Structural Pharyngeal Issues Causing Aerophagia with PAP Therapy
The primary structural pharyngeal abnormalities causing aerophagia during PAP therapy are excessive upper airway obstruction in the nasal cavity (septal deviation, turbinate hypertrophy) and oropharynx (tonsillar hypertrophy, high-grade palatal position), which force higher therapeutic pressures that promote air swallowing. 1
Nasal Cavity Structural Abnormalities
The nasal cavity represents the first critical anatomical site where structural issues contribute to PAP-related aerophagia:
- Septal deviation is significantly more prevalent in PAP nonadherent patients who report aerophagia symptoms, with higher grades of deviation correlating with increased subjective discomfort including mouth dryness and chest discomfort 1
- Inferior turbinate hypertrophy creates additional nasal resistance, forcing patients to require higher therapeutic pressures that directly promote aerophagia 1
- These nasal obstructions necessitate elevated CPAP pressures to overcome resistance, and increased CPAP pressure level is an independent risk factor for aerophagia development (odds ratio 1.24) 2
Oropharyngeal Structural Abnormalities
The oropharynx contains multiple structural elements that contribute to aerophagia:
- Tonsillar hypertrophy (larger tonsil size) is significantly more common in CPAP nonadherent subjects experiencing aerophagia 1
- High-grade palatal position (Friedman palatal position grade III-IV) creates oropharyngeal narrowing that requires higher pressures to maintain airway patency 1
- Redundant soft palate contributes to retropalatal obstruction, necessitating increased therapeutic pressures 3
Hypopharyngeal and Tongue Base Abnormalities
Lower pharyngeal structures can create fixed obstructions that PAP cannot overcome:
- Mandibular retrusion with jaw laxity at sleep onset results in complete fixed tongue base obstruction that PAP therapy cannot overcome, particularly when delivered via oronasal interfaces 4
- Tongue base collapse represents a multilevel obstruction that may persist despite adequate PAP pressures, forcing pressure escalation that promotes aerophagia 4
- Hypopharyngeal obstruction at the tongue base occurs in approximately 80% of surgical candidates with maxillomandibular abnormalities, often combined with small oral cavities 5
Maxillomandibular Skeletal Abnormalities
Underlying skeletal deficiencies create pharyngeal narrowing throughout multiple levels:
- Retrognathia (mandibular deficiency with SNB angle <77°) creates narrower velopharyngeal and linguopharyngeal spaces 5
- Maxillary deficiency combined with mandibular retrusion produces pharyngeal narrowing at the basal lingual level 5
- These skeletal abnormalities create a smaller posterior airway space requiring higher PAP pressures to maintain patency, directly promoting aerophagia 6
Post-Surgical Anatomical Changes
Previous upper airway surgery can paradoxically worsen PAP-related aerophagia:
- Prior uvulopalatopharyngoplasty (UPPP) is a risk factor for CPAP non-compliance, with increased leaks and mouth dryness that may contribute to aerophagia 5
- Velopharyngeal insufficiency following pharyngoplasty causes temporary postoperative problems with liquid regurgitation and phonetic deficits 5
- Long-term side effects including dysphagia, globus pharyngeus, and abnormal swallowing persist in 58% of UPPP patients, potentially altering swallowing mechanics and promoting aerophagia 5
Clinical Pitfalls and Practical Considerations
The key pitfall is assuming aerophagia is purely pressure-related when underlying structural abnormalities are the root cause. Simply reducing pressure may worsen OSA control without addressing the anatomical obstruction requiring higher pressures 7.
When evaluating patients with PAP-related aerophagia, systematically assess:
- Nasal patency (septal deviation, turbinate size) requiring potential septoplasty or turbinate reduction 3
- Oropharyngeal anatomy (tonsil size, palatal position) that may benefit from surgical correction 1
- Mandibular position during sleep, particularly with oronasal masks, which may require drug-induced sleep endoscopy evaluation 4
- Comorbid gastroesophageal reflux disease (GERD), which independently promotes aerophagia (odds ratio 2.52) 2
Switching from CPAP to autotitrating PAP (APAP) reduces median and 95th centile pressures, significantly decreasing bloating, flatulence, and belching symptoms without compromising residual AHI control 7. This represents a practical first-line intervention before pursuing surgical correction of structural abnormalities.