Nasal function and CPAP use in patients with obstructive sleep apnoea: a systematic review

This systematic review was conducted to answer the following 3 questions: 'Does nasal pathology affect CPAP use?', 'What is the effect of CPAP on the nose?' and 'Does treatment of nasal pathology affect CPAP use?'.

Pubmed and Scopus databases were searched for articles relevant to the study questions up to October 2020.

Sixty-three articles were selected, of which a majority were observational studies. Most studies identified a correlation between larger nasal cross-sectional area or lower nasal resistance and higher CPAP compliance or lower CPAP pressures; however, nasal symptoms at baseline did not appear to affect CPAP use. The effect of CPAP on the nose remains uncertain: while most studies suggested increased mucosal inflammation with CPAP, those investigating symptoms presented contradictory results, with some reporting an increase and others an improvement in nasal symptoms. Evidence is clearer for nasal surgery leading to an increase in CPAP compliance and a decrease in CPAP pressures, whereas there is little evidence available for the use of topical nasal steroids.

There appears to be a link between nasal volumes or nasal resistance and CPAP compliance, an increase in nasal inflammation caused by CPAP and a beneficial effect of nasal surgery on CPAP usage, but no significant effect of CPAP on nasal patency or effect of topical steroids on CPAP compliance. Results are more mitigated with regard to the effect of nasal symptoms on CPAP use and vice versa, and further research in this area would help identify patients who may benefit from additional support or treatment alongside CPAP.