Intravenous GLP-1 (7-36) amide for prevention of hyperglycemia during cardiac surgery: a randomized, double-blind, placebo-controlled study.

OBJECTIVE: The authors sought to evaluate the efficacy of an intravenous glucagon-like peptide-1 (GLP-1) infusion, compared with placebo, to mitigate intraoperative hyperglycemia. DESIGN: Prospective, double-blinded, randomized, placebo-controlled. SETTING: University hospital. PARTICIPANTS: Diabetic (non-insulin dependent) and non-diabetic patients undergoing elective cardiac surgery with cardiopulmonary bypass. INTERVENTIONS: Patients were randomized in a 1:1 fashion to GLP-1 (7-36) amide infusion (1.5 pmol/kg/min) or placebo. Insulin was administered intraoperatively to both groups per a standardized protocol. MEASUREMENTS AND MAIN RESULTS: A total of 77 patients were included for analysis (GLP-1, n = 37; placebo, n = 40). Mean blood glucose during cardiopulmonary bypass was 127.5 mg/dL and 142.5 mg/dL (p = 0.002) in the GLP-1 and placebo groups, respectively. Mean blood glucose values during the entire intraoperative course were 12.2 mg/dL lower for subjects given GLP-1 (95% CI 2.3, 22, p = 0.015), independent of time. During the period of cardiopulmonary bypass, mean blood glucose values in subjects given GLP-1 were 14.1 mg/dL lower than those who received placebo (95% CI 3.5, 24.8, p = 0.009), independent of time. The incidence of hypoglycemia did not differ significantly between the 2 groups. CONCLUSIONS: Administration of intravenous GLP-1 (7-36) amide to patients undergoing cardiac surgery significantly reduced their plasma glucose levels intraoperatively and may represent a novel therapeutic strategy to prevent perioperative hyperglycemia.

Implementation of an intraoperative glycemic control protocol for cardiac surgery in a high-acuity academic medical center: an observational study.

STUDY OBJECTIVE: To examine the effect on morbidity and mortality of an established intraoperative insulin protocol in cardiac surgical patients. DESIGN: Retrospective observational study. SETTING: Single-center, 782 bed, metropolitan academic hospital. PATIENTS: 1,616 adult patients undergoing cardiac surgical procedures with cardiopulmonary bypass (CPB). INTERVENTIONS: An intraoperative, intravenous (IV) insulin protocol designed to maintain blood glucose values less than 150 mg/dL was implemented. MEASUREMENTS: Blood glucose was evaluated on entry to the operating room, every 30 minutes during CPB, and at least once after discontinuation of CPB. Blood glucose values were followed postoperatively, as dictated by institutional policy. MAIN RESULTS: Intraoperative predictors of 30-day mortality using multivariate logistic regression included hyperglycemia on initiation of CPB (OR 1.0, P = 0.05). The strongest predictor of 30-day mortality was the development of postoperative renal failure requiring hemodialysis (OR 3.26, P = 0.001). CONCLUSIONS: Implementation of an intraoperative IV insulin protocol, while associated with improved glycemic control, was not associated with improved outcomes. While improved glycemic control on initiating CPB was associated with decreased 30-day mortality, the effect was small. Implementation of our insulin protocol was highly associated with decreased renal failure postoperatively. Further prospective studies are warranted to better establish causality.