BACKGROUND King Vision and McGrath MAC video laryngoscopes (VLs) are increasingly used. The purpose of this study was to evaluate the performance of nasotracheal intubation in patients with predicted difficult intubations using non-channeled King Vision VL, McGrath MAC VL or Macintosh laryngoscope by experienced intubators. METHODS Ninety nine ASA I or II adult patients, scheduled for oral maxillofacial surgeries with El-Ganzouri risk index 1-7 were enrolled. Patients were randomly allocated to intubate with one of three laryngoscopes (non-channeled King Vision, McGrath MAC and Macintosh). The intubators were experienced with more than 100 successful nasotracheal intubations using each device. The primary outcome was intubation time. The secondary outcomes included first success rate, time required for viewing the glottis, Cormack-Lehane grade of glottis view, the number of assist maneuvers, hemodynamic responses, the subjective evaluating of sensations of performances and associated complications. RESULTS The intubation time of King Vision and McGrath group was comparable (37.6 ± 7.3 s vs. 35.4 ± 8.8 s) and both were shorter than Macintosh group (46.8 ± 10.4 s, p < 0.001). Both King Vision and McGrath groups had a 100% first attempt success rate, significantly higher than Macintosh group (85%, p < 0.05). The laryngoscopy time was comparable between King Vision and McGrath group (16.7 ± 5.5 s vs. 15.6 ± 6.3 s) and was shorter than Macintosh group (22.8 ± 7.2 s, p < 0.05) also. Compared with Macintosh laryngoscope, Glottis view was obviously improved when exposed with either non-channeled King Vision or McGrath MAC VL (p < 0.001), and assist maneuvers required were reduced (p < 0.001). The maximum fluctuations of MAP were significantly attenuated in VL groups (47.7 ± 12.5 mmHg and 45.1 ± 10.3 mmHg vs. 54.9 ± 10.2 mmHg, p < 0.05 and p < 0.01). Most device insertions were graded as excellent in McGrath group, followed by Macintosh and King Vision group (p = 0.0014). The tube advancements were easier in VLs compared with the Macintosh laryngoscope (p < 0.001). Sore throat was found more frequent in Macintosh group compared with King Vision group (p < 0.05). CONCLUSIONS Non-channeled King Vision and McGrath MAC VLs were comparable and both devices facilitated nasotracheal intubation in managing predicted difficult intubations compared with Macintosh laryngoscope. TRIAL REGISTRATION ClinicalTrials registration number NCT03126344 . Registered on April 24, 2017.

中文翻译：

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预测困难插管的非气道镜，McGrath MAC视频喉镜和Macintosh直接喉镜用于鼻气管插管的随机对照比较。

背景技术King Vision和McGrath MAC视频喉镜（VLs）越来越多地被使用。这项研究的目的是通过经验丰富的插管器，使用无通道的King Vision VL，McGrath MAC VL或Macintosh喉镜评估在预计有困难插管的患者的气管插管的性能。方法入选了99例ASA I或II型ASA I成年患者，这些患者计划进行El-Ganzouri危险指数1-7的口腔颌面外科手术。使用三个喉镜（无通道的King Vision，McGrath MAC和Macintosh）之一将患者随机分配至插管。使用每种设备对插管者进行了100多次成功的鼻气管插管。主要结果是插管时间。次要结果包括首次成功率，检查声门所需的时间，声门检查的Cormack-Lehane评分，辅助动作次数，血液动力学反应，对表现感觉及相关并发症的主观评估。结果King Vision和McGrath组的插管时间相当（37.6±7.3 s vs. 35.4±8.8 s），两者均短于Macintosh组（46.8±10.4 s，p <0.001）。King Vision和McGrath组的首次尝试成功率均为100％，显着高于Macintosh组（85％，p <0.05）。King Vision和McGrath组的喉镜检查时间相当（16.7±5.5 s和15.6±6.3 s），也比Macintosh组（22.8±7.2 s，p <0.05）短。与Macintosh喉镜相比，使用非通道的King Vision或McGrath MAC VL曝光时，声门的视野明显改善（p <0.001），并减少了所需的辅助动作（p <0.001）。VL组的MAP的最大波动显着减弱（47.7±12.5 mmHg和45.1±10.3 mmHg对54.9±10.2 mmHg，p <0.05和p <0.01）。McGrath组中大多数设备插入被评为优秀，其次是Macintosh和King Vision组（p = 0.0014）。与Macintosh喉镜相比，VL的输液管更容易（p <0.001）。与King Vision组相比，Macintosh组的喉咙痛更为常见（p <0.05）。结论非通道的King Vision和McGrath MAC VL相当，并且与Macintosh喉镜相比，这两种设备都有助于鼻气管插管在管理预测的困难插管中。试验注册临床试验注册号NCT03126344。2017年4月24日注册。