Ever wonder if the high potassium value you are getting from the lab report is correct? Especially when it seems totally outside of your patient’s normal potassium value?
It’s possible that you could be looking at pseudohyperkalemia – falsely elevated potassium. Keep reading to learn more.
Where this information comes from?
In 2020 the Kidney Disease Improving Global Outcomes (KDIGO) group published consensus statements on the management of serum potassium levels in CKD. In this work they discuss pseudohyperkalemia.
What is pseudohyperkalemia?
Pseudohyperkalemia occurs when the lab reports a value as high but the value is false. Pseudohyperkalemia can occur due to:
- Hemolysis of the blood sample
- Mechanical trauma (e.g. lots of poking or digging around with the needle to get the blood sample)
- Tourniquet use greater than 1 minute
- Elevated white blood cell or platelet counts (rare – see my note below)
White cells, platelets and hyperkalemia
I just want to add a side bar note about the white blood cells/platelets. In my clinical practice I see many patients with elevated white blood cells and platelet counts without hyperkalemia. The reference KDIGO used for this bullet point is based off of this study. This study summarizes a case report of 1 patient who experienced pseudohyperkalemia and was living with chronic lymphocytic leukemia.
So my take away is: This association is rare – but if you have a patient living with chronic lymphocytic leukemia with hyperkalemia and you are concerned that they may be experiencing pseudohypekalemia, it may be worthwhile to share this article with the medical team.
Reference: Alhaj Moustafa, Muhamad, et al. “A challenging case of pseudohyperkalemia in chronic lymphocytic leukemia.” Journal of Investigative Medicine High Impact Case Reports 5.4 (2017): 2324709617746194.
Take Aways
When I am doing a hyperkalemia assessment – I ask patients if they had a difficult lab draw. I also check the lab reports to see if there is any mention about the sample being hemolyzed. Sometimes, depending on your available lab data you can also ask a patient about the time of the lab draw and compare that to the reported time and date. If it took the lab a long time to report (or longer than is normal for your lab) it is possible the value could be inaccurate.
That being said, I still do my due diligence and ensure my patients haven’t accidently ingested a big, highly-bioavailable potassium load (e.g. orange juice, gatorade, etc). My new hyperkalemia assessment template has a quick food frequency questionnaire that I use to help ensure I am not missing any of these high potassium culprits in my assessments.
