Department of Anesthesiology, Chiba University Hospital, and Department of Anesthesiology, Graduate School of Medicine, Chiba University, Chiba, Japan.
Anesthesiology. 2012 Sep;117(3):487-93. doi: 10.1097/ALN.0b013e3182668670.
Recent studies suggest advantages of muscle relaxants for facemask ventilation. However, direct effects of muscle relaxants on mask ventilation remain unclear because these studies did not control mechanical factors influencing ventilation. We tested a hypothesis that muscle relaxants, either rocuronium or succinylcholine, improve mask ventilation.
In anesthetized adult persons with normal upper airway anatomy, tidal volumes during facemask ventilation were measured while maintaining the neutral head and mandible positions and the airway pressures of a ventilator before and during muscle paralysis induced by either rocuronium (n=14) or succinylcholine (n=17). Tidal volumes of oral and nasal airway routes were separately measured with a custom-made oronasal portioning full facemask. Behavior of the oral airway was observed by an endoscope in six additional subjects receiving succinylcholine.
Total, oral, and nasal tidal volumes did not significantly change at complete muscle paralysis with rocuronium. In contrast, succinylcholine significantly increased total tidal volumes at 60 s after its administration (mean±SD; 4.2±2.1 vs. 5.4±2.6 ml/kg, P=0.02) because of increases of ventilation through both airway routes. Abrupt tidal volume increase occurred more through oral airway route than nasal route. Dilation of the space at the isthmus of the fauces was endoscopically observed during pharyngeal fasciculation in all six subjects.
Rocuronium did not deteriorate facemask ventilation, and it was improved after succinylcholine administration in association with airway dilation during pharyngeal fasciculation. This effect continued to a lesser degree after resolution of the fasciculation.
最近的研究表明肌肉松弛剂对面罩通气有优势。然而，由于这些研究没有控制影响通气的机械因素，因此肌肉松弛剂对面罩通气的直接影响仍不清楚。我们检验了一个假设，即肌肉松弛剂罗库溴铵或琥珀酰胆碱可改善面罩通气。
在具有正常上呼吸道解剖结构的麻醉成年患者中，在使用定制口鼻分流全面罩分别测量口腔和鼻腔气道的潮气量之前和之后，通过罗库溴铵（n=14）或琥珀酰胆碱（n=17）诱导肌肉麻痹，测量面罩通气时的潮气量。保持中性头部和下颌位置以及呼吸机的气道压力。在接受琥珀酰胆碱的另外 6 名受试者中，通过内窥镜观察口腔气道的行为。
罗库溴铵完全麻痹时，总潮气量、口腔潮气量和鼻腔潮气量均无显著变化。相比之下，琥珀酰胆碱给药 60 秒后总潮气量显著增加（平均值±标准差；4.2±2.1 比 5.4±2.6 ml/kg，P=0.02），这是因为通过两个气道都增加了通气。突然的潮气量增加更多地通过口腔气道途径而不是鼻腔途径。在所有 6 名受试者的咽肌震颤期间，内窥镜观察到会厌峡部空间扩张。
罗库溴铵不会使面罩通气恶化，而琥珀酰胆碱给药后会改善，这与咽肌震颤时气道扩张有关。这种效应在震颤消退后仍会持续一定程度。
