Clinical Practice and Cases in Emergency Medicine

Introduction: Both hyperkalemia and pseudohyperkalemia occur in the emergency department. True hyperkalemia necessitates emergent treatment while pseudohyperkalemia requires recognition to prevent inappropriate treatment. It is imperative that the emergency physician (EP) have an understanding of the causes and clinical presentations of both phenomena.

Case Report: We present a case of an 88-year-old male with chronic lymphocytic leukemia (CLL) and suspected blast crisis who was found to have elevated serum potassium levels without other manifestations of hyperkalemia and eventually was determined to have pseudohyperkalemia due to white cell fragility.

Discussion: Differentiation of hyperkalemia and pseudohyperkalemia is a critical skill for the EP. We discuss multiple causes of hyperkalemia and pseudohyperkalemia in an effort to broaden the knowledge base.

Conclusion: We present a case of CLL as an unusual cause of pseudohyperkalemia and review common causes of pseudohyperkalemia.