(124) Incidence of Mediastinitis in Cardiac Surgery Utilizing Blood Glucose Targets of 110-150 mg/dL

Introduction: The role of tight glycemic control for prevention of mediastinitis in patients undergoing cardiac surgery is evolving. This study aims to clarify the importance of glycemic control with a blood glucose target between 110-150 mg/dL in the immediate days after cardiac surgery and the relation to mediastinitis incidence.

Methods: This retrospective, single-center, case-control study evaluated the effectiveness of maintaining post-sternotomy patients in a blood glucose target of 110 – 150 mg/dL in decreasing the risk of mediastinitis. To be included in this study, patients must have undergone cardiac surgery with a median sternotomy at our institution and had a diagnosis of mediastinitis within 14 days of their sternotomy. Patients were selected from the Society of Thoracic Surgeons (STS) database between March 1, 2016 – December 31, 2022.

Results: During the study period, 22 patients diagnosed with mediastinitis were identified and matched to 44 control patients. Mediastinitis patients were maintained within the blood glucose target a median of 56.4% of the time compared to a median of 53.5% in the matched control patients (p=0.698). Hypoglycemia was more prevalent in the control group, but this was not found to be statistically significant. Additionally, systemic corticosteroid use was more prevalent in the mediastinitis group with 12 out of 22 patients (54.5%) receiving steroids prior to diagnosis compared to 13 out of 44 patients in the matched cohort (30.2%). Mediastinitis was more common in the patients with their first redo sternotomy (40.9% vs 18.2%, p=0.047). A longer intensive care unit (ICU) length of stay (p=0.013) and total admission length of stay (p=0.002) was identified with the patients who developed mediastinitis. No significant difference in mortality was seen between the mediastinitis and control groups (p=0.364).

Conclusions: There were no overt differences in glycemic control after sternotomy between mediastinitis and control groups, with patients remaining in the blood glucose target of 110 – 150 mg/dL for a similar amount of time during their admission. To the best of our knowledge, a goal time in the blood glucose target range for patients’ post-cardiac surgery has not been readily reported.