Factors associated with hypoglycemia in cardiovascular surgery

Introduction: An inadequate glycemic control in cardiovascular postoperative is a predictor of mortality, postoperative infections and a prolonged hospital stay. This study evaluates the incidence of hypoglycemia in the first 72 h of postoperative and its association with different factors, such as tissue perfusion parameters, and the administration of medicines that induct hypoglycemia during surgery, in patients that undergo cardiovascular surgery in a 4th level hospital in Bogota, Colombia. Methods and materials: A nested cases and controls study was developed, taking as cases the patients that presented hypoglycemia episodes (<70 mg/dl) and the controls were the patients without this outcome. A systematic record of the glycemic control in the first 72 h of postoperative was registered. An univariate and multivariate analysis was conducted to determine the factor associated with hypoglycemia. Results: 327 patients were evaluated (35% with coronary bypass and 27% with valvular replacement). 7.65% of the patients presented at least one episode of hypoglycemia <70 mg/dL (25 episodes). The multivariate analysis showed an association with chronic kidney failure in dialysis (OR6,21; IC:0,97–43.27,p:0.05), administration of preoperative steroids (OR4,41; IC:1,27-15,20,p:0.02), intraoperative insulin (OR2,61; IC:1.09–6,22, p:0.03), and postoperative hydrocortisone (OR 7,15; IC 1,46-34,9 p:0.01). Conclusions: Hypoglycemia is frequent in patients that undergo a cardiovascular surgery. The associated factors were chronic kidney failure in dialysis, administration of preoperative steroids, intraoperative insulin and hydrocortisone during postoperative. Other factors such as tissue perfusion, administration of vasoactive or beta blockers substances, showed no association with hypoglycemia.