Wilcox P G, Paré P D, Road J D, Fleetham J A
Department of Medicine, University of British Columbia, Vancouver, Canada.
Am Rev Respir Dis. 1990 Sep;142(3):533-9. doi: 10.1164/ajrccm/142.3.533.
Obstructive sleep apnea (OSA) is characterized by recurrent upper airway obstruction during sleep. Inspiratory muscles may be subjected to potentially fatiguing loads during an obstructive apnea and this may be related to the termination of obstructive apnea. We have measured transdiaphragmatic pressure (Pdi) and breathing patterns in six male patients with OSA during sleep to characterize respiratory muscle function in OSA and determine whether apnea termination is consistently related to a pressure time index of the diaphragm (PTI) associated with respiratory muscle fatigue. There was a large intersubject variability in Pdi generation during apnea. No consistent level of PTI was associated with apnea termination. During prolonged apneas, the respiratory duty cycle plateaued, which is suggestive of an inhibitory reflex possibly mediated by chest wall afferents. There were intersubject differences in both inspiratory and expiratory muscle recruitment during apnea. In the majority of patients, the diaphragm appeared to be the primary inspiratory muscle during apnea, but in some it appeared to be the intercostal/accessory muscles. The majority of patients demonstrated an increase in gastric pressure and inward abdominal movement during the expiratory phases of an apnea, consistent with abdominal muscle recruitment stimulated by increased ventilatory drive.
阻塞性睡眠呼吸暂停（OSA）的特征是睡眠期间上呼吸道反复阻塞。在阻塞性呼吸暂停期间，吸气肌可能会承受潜在的疲劳负荷，这可能与阻塞性呼吸暂停的终止有关。我们测量了6名患有OSA的男性患者睡眠期间的跨膈压（Pdi）和呼吸模式，以表征OSA患者的呼吸肌功能，并确定呼吸暂停的终止是否始终与与呼吸肌疲劳相关的膈肌压力时间指数（PTI）有关。呼吸暂停期间Pdi产生存在较大的个体间差异。没有一致的PTI水平与呼吸暂停终止相关。在长时间呼吸暂停期间，呼吸负荷周期趋于平稳，这提示可能由胸壁传入神经介导的抑制性反射。呼吸暂停期间吸气肌和呼气肌募集存在个体间差异。在大多数患者中，膈肌在呼吸暂停期间似乎是主要的吸气肌，但在一些患者中似乎是肋间肌/辅助肌。大多数患者在呼吸暂停的呼气阶段表现出胃内压升高和腹部向内运动，这与通气驱动增加刺激腹部肌肉募集一致。
