Lung volume and continuous positive airway pressure requirements in obstructive sleep apnea.
Raphael C Heinzer, Michael L Stanchina, Atul Malhotra, Robert B Fogel, Sanjay R Patel, Amy S Jordan, Karen Schory, David P White
American Journal of Respiratory and Critical Care Medicine | Published : 2005
Previous studies have demonstrated that lung volume during wakefulness influences upper airway size and resistance, particularly in patients with sleep apnea. We sought to determine the influence of lung volume on the level of continuous positive airway pressure (CPAP) required to prevent flow limitation during non-REM sleep in subjects with sleep apnea. Seventeen subjects (apnea-hypopnea index, 42.6 +/- 6.2 [SEM]) were studied during stable non-REM sleep in a rigid head-out shell equipped with a positive/negative pressure attachment for manipulation of extrathoracic pressure. An epiglottic pressure catheter plus a mask/pneumotachometer were used to assess flow limitation. When lung volume w..View full abstract