Background / Aims: Obstructive sleep apnoea (OSA) is a common health problem in CMDHB patients. OSA patients are often unable to use continuous positive airway pressure (n-CPAP) because of complaints about nasal drying. The nasal cycle, a periodic change in nasal airflow between the two nares is important in nasal health and normal sleep. It ensures that entrapped debris and pathogens on one side are disposed of, while simultaneously meeting air-conditioning demands on the other side. The purpose of this study was to investigate the influence n-CPAP therapy has on both the nasal cycle and on nasal geometry.
Methods: Airflow through each naris of twenty healthy participants was measured during ambient air pressure nasal breathing followed by n-CPAP breathing at 10 cm H2O pressure.
Another eight participants undertook magnetic resonance imaging (MRI) of their nasal region during spontaneous ambient air pressure nasal breathing, and then n-CPAP breathing over a range of air pressures spanning six to fifteen cm H2O.
Results: During n-CPAP breathing, a simultaneous reduction in airflow through the patent airway together with a corresponding increase within the congested airway were observed in sixteen of the twenty participants. MRI data analysis showed airway cross-sectional area was reduced along the patent side while the congested airway experienced an increase in this parameter. Statistical analysis using 2 sided paired t-test, comparing the median value of each airway at each location found a significant difference in response to pressure augmentation between the patent and congested airway (p < 0.0001).
Conclusions: During awake breathing, n-CPAP therapy disturbs the normal inter-nasal airflow partitioning. This could partially explain the adverse nasal drying symptoms and poor n-CPAP utilisation reported by many OSA suffers. The development of a n-CPAP machine that mimics the nasal cycle could improve n-CPAP utilisation. This is currently underway.
Counties Manukau Health