[Pathophysiology and therapy of diabetic ketoacidosis and of non-ketoacidotic hyperosmolar diabetic coma].

Metabolic derangements in diabetic coma are the sequelae of insulin deficiency. These defects are aggravated by the actions of insulin counteracting ("diabetogenic") hormones and hypertonic dehydration, which both impair insulin action. Conversely, it has been shown that hypo-osmolar rehydration of a hyperosmolar, severely hyperglycaemic diabetic patient reduces insulin resistance and restores biological responsiveness of previously dehydrated insulin-dependent tissues towards insulin. Thus treatment of diabetic coma requires appropriate fluid and electrolyte replacement as a life-saving emergency action alongside insulin replacement. The use of proper rehydration during the past decade might also explain the reported fall in the insulin requirement for the treatment of diabetic coma from approximately 1,000 units per coma to low-dose insulin therapy. In order to guarantee proper treatment of severe hyperglycaemia and normalization of the hyperosmolar state, we feel that hypo-osmolar rehydration has to be initiated in parallel with low-dose insulin therapy (5 to 6 U/h) to restore the physiological response of the respective target tissues to insulin action and to ameliorate glucose utilization. This approach probably avoids a too rapid fall in plasma osmolarity, minimizes the risk of cerebral oedema and hypokalaemia, and improves survival. The development of severe diabetic ketoacidosis or of hyperosmolar non-ketotic diabetic coma should be prevented by advice to patients on the importance of metabolic monitoring, which can be done by proper self-monitoring of blood glucose. In addition, information should be provided on the detrimental metabolic effects of both dehydration and stress.