Purpose: This purpose of this prospective study was to use a continuous glucose monitoring (CGM) system to evaluate the suitability of our institution's glucose management protocol after cardiovascular surgery and to clarify the impact of glycemic variability on postoperative complications.
Methods: In all, 76 patients who underwent elective cardiovascular surgery and were monitored perioperatively using a CGM system were evaluated. Postoperative glucose management consisted of continuous intravenous insulin infusion (CIII) in the intensive care unit, and subcutaneous insulin injections (SQII) after oral food intake started. CIII and subcutaneous injections were initiated when blood glucose level exceeded 150 mg/dL. CGM data were used to analyze perioperative glycemic variability and association with postoperative complications.
Results: Target glucose levels (71-180 mg/dL) were achieved during 97.1 ± 5.5% and 86.4 ± 19.0% of the continuous insulin infusion and subcutaneous injection periods, respectively. Major postoperative complications were surgical site infections, found in 6.6% of total patients, and atrial fibrillation, found in 44% of patients with off-pump coronary artery bypass grafting. High glycemic variability during SQII was associated with increased risk for both complications.
Conclusion: Data analysis revealed that our glucose management protocol during CIII was adequate. However, the management protocol during SQII required improvement.
Keywords: cardiac surgery; continuous glucose monitoring; glucose management protocol; glycemic variability; operative morbidity.