The effects of dexmedetomidine on thiol/disulphide homeostasis in coronary artery bypass surgery: a randomized controlled trial.

Background: Thiol-disulfide homeostasis (TDH) plays a pivotal role in various physiological mechanisms, including antioxidant defence, detoxification, apoptosis, regulation of enzyme activities and cellular signal transduction. TDH can be used as a biomarker to detect oxidative stress (OS) levels and ischemia status in the tissues. Coronary artery bypass grafting (CABG) surgery is a procedure associated with high oxidative stress. Dexmedetomidine, an alpha-2 agonist anaesthetic agent, has antioxidant effects. In this study, the effects of dexmedetomidine on oxidative stress in CABG surgery were investigated. Methods: Patients who underwent on-pump CABG surgery were divided into two groups: those receiving dexmedetomidine (Group D) and those not receiving dexmedetomidine (Group C). From anesthesia induction to the end of surgery, patients in Group D received intravenous infusions of 0.05–0.2 mcg/kg/min remifentanil and 0.2–0.7 mcg/kg/h dexmedetomidine. Patients in Group C received intravenous infusion of 0.05–0.2 mcg/kg/min remifentanil. Blood samples were collected from the patients 30 min before induction of anesthesia (T1), 30 min after removal of the aortic cross-clamp (T2), and at the end of the surgery (T3). Thiol-disulfide homeostasis (TDH) was assessed using a novel method. A novel automated method enables the determination of native thiols, total thiols and disulfides levels in plasma, allowing the calculation of their respective ratios. Results: In patients receiving dexmedetomidine, lower postoperative levels of disulfide, disulfide/native thiol, and disulfide/total thiol, along with higher native thiol/total thiol, were observed compared to the control group. (p < 0.05) Postoperative native thiol and total thiol levels were similar for both groups. (p > 0.05) Conclusions: In our study, through dynamic thiol-disulfide measurements, we found that levels of oxidative stress (OS) were lower in patients who received dexmedetomidine. We believe that the positive effects of dexmedetomidine on OS could be beneficial in CABG surgery. Furthermore, we anticipate that with further studies conducted in larger patient cohorts, the clinical utilization of dexmedetomidine will become more widespread. Trial registration number: NCT05895331 / 06.07.2023. [ABSTRACT FROM AUTHOR]