(184) Impact of Intraoperative Blood Glucose Control on Morbidity and Mortality in Cardiac Surgery

Introduction: Perioperative hyperglycemia during cardiac surgery leads to increased complications. Guidelines recommend perioperative use of continuous insulin infusions to maintain blood glucose less than 180 mg/dL to improve outcomes. The goal of this study is to evaluate the impact of maintaining blood glucose less than 180 mg/dL during cardiac surgery on morbidity and mortality.

Methods: A retrospective cohort analysis of patients who underwent cardiac surgery with cardiopulmonary bypass between January 1, 2022 and December 31, 2022 was performed. Patients were identified by the Society of Thoracic Surgeons database. Patients were considered controlled if all intraoperative blood glucose levels were less than 180 mg/dL and uncontrolled if any intraoperative blood glucose level was 180 mg/dL or greater. The primary outcome was a composite of 30-day mortality and morbidity, including surgical site complications, sepsis, positive blood cultures, pneumonia, stroke, and myocardial infarction. Secondary outcomes included individual components of the primary outcome, intensive care unit and hospital length of stay, and new onset arrhythmias.

Results: Of 473 patients, 265 (56%) were controlled and 208 (44%) were uncontrolled. The uncontrolled group included more females, patients with diabetes, higher pre-operative glucose, and glycated hemoglobin. Type of cardiac procedure performed was similar between groups. Average (131.3 vs. 159.3 mg/dL, P < 0.001) and peak (157 vs 202.5 mg/dL. P < 0.001) intraoperative glucose were lower in the controlled vs. uncontrolled group. Uncontrolled patients required a longer duration of continuous insulin infusion post-operatively vs. controlled patients (46 vs. 35 hours, P < 0.001). The primary composite outcome was not different between controlled and uncontrolled groups, respectively (15.5% vs. 19.7%, P = 0.227). There was no difference in secondary outcomes.

Conclusions: There was no difference in 30-day morbidity and mortality between patients with all intraoperative blood glucoses less than 180 mg/dL and those with any blood glucose 180 mg/dL or greater during cardiac surgery. Further, larger studies are needed to determine optimal intraoperative blood glucose levels for patients undergoing cardiopulmonary bypass.