Influence of psychological factors and pain sensitivity on the efficacy of opioid-free anesthesia: A randomized clinical trial.

OBJECTIVE

This study aimed to investigate the effects of opioid-free anesthesia (OFA) in laparoscopic gastrectomy and identify the psychological factors that could influence the efficacy of OFA.

METHOD: 120 patients undergoing laparoscopic gastrectomy were allocated to either the opioid-based anesthesia group (OA) (n = 60) or the OFA (n = 60) group. Remifentanil was administered to the OA group intraoperatively, whereas dexmedetomidine and lidocaine were administered to the OFA group. The interaction effect of the psychological factors on OFA was analyzed using the aligned rank transform for nonparametric factorial analyses.

RESULTS

The opioid requirement for 24 h after surgery was lower in the OFA group than in the OA group (fentanyl equivalent dose 727 vs. 650 μg, p = 0.036). The effect of OFA was influenced by the pain catastrophizing scale (p = 0.041), temporal pain summation (p = 0.046), and pressure pain tolerance (p = 0.034). This indicates that patients with pain catastrophizing or high pain sensitivity significantly benefited from OFA, whereas patients without these characteristics did not.

CONCLUSIONS

This study demonstrated that OFA with dexmedetomidine and lidocaine effectively reduced the postoperative 24-h opioid requirements following laparoscopic gastrectomy, which was modified by baseline pain catastrophizing and pain sensitivity.

CLINICAL TRIAL REGISTRY: The study protocol was approved by the Institutional Review Board of Yonsei University Health System Gangnam Severance Hospital (#3-2021-0295) and registered at ClinicalTrials.gov (NCT05076903).