Pseudohyperkalemia: Two Case Reports with Literature Review.

BACKGROUND

Pseudohyperkalemia, a common pre-analytical error, may lead to misdiagnosis and unnecessary interventions. This report presents two cases emphasizing the critical role of pre-analytical vigilance and interdisciplinary communication.

METHODS

Laboratory staff identified discrepancies in potassium measurements and initiated a root-cause analysis, encompassing sample inspection, clinical history review, and experimental validation.

RESULTS

In Case 1, delayed processing in a patient with erythrocytosis (RBC 8.4 x 10¹²/L) caused potassium leak-age. Case 2 involved artifactual hyperkalemia due to double centrifugation. Case 1 was ultimately diagnosed with polycythemia vera. Experimental validation confirmed that delayed/repeated centrifugation elevates potassium levels, with a mean bias of 23.1% (range: 5.9 - 51.1%).

CONCLUSIONS

Proactive laboratory-driven investigations, coupled with interdisciplinary collaboration, are imperative to differentiate pseudohyperkalemia from true hyperkalemia and mitigate diagnostic errors.