Pseudohyperkalemia in a Patient With Chronic Lymphocytic Leukemia

Abstract

Hyperkalemia is a common electrolyte disorder with potentially life-threatening consequences, including cardiac dysrhythmias. Pseudohyperkalemia must always be ruled out before implementing treatment for true hyperkalemia. Here, we present a case of a 63-year-old male with chronic lymphocytic leukemia (CLL) with a white blood cell count greater than 200 thousand/mm 3 and persistently high serum potassium concentration as high as 8.4 mmol/L. A venous blood gas analysis was performed, which confirmed the patient's plasma potassium levels were within the normal range (3.7-4.4 mmol/L). In patients with CLL, due to the increased fragility of their white blood cells, mechanical stress such as centrifugation can lead to cell lysis resulting in pseudohyperkalemia. Our emphasis with clinicians is to familiarize themselves with these spurious laboratory values and prevent unnecessary invasive testing and treatment.

Pseudohyperkalemia in chronic lymphocytic leukemia and diabetic ketoacidosis

“…Our hospital currently uses BD Vacutainer® PST™ gel and lithium heparin tubes, which exert additional pressure onto the blood sample prior to centrifugation. When the heparin in these tubes is centrifuged, it can cause cell destruction and potassium release as well 14 . Whole blood can be analyzed on the floor using a device such as the i‐Stat® that provides immediate results.…”

“…When the heparin in these tubes is centrifuged, it can cause cell destruction and potassium release as well. 14 Whole blood can be analyzed on the floor using a device such as the i‐Stat® that provides immediate results. However, our hospital only allows whole blood testing in the emergency department.…”