Effect of intravenous lidocaine on nociception level-directed management in robot-assisted laparoscopic radical prostatectomy: protocol for a single-centre, factorial-randomised controlled trial (VALINOR study).
To evaluate the efficacy of intra-operative lidocaine administration combined with nociception level-guided opioid management and to compare two minimum remifentanil infusion rate limits (0.11 vs. 0.05 μg.kg¹.min¹) during robot-assisted radical prostatectomy. Single-centre, double-blinded, two-by-two factorial randomised controlled trial. Operating theatres at Nara Medical University Hospital, Nara, Japan. Eighty-four adult patients scheduled for elective robot-assisted radical prostatectomy were participated in the study. Participants will be randomised into four groups (lidocaine/0.11, lidocaine/0.05, placebo/0.11 and placebo/0.05). All groups will receive nociception level-guided intra-operative opioid management. The primary outcome is the numerical rating scale score during movement 2 hours after surgery. Secondary outcomes include plasma concentrations of peri-operative inflammatory biomarkers (interleukin-6, cortisol and C-reactive protein), intra-operative remifentanil consumption, Quality of Recovery-15 scores (pre-operative and postoperative days 1 and 2), postoperative numerical rating scale scores up to postoperative day 7, peri-operative fentanyl consumption and the presence of prolonged postoperative pain at 3 months. Lidocaine will decrease intra-operative remifentanil requirements and early postoperative pain without increasing the inflammatory biomarker levels and the minimum remifentanil infusion rate limit will not significantly impact clinical outcomes. This trial will evaluate the effects of intra-operative lidocaine administration and minimum remifentanil infusion rate limit based on nociception level-guided opioid management in patients undergoing robot-assisted radical prostatectomy. Japan Registry of Clinical Trials, jRCTs052240226 (registered on 26 December 2024, https://jrct.mhlw.go.jp/latest-detail/jRCTs052240226). This protocol was approved by the Certified Review Board of Nara Medical University on 11 December 2024 (nara0063). Recruitment is planned from January 2025 to December 2026, with final follow-up completed in March 2027.