Comparison of the effects of dexmedetomidine and lidocaine on postoperative analgesia and recovery characteristics: a meta-analysis of randomized controlled trials.
Dexmedetomidine and lidocaine are commonly used adjuvants in postoperative pain management; however, their comparative efficacy is unclear. This meta-analysis compared the effects of intravenous dexmedetomidine and lidocaine on postoperative analgesia and recovery. Cochrane Library, Medline, Embase, and Google Scholar were searched from their inception to July 1, 2024, to identify relevant randomized controlled trials (RCTs) comparing intravenous dexmedetomidine and lidocaine in adult patients undergoing non-cardiac surgery under general anesthesia. The primary outcomes were the postoperative pain score at 24 h and postoperative opioid consumption. The secondary outcomes included early postoperative pain scores, intraoperative opioid/anesthetic requirements, hemodynamic parameters, recovery characteristics, and inflammatory markers. Twenty-four studies (1,697 patients) were included. There was no significant difference between dexmedetomidine and lidocaine in terms of pain scores at 24 h (mean difference [MD]: 0.01, p = 0.88) or overall postoperative opioid consumption (standardized MD[SMD]: -0.51, p = 0.06). However, dexmedetomidine was associated with lower pain scores at 2-4 h postoperatively (MD:-0.41, p = 0.02), reduced intraoperative anesthetic agent requirements (SMD:-1.1, p = 0.004), a longer time to rescue analgesic (MD: -29.93 min, p < 0.00001), and improved quality of recovery scores (SMD: 1.72, p = 0.01). Dexmedetomidine resulted in lower heart rate and blood pressure compared to lidocaine, without differences in other recovery characteristics and inflammation. Both dexmedetomidine and lidocaine are effective adjuvants for improving postoperative outcomes. Nevertheless, dexmedetomidine has shown advantages in terms of early pain control, reduced anesthetic requirements, and improved quality of recovery. The choice of these agents should be based on individual patient factors and specific surgical procedures.