Effect of wearing an N95 respirator on the internal nasal valve and the association with external nasal anatomy - a cohort study.

ABSTRACT

OBJECTIVES: To determine whether the N95 respirator affects nasal valve patency; placement on the bony vault improves patency; and external nasal anatomy affects the outcome. METHODS: A prospective study with 50 participants was conducted. Nasal patency was measured by the minimal cross-sectional area via acoustic rhinometry, and using the Nasal Obstruction Symptom Evaluation survey, before and after wearing the N95 respirator and after adjustment. RESULTS: The minimal cross-sectional area was narrowed by 27 per cent when wearing the N95 respirator (p < 0.001), and improved by 9.2 per cent after adjustment (p = 0.003). The total Nasal Obstruction Symptom Evaluation score increased from 10.2 to 25.4 after donning the N95 respirator (p < 0.001), and decreased from 25.4 to 15.6 after adjustment (p < 0.001). There was no correlation with external nasal anatomy parameters. CONCLUSION: Wearing the N95 respirator causes narrowing of the nasal valve, and adjustment onto the bony vault improves symptoms. The findings were not affected by external nasal anatomy.