Pseudohyperkalemia in chronic lymphocytic leukemia and diabetic ketoacidosis

Pseudohyperkalemia can lead to inaccurate hyperkalemia diagnosis, inappropriate initiation of potassium‐lowering therapies, and overall unnecessary treatment possibly inducing iatrogenic hypokalemia. Patients with leukocytosis and thrombocytosis should raise clinical suspicion that hyperkalemic laboratory results in the absence of other traditional signs of hyperkalemia may be indicative of pseudohyperkalemia. Here we present a case of severe leukocytosis with chronic lymphocytic leukemia (CLL) found to have critically elevated potassium levels on admission to the intensive care unit (ICU). The patient was also diagnosed with diabetic ketoacidosis (DKA) at admission, requiring an increased frequency of electrolyte monitoring. The events leading to the prompt recognition of pseudohyperkalemia in this patient will be delineated alongside our recommendations for revising the institutional protocol to avoid false hyperkalemia diagnoses in patients with CLL.