Goyagi T, Tanaka M, Nishikawa T
Department of Anesthesia, Akita University School of Medicine, Akita-shi, Akita-ken, Japan.
Can J Anaesth. 2000 Jul;47(7):627-30. doi: 10.1007/BF03018994.
To determine the effect of oral clonidine premedication on propofol requirement (ED(50)) for the insertion of the laryngeal mask airway (LMA) in healthy patients undergoing abdominal hysterectomy.
After ethics committee approval and informed consent, 41 patients were randomly assigned to receive 5 microg x kg(-1) clonidine po premedication 90 min before entering the operating room (n = 22), or no clonidine (n = 19). To alleviate pain associated with iv propofol, 3 ml lidocaine 2%iv were administered. General anesthesia was induced, 30 sec later, with propofol at a rate of 100 mg x min(-1) (600 ml x hr(-1)) iv. The dose of propofol at which insertion of the LMA was attempted was predetermined by modification of Dixon's up-and-down method with an initial dose of 2.5 mg x kg(-1) and 0.25 mg x kg(-1) as the step size. An LMA was inserted, without muscle relaxants or other adjuvants 90 sec after completion of the propofol injection, by an anesthesiologist blinded to the treatment of the patient.
The ED(50) of propofol for LMA insertion in clonidine-treated patients (2.0 +/- 0.2 mg x kg(-1), 1.8-2.3 mg x kg(-1) [95% confidence interval]), was less than that in patients without clonidine (2.5 +/- 0.1 mg x kg(-1), 2.4-2.6 mg x kg(-1), P < 0.01).
Oral clonidine premedication reduces propofol requirement for LMA insertion.
确定口服可乐定术前用药对行腹部子宫切除术的健康患者插入喉罩气道（LMA）时丙泊酚需求量（ED50）的影响。
经伦理委员会批准并获得知情同意后，41例患者被随机分为两组，一组在进入手术室前90分钟口服5μg·kg-1可乐定进行术前用药（n = 22），另一组不使用可乐定（n = 19）。为减轻静脉注射丙泊酚时的疼痛，静脉注射3ml 2%利多卡因。30秒后，以100mg·min-1（600ml·hr-1）的速度静脉注射丙泊酚诱导全身麻醉。插入LMA时尝试使用的丙泊酚剂量通过改良的Dixon上下法预先确定，初始剂量为2.5mg·kg-1，步长为0.25mg·kg-1。在丙泊酚注射完成90秒后，由对患者治疗情况不知情的麻醉医生在不使用肌肉松弛剂或其他佐剂的情况下插入LMA。
可乐定治疗组患者插入LMA时丙泊酚的ED50为（2.0±0.2mg·kg-1，1.8 - 2.3mg·kg-1[95%置信区间]），低于未使用可乐定的患者（2.5±0.1mg·kg-1，2.4 - 2.6mg·kg-1，P < 0.01）。
口服可乐定术前用药可降低插入LMA时的丙泊酚需求量。
