Tanaka M, Nishikawa T
Department of Anaesthesia, Akita University School of Medicine, Hondo 1-1-1, Akita-city, Akita 010-8543, Japan.
Br J Anaesth. 2003 Jan;90(1):14-20.
The cuffed oropharyngeal airway (COPA) is a modified Guedel-type oral airway with a cuff at its distal end. The objectives of this prospective, randomized study were to compare the COPA and the laryngeal mask airway (LMA) in terms of propofol requirement with and without fentanyl pretreatment for smooth insertions.
Seventy-five patients undergoing general anaesthesia were randomly assigned to either a COPA (n=38) or LMA (n=37) group for airway management, and each group was further randomized to a saline-propofol or fentanyl-propofol group for anaesthesia induction. The saline-propofol group received i.v. saline and the fentanyl-propofol group received i.v. fentanyl 1 micro g kg(-1) followed 30 s later by i.v. propofol. Insertion of the device was attempted 90 s after propofol administration without the use of neuromuscular blocking agents or other adjuvants, and the responses of 'movement' or 'no movement' were judged by three observers blinded to the drug dose. Each dose of propofol at which insertion was attempted was predetermined by modification of Dixon's up-and-down method with 0.5 mg kg(-1) as the step size, and 2 mg kg(-1) as an initial dose.
Without fentanyl pretreatment, propofol requirement [mean (SD), 95% CI] for COPA placement [2.17 (0.38), 1.77-2.56 mg kg(-1)] was significantly less than for LMA insertion [3.42 (0.26), 3.15-3.69 mg kg(-1), P<0.001]. In contrast, propofol requirements after fentanyl were comparable between the COPA and LMA groups [1.50 (0.42), 1.06-1.94 and 1.42 (0.26), 1.15-1.69 mg kg(-1), respectively], but were less than for the placebo group with both devices (P<0.05). Haemodynamic changes and duration of apnoea were similar with both devices irrespective of fentanyl pretreatment.
Insertion of the COPA can be accomplished with a smaller bolus dose of propofol compared with the LMA, but propofol requirements are similar with both devices after a small dose of fentanyl.
带套囊口咽气道（COPA）是一种改良的古德尔型口咽气道，其远端带有一个套囊。这项前瞻性随机研究的目的是比较COPA和喉罩气道（LMA）在有无芬太尼预处理情况下插入操作顺利时丙泊酚的需求量。
75例接受全身麻醉的患者被随机分为COPA组（n = 38）或LMA组（n = 37）进行气道管理，每组又进一步随机分为生理盐水 - 丙泊酚组或芬太尼 - 丙泊酚组进行麻醉诱导。生理盐水 - 丙泊酚组静脉注射生理盐水，芬太尼 - 丙泊酚组静脉注射1μg/kg芬太尼，30秒后静脉注射丙泊酚。在不使用神经肌肉阻滞剂或其他佐剂的情况下，丙泊酚给药后90秒尝试插入装置，由三位对药物剂量不知情的观察者判断“有动作”或“无动作”反应。每次尝试插入时的丙泊酚剂量通过改良的狄克逊上下法预先确定，步长为0.5mg/kg，初始剂量为2mg/kg。
在没有芬太尼预处理的情况下，放置COPA所需的丙泊酚量[均值（标准差），95%置信区间]为[2.17（0.38），1.77 - 2.56mg/kg]，显著低于插入LMA所需的丙泊酚量[3.42（0.26），3.15 - 3.69mg/kg，P<0.001]。相比之下，芬太尼预处理后COPA组和LMA组的丙泊酚需求量相当[分别为1.50（0.42），1.06 - 1.94和1.42（0.26），1.15 - 1.69mg/kg]，但均低于使用两种装置的安慰剂组（P<0.05）。无论是否进行芬太尼预处理，两种装置的血流动力学变化和呼吸暂停持续时间相似。
与LMA相比，插入COPA时所需的丙泊酚推注剂量较小，但小剂量芬太尼预处理后两种装置的丙泊酚需求量相似。
