Department of Anaesthesia and Pain Medicine, King Edward Memorial Hospital for Women, Subiaco, Western Australia, Australia.
Int J Obstet Anesth. 2013 Jan;22(1):47-51. doi: 10.1016/j.ijoa.2012.10.007. Epub 2012 Dec 7.
Most patients undergoing caesarean delivery with general anaesthesia require systemic opioid administration. Due to its rapid onset and long duration of action, intravenous methadone may make it suitable for analgesia after caesarean delivery. Intraoperative methadone combined with postoperative intravenous patient-controlled analgesia with fentanyl or morphine has recently been introduced in our unit.
A retrospective case-control study of 25 patients who had received methadone was performed. Fifty control patients undergoing elective or emergency caesarean delivery were matched for the use of postoperative intravenous patient-controlled analgesia, transversus abdominis plane (TAP) block and regular non-steroidal anti-inflammatory drugs. Exclusion criteria included preoperative neuraxial analgesia or pre-delivery opioid consumption greater than 10 mg of intravenous morphine equivalents.
Patients in the methadone group had lower pain scores and were less likely to require intravenous opioid supplementation in the post-anaesthetic care unit (P<0.001). Opioid consumption over 48 h was significantly lower in the methadone group. Delayed discharge from the post-anaesthesia care unit was due to sedation in one patient in the methadone group compared to three control patients in whom it was due to sedation and inadequate analgesia.
A single intraoperative bolus of intravenous methadone appeared to provide effective analgesia with an acceptable side-effect profile.
大多数接受全身麻醉剖宫产的患者需要给予阿片类药物全身给药。由于其起效迅速、作用时间长，静脉注射美沙酮可能使其适合剖宫产术后镇痛。我们科室最近引入了术中给予美沙酮联合术后静脉自控镇痛给予芬太尼或吗啡。
对 25 例接受美沙酮治疗的患者进行了回顾性病例对照研究。50 例接受择期或急诊剖宫产的对照患者在术后静脉自控镇痛、腹横肌平面（TAP）阻滞和常规非甾体抗炎药的使用方面进行了匹配。排除标准包括术前椎管内镇痛或分娩前阿片类药物使用量超过 10 毫克静脉吗啡等效物。
美沙酮组患者疼痛评分较低，麻醉后恢复室（PACU）中需要静脉给予阿片类药物补充的可能性较低（P<0.001）。美沙酮组的阿片类药物消耗在 48 小时内明显较低。与 3 例因镇静和镇痛不足而延迟离开 PACU 的对照患者相比，美沙酮组有 1 例患者因镇静而延迟离开 PACU。
单次术中静脉注射美沙酮似乎可以提供有效的镇痛，且具有可接受的不良反应谱。
