Pseudohyperkalemia caused by essential thrombocythemia in a patient with chronic renal failure: A case report

Hyperkalemia is one of the most common complications of chronic renal failure. Pseudohyperkalemia is caused by elevated levels of serum potassium in vitro and is usually accompanied by thrombocythemia. Although an elevated level of potassium is typically correlated with impaired renal function, pseudo-hyperkalemia has been rarely reported in patients with chronic renal failure. Here, we conducted a review of the literature to study the case of pseudo-hyperkalemia caused by the essential thrombocythemia in a patient with chronic renal failure.

A 73-year-old woman was admitted to our hospital with complaints of palpitation, dyspnea, and acratia for 2 d and a history of essential throm-bocythemia for 1 year. The routine blood test showed platelet count of 1460 × 10⁹/L, and biochemistry tests showed that the patient suffered from hyperkalemia (potassium: 7.50 mmol/L) and renal failure (estimated glomerular filtration rate: 8.88 mL/min). Initial treatment included medicines to lower her potassium-levels and hemodialysis. However, the therapy did not affect her serum potassium levels. Plasma potassium concentration measurements and a history of essential thrombocythemia established the diagnosis of pseudohyperkalemia. The treatments of the platelet disorder gradually normalized serum potassium levels; however, the treatments had to be discontinued later due to the severe leukopenia, and enhanced levels of serum potassium concentrations were observable in the patient. Since plasma sampling was not permitted, doctors had to use a diuretic just in case. Finally, the patient collapsed into unconsciousness and died due to multiple organ dysfunction and electrolyte disturbance.

We reviewed the literature and suggest that serum and plasma potassium values should both be measured for patients whose platelet counts exceed 500 × 10⁹/L to eliminate chances of pseudohyperkalemia, especially for those with chronic renal failure. An inappropriate treatment for pseudohyperkalemia can aggravate a patient's condition.