Dept of Anesthesiology, Graduate School of Medicine, Chiba University, Japan.
Dept of Anesthesiology, Graduate School of Medicine, Chiba University, Japan.
Respir Physiol Neurobiol. 2020 Aug;279:103445. doi: 10.1016/j.resp.2020.103445. Epub 2020 May 11.
The purpose of this study is to compare changes in breathing patterns elicited by hypoxic stress and/or anesthetic stress in mice. Spontaneously breathing anesthetized mice whose tracheae were intubated with a tracheal cannula were challenged with hypoxic stress and/or sevoflurane-induced anesthetic stress while ventilation was measured with a pneumotachograph. When anesthesia was maintained at a light level with inhalation of 2.3 % sevoflurane (0.7 MAC), exposure to severe hypoxic gas (5% O in N) triggered a breathing pattern characterized by gasping respiration. Inhalation of a high concentration of sevoflurane (6.5 %: 2.0 MAC) under hyperoxia elicited the same gasping. Also, the combination of mild hypoxia (inhalation of 10 % O in N) and moderate sevoflurane anesthesia (3.25 %: 1.0 MAC) consistently elicited the same gasping, while mild hypoxic and moderate anesthetic stress alone did not elicit any gasping. These findings suggest that both hypoxia-induced gasping and sevoflurane-induced gasping could be generated by the same intrinsic mechanism within the brainstem.
本研究旨在比较低氧应激和/或麻醉应激引起的呼吸模式变化在小鼠中的变化。通过气管插管将气管套管插入自主呼吸麻醉的小鼠，并用呼吸描记器测量通气，以应对低氧应激和/或七氟醚诱导的麻醉应激。当以吸入 2.3%七氟醚（0.7 MAC）维持轻度麻醉时，暴露于严重低氧气体（5% O 在 N）会引发以喘息呼吸为特征的呼吸模式。在高氧下吸入高浓度七氟醚（6.5%：2.0 MAC）也会引起相同的喘息。此外，轻度低氧（吸入 10% O 在 N）和中度七氟醚麻醉（3.25%：1.0 MAC）的组合始终引起相同的喘息，而轻度低氧和中度麻醉应激本身并不引起任何喘息。这些发现表明，脑桥内的相同内在机制可能引起缺氧诱导的喘息和七氟醚诱导的喘息。
