Effect of dexmedetomidine on pulmonary nuclear factor-κB pathway in patients undergoing minimally invasive coronary artery bypass grafting

Objective To observe the effect of dexmedetomidine on pulmonary nuclear factor-κB (NF-κB) signaling pathway in patients undergoing minimally invasive coronary artery bypass grafting. Methods Twenty-two patients undergoing minimally invasive coronary artery bypass grafting were randomly divided into dexmedetomidine group and control group. The intravenous general anesthesia was induced in both groups and maintained by intravenous infusion of propofol and sufentanil, and intermittent intravenous injection of cisatracurium was done. In dexmedetomidine group, dexmedetomidine was intravenously pumped at 1.0 μg/(kg·h) for 10 min before anesthesia induction, and then continuously intravenously pumped at 0.5 μg/(kg·h) for maintenance. The control group received the same amount of normal saline at the same time. 4 ml of jugular vein blood was collected at T1 (after tracheal intubation), T2 (before one lung ventilation, 30 min of anastomosis), T3 (immediate after double lung ventilation), T4 (6 h after operation) and T5 (3 days after operation). The concentrations of HMGB1 and NF-κB in plasma and alveolar lavage fluid were determined by enzyme-linked immunosorbent assay (ELISA) at T1-T3 time points. Results The plasma levels of HMGB1 and NF-κB in the dexmedetomidine group were lower than those in the control group at T3, T4 and T5 (for HMGB1: 1.81±0.09 vs. 2.45±0.13, P=0.010; 2.25±0.16 vs. 3.52±0.21, P=0.001; 2.17±0.20 vs. 3.48±0.23, P=0.001. for NF-κB: 40.05±1.85 vs. 84.62±3.25, P=0.001; 45.52±1.21 vs. 96.21±2.36, P=0.010; 43.48±1.23 vs. 88.53±2.12, P=0.001). The levels of HMGB1 and NF-κB in the lung lavage fluid of dexmedetomidine group were lower than those in the control group (for HMGB1 at T2 and T3: 3.78±0.67 vs. 5.14±0.85, P=0.001; 4.83±0.64 vs. 8.25±1.13, P=0.001. For NF-κB: 50.02±2.13 vs. 66.60±2.27, P=0.001; 62.01±2.85 vs. 86.61±3.15, P=0.001). Conclusion Dexmedetomidine may exert its anti-inflammatory effects by decreasing HMGB1 and NF-κB levels and inhibiting NF-κB signaling pathway in patients undergoing minimally invasive coronary artery bypass grafting. Key words: Dexmedetomidine; Minimally invasive coronary artery bypass grafting; Nuclear factor-κB