Effect of preoperative gabapentin on pain intensity and development of chronic pain after carpal tunnel syndrome surgical treatment in women: randomized, double-blind, placebo-controlled study

ABSTRACT CONTEXT AND OBJECTIVES: Effective postoperative analgesia is important for reducing the incidence of chronic pain. This study evaluated the effect of preoperative gabapentin on postoperative analgesia and the incidence of chronic pain among patients undergoing carpal tunnel syndrome surgical treatment. DESIGN AND SETTINGS: Randomized, double-blind controlled trial, Federal University of São Paulo Pain Clinic. METHODS: Forty patients aged 18 years or over were randomized into two groups: Gabapentin Group received 600 mg of gabapentin preoperatively, one hour prior to surgery, and Control Group received placebo. All the patients received intravenous regional anesthesia comprising 1% lidocaine. Midazolam was used for sedation if needed. Paracetamol was administered for postoperative analgesia as needed. Codeine was used additionally if the paracetamol was insufficient. The following were evaluated: postoperative pain intensity (over a six-month period), incidence of postoperative neuropathic pain (over a six-month period), need for intraoperative sedation, and use of postoperative paracetamol and codeine. The presence of neuropathic pain was established using the DN4 (Douleur Neuropathique 4) questionnaire. Complex regional pain syndrome was diagnosed using the Budapest questionnaire. RESULTS: No differences in the need for sedation, control over postoperative pain or incidence of chronic pain syndromes (neuropathic or complex regional pain syndrome) were observed. No differences in postoperative paracetamol and codeine consumption were observed. CONCLUSIONS: Preoperative gabapentin (600 mg) did not improve postoperative pain control, and did not reduce the incidence of chronic pain among patients undergoing carpal tunnel syndrome surgery.

研究背景与目标：有效的术后镇痛对于降低慢性疼痛的发生率具有重要意义。本研究旨在评估术前应用加巴喷丁对接受腕管综合征手术治疗患者的术后镇痛效果及慢性疼痛发生率的影响。
研究设计与实施场景：随机双盲对照试验，巴西圣保罗联邦大学疼痛门诊。
研究方法：本研究纳入40名年龄≥18岁的患者，随机分为两组：加巴喷丁组于术前1小时口服600mg加巴喷丁，对照组给予安慰剂。所有患者均接受包含1%利多卡因的静脉区域麻醉，必要时给予咪达唑仑进行镇静。术后必要时给予对乙酰氨基酚镇痛，若对乙酰氨基酚镇痛效果不佳，则额外加用可待因。本研究评估的指标包括术后6个月内的疼痛强度、术后6个月内的神经病理性疼痛发生率、术中镇静需求，以及术后对乙酰氨基酚与可待因的使用量。神经病理性疼痛的诊断采用DN4（Douleur Neuropathique 4）问卷进行评估，复杂区域疼痛综合征则采用布达佩斯问卷进行诊断。
研究结果：未观察到两组在术中镇静需求、术后疼痛控制效果或慢性疼痛综合征（神经病理性或复杂区域疼痛综合征）发生率方面存在显著差异；两组术后对乙酰氨基酚与可待因的使用量亦无显著差异。
研究结论：术前给予600mg加巴喷丁未能改善腕管综合征手术患者的术后疼痛控制效果，亦未降低其慢性疼痛的发生率。