Intraoperative insulin therapy does not reduce the need for inotropic or antiarrhythmic therapy after cardiopulmonary bypass

Objective: To determine whether attempted glucose control through intraoperative insulin therapy reduces the need for inotropic or antiarrhythmic therapy after cardiopulmonary bypass (CPB). Design: Post hoc analysis of a randomized, masked clinical trial of insulin therapy for prevention of neurobehavioral deficits. Setting: Single university hospital. Participants: Nondiabetic patients undergoing elective coronary artery bypass graft surgery (n = 381). Interventions: Patients received either insulin infusions in an attempt to maintain blood glucose at 80 to 120 mg/dL (n = 188) or placebo (saline; n = 193). Inotropic therapy was defined as the initiation of vasoactive support with epinephrine or amrinone infusions or mechanical support with the initiation of an intra-aortic balloon pump in the operating room or within 12 hours postoperatively. Antiarrhythmic therapy was defined as cardioversion, antiarrhythmic medications, or pacing. Measurements and Main Results: Of patients, 64 in the placebo group and 71 in the insulin group required inotropic support after CPB (p = not significant). The use of cardioversion (55 in placebo group v 61 in insulin group), antiarrhythmic medications (64 in placebo group v 76 in insulin group), and pacing (118 in placebo group v 117 in insulin group) was similar between groups. Inotropic drug support was associated with age >60 years, female gender, reduced preoperative ejection fraction, history of angina, and increased duration of CPB. Conclusion: Intraoperative insulin therapy did not reduce the use of inotropic or antiarrhythmic support after cardiac surgery with CPB. The lack of benefit may be due to the inability to prevent hyperglycemia during the physiologic stress of CPB or a tribute to the effectiveness of modern myocardial preservation techniques. Copyright 2002, Elsevier Science (USA). All rights reserved.