The effect of opioid-free anesthesia on the quality of recovery after gynecological laparoscopy: study protocol for a prospective randomized controlled trial

BACKGROUND: Because of the indiscriminate use of opioids during the perioperative period, opioid-free anesthesia (OFA) has been increasingly required. Nevertheless, the studies on the detailed techniques and effects of OFA are not sufficient. The Quality of Recovery-40 (QoR-40) questionnaire is a validated assessment tool for measuring recovery from general anesthesia. However, no study has used the QoR-40 to determine if OFA leads to better recovery than standard general anesthesia. Therefore, we aim to perform this study to determine the effects of OFA using dexmedetomidine and lidocaine on the quality of recovery as well as the various postoperative outcomes. METHODS: The participants (n = 78) will be allocated to one of the two groups; the study group will receive bolus and infusion of dexmedetomidine and lidocaine, and the control group will receive remifentanil infusion during general anesthesia for gynecological laparoscopy. The other processes including anesthetic and postoperative care will be performed similarly in the two groups. Intraoperative hemodynamic, anesthetic, and nociceptive variables will be recorded. Postoperative outcomes such as QoR-40, pain severity, and opioid-related side effects will be assessed. Additionally, an ancillary cytokine study (inflammatory cytokine, stress hormone, and reactive oxygen species) will be performed during the study period. DISCUSSION: This will be the first study to determine the effect of OFA, using the combination of dexmedetomidine and lidocaine, on the quality of recovery after gynecological laparoscopy compared with standard general anesthesia using remifentanil. The findings from this study will provide scientific and clinical evidence on the efficacy of OFA. TRIAL REGISTRATION: ClinicalTrials.gov NCT04409964. Registered on 28 May 2020