportunities to learn new things. Thank you for sharing information and stay safe!

[onlineallthetime]

Yes, some MPN can cause you can have pseudohyperkalemia because the destruction of red blood cells releases potassium into the blood. The serum value will be falsely elevated and pseudohyperkalemia can be confirmed with testing the potassium level in a plasma sample. I agree with ainslie that your hematologist should know about it but they don't always. They may want you to take a potassium binder which could be dangerous if it is pseudohyperkalemia so print out some info about it and bring to your next appointment if they've been testing serum only.

[Mishie14 in reply to onlineallthetime]

Thank you for adding confirmation! Yes, hematology should know about this and will be talking with that team later today about it. The primary nurse there is trying to work through a process for the lab to use for drawing my blood. I don't like being an exception but there are times when being an exception is necessary. Opportunities include education for those who are on the fringes of MPN and those who are in the treatment process like the hospital lab but don't know anything about it or at least do not understand what their processes do to alter blood content. Stay safe!

[lynnieb]

had this issue for years; sky high potassium, 2am dashes to the hospital, only to be told the potassium was ok. When I finally got diagnosed with ET, my haematologist THEN informs me that high platelets affects potassium levels, giving a false positive. That along with the way blood is taken, (as you say) means a lot of people get very frightening phone calls. Hope this helps

[Mishie14 in reply to lynnieb]

yes, thank you for confirmation I am not alone and process and pathology are key to understanding high potassium. As you noted, getting alerts to go to ER and repeat the blood taking drill is not pleasant. As ER doctor told me, you cannot tell if high potassium is real or not without another blood test. There are no symptoms until possibly too late. What are the odds high potassium is real and a heart attack is now more probable than possible? Still have more questions than answers but the topic is getting clearer. Appreciate your adding to the story. Stay safe!

[ETket in reply to lynnieb]

I had a panicky GP ringing me to check how I was because my potassium levels appeared so high in a blood test. I felt somewhat bemused as I felt absolutely fine and just swum sixty lengths.

[PhysAssist in reply to lynnieb]

Hi LynnieB,

Glad to hear that your MD knew about pseudo-hyperkalemia, and advised you before overreacting.

I wish my MPN specialist had done so- instead they pushed a low-K diet and told me to contact my PCP re: lowering my potassium levels- even though the only new drug I've been started on since before the K shot up is Besremi, and before that HU.

Not very helpful and scared the bejesus out of SWMBO, who is an RN, but not an MPN specialist [yet]. Fortunately, they did respond well to my having sent them the articles about it that I posted here, and now they order both the serum and whole blood potassium at each draw- and I'm trying to educate the phlebotomists where I get drawn, but since they rotate in and out of the lab so often, I haven't had much luck yet.

Best,

PA

[Mishie14 in reply to PhysAssist]

same challenge here with lab having protocol that is not wavering. I have not hesitated to share articles and info from this site with my hematologist, liver specialist and dermatologist. The latter was greatly surprised when I told her what the weird spot on my shin likely was. She had not seen a spot like that before. She did not have another patient being treated with interferon before either. I get strange looks when I reveal interferon. So much for being special all the time. Stay strong!

[PhysAssist]

Hi Mishie14,

I feel your pain! i have been through the same gamut- told to go on a low potassium diet, told to go see my PCP MD, and all because they don't read their own literature.

Here is what I found:

Pseudohyperkalemia occurring in a patient with chronic renal failure and polycythemia vera without severe leukocytosis or thrombocytosis

pubmed.ncbi.nlm.nih.gov/125...

Pseudohyperkalemia in Serum: A New Insight into an Old Phenomenon

clinmedres.org/content/6/1/...

kjim.org/upload/kjim-5-2-97...

Pseudohyperkalemia Related to Essential Thrombocytosis

proceedings.med.ucla.edu/wp...

It turns out that even erythrocytosis [the defining characteristic of PV] can cause falsely elevated potassium results!

They need to order serum and plasma potassium leves to rule this out.

Best,

PA

[Mishie14 in reply to PhysAssist]

Thank you!!!!!! I really appreciate having references to expand my knowledge. I also don't hesitate to pass along to my medical support team. Today my hematology nurse drew blood just focusing on potassium after the lab reported 5.9 again this morning. The nurse used a 20 gauge needle (it's a big one) to draw one vial for testing. She was already aware of not so tight tourniquet, no fist, etc. from our conversations. She then carefully walked the vial to the local lab in their building for testing. Within an hour their local lab result came back as 5.2! Potassium does not change dramatically like that in just 4 hours. Changing the needle to a bigger size made all the difference. That may be too big a size but it proved a point. We have a call set up for tomorrow with the hematology doctor to review. While we may come to a consensus, it's not clear yet what it takes to change the hospital lab technique and processes that are reporting inflated numbers. Stay safe!