External nasal dilator decreases N95 respirator-related respiratory effort and symptoms in gastrointestinal endoscopy unit staff

Abstract

Background/ study aims: N95 filtering facepiece respirators (FFR) use is associated with physiological changes and symptoms due to impaired nasal airflow and increased breathing resistance. We prospectively studied the effect of using an external nasal dilator (END) in gastroenterology laboratory (GI lab) staff using N95FFR. Participants/ materials and methods: N95FFR qualitative saccharine fit testing was performed on study participants with and without an END. Prospective data collection and comparisons included: 1) survey of perceived symptoms and difficulty of performing one day of GI procedures with N95FFR and one day of GI procedures with END plus N95FFR in random sequence and 2) vitals and respiratory belt plethysmography in ten gastroenterologists performing simulated colonoscopy while wearing a surgical mask (SM), N95FFR plus SM, END plus N95FFR plus SM for 20 minutes each in random sequence and rapid succession. Results: Twenty-nine of 31 participants passed the N95FFR and the END plus N95FFR fit test. Twenty-two participants (12 physicians; 11 males; mean age 44.1 years, range 31-61) performed one day of GI procedures with an N95FFR and one day of GI procedures with an END plus N95FFR. Significantly less difficulty with nasal breathing and severity of symptoms including breathing difficulty, headache, fatigue and frustration occurred while using an END plus N95FFR. Respiratory plethysmography peak to trough measurement showed an increase during the N95FFR stage compared to the END plus N95FFR stage and the SM stage. Conclusions: N95FFR related respiratory changes and symptom development may be mitigated by END use.