A comparison among infusion of lidocaine and dexmedetomidine alone and in combination in subjects undergoing coronary artery bypass graft: A randomized trial

Background: Previous studies have reported the cardioprotective effect of dexmedetomidine and lidocaine. We compared the effect of lidocaine and dexmedetomidine infusion during off-pump coronary artery bypass graft (OPCAB). Methods: 153 patients undergoing OPCAB were enrolled. The lidocaine group (n. =. 36, Group LIDO) received an infusion of lidocaine 2. mg/kg/h after bolus 1.5. mg/kg; the dexmedetomidine group (n. =. 40, Group DEX) received dexmedetomidine 0.3-0.7. μg/kg/h; the combined group (n. =. 39, Group Combined) received infusion of both drugs; and the control group (n. =. 38) received nothing. We measured serum creatinine kinase-myocardial band (CK-MB) and cardiac troponin I (cTnI) concentration before and immediately after the surgery, postoperative day (POD)#1 and #2. The complication rate and clinical outcomes were compared. Results: The concentration of cTnI was significantly lower in the Group LIDO and Group Combined than the control group on POD#2. The concentration of CK-MB was significantly lower in the Group LIDO and Group Combined compared to the control group on POD#1 and #2 [CK-MB on POD#1: 7.67 (5.78-11.92) vs. 7.18 (5.01-11.72) vs. 13.19 (6.85-23.87) in the Group LIDO, combined and control, respectively, Group LIDO vs. control: p. =. 0.003, Group Combined vs. control: p. =. 0.015]. The AUC of CK-MB was significantly lower in the Group LIDO and Group Combined than the control group. However, clinical variables including complication rate, ICU stay and one-year mortality were not different. Conclusions: Lidocaine infused at 2. mg/kg/h, but not dexmedetomidine infused at 0.3-0.7. μg/kg/h reduced postoperative myocardial injury marker levels compared with the control group. However, no other clinical benefits were observed.