A life-threatening complication of extreme hyperkalemia in a patient on maintenance hemodialysis.

A 68-year-old female on two-year chronic hemodialysis for chronic renal failure due to chronic pyelonephritis, was admitted to hospital for weakness, dulled sensorium and dizziness. On examination the patient was in a state of circulatory collapse, the electrocardiogram showed an accelerated idioventricular rhythm and laboratory analysis revealed extreme hyperkalemia (K+ 10.1 mmol/l). There were no common causes of shock, such as hypovolemia, sepsis, heart failure and presence of vasodilator drugs. The patient was treated with calcium gluconate, sodium bicarbonate and sodium chloride (to oppose the effects of hyperkalemia on the cell membrane to minimize cardiac and neuromuscular toxicity), insulin and dextrose (to increase the transport of K+ from the extracellular to the intracellular compartment), and hemodialysis (to remove K+ from the body). At the end of the hemodialysis session, the patient was in a clinically good condition, blood pressure was 160/90 mm Hg and the serum K+ concentration was normal. The case appeared to suggest that extreme hyperkalemia may have direct effects on vascular resistance, causing hypotension and shock.