近一半的乳腺癌手术患者会经历术后疼痛。胸神经筋膜间平面 (PECS) 阻滞以及右美托咪定可以缓解这种疼痛。在机构伦理委员会批准并书面知情同意后，这项随机、双盲研究针对 60 名 18-60 岁女性患者进行，计划在全身麻醉下进行改良根治性乳房切除术（MRM）的患者。患者被随机分为 L 组（20 ml 0.25% 左布比卡因）和 DL 组（20 ml 0.25% 左布比卡因加 0.5 µg/kg 右美托咪定）。切除肿瘤并止血后，在严格的无菌操作下，由手术医生在直视下在胸大肌和胸小肌之间注射10 ml研究药物，在胸小肌和前锯肌之间注射10 ml研究药物（直接PECS阻滞） ）。主要结果是比较镇痛持续时间。使用Student t 检验比较正态分布变量，使用Mann-Whitney U 检验比较非正态分布变量。使用卡方/费舍尔精确检验分析定性数据。统计显着性保持在 P < 0.05。 L 组首次需要镇痛的中位时间为 8 [四分位距 (IQR)：6-8] h，DL 组为 18 (IQR：16-20) h（ W = 17.000，P < 0.001）。 L 组前 24 小时平均阿片类药物总消耗量为 12.53 [标准差 (SD): 2.29] mg，DL 组为 6.93 (SD: 1.89) mg。在 20 ml 左布比卡因中添加 0.5 μg/kg 右美托咪定可增强接受 MRM 的患者直接 PECS 阻滞的镇痛持续时间。版权所有：© 2024 Indian Journal of Anaesthesia。

Nearly half of the patients following breast cancer surgery experience postoperative pain. The interfascial plane for the pectoral nerve (PECS) block, along with dexmedetomidine, can alleviate this pain.After institutional ethics committee clearance and written informed consent, this randomised, double-blind study was conducted on 60, 18-60 years female patients, who were scheduled for modified radical mastectomy (MRM) under general anaesthesia. Patients were randomised into Group L (20 ml of 0.25% levobupivacaine) and Group DL (20 ml of 0.25% levobupivacaine with 0.5 µg/kg of dexmedetomidine). After resection of the tumour and securing haemostasis, under strict aseptic precaution, 10 ml of the study drug was injected under direct vision between the pectoralis major and pectoralis minor and 10 ml between pectoralis minor and serratus anterior muscles by the operating surgeon (direct PECS block). The primary outcome was to compare the duration of analgesia. Normally distributed variables were compared using Student's t-test, and non-normally distributed variables were compared using the Mann-Whitney U-test. Qualitative data were analysed using Chi-square/Fisher's exact test. Statistical significance was kept at P < 0.05.The median time of the first analgesic requirement was 8 [inter-quartile range (IQR): 6-8] h in Group L and 18 (IQR: 16-20) h in Group DL (W = 17.000, P < 0.001). The mean total opioid consumption of Group L was 12.53 [standard deviation (SD): 2.29] mg in the first 24 h and 6.93 (SD: 1.89) mg in Group DL.Adding 0.5 μg/kg dexmedetomidine to 20 ml of levobupivacaine enhances the duration of analgesia of direct PECS block in patients undergoing MRM.Copyright: © 2024 Indian Journal of Anaesthesia.