Department of Emergency and Critical Care Medicine, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.
Critical Care Medical Center, Hiroshima Prefectural Hospital, Hiroshima, Japan.
PLoS One. 2019 Jul 19;14(7):e0220006. doi: 10.1371/journal.pone.0220006. eCollection 2019.
The presence of vomit, blood, or other foreign liquid materials in the upper airway is a major obstacle in difficult tracheal intubations (TIs) especially in prehospital care. However, the usefulness of video laryngoscopes (VLs) in these situations has not been investigated. The objective of this study was to compare the Airway Scope (AWS) and the Macintosh laryngoscope (ML) for their performance in TIs performed by emergency medical technicians (EMTs) using mannequin models with liquids in the airway. Rice gruel and mock blood were used to fill the upper airways of mannequins to create mock vomit and hematemesis models, respectively. TIs were performed by certified EMTs after visualizing the glottis using an AWS with an 18-Fr suction catheter and a ML with an 18-Fr suction catheter. TIs with AWS and ML were performed in random order in a comparative crossover trial. The TI success rate was evaluated based on the following: (a) the time taken from laryngoscope insertion into the oral cavity to glottis visualization, tracheal tube passage through the glottis, until the initiation of ventilation and (b) the subjective level of difficulty, which was assessed using a visual analog scale (VAS). TIs in vomiting and hematemesis scenarios were performed by 25 and 26 EMTs, respectively. The TI success rates for these scenarios were 100% with both AWS and ML. The median time required until successful ventilation was significantly shorter with AWS than with ML in both the vomiting (42 vs. 58 s) and hematemesis models (33 vs. 39 s), respectively. In the hematemesis scenarios, difficulty assessed using a VAS was lower with AWS than with ML (13 vs. 38 in median), respectively. Compared to the ML, the AWS was capable of faster and easier TIs, in a simulated model of liquid foreign material in the upper airway.
上呼吸道中存在呕吐物、血液或其他外来液体物质是困难气管插管（TI）的主要障碍，尤其是在院前急救中。然而，视频喉镜（VL）在这些情况下的实用性尚未得到研究。本研究的目的是比较气道镜（AWS）和 Macintosh 喉镜（ML）在 EMT 用模型模拟上呼吸道中有液体的情况下进行 TI 的性能。米浆和模拟血液被用于填充模型的上呼吸道，分别模拟呕吐物和呕血模型。在使用 AWS 带有 18Fr 吸引导管和 ML 带有 18Fr 吸引导管可视化声门后，由经过认证的 EMT 进行 TI。AWS 和 ML 的 TI 以随机交叉试验的顺序进行比较。TI 成功率根据以下标准进行评估：（a）从喉镜插入口腔到声门可视化、气管导管通过声门直至开始通气的时间，以及（b）使用视觉模拟量表（VAS）评估的主观难度级别。25 名 EMT 进行了呕吐场景的 TI，26 名 EMT 进行了呕血场景的 TI。AWS 和 ML 对这两种场景的 TI 成功率均为 100%。在呕吐（42 秒对 58 秒）和呕血模型（33 秒对 39 秒）中，AWS 直到成功通气所需的中位数时间明显短于 ML。在呕血场景中，使用 VAS 评估的难度也低于 ML（中位数分别为 13 对 38）。与 ML 相比，AWS 能够更快、更容易地进行 TI，在模拟的上呼吸道中有液体异物的模型中。
