Continuous insulin infusion reduces infectious complications in diabetics following coronary surgery

Background: This study was undertaken to evaluate the effects of a continuous insulin infusion protocol on postoperative infection and mortality. Methods: Patients who underwent coronary artery bypass grafting from January 1997 until December 1998 were included in this study (n = 761). A continuous insulin drip protocol (IDP) designed to titrate blood sugar levels to 120-160 mg/dL in the immediate postoperative period was instituted in 1998. Comparisons of diabetic and nondiabetic data before and after initiation of the IDP were made. Results: Of the 761 patients who underwent coronary revascularization, diabetics accounted for 32%. There was no significant difference in age, gender, diabetic status, urgency of operation, or operative time between 1997 and 1998 diabetics and nondiabetics. Overall, wound infections occurred in 3% (231761) of patients. In 1997, the infection rate was significantly higher in diabetics than nondiabetics (p = 0.0007). After initiation of the IDP in 1998, the infection rate for the diabetic population was reduced to that of the nondiabetic population. There was no significant difference in the mortality rate between 1997 diabetics (4%) and 1998 diabetics (5%) (p = 0.5759) or in the length of stay for 1997 diabetics versus nondiabetics (p = 0.1906). There were no mortalities among patients with wound infections. Conclusion: Initiation of the IDP and the subsequent tight control of blood sugars in the immediate postoperative period proved to reduce the incidence of wound infection in the diabetic population. There was no significant difference in the mortality rate or length of hospitalization.