Changes in the nasal airway mucosa and in nasal symptoms following continuous positive airway pressure (N-CPAP) for obstructive sleep apnoea

Objective: To study and try to establish a relationship between nasal CPAP, nasal mucosa changes and symptoms in a prospective study using acoustic rhino-manometry. Materials and Methods: Patients with confirmed OSA were randomly selected for the study. Assessment was done before and after 4-6 weeks of using nasal CPAP, in controlled environment. Acoustic rhinomanometry was performed for nasal valve cross sectional area & nasal volume calculation. VAS (visual analogue scale) was used to record symptoms (existing, new and changes secondary to nasal CPAP). Results: A significant proportion of patients who were given nasal CPAP either develop nasal symptoms (22 - 44%) or experience an exacerbation of their existing symptoms (20 - 75%). Nasal valve cross sectional area increased by 26.9% and nasal volume by 20.46%. These are all statistically significant. Conclusion: This study confirmed that nasal symptoms tend to worsen with use of nasal CPAP. But it surprisingly showed an increase in nasal valve cross-sectional area and nasal volume, both of these do not correlate with the symptoms. This indicates that changes that take place with nasal CPAP are more complex and possibly may be at the level of cilia, sensory nerve endings and epithelium.