Kumagai Motoi, Yamada Naoto, Wakimoto Masahiro, Ogawa Shohei, Watanabe Sho, Sato Kotaro, Suzuki Kenji S
Department of Anesthesiology, School of Medicine, Iwate Medical University Hospital, 2-1-1 Idai-dori, Yahaba-cho, Japan.
Department of Orthopedic Surgery, School of Medicine, Iwate Medical University, Yahaba-cho, Japan.
J Clin Monit Comput. 2025 Jan 29. doi: 10.1007/s10877-025-01264-4.
The analgesia nociception index (ANI), also referred to as the high frequency variability index (HFVI), is reported to be an objective measure of nociception. This study investigated changes in ANI after peripheral nerve blocks (PNB) under general anesthesia. Understanding these changes could enhance assessment of PNB efficacy before emergence from general anesthesia.
This study enrolled 30 patients undergoing elective upper limb surgery. After surgery, median and maximum ANI values were recorded during two periods: a 5-minute period before PNB and a 20-minute period after PNB. The numeric rating scale (NRS) for pain was assessed twice: immediately after emergence from general anesthesia (N1) and the maximum pain experienced by the following morning after PNB effects subsided (N2). The difference in ANI before and after PNB was tested using the Wilcoxon signed-rank test. Statistical significance was set at P < 0.05.
The ANI significantly increased after PNB in both the median (pre vs. post PNB value: 53.5 [44.0-68.0] vs. 59.0 [47.0-78.3], median [interquartile range]; P < 0.05) and maximum values (64.0 [56.3-79.5] vs. 74.5 [61.5-85.3]; P < 0.01). Secondary analysis revealed that significant ANI increases in both median (48.0 [42.3-66.5] vs. 61.0 [50.0-76.5]; P < 0.01) and maximum values (58.5 [50.3-75.3] vs. 76.0 [71.8-83.5]; P < 0.01) in the 18 cases with N2 ≥ 4 whereas no statistical differences were observed in the 12 cases with N2 < 4.
The increased ANI value after PNB under propofol anesthesia may be a valuable indicator for assessing PNB efficacy.
UMIN000050334.
February 28, 2023.
镇痛伤害感受指数（ANI），也被称为高频变异性指数（HFVI），据报道是一种伤害感受的客观测量指标。本研究调查了全身麻醉下外周神经阻滞（PNB）后ANI的变化。了解这些变化有助于在全身麻醉苏醒前评估PNB的疗效。
本研究纳入了30例行择期上肢手术的患者。术后，在两个时间段记录ANI的中位数和最大值：PNB前5分钟和PNB后20分钟。疼痛数字评分量表（NRS）评估两次：全身麻醉苏醒后立即评估（N1）以及PNB效果消退后次日早晨经历的最大疼痛程度（N2）。使用Wilcoxon符号秩检验来测试PNB前后ANI的差异。设定统计学显著性为P < 0.05。
PNB后ANI的中位数（PNB前与PNB后值：53.5 [44.0 - 68.0] 对 59.0 [47.0 - 78.3]，中位数 [四分位间距]；P < 0.05）和最大值（64.0 [56.3 - 79.5] 对 74.5 [61.5 - 85.3]；P < 0.01）均显著增加。二次分析显示，在N2≥4的18例患者中，ANI的中位数（48.0 [42.3 - 66.5] 对 61.0 [50.0 - 76.5]；P < 0.01）和最大值（58.5 [50.3 - 75.3] 对 76.0 [71.8 - 83.5]；P < 0.01）均显著增加，而在N2 < 4的12例患者中未观察到统计学差异。
丙泊酚麻醉下PNB后ANI值升高可能是评估PNB疗效的一个有价值指标。
UMIN000050334。
2023年2月28日。
