Treatment of blood sugar levels in intensive care patients results in reduction in mortality

Mayo Clinic Proceedings study highlights Òreal-lifeÓ ICU experience

A study in the August issue of Mayo Clinic Proceedings outlines how strictly controlling the levels of glucose, or sugar, in a patient’s blood can increase the survival rate of critically ill patients.

James Krinsley, M.D., the author of the study, is director of critical care at The Stamford Hospital in Stamford, Conn., and associate clinical professor of medicine at Columbia University College of Physicians and Surgeons. Dr. Krinsley says conducting the study in a community hospital should give other hospitals confidence that they can maintain the necessary level of glucose monitoring and treatment without being a large-scale research hospital.

“This is a low-cost, effective intervention that can profoundly affect patients,” says Dr. Krinsley. “Intensive glucose management will eventually become a standard of care in ICUs (intensive care units) worldwide.”

The Stamford Hospital Intensive Care Unit has 14 beds and cares for a mixed adult population of medical, surgical and cardiac patients. Dr. Krinsley analyzed 800 consecutive patients admitted to the unit just prior to institution of the glucose management protocol and compared them to the first 800 consecutive patients admitted after the protocol was put into place. The protocol involved intensive monitoring of the glucose levels in patients and treating any elevation over 140 milligrams per deciliter (mg/dL) with injections of insulin under the skin or continuous intravenous insulin infusions, depending on the level of elevation. The normal range of blood glucose is 80-110 mg/dL.

The hospital mortality rate of the treated patients decreased 29.3 percent. This represents 49 saved lives from the first 800 patients treated with the protocol. There was also a decrease in the development of new kidney failure and a decrease in the need for red blood cell transfusions. The ICU length of stay decreased among the patients treated with the protocol. Finally, there was no increase in nursing staff as a result of the change in practice.

Intensive glucose management among critically ill patients was pioneered by Greet Van den Berghe, M.D., Ph.D., of the Department of Intensive Care Medicine at the University of Leuven in Leuven, Belgium. She reported decreased mortality and organ dysfunction among a population of surgical ICU patients requiring mechanical ventilation to aid breathing, 62 percent of whom had undergone cardiac surgery. Dr. Van den Berghe’s study, published in The New England Journal of Medicine in 2001, prompted Dr. Krinsley to analyze his own ICU’s experience. Dr. Krinsley’s paper describing the relationship between increasing glucose levels and increasing mortality among critically ill patients was published by Mayo Clinic Proceedings in December 2003.

The current study from Stamford Hospital is the first to show that intensive glucose management can improve survival among a general population of critically ill patients, similar to the patients found in the majority of ICUs around the world. Dr. Van den Berghe’s editorial in the August issue of Mayo Clinic Proceedings corroborates this. She wrote that the study by Dr. Krinsley shows the impact of tight glucose control in a “real life” ICU. She congratulated the Stamford Hospital ICU team for “thoroughly studying the impact of implementation of a novel ’routine’ strategy in the ICU on patients’ outcomes and on the workload of the unit” and stated that the current study “extended the knowledge” gained from her study “by showing that the benefit [of tight glucose control] is present in a medical-surgical population.”

Blood glucose levels increase commonly in critical illness due in part to stress hormone responses and the effect of medications and nutritional interventions given as part of patient treatment. The standard of care in ICUs until recently was to accept moderate elevations of glucose, even up to 200-225 mg/dL, without using insulin treatment, says Dr. Krinsley. The current study will help to change that paradigm, he says.