nrolling academic centers with an upper or lower limb amputation and established phantom pain received a single-injection ropivacaine peripheral nerve block(s) and perineural catheter insertion(s). They were subsequently randomized to receive a 6-day ambulatory perineural infusion of either ropivacaine 0.5% or normal saline in a double-masked fashion. Participants were contacted by telephone 1, 7, 14, 21, and 28 days after the infusion started, with pain measured using the Numeric Rating Scale. Treatment effects were assessed using the Wilcoxon rank-sum test at each time point. Adjusting for 4 time points (days 1, 7, 14, and 21), P < .0125 was deemed statistically significant. Significance at 28 days was reported using methods from the original, previously published article. RESULTS: Pretreatment average phantom and residual pain scores were balanced between the groups. The day after infusion initiation (day 1), average phantom, and residual limb pain intensity was lower in patients receiving local anesthetic (n = 71) versus placebo (n = 73): median [quartiles] of 0 [0–2.5] vs 3.3 [0–5.0], median difference (98.75% confidence interval [CI]) of −1.0 (−3.0 to 0) for phantom pain (P = .001) and 0 [0–0] vs 0 [0–4.3], and median difference 0.0 (−2.0 to 0.0) for residual limb pain (P < .001). Pain’s interference with physical and emotional functioning as measured with the interference domain of the Brief Pain Inventory improved during the infusion on day 1 for patients receiving local anesthetic versus placebo: 0 [0–10] vs 10 [0–40], median difference (98.75% CI) of 0.0 (−16.0 to 0.0), P = .002. Following infusion discontinuation (day 6), a few differences were found between the active and placebo treatment groups between days 7 and 21. In general, sample medians for average phantom and residual limb pain scores gradually increased after catheter removal for both treatments, but to a greater degree in the control group until day 28, at which time the differences between the groups returned to statistical significance. CONCLUSIONS: This secondary analysis suggests that a continuous peripheral nerve block decreases phantom and residual limb pain during the infusion, although few improvements were again detected until day 28, 3 weeks following catheter removal....

中文翻译：

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连续外周神经阻滞对截肢后幻肢痛和残余肢体疼痛的直接影响：来自多中心随机对照临床试验的次要结果

注册上肢或下肢截肢并出现幻痛的学术中心接受单次注射罗哌卡因周围神经阻滞和神经周围导管插入。随后，他们被随机分配接受 6 天非卧床神经周围输注 0.5% 罗哌卡因或双盲方式生理盐水。在开始输注后 1、7、14、21 和 28 天通过电话联系参与者，并使用数字评定量表测量疼痛。在每个时间点使用 Wilcoxon 秩和检验评估治疗效果。调整 4 个时间点（第 1、7、14 和 21 天），P < .0125 被认为具有统计学意义。使用先前发表的原始文章中的方法报告了 28 天的显着性。结果：治疗前平均幻影和残留疼痛评分在各组之间保持平衡。输注开始后的第二天（第 1 天），接受局麻药的患者（n = 71）与安慰剂（n = 73）相比，平均幻影和残肢疼痛强度较低：中位数 [四分位数] 为 0 [0–2.5] 与3.3 [0–5.0]，幻肢痛 (P = .001) 和 0 [0–0] 与 0 [0–4.3] 的中位数差异（98.75% 置信区间 [CI]）为 -1.0（-3.0 到 0） ，残肢痛的中位数差异为 0.0（-2.0 至 0.0）（P < .001）。对于接受局麻药与安慰剂的患者，在第 1 天输注期间，疼痛对身体和情绪功能的干扰通过简短疼痛量表的干扰域有所改善：0 [0-10] 与 10 [0-40]，中值差异（ 98.75% CI) 为 0.0（-16.0 至 0.0），P = .002。停止输注后（第 6 天），在第 7 天和第 21 天之间发现活性治疗组和安慰剂治疗组之间存在一些差异。一般而言，两种治疗在拔除导管后平均幻肢痛和残肢痛评分的样本中位数逐渐增加，但直到第 28 天，对照组的程度更高，此时各组之间的差异恢复到统计学显着性。结论：该次要分析表明，持续的周围神经阻滞可减少输注过程中的幻肢痛和残肢痛，尽管直到第 28 天，即拔除导管 3 周后才再次检测到改善。... 两种治疗方法在拔除导管后，平均幻肢痛和残肢痛评分的样本中位数逐渐增加，但在对照组中增加的程度更大，直到第 28 天，此时各组之间的差异恢复到统计学显着性。结论：该次要分析表明，持续的外周神经阻滞可减少输注过程中的幻肢痛和残肢痛，尽管直到第 28 天，即拔除导管 3 周后才再次检测到改善。... 两种治疗方法在拔除导管后，平均幻肢痛和残肢痛评分的样本中位数逐渐增加，但在对照组中增加的程度更大，直到第 28 天，此时各组之间的差异恢复到统计学显着性。结论：该次要分析表明，持续的外周神经阻滞可减少输注过程中的幻肢痛和残肢痛，尽管直到第 28 天，即拔除导管 3 周后才再次检测到改善。...