The Role of the Nose in Obstructive Sleep Apnoea - can nasal decongestants be an effective treatment for Mild - Moderate OSA?

Abstract

Obstructive sleep apnoea is a highly prevalent condition characterised by repetitive episodes of complete or partial upper airway obstruction during sleep. Continuous positive airway pressure is an effective treatment for OSA, shown to improve symptoms and quality of life. However, many CPAP users wish to take breaks from treatment due to various factors, including device discomfort and lifestyle constraints. This thesis presents the results of the DOSA study and associated sub-studies to investigate whether decongestant sprays can be used to prolong the period before the return of OSA, facilitating a pause in CPAP treatment. A double-blinded randomised controlled trial was conducted at two UK sleep clinics, recruiting participants with mild to moderate OSA (4% oxygen desaturation index (4%ODI) 15-40 events per hour) who were established CPAP users. Eligible participants were randomised to either a decongestant spray (Xylometazoline 0.1%) or a placebo. Participants discontinued CPAP therapy and were monitored remotely with nightly oximetry recordings. Participants were advised to return to CPAP if they recognised significant symptoms, had three consecutive nights of oximetry data identifying moderate OSA, or completed 28 nights off CPAP therapy. The primary outcome was the number of nights before returning to CPAP therapy. 87 participants completed the study. The time until CPAP return was longer in participants using the decongestant spray than in the placebo group, although this did not meet statistical significance (Hazard Ratio 0.715 95%CI 0.441-1.159, p=0.149). The decongestant spray group managed a mean of 11.2 nights (8.0-14.6) before returning to CPAP versus 7.8 nights (5.2 -10.2) in the placebo group. 24% of the decongestant group completed the full 28 nights off CPAP without return of OSA compared to 12% in the placebo group. The DOSA study indicated that decongestant sprays did not significantly delay the return of OSA symptoms when CPAP therapy was withdrawn for short periods. Unfortunately, the trial failed to achieve its recruitment target, increasing the risk of a type II error. Decongestants may provide some patients with OSA a cost-effective, portable alternative to facilitate a ‘holiday’ off CPAP therapy.