Effect of Continuous Intraoperative Dexmedetomidine on Interleukin-6 and Other Inflammatory Markers After Coronary Artery Bypass Graft Surgery: A Randomized Controlled Trial

<i>Background and Objectives:</i> Coronary artery bypass graft (CABG) surgery is the most common cardiac surgery. One of the main causes of postoperative complications and increased mortality after CABG is the inflammatory response. The aim of this study was to investigate whether continuous intraoperative dexmedetomidine can reduce the increase of IL-6 and other inflammatory markers after CABG surgery. <i>Materials and Methods:</i> The study is registered with ClinicalTrials.gov, NCT06378827, accessed on 23 April 2024. This prospective experimental study was conducted from April to December 2024 and included 100 patients undergoing CABG surgery. Patients in the experimental group (50 patients) received a continuous infusion of dexmedetomidine (0.5 μg/kg/h) from anesthesia induction until the end of surgery, while the patients in the control group (50 patients) received the same volume of saline. The primary outcomes were the changes in the values of interleukin-6 (IL-6), C-reactive protein (CRP), white blood cells (WBC), and fibrinogen on the first postoperative day (POD1) compared to the basal, preoperative values. <i>Results:</i> The patients in the control group were on average 65.26 years old, and the patients in the experimental group were 66.28 years old (<i>p</i> = 0.555). From the control group, 40 (80%) patients were male compared to 37 (74%) patients from the experimental group (<i>p</i> = 0.635). Median IL-6 before surgery was 2.0 pg/mL, while on POD 1 it was 76.2 pg/mL (<i>p</i> < 0.001). Median CRP before surgery was 2.5 mg/dL, while the POD1 value was 45.5 mg/dL (<i>p</i> < 0.001). Median WBC values were 6.7 × 10⁹/L before surgery and 13.6 × 10⁹/L on POD1 (<i>p</i> < 0.001). The average value of fibrinogen was 3.19 g/L before surgery, while on POD1 it was 3.37 g/L (<i>p</i> = 0.024). The increase in IL-6 on POD1 (ΔIL-6) was 72.4 pg/mL in the control group and 73.0 pg/mL in the experimental group (<i>p</i> = 0.427). ΔCRP was 41.2 mg/mL (control group) and 38.0 mg/mL (experimental group) (<i>p</i> = 0.725). ΔWBC was 7.45 × 10⁹/L (control group) and 6.81 × 10⁹/L (experimental group) (<i>p</i> = 0.407). Δfibrinogen was 0.16 g/L (control group) and 0.2 g/L (experimental group) (<i>p</i> = 0.771). <i>Conclusions:</i> Intraoperative administration of dexmedetodine during CABG surgery at a dose of 0.5 µg/kg/h without a loading dose does not lead to a decrease in the intensity of the inflammatory response after surgery.