Effect of nociception level-directed analgesic management on opioid usage in robot-assisted laparoscopic radical prostatectomy: a single-center, single-blinded, randomized controlled trial.

Purpose: To assess the importance of appropriate opioid administration methods according to nociceptive monitoring.

Methods: We conducted a randomized controlled trial involving 54 patients who underwent robot-assisted laparoscopic radical prostatectomy at our hospital. Patients were randomly allocated to either receive nociception level (NOL)-directed intraoperative opioid management with a minimum flow of remifentanil (NOL group) or conventional intraoperative analgesic management (control group). The primary outcome was the mean intraoperative remifentanil infusion flow rate (intraoperative remifentanil usage [μg]/ideal body weight [kg]/operation time [min]). The main secondary outcomes were plasma concentrations of three perioperative inflammatory biomarkers (interleukin-6, C-reactive protein [CRP], and cortisol levels) and postoperative pain (Numeric Rating Scale [NRS]) scores 2 h postoperatively and on postoperative days 1, 2, 3, and 7.

Results: Compared with standard analgesia management, NOL-directed analgesic management reduced remifentanil consumption by 20% ( - 0.038; 95% confidence interval, - 0.059 to - 0.017; p = 0.0007). NOL-directed management did not lead to an increase in IL-6, CRP, or cortisol levels compared with conventional analgesic management. Furthermore, this protocol led to improvements in the NRS scores at rest 2 h postoperatively and upon movement up to postoperative day 3.

Conclusion: NOL-directed analgesic management reduced remifentanil consumption by 20% and the NRS scores at rest 2 h postoperatively and upon movement up to postoperative day 3 without an increase in inflammatory marker levels.

Registry number: Japan Registry of Clinical Trials, JRCTs052220034.