title: Nasal airway responses to nasal continuous positive airway pressure breathing: An in-vivo pilot study.
abstract: The nasal cycle, through variation in nasal airflow partitioning, allows the upper airway to accommodate the contrasting demands of air conditioning and removal of entrapped air contaminants. The purpose of this study was to investigate the influence of nasal continuous positive airway pressure (nCPAP) breathing has on both nasal airflow partitioning and nasal geometry. Using a custom-made nasal mask, twenty healthy participants had the airflow in each naris measured during normal nasal breathing followed by nCPAP breathing. Eight participants also underwent magnetic resonance imaging (MRI) of the nasal region during spontaneous nasal breathing, and then nCPAP breathing over a range of air pressures. During nCPAP breathing, a simultaneous reduction in airflow through the patent airway together with a corresponding increase in airway flow within the congested nasal airway were observed in sixteen of the twenty participants. Nasal airflow resistance is inversely proportional to airway cross-sectional area. MRI data analysis during nCPAP breathing confirmed airway cross-sectional area reduced along the patent airway while the congested airway experienced an increase in this parameter. During awake breathing, nCPAP disturbs the normal inter-nasal airflow partitioning. This could partially explain the adverse nasal drying symptoms frequently reported by many users of this therapy.
authors.affiliation: School of Engineering, Computer and Mathematical Sciences, Auckland University of Technology, Auckland, New Zealand. Electronic address: david.white@aut.ac.nz.
authors.forename: David E
authors.initials: DE
authors.lastname: White
authors.affiliation: Department of Otolaryngology - Head and Neck Surgery, Counties District Health Board, Manukau, Auckland, New Zealand; Department of Surgery, University of Auckland, Auckland, New Zealand.
authors.forename: Jim
authors.initials: J
authors.lastname: Bartley
authors.affiliation: Department of Otolaryngology - Head and Neck Surgery, Counties District Health Board, Manukau, Auckland, New Zealand.
authors.forename: Muhammad
authors.initials: M
authors.lastname: Shakeel
authors.affiliation: School of Engineering, Computer and Mathematical Sciences, Auckland University of Technology, Auckland, New Zealand.
authors.forename: Roy J
authors.initials: RJ
authors.lastname: Nates
authors.affiliation: School of Engineering, Computer and Mathematical Sciences, Auckland University of Technology, Auckland, New Zealand.
authors.forename: Robin K S
authors.initials: RKS
authors.lastname: Hankin
mesh_terms: D000328:Adult; D045422:Continuous Positive Airway Pressure; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009296:Nasal Cavity / Q000000981:diagnostic imaging / Q000502:physiology*; D010865:Pilot Projects; D012119:Respiration; D055815:Young Adult
keywords: CPAP; MRI; Nasal airflow partitioning; Nasal cycle; Nasal geometry