The Nociception Level index (NOL™) is a multiparameter index, based on artificial intelligence for the monitoring of nociception during anesthesia. We studied the influence of NOL-guided analgesia on postoperative pain scores in patients undergoing major abdominal surgery during sevoflurane/fentanyl anesthesia. This study was designed as a single-center, prospective randomized, controlled study. After Institutional Review Board approval and written informed consent, 75 ASA 1–3 adult patients undergoing major abdominal surgery, were randomized to NOL-guided fentanyl dosing (NOL) or standard care (SOC) and completed the study. The sevoflurane target MAC range was 0.8–1.2. In the NOL-guided group (N = 36), when NOL values were > 25 for at least 1 min, a weight adjusted fentanyl bolus was administered. In the control group (N = 39) fentanyl administration was based on hemodynamic indices and clinician judgement. After surgery, pain, was evaluated using the Numerical Rating Scale (NRS) pain scale, ranging from 0 to 10, at 15 min intervals for 180 min or until patient discharge from the PACU. Median postoperative pain scores reported were 3.0 [interquartile range 0.0–5.0] and 5.0 [3.0–6.0] at 90 min in NOL-guided and control groups respectively (Bootstrap corrected actual difference 1.5, 95% confidence interval 0.4–2.6). There was no difference in postoperative morphine consumption or intraoperative fentanyl consumption. Postoperative pain scores were significantly improved in nociception level index-guided patients. We attribute this to more objective fentanyl dosing when timed to actual nociceptive stimuli during anesthesia, contributing to lower levels of sympathetic activation and surgical stress. Clinicaltrials.gov identifier: NCT03970291 date of registration May 31, 2019.

伤害感受水平指数 (NOL™) 是一个多参数指数，基于人工智能，用于监测麻醉期间的伤害感受。我们研究了七氟烷/芬太尼麻醉期间 NOL 引导镇痛对接受腹部大手术患者术后疼痛评分的影响。本研究设计为单中心、前瞻性随机对照研究。在机构审查委员会批准和书面知情同意后，75 名接受腹部大手术的 ASA 1-3 成年患者被随机分配到 NOL 指导的芬太尼剂量 (NOL) 或标准治疗 (SOC) 并完成了研究。七氟醚目标 MAC 范围为 0.8–1.2。在 NOL 指导组 (N = 36) 中，当 NOL 值 > 25 至少 1 分钟时，给予经过体重调整的芬太尼推注。在对照组 (N = 39) 中，芬太尼给药基于血液动力学指标和临床医生判断。手术后，使用数值评定量表 (NRS) 疼痛量表评估疼痛，​​范围从 0 到 10，以 15 分钟的间隔持续 180 分钟或直到患者从 PACU 出院。NOL 指导组和对照组在 90 分钟时报告的中位术后疼痛评分分别为 3.0 [四分位数范围 0.0-5.0] 和 5.0 [3.0-6.0]（Bootstrap 校正实际差异 1.5，95% 置信区间 0.4-2.6）。术后吗啡消耗量或术中芬太尼消耗量没有差异。伤害感受水平指数指导的患者术后疼痛评分显着改善。我们将此归因于在麻醉期间根据实际的伤害性刺激定时给予更客观的芬太尼剂量，有助于降低交感神经激活和手术应激水平。Clinicaltrials.gov 标识符：NCT03970291，注册日期为 2019 年 5 月 31 日。