Dept of Internal Medicine, Bnai-Zion Medical Center, Technion, Israel.
Eur Respir J. 2013 Jan;41(1):74-84. doi: 10.1183/09031936.00159611. Epub 2012 May 3.
Pharyngeal collapsibility during sleep is believed to increase due to a decline in dilator muscle activity. However, genioglossus electromyogram (EMG) often increases during apnoeas and hypopnoeas, often without mechanical effect. 17 patients with obstructive sleep apnoea were anaesthetised and evaluated from termination of propofol administration to awakening. Genioglossus EMG, flow and pharyngeal area (pharyngoscopy) were monitored. Prolonged hypopnoeas enabled evaluation of the relationships between genioglossus EMG and mechanical events, before and after awakening. Additional dilator muscle EMGs were recorded and compared to the genioglossus. Electrical stimulation of the genioglossus was used to evaluate possible mechanical dysfunction. Prolonged hypopnoeas during inspiration before arousal triggered an increase in genioglossus EMG, reaching mean ± SD 62.2 ± 32.7% of maximum. This augmented activity failed to increase flow and pharyngeal area. Awakening resulted in fast pharyngeal enlargement and restoration of unobstructed flow, with marked reduction in genioglossus EMG. Electrical stimulation of the genioglossus under propofol anaesthesia increased the inspiratory pharyngeal area (from 25.1 ± 28 to 66.3 ± 75.5 mm(2); p<0.01) and flow (from 11.5 ± 6.5 to 18.6 ± 9.2 L · min(-1); p<0.001), indicating adequate mechanical response. All additional dilators increased their inspiratory activity during hypopnoeas. During propofol anaesthesia, pharyngeal occlusion persists despite large increases in genioglossus EMG, in the presence of a preserved mechanical response to electrical stimulation.
人们认为，在睡眠过程中，由于辅助呼吸肌活动减少，咽壁塌陷的可能性增加。然而，颏舌肌肌电图（EMG）在呼吸暂停和低通气期间常常增加，通常没有机械作用。17 例阻塞性睡眠呼吸暂停患者在异丙酚给药结束至苏醒期间接受麻醉评估。监测颏舌肌 EMG、气流和咽腔面积（喉镜）。延长的低通气使我们能够在苏醒前后评估颏舌肌 EMG 与机械事件之间的关系。记录了额外的辅助呼吸肌 EMG 并与颏舌肌进行了比较。使用颏舌肌电刺激来评估可能的机械功能障碍。在觉醒前的吸气过程中，长时间的低通气会触发颏舌肌 EMG 增加，达到平均±SD62.2±32.7%的最大水平。这种增加的活动并不能增加气流和咽腔面积。觉醒导致咽腔迅速扩张，恢复无阻塞的气流，颏舌肌 EMG 明显减少。异丙酚麻醉下颏舌肌电刺激增加了吸气时的咽腔面积（从 25.1±28 增加到 66.3±75.5mm2；p<0.01）和气流（从 11.5±6.5 增加到 18.6±9.2L·min-1；p<0.001），表明有足够的机械反应。所有额外的辅助呼吸肌在低通气期间增加了吸气时的活动。在异丙酚麻醉下，尽管颏舌肌 EMG 大幅增加，但在存在对电刺激的机械反应的情况下，仍会发生咽腔闭塞。
