Effect of opioid titration protocol using nociception monitors in gynecologic laparoscopic surgery with total hysterectomy: A randomized controlled trial (OPTIMIST-h study)

Study objective: This study aims to assess the importance of administering opioids appropriately based on nociceptive monitoring. Design: Randomized controlled trial. Setting: Single center, operating room. Patients: The study will include 75 patients scheduled to undergo a robot-assisted or total laparoscopic hysterectomy (TLH). Interventions: Patients will be allocated randomly to receive nociception level-directed intraoperative opioid management, high-frequency variability index-directed management, or conventional intraoperative analgesic management (control group). Measurements: The primary outcome will be the mean intraoperative remifentanil infusion flow rate (intraoperative remifentanil usage [μg] divided by ideal body weight [kg] and operation time [min]). The secondary outcomes will be the plasma concentrations of 3 perioperative inflammatory biomarkers (interleukin-6, C-reactive protein, and cortisol), Quality of Recovery-15 scores (preoperative and postoperative days 1 and 2), postoperative fentanyl consumption, postoperative pain (numeric rating scale) scores (2 hours postoperatively and on postoperative days 1, 2, and 3), and presence of chronic postsurgical pain. Main results: We expect that the patients in the intervention groups will have reduced intraoperative remifentanil usage without worsening inflammatory markers, numeric rating scale scores, or Quality of Recovery-15 scores compared with those in the control group. The results of this study may provide important insights into analgesic dose-adjustment strategies using nociception monitors in TLH. Conclusion: This trial will evaluate the effects of nociception monitor-directed opioid management and investigate perioperative levels of interleukin-6, cortisol, and C-reactive protein. In addition, this study is expected to compare monitors, including sedation monitors combined with nociception monitors, in TLH.