Beating the odds--surviving extreme hyperkalemia

Severe hyperkalemia (>7 mmol/L) is a medical emergency because of possible fatal arrhythmias. We here report the case of a 58-year-old woman surviving extreme hyperkalemia (>10 mmol/L). The patient with a history of congestive heart failure, a DDD pacemaker and mild chronic renal insufficiency was admitted with progressive weakness and sudden onset of hypotension and bradycardia in the absence of any pacemaker action. Laboratory tests revealed an extreme serum potassium level of 10.1 mmol/L, with a slightly elevated serum creatinine of 149 μmol/L. Treatment with norepinephrine, sodium bicarbonate, and insulin improved both the hemodynamic situation and the serum potassium with subsequent regaining pacemaker actions even before additional hemodialysis normalized the potassium level. A thorough investigation demonstrated that several mechanisms contributed to the extreme potassium level: urinalysis and a low transtubular potassium gradient in the presence of metabolic acidosis with normal anion gap pointed to preexisting interstitial nephritis, with renal tubular acidosis type IV as the predisposing factor, whereas several drugs and acute impairment of renal function contributed to the dangerous situation. Despite the odds for fatal outcome, the patient recovered completely, and long-term management was initiated to prevent recurrent hyperkalemia.