Department of Anaesthesiology and Intensive Care Medicine, University of Cologne, Faculty of Medicine and University Hospital of Cologne, Kerpener Str. 67, 50937, Cologne, Germany.
Department of Anaesthesiology, Privatklinik Hochrum, Sanatorium der Kreuzschwestern, Rum, Austria.
BMC Emerg Med. 2021 Jan 22;21(1):12. doi: 10.1186/s12873-021-00407-5.
Failed airway management is the major contributor for anaesthesia-related morbidity and mortality. Cannot-intubate-cannot-ventilate scenarios are the most critical emergency in airway management, and belong to the worst imaginable scenarios in an anaesthetist's life. In such situations, apnoeic oxygenation might be useful to avoid hypoxaemia. Anaesthesia guidelines recommend careful preoxygenation and application of high flow oxygen in difficult intubation scenarios to prevent episodes of deoxygenation. In this study, we evaluated the decrease in oxygen concentration in a model when using different strategies of oxygenation: using a special oxygenation laryngoscope, nasal oxygen, nasal high flow oxygen, and control.
In this experimental study we compared no oxygen application as a control, standard pure oxygen application of 10 l·min via nasal cannula, high flow 90% oxygen application at 20 l·min using a special nasal high flow device, and pure oxygen application via our oxygenation laryngoscope at 10 l·min. We preoxygenated a simulation lung to 97% oxygen concentration and connected this to the trachea of a manikin model simulating apnoeic oxygenation. Decrease in oxygen concentration in the simulation lung was measured continuously for 20 min.
Oxygen concentration in the simulation lung dropped from 97 ± 1% at baseline to 40 ± 1% in the no oxygen group, to 80 ± 1% in the standard nasal oxygen group, and to 73 ± 2% in the high flow nasal oxygenation group. However, it remained at 96 ± 0% in the oxygenation laryngoscope group (p < 0.001 between all groups).
In this technical simulation, oxygenation via oxygenation laryngoscope was more effective than standard oxygen insufflation via nasal cannula, which was more effective than nasal high flow insufflation of 90% oxygen.
气道管理失败是导致麻醉相关发病率和死亡率的主要原因。无法插管-无法通气的情况是气道管理中最危急的情况，属于麻醉医生最糟糕的情况。在这种情况下，无通气给氧可能有助于避免低氧血症。麻醉指南建议在困难插管的情况下进行仔细的预充氧和高流量氧气的应用，以防止缺氧发作。在这项研究中，我们评估了在使用不同给氧策略时模型中氧浓度的下降情况：使用特殊的给氧喉镜、鼻氧、鼻高流量氧和对照。
在这项实验研究中，我们将无氧气应用作为对照进行比较，标准的纯氧通过鼻导管以 10 l·min 的速度应用，高流量 90%的氧气以 20 l·min 的速度通过特殊的鼻高流量装置应用，以及我们的给氧喉镜以 10 l·min 的速度应用纯氧。我们将模拟肺预充氧至 97%的氧浓度，并将其连接到模拟无通气给氧的人体模型的气管上。连续 20 分钟测量模拟肺中的氧浓度下降情况。
模拟肺中的氧浓度从基线时的 97±1%下降到无氧气组的 40±1%，标准鼻氧组的 80±1%，鼻高流量氧组的 73±2%。然而，在给氧喉镜组中氧浓度仍保持在 96±0%（所有组之间的差异均有统计学意义，p<0.001）。
在这项技术模拟中，与标准的鼻导管给氧相比，通过给氧喉镜给氧更为有效，而鼻高流量给氧（90%）更为有效。
