From the Department of Anesthesiology, Sapporo Medical University School of Medicine, Sapporo, Japan.
Department of Anesthesiology, Takikawa Municipal Hospital, Takikawa, Japan.
Anesth Analg. 2021 Mar 1;132(3):818-826. doi: 10.1213/ANE.0000000000005150.
Second-generation supraglottic airway (SGA) devices are useful for airway management during positive pressure ventilation in general anesthesia and emergency medicine. In some clinical settings, such as the anesthetic management of awake craniotomy, SGAs are used in the head-rotated position, which is required for exposure of the surgical field, although this position sometimes worsens the efficiency of mechanical ventilation with SGAs. In this study, we investigated and compared the influence of head rotation on oropharyngeal leak pressures (OPLP) of the i-gel and LMA® Supreme™, which are second-generation SGA devices.
Patients who underwent elective surgery under general anesthesia were enrolled in this study and randomly divided into i-gel or LMA Supreme groups. After induction of anesthesia with muscle relaxation, the i-gel or LMA Supreme was inserted according to computerized randomization. The primary outcome was the OPLP at 0°, 30°, and 60° head rotation. The secondary outcomes were the maximum airway pressure and expiratory tidal volume when patients were mechanically ventilated using a volume-controlled ventilation mode with a tidal volume of 10 mL/kg (ideal body weight), ventilation score, and fiber-optic views of vocal cords.
Thirty-four and 36 participants were included in the i-gel and LMA Supreme groups, respectively. The OPLPs of the i-gel and LMA Supreme significantly decreased as the head rotation angle increased (mean difference [95% confidence interval], P value: i-gel; 0° vs 30°: 3.5 [2.2-4.8], P < .001; 30° vs 60°: 2.0 [0.6-3.5], P = .002; 0° vs 60°: 5.5 [3.3-7.8], P < .001, LMA Supreme; 0° vs 30°: 4.1 [2.6-5.5], P < .001; 30° vs 60°: 2.4 [1.1-3.7], P < .001; 0° vs 60°: 6.5 [5.1-8.0], P < .001). There were statistically significant differences in expiratory tidal volume and ventilation score between 0° and 60° in the i-gel group and in ventilation score between 30° and 60° in the LMA Supreme group. There was no statistically significant difference between the 2 devices in all outcome measures. The incidences of adverse events, such as hoarseness or sore throat, were not significantly different between i-gel and LMA Supreme.
Head rotation to 30° and 60° reduces OPLP with both i-gel and LMA Supreme. There is no difference in OPLP between i-gel and LMA Supreme in the 3 head rotation positions.
第二代声门上气道（SGA）设备在全身麻醉和急诊医学中的正压通气期间用于气道管理非常有用。在某些临床情况下，例如清醒开颅术的麻醉管理，需要暴露手术部位，因此 SGA 被用于头部旋转位置，尽管这种位置有时会降低 SGA 进行机械通气的效率。在这项研究中，我们研究并比较了头旋转对第二代 SGA 设备 i-gel 和 LMA® Supreme™ 的口咽漏压（OPLP）的影响。
本研究纳入了接受全身麻醉下择期手术的患者，并将其随机分为 i-gel 或 LMA Supreme 组。在使用肌肉松弛剂诱导麻醉后，根据计算机化随机分配插入 i-gel 或 LMA Supreme。主要结局是 0°、30°和 60°头旋转时的 OPLP。次要结局是使用容量控制通气模式（潮气量 10 mL/kg[理想体重]）进行机械通气时的最大气道压力和呼气潮气量、通气评分和纤维光学声带视图。
i-gel 和 LMA Supreme 组分别纳入了 34 名和 36 名参与者。随着头旋转角度的增加，i-gel 和 LMA Supreme 的 OPLP 显著降低（平均差异[95%置信区间]，P 值：i-gel；0°比 30°：3.5[2.2-4.8]，P<.001；30°比 60°：2.0[0.6-3.5]，P=.002；0°比 60°：5.5[3.3-7.8]，P<.001，LMA Supreme；0°比 30°：4.1[2.6-5.5]，P<.001；30°比 60°：2.4[1.1-3.7]，P<.001；0°比 60°：6.5[5.1-8.0]，P<.001）。i-gel 组在 0°和 60°之间以及 LMA Supreme 组在 30°和 60°之间的呼气潮气量和通气评分存在统计学显著差异。在所有结局指标中，i-gel 和 LMA Supreme 之间没有统计学显著差异。i-gel 和 LMA Supreme 的不良反应发生率，如声音嘶哑或喉咙痛，没有显著差异。
头旋转至 30°和 60°会降低 i-gel 和 LMA Supreme 的 OPLP。在 3 个头旋转位置，i-gel 和 LMA Supreme 的 OPLP 没有差异。
