Intraoperative Insulin Infusion Regimen versus Insulin Bolus Regimen for Glucose Management during CABG Surgery: A Randomized Clinical Trial

Abstract

Background and Aim: The stress induced by surgery disrupts the delicate balance between hepatic glucose production and glucose utilization in the body. Despite the significance of intraoperative glycaemic control for diabetic patients, limited attention has been given to this aspect. Two methods for administering insulin to manage glucose levels during surgery exist. This study aimed to compare intraoperative glucose levels in diabetic patients undergoing Coronary Artery Bypass Graft (CABG) surgery using either insulin infusion or the bolus method. Method: This was a Randomized Clinical Trial (RCT). Seventy diabetic patients aged 40 or older scheduled for CABG surgery were enrolled in the trial. They were randomly assigned, using block randomization, to receive intraoperative insulin via either infusion or the bolus method. The primary outcome measure was intraoperative glucose levels. Subsequent insulin unit requirements and intraoperative potassium levels were secondary outcomes. Data was monitored throughout the CABG procedure and recorded at six different checkpoints. Results: Male patients constituted the majority in both groups, with no significant differences in the preoperative characteristics of patients, including HbA1c levels and comorbidities. The infusion regimen demonstrated a statistically significant reduction in glucose levels (-19.12 mg/dL, 95% CI: -27.68 to -10.55, P<0.001, Cohen's d=1.06) compared to the bolus regimen. The total insulin units administered in the infusion group were 480 units, as opposed to 600 units in the bolus group (P=0.001, Cohen's d=0.85). Importantly, no cases of hypoglycemia or hyperkalemia were reported among the patients. Conclusion: Intraoperative glucose control using insulin was effective for CABG patients with diabetes. However, the infusion regimen exhibited statistically superior results compared to the bolus regimen. Clinical Trials Registry and Registration Number: The trial received approval from the Ethics Committee on 2/1/2019/2020 and was registered on Clinicaltrials.gov under ID: NCT04824586.