Pierce R, White D, Malhotra A, Edwards J K, Kleverlaan D, Palmer L, Trinder J
Institute for Breathing and Sleep, Bowen Centre, Austin Hospital, Heidelberg, Victoria 3084, Australia.
Eur Respir J. 2007 Aug;30(2):345-53. doi: 10.1183/09031936.00063406. Epub 2007 Apr 25.
The calibre of the upper airway is thought to be dependant upon its passive anatomy/collapsibility and the activation of pharyngeal dilator muscles. During awake periods, the more collapsible upper airway in obstructive sleep apnoea (OSA) increases the dilator muscle activity through a negative-pressure reflex. A direct correlation between the critical closing pressure (P(crit)), as a measure of anatomy/collapsability and electromyogram (EMG) activity of genioglossus EMG (GG-EMG) and tensor palatini EMG (TP-EMG), was hypothesised. The relationship between these indices and pharyngeal resistance (R(phar)) was also examined. The study involved eight males with a mean age of 48 (interquartile range 46-52) yrs with OSA, and an apnoea/hypopnoea index of 75 (65-101).hr(-1) on two nights breathing normally and on nasal continuous positive airway pressure (nCPAP). The P(crit )was measured during nonrapid eye movement sleep on nCPAP using brief, incremental reductions in mask pressure. GG-EMG and TP-EMG were measured breath-by-breath, awake, during sleep onset and on nCPAP. R(phar) was measured using airway pressures and flow. Wakeful GG-EMG, early sleep TP-EMG and the sleep decrement in TP-EMG were directly related to P(crit). Muscle activation was negatively correlated with R(phar) for TP-EMG awake and GG-EMG early in sleep. In conclusion these results confirm that dilator muscle activation is directly related to airway narrowing and reduces resistance across patients with obstructive sleep apnoea.
上气道的口径被认为取决于其被动解剖结构/可塌陷性以及咽扩张肌的激活。在清醒期间，阻塞性睡眠呼吸暂停（OSA）中更易塌陷的上气道通过负压反射增加扩张肌活动。有人提出，作为解剖结构/可塌陷性指标的临界关闭压（P(crit)）与颏舌肌肌电图（GG-EMG）和腭帆张肌肌电图（TP-EMG）的肌电图（EMG）活动之间存在直接相关性。还研究了这些指标与咽阻力（R(phar)）之间的关系。该研究纳入了8名平均年龄为48岁（四分位间距46 - 52岁）的男性OSA患者，其呼吸暂停/低通气指数在正常呼吸的两个晚上以及使用鼻持续气道正压通气（nCPAP）时为75（65 - 101）次/小时。在使用nCPAP进行非快速眼动睡眠期间，通过短暂逐步降低面罩压力来测量P(crit)。在清醒、入睡期间以及使用nCPAP时逐次测量GG-EMG和TP-EMG。使用气道压力和流量来测量R(phar)。清醒时的GG-EMG、睡眠早期的TP-EMG以及TP-EMG的睡眠期下降与P(crit)直接相关。对于清醒时的TP-EMG和睡眠早期的GG-EMG，肌肉激活与R(phar)呈负相关。总之，这些结果证实扩张肌激活与气道狭窄直接相关，并降低了阻塞性睡眠呼吸暂停患者的阻力。
