Hypoglycemia in the intensive care unit

To review recent articles and evaluate hypoglycemia as a major complication of intensive insulin therapy in anticipation of emerging data from current clinical studies.

Following the 2001 landmark Leuven study demonstrating that intensive insulin therapy in the surgical intensive care unit reduces mortality, many studies have evaluated aspects of intensive insulin therapy with respect to improved clinical outcome and the impact of hypoglycemia. Specific risk factors for hypoglycemia in the intensive care unit with intensive insulin therapy are diabetes, octreotide therapy, nutrition support, continuous venovenous hemofiltration with bicarbonate replacement fluid, sepsis and need for inotropic support. In prospective studies with a comparator group, the incidence of hypoglycemia in intensive care unit patients treated with intensive insulin therapy is up to 25%, corresponding to a relative risk of 5.0. In studies without a comparator group, however, the incidence is less than 7%.

Hypoglycemia is associated with adverse outcome in intensive care unit patients. It remains unclear whether intensive insulin therapy-induced hypoglycemia per se is responsible for this adverse outcome. The threat of hypoglycemia is a barrier to intensive insulin therapy in critical care, supporting the need for frequent glucose monitoring, readily available concentrated intravenous dextrose infusions, better training of nurses and technological advances in glucose-sensing and insulin-dosing algorithms.