Glucose in the ICU — Evidence, Guidelines, and Outcomes

September 7, 2012 (10.1056/NEJMe1209429)

Just over a decade ago, a single-center Belgian study showed that normalization of blood glucose in critically ill patients lowered hospital mortality by more than 30%.1 Although subsequent studies were unable to reproduce these findings, the appeal of such a straightforward intervention was too great to resist: guidelines from professional organizations2,3 were published, and editorial commentary4 highlighted initiatives by the Institute for Healthcare Improvement, the Joint Commission on Accreditation of Healthcare Organizations, and the Volunteer Hospital Association that incorporated tight glucose control as a standard. Indeed, the prestigious Codman Award of the Joint Commission was presented in 2004 for a program of glycemic control in critical care that “saved” patients’ lives.5 Tight glucose control for critically ill patients was in vogue.

The publication in 2009 of a large international trial (the Normoglycemia inIntensive Care Evaluation–Survival Using Glucose Algorithm Regulation [NICE-SUGAR] study6) followed that of several negative trials. The NICE-SUGAR study, which involved more than 6100 patients, showed that tight glycemic control didn’t decrease mortality — it increased it. Most guidelines were hastily revised. However, in the same year a separate study by Vlasselaers et al.7 in pediatric intensive care unit (ICU) patients, most of whom had undergone cardiac surgery, showed that normalizing glucose decreased mortality from 6% to 3%, keeping open the question — at least in critically ill children.

The study by Agus et al.8 now reported in the Journal provides new key data. A total of 980 children (up to 36 months of age) admitted to an ICU after cardiac surgery were randomly assigned to usual care or tight glucose control. The results are clear — there was no significant difference in the incidence of health care–associated infections (the primary outcome) or in any of the secondary outcomes, including survival. Moreover, the rate of hypoglycemia (blood glucose level <40 mg per deciliter [2.2 mmol per liter]) in the intervention group (3%) was far less than that previously reported (25%).

CMMENT:  This is an excerpt from a New Englnd Journal editorial published this month.  Combined with the recent study on the increased mortality following hypoglycemia that i have previously posted the use of intensive glucose control in ICUs needs to be tempered.  Perhaps the most reasonable approach is to attempt to achieve the level of glucose control that you have the resources to achieve safely.  The larger the ICU and the more technology that you have to closely monitor and prevent hypoglycemia, the lower reasonble glucose targets you can achieve.  Given that, however, the benefit of glucose means lower than 180 mg/dL remains to be proven http://www.nejm.org/doi/full/10.1056/NEJMoa0810625 In that study targets below 110 mg/dL were associated with increased mortality similar to the NICE-SUGAR results.