Fatal coma in diabetes.

Analysis of causes of death in a population of 3,113 diabetics was carried out for a period of eight years and those patients dying of some form of diabetic coma identified. Of 1,274 deaths, only 22 (1.73%) were primarily due to coma; 7 hypoglycaemia, 8 ketoacidosis, 3 hyperosmolar coma and 4 lactic acidosis. Three of the ketoacidosis patients may have died from other causes. Most deaths occurred in patients with long-standing diabetes. In the hypoglycaemic group all were on insulin and several had been difficult to control for many years. Infection was an important precipitating factor for ketoacidosis and hyperosmolar coma. Phenformin was the cause of all cases of fatal lactic acidosis. It is reassuring that death from coma is a comparatively rare event in known treated diabetic patients.