Hyperkalaemia in acute leukaemia: a sign of adrenocortical insufficiency.

Abstract

OBJECTIVES: To evaluate adrenal cortical reserve function in hyperkalaemic patients with acute leukaemia (AL). DESIGN: In hyperkalaemic AL patients, after basal blood collection for cortisol, rapid adrenocorticotropic hormone (ACTH) stimulation test was performed with human a1-24-ACTH 0.25 mg, intravenously. Sixty minutes following injection, additional plasma was obtained for cortisol. Normal response was a peak cortisol level greater than 15 micrograms dL-1 with an increment greater than 5 micrograms dL-1. SETTING: Hacettepe University Hospital, Ankara, Turkey. SUBJECTS: Newly diagnosed AL patients with plasma K+ values exceeding 4.5 mmol L-1, who had never received antileukaemia therapy were eligible for entry into the trial. Thirteen patients fulfilled these criteria. Twenty AL patients with normal serum K+ levels were studied as controls. RESULTS: In six patients with hyperkalaemia, adrenal cortical response to rapid ACTH test was inadequate. One patient died during induction chemotherapy due to sepsis. Five of the remaining patients entered remission. Repeat ACTH tests during remission revealed normalization of the adrenocortical function in these patients. However, in only one patient with normal serum K+ level, adrenocortical reserve was decreased. CONCLUSIONS: We suggest that in any AL patient with hyperkalaemia, adrenal reserve function should be evaluated with rapid ACTH stimulation test. In states of resistant hypotension and hyperkalaemia, steroids may be life saving.