This prospective observational study described the evolution in management of cardiac surgical patients with diabetes mellitus from a strategy of intermittent subcutaneous injections of insulin to one of continuous intrave- nous insulin infusion with decreasing target glucose concentra- tions. As this management strategy evolved, the upper target serum glucose concentrations declined from 200 mg/dL to 110 mg/dL, with which significant reductions in operative and cardiac-related death (arrhythmias and acute ventricular failure) were noted.581 In addition, continuous intravenous insulin to maintain a serum glucose concentration of 120 mg/dL to 160 mg/dL resulted in a reduced incidence of deep sternal wound infection.593,594 As a result, most centers now emphasize tight glucose control (target serum glucose concentration 180 mg/ dL, accomplished with a continuous intravenous insulin infu- sion) during surgery and until the morning of the third postop- erative day. Hillis et al 2011 ACCF/AHA CABG Guideline e679 Whether extremely tight intraoperative glucose control can further reduce morbidity or mortality rate is controversial. 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. 