A prospective trial from the Mayo Clinic randomly assigned 400 patients to intensive treatment (continuous insulin infu- sion during surgery) or conventional treatment (insulin given only for a glucose concentration 200 mg/dL).586 Postoper- ative ICU management was similar in the 2 groups. Although no difference was noted between groups in a composite endpoint of death, deep sternal wound infection, prolonged ventilation, cardiac arrhythmias, stroke, or renal failure within 30 days of surgery, intensive treatment caused an increased incidence of death and stroke, thereby raising concerns about this intervention.586 In a prospective RCT in 381 CABG patients without diabetes, those with an intraop- erative blood glucose concentration 100 mg/dL were as- signed to an insulin infusion or no treatment.584 Those receiving insulin had lower intraoperative glucose concentra- tions, but no difference between groups was observed in the occurrence of new neurological, neuro-ophthalmologic, or neurobehavioral deficits or neurology-related deaths. Of note, no difference in need for inotropic support, hospital length of stay, or operative mortality rate was seen between the groups.584 A retrospective analysis of intraoperative and postoperative ICU glucose concentrations in 4300 patients undergoing cardiac surgery at the Cleveland Clinic observed that a blood glucose concentration 200 mg/dL in the operating room or ICU was associated with worse outcomes, but intraoperative glucose concentrations 140 mg/dL were not associated with improved outcomes compared with se- vere hyperglycemia, despite infrequent hypoglycemia. Dia- betic status did not influence the effects of hyperglycemia.585 In short, until additional information is available, extremely tight intraoperative glucose control is not recommended. 