Preinduction glycemia and body mass index are important predictors of perioperative insulin management in patients undergoing cardiac surgery.

Study Objective: To investigate whether preinduction glucose is an important predictor for perioperative insulin management in patients undergoing cardiac surgery.

Design: Prospective cohort study.

Setting: Large community hospital.

Patients: 80 consecutive patients scheduled for cardiac surgery.

Interventions: Patients were subdivided into those with a preinduction blood glucose of 110 mg/dL or lower with or without history of diabetes (group 1) and those with a preinduction blood glucose of above 110 mg/dL with or without history of diabetes (group 2). In group 1, there were no known diabetics. In group 2, 31% (11/35) had diabetes (group 2DM), while 24/35 (69%) did not (group 2NDM). An insulin infusion was started intraoperatively and adjusted according to a strict protocol in order to maintain normoglycemia (80-110 mg/dL) until discharge from intensive care.

Measurements And Main Results: In patients with preinduction glucose above 110 mg/dL, whether or not previously treated for diabetes, perioperative insulin requirements were higher, and intraoperative insulin management was more difficult than in those with lower preinduction glucose. In patients with a preinduction glucose above 110 mg/dL, hospital stay was longer, and inhospital mortality was significantly higher than in those with lower preinduction glucose. Multivariate analyses showed that preinduction glycemia was a good predictor of intraoperative insulin consumption, as was the body mass index (BMI) for intensive care and total insulin needs.

Conclusions: In cardiac surgical patients with a preinduction glucose above 110 mg/dL, even if diabetes was not previously suspected, perioperative insulin requirements were higher, and intraoperative insulin management is more difficult than in those with a preinduction glucose 110 mg/dL or lower. Preinduction glycemia and BMI are good predictors of perioperative insulin management. Preinduction glycemia above 110 mg/dL predicts difficult perioperative glucose control and, moreover, that a preinduction blood glucose of 110 mg/dL or lower is associated with less insulin need.