Objective: Nasal-valve dilation reduces nasal resistance and increases air flow. It is possible that this mechanism prevents hypopharyngeal collapse and sleep apneas. We investigated the effect of a plastic device (Nozovent; Prevancure AB; Västra Frölunda, Sweden)-which dilates the nasal valve-on patients with obstructive sleep apnea (OSA).
Design: Prospective interventional study.
Subjects: Twenty-six consecutive patients with OSA were included (22 men; mean +/- SD age, 54.8+/-11.3 years; respiratory disturbance index [RDI], 34.4+/-18.5 events/h; body mass index, 31.6+/-5.7 kg/m(2)).
Intervention: The nasal dilator was inserted during sleep into the nares and fitted to exert a dilating force on the nasal valves by means of its elasticity.
Measurements: Polysomnographic studies were performed before and after 1 month of treatment. A responder is defined as one with a reduction in RDI to < 50% of the baseline value and RDI of < or =10 events/h during treatment.
Results: Five patients dropped out. As a result, only 21 patients were analyzed. Four patients responded, and 17 patients were nonresponders. In the whole population, neither the mean values for respiration during sleep nor sleep staging changed significantly with the device.
Conclusions: The investigated nasal dilator had no effect on sleep-related breathing disorders in patients with moderate to severe OSA. The reduction in nasal resistance does not prevent hypopharyngeal obstruction.