Pseudohyperkalemia in Chronic Lymphocytic Leukemia: An Often Overlooked Clinical Entity

Patients with chronic lymphocytic leukemia (CLL), particularly with unstable disease, are prone to severe metabolic complications such as hyperkale­mia. Pseudohyperkalemia, or spurious hyperkalemia, has serious clinical consequences such as masking clinically important hypokalemia if serum potassium concentration is normal; this can be prevented with early identification and differentiation from hyperkalemia. However, pseudohyperkalemia is not well recognized in nursing literature. This case report describes the acute development of pseudohyperka­lemia in a patient with unstable CLL receiving care at a large academic cancer center.

At a Glance:

• Consider pseudohyperkalemia in the absence of abnormal physical examination and electrocar­diogram findings consistent with hyperkalemia.
• The use of a pneumatic tube system may induce pseudohyperkalemia in patients with CLL through intracellular cell lysis, particularly in the setting of severe leukocytosis.
• Advanced practice providers’ ability to accurately diagnose and manage pseudohyperkalemia and hyperkalemia promotes better cardiac-associated health in patients with CLL.