[Life threatening hyperkalemia: the value of the electrocardiogram]

In two men, aged 19 and 64, with chronic renal insufficiency and subacute symptoms of malaise and weakness of the leg muscles, broad QRS complexes were seen in the ECG. The younger patient developed an asystole and resuscitation was unsuccessful. His blood potassium level was found to be 8.3 mmol/l. The older patient recovered after administration of calcium gluconate. His blood potassium level was found to be 8.5 mmol/l. An 80-year-old woman who was taking various drugs because of heart failure also complained of muscle weakness. Her blood potassium level was 7.2 mmol/l and her ECG showed narrow complexes. She recovered without calcium gluconate after a change in medication. Hyperkalemia is a potentially life-threatening electrolyte disorder that may require immediate treatment. The changes in the ECG, especially widening of the QRS complexes, are the most important clues to the severity of the hyperkalemia. A treatment protocol based on ECG changes may reduce the mortality in these patients.