High incidence of posterior nasal cavity obstruction in obstructive sleep apnea patients

Background: Nasal obstruction is a common problem in patients with obstructive sleep apnea (OSA). Systematic evaluation of nasal obstruction remains challenging due to the high number of variables and factors that contribute to nasal obstruction. Nasal examination by means of anterior rhinoscopy is limited to the evaluation of anterior septal deviation, internal nasal valve angle, and inferior turbinate size, but obstruction due to posterior septal deviation and nasal polyposis may go undiagnosed. The primary objective of this study was to determine the incidence of posterior nasal obstruction in OSA patients. Specifically, we were interested in other causes of posterior nasal obstruction that were difficult to assess by anterior rhinoscopy examination alone, and that required nasal endoscopy for identification. Methods: This is a retrospective case series study. Flexible fiberoptic examination of the nasal cavity was performed on 274 consecutive OSA patients evaluated at the Stanford Sleep Surgery Clinic. Examination video files were recorded and later reviewed and scored by a single investigator blinded to the patients’ subjective nasal complaints. Anatomic features that contribute to posterior nasal obstruction were noted. Results: Posterior septal deviation was the most common incidental finding in OSA patients with posterior nasal obstruction. Other causes included nasal polyposis, nasal mucosal inflammation, and purulent mucosal discharge. In total, there were 73/274 (26.6%) patients for whom nasal endoscopy provided findings that directed management. Conclusion: Nasal endoscopy provides additional diagnostic information in a significant number of OSA patients who complain of nasal obstruction. Our findings suggest the use of nasal endoscopy for OSA patients who complain of nasal obstruction or CPAP intolerance, despite unremarkable anterior rhinoscopy examination.