Pathophysiology of Obstructive Apneas

1. Initial pharyngeal obstruction:
   • Usually occurs at level of velopharynx, may also occur in hypopharynx
   • Pharyngeal dilator muscle hypotonia, especially during REM sleep
   • Compromised anatomy of upper airway
2. Consequences of occlusion
   • Hypoxemia
   • Hypercapnia
   • Arousal
3. Post-apneic Ventilation