Breathe deeply the sweet air: ruminations on glycemic control.

Douglas B. Coursin, MD† Humans are the most complex organisms in the known universe. Humanity has added to this complexity by organizing itself into families, communities, cities, and states. This organization promoted the development of science and medicine. The scientific community has become a powerful force for the accumulation and application of knowledge. Physicians increasingly demand evidence for their practices, which adds further levels of complexity to scientific foundations. Dissemination of newly acquired knowledge has relied on both established and innovative methods of communication. The era of electronic publishing has allowed us to quickly access the latest medical data, and new studies appear in the literature at a breakneck pace. However, the constant presentation of novel information, much of it potentially important, may overwhelm us. We may be caught up in a whoosh of populism. Through no one’s fault, certain ideas, often good ones, are heavily promoted, sometimes even as “absolute truths. ” Respected colleagues implement certain strategies and we emulate them, despite the lack of availability of published supporting evidence. Regulatory authorities put their administrative weight behind specific practices and we feel that we must keep up. As we attempt to make sense of the complexities of modern medicine, we may not have time to “catch our breath. ” The recent story of glycemic control is an example of practice guidance developing at a rapid pace. Since the discovery of insulin in the 1920s, control of serum glucose has been possible and found to be beneficial. In the past decade, however, glycemic control became more than simply useful and necessary. The pivotal 2001 study led by Professor Greet Van den Berghe, an anesthesiologist and critical care physician from Leuven in Belgium, stimulated a popular movement. She and her colleagues demonstrated that using continuous insulin infusions to achieve tight glycemic control greatly improved outcome in their critically ill patients. Although this seminal study had limitations (the inclusion of many cardiac surgical patients with relatively high mortality rate, aggressive nutrition practices, intensive resource utilization, nonblinded, single-center study with potential Hawthorne effect), it nonetheless served as a “tipping point. ” Insulin infusions became ubiquitous in the intensive care unit (ICU), though there was debate about the target glucose and concern regarding the potential effects of hypoglycemia. Many intensivists thus jumped on the “glycemic control express. ” While anesthesiologists debated the merits of glycemic control in the perioperative period, the Institute for Healthcare Improvement and the Surgical Care Improvement Project mandated adherence to glycemic control targets in some patient populations. *† Some physicians expressed concerns regarding the enthusiasm for tight glycemic control; they warned against changing practice based on a single study or even series of studies. The reluctant physicians were supported by the publication of individual studies and meta-analyses that provided support for a more cautious approach. The year 2009 was important for the continuing saga of glycemic control. In March, the second largest randomized prospective trial in the history of critical care medicine was published. The Normoglycemia in Intensive Care Evaluation—Survival Using Glucose Algorithm Regulation From the *Division of Critical Care, Department of Anesthesiology, Mayo Clinic and Mayo Clinic College of Medicine, Rochester, Minnesota; and †Departments of Anesthesiology and Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin. Accepted for publication July 2, 2009. MTK wrote the first draft based on discussions between both authors. DBC reviewed and edited the first draft. Both authors reviewed and edited multiple subsequent drafts. Address correspondence and reprint requests to Mark T. Keegan, MD, Department of Anesthesiology, Charlton 1145, Mayo Clinic, 200 1st St. SW, Rochester, MN 55905. Address e-mail to keegan.mark@mayo.edu. *Institute for Healthcare Improvement at http://www.ihi. org/ihi. Accessed June 2009. †Joint Commission at http://www.joint commission.org/PerformanceMeasurement/ PerformanceMeasurement/SCIP Core Measure Set.htm. Accessed June 2009. Copyright © 2010 International Anesthesia Research Society