Department of Anesthesiology and Critical Care, Arak University of Medical Sciences, Arak, Iran.
Department of Orthopedic Surgery, Arak University of Medical Sciences, Arak, Iran.
Med Gas Res. 2020 Jan-Mar;10(1):1-7. doi: 10.4103/2045-9912.279977.
Dexmedetomidine (DEX) can prolong duration of anesthesia and shorten onset of sensory and motor block relative to clonidine. This study attempted to compare the efficacy of intravenous DEX and clonidine for hemodynamic changes and block after spinal anesthesia with ropivacaine in lower limb orthopedic surgery. In a double-blind randomized clinical trial, 120 patients undergoing spinal anesthesia in lower limb orthopedic surgery were recruited and divided into three groups using balanced block randomization: DEX group (n = 40; intravenous DEX 0.2 µg/kg), clonidine group (n = 40; intravenous clonidine 0.4 µg/kg), and placebo group (n = 40; intravenous normal saline 10 mL) in which pain scores were assessed using visual analogue scales (at recovery, and 2, 4, 6, and 12 hours after surgery) and time to achieve and onset of sensory and motor block. Statistically significant differences were found in mean arterial pressure among the groups at all times except baseline (P = 0.001), with a less mean arterial pressure and a prolonged duration of sensory and motor block (P = 0.001) in the DEX group where pain relieved in patients immediately after surgery and at above mentioned time points (P = 0.001). Simultaneous administration of intravenous DEX with ropivacaine for spinal anesthesia prolongs the duration of sensory and motor block and relieves postoperative pain, and however, can decrease blood pressure. Although intravenous DEX as an adjuvant can be helpful during spinal anesthesia with ropivacaine, it should be taken with caution owing to a lowering of mean arterial pressure in patients especially in the older adults. This study was approved by Ethical Committee of Arak University of Medical Sciences (No. IR.Arakmu.Rec.1395.450) in March, 2017, and the trial was registered and approved by the Iranian Registry of Clinical Trials (IRCT No. IRCT2017092020258N60) in 2017.
右美托咪定（DEX）可延长麻醉时间，并缩短感觉和运动阻滞的起效时间相对于可乐定。本研究试图比较静脉内 DEX 和可乐定用于下肢矫形外科罗哌卡因脊麻后对血流动力学变化和阻滞的影响。在一项双盲随机临床试验中，招募了 120 例接受下肢矫形外科脊麻的患者，并使用平衡块随机化将其分为三组：DEX 组（n = 40；静脉内 DEX 0.2μg/kg）、可乐定组（n = 40；静脉内可乐定 0.4μg/kg）和安慰剂组（n = 40；静脉内生理盐水 10mL），使用视觉模拟评分法（在恢复时以及手术后 2、4、6 和 12 小时）评估疼痛评分，并评估感觉和运动阻滞的起效时间。除基线外（P=0.001），所有时间点的平均动脉压在组间均存在统计学差异，DEX 组的平均动脉压低，感觉和运动阻滞持续时间延长（P=0.001），患者在手术后立即和上述各时间点疼痛缓解（P=0.001）。罗哌卡因脊麻时同时静脉内给予 DEX 可延长感觉和运动阻滞的持续时间并缓解术后疼痛，但会降低血压。虽然静脉内 DEX 作为佐剂在罗哌卡因脊麻时可能会有所帮助，但由于患者特别是老年人的平均动脉压低，因此应谨慎使用。本研究于 2017 年 3 月获得阿拉克医科大学伦理委员会的批准（编号：IR.Arakmu.Rec.1395.450），并于 2017 年由伊朗临床试验注册中心（IRCT 编号：IRCT20170920258N60）注册和批准。
