High blood-sugar levels indicate greater chance of death for critically ill patients

Mayo Clinic Proceedings study emphasizes blood sugar level management

A study in the December issue of Mayo Clinic Proceedings on blood-sugar levels in 1,826 intensive care unit patients showed that hyperglycemia (high blood-sugar levels) increased the patient’s chance of death. The findings have important implications for the management of blood sugar in critically ill patients.

Even a modest degree of hyperglycemia was associated with a substantial increase in deaths in patients with a wide range of medical and surgical diagnoses, says James Krinsley, M.D., director of critical care at The Stamford Hospital in Stamford, Conn., and author of the study.

Hyperglycemia is common in critically ill adults. Standard clinical practice has been to tolerate a moderate degree of hyperglycemia in these patients. However, Dr. Krinsley says the findings from this study suggest a new approach to glucose management in the intensive care unit, and should prompt additional studies.

“Although hyperglycemia can be a marker of severity of illness, it may also worsen outcomes,” Dr. Krinsley says. “We think that tight glucose control results in improved vascular function and lower risk of infection.”

Dr. Krinsley, who is an associate clinical professor of medicine at the Columbia University College of Physicians and Surgeons, reviewed data for 1,826 patients whose glucose values were obtained during their intensive care unit stay at The Stamford Hospital between Oct. 1, 1999, and April 4, 2002. The lowest death rates occurred in patients whose average glucose levels were in the lower end of the normal range. Death rates increased as the average glucose levels increased. This association was noted among people with and without diabetes.

Based on these findings, a multidisciplinary team at The Stamford Hospital has developed a protocol for intensive monitoring and treatment of glucose levels of patients admitted to the critical care unit. The team is studying whether tighter management of glucose levels in the intensive care unit will result in lower death rates and lower organ system dysfunction. Dr. Krinsley will be reporting those results soon.

An editorial in the same issue of Mayo Clinic Proceedings, authored by Douglas Coursin, M.D., of the departments of Anesthesiology and Internal Medicine at the University of Wisconsin-Madison, and Michael Murray, Ph.D., M.D., of the Department of Anesthesiology at Mayo Clinic in Jacksonville, Fla., says the report provides potentially useful information and the basis for further studies. The study provides some insights into the generalized applicability of normal blood-sugar levels in a wide range of adult intensive care unit patients, say Drs. Coursin and Murray.

The editorialists say randomized controlled studies of a broader and greater range of patients need to be done to allow for analysis of subsets of patients, including critically ill adults and pediatric patients — be they medical, surgical, transplantation, neurologic, trauma or other patients.

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The Stamford Hospital is a major teaching affiliate of the Columbia University College of Physicians and Surgeons. In 2002 the National Coalition of Healthcare and the Institute for Healthcare Improvement recognized the hospital’s intensive care unit as one of 11 “best practices” in the nation for its work in integrating a comprehensive data system with multiple clinical protocols to improve patient outcomes.

A peer-reviewed journal, Mayo Clinic Proceedings publishes original articles and reviews dealing with clinical and laboratory medicine, clinical research, basic science research and clinical epidemiology. Mayo Clinic Proceedings is published monthly by Mayo Clinic as part of its commitment to the medical education of physicians. The journal has been published for more than 75 years and has a circulation of 130,000 nationally and internationally.