Abdelmageed Waleed M, Elquesny Kaled M, Shabana Ramadn I, Abushama Hossam M, Nassar Ahmad M
Department of Anesthesia, Faculty of Medicine, Ain-Shams University, Cairo, Egypt.
Saudi J Anaesth. 2011 Apr;5(2):150-6. doi: 10.4103/1658-354X.82782.
Dexmedetomidine is an alpha(2) -adrenergic agonist with sedative and analgesic properties. This study aimed to investigate if the use of a continuous dexmedetomidine infusion with i.v. morphine patient-controlled analgesia (PCA) could improve postoperative analgesia while reducing opioid consumption and opioid-related side effects.
In this prospective randomized, double-blinded, controlled study, 39 patients with obstructive sleep apnea syndrome undergoing uvulopalatopharyngoplasty were assigned to two groups. Group D (dexmedetomidine group) received a loading dose of dexmedetomidine 1 μg.kg(-1) i.v., 30 minutes before the anticipated end of surgery, followed by infusion at 0.6 μg.kg(-1) h(-1) for 24 hours. Group P (placebo group) received a bolus and infusion of placebo. In both groups, postoperative pain was initially controlled by i.v. morphine titration and then PCA with morphine. Cumulative PCA morphine consumption, pain intensities, sedation scores, cardiovascular and respiratory variables and opioid-related adverse effects were recorded for 48 hours after operation.
Compared with placebo group, patients in the dexmedetomidine group required 52.7% less PCA morphine during the first 24 hours postoperatively, with significantly better visual analogue scale scores, less incidence of respiratory obstruction (5 vs. 12 patients, respectively; P = .037) and longer time to first analgesic request (21 (11) vs. 9 (4) minutes; P = .002). Fewer patients in group D experienced nausea and vomiting than those in group P (7 vs. 24 patients, respectively; P < .05).
Continuous dexmedetomidine infusion may be a useful analgesic adjuvant for patients susceptible to opioid-induced respiratory depression.
右美托咪定是一种具有镇静和镇痛特性的α₂肾上腺素能激动剂。本研究旨在探讨持续静脉输注右美托咪定联合静脉注射吗啡患者自控镇痛（PCA）是否能改善术后镇痛效果，同时减少阿片类药物的用量及与阿片类药物相关的副作用。
在这项前瞻性随机、双盲、对照研究中，39例接受悬雍垂腭咽成形术的阻塞性睡眠呼吸暂停综合征患者被分为两组。D组（右美托咪定组）在预计手术结束前30分钟静脉注射负荷剂量右美托咪定1μg·kg⁻¹，随后以0.6μg·kg⁻¹·h⁻¹的速度输注24小时。P组（安慰剂组）接受安慰剂推注和输注。两组术后疼痛最初均通过静脉注射吗啡滴定控制，然后采用吗啡PCA。记录术后48小时内PCA吗啡的累积用量、疼痛强度、镇静评分、心血管和呼吸变量以及与阿片类药物相关的不良反应。
与安慰剂组相比，右美托咪定组患者术后前24小时PCA吗啡用量减少52.7%，视觉模拟评分显著更好，呼吸梗阻发生率更低（分别为5例和12例；P = 0.037），首次镇痛需求时间更长（分别为21（11）分钟和9（4）分钟；P = 0.002）。D组恶心和呕吐的患者少于P组（分别为7例和24例；P < 0.05）。
持续输注右美托咪定可能是对阿片类药物引起的呼吸抑制易感患者有用的镇痛辅助药物。
