Dichotomous physiological effects of nocturnal external nasal dilation in heavy snorers: The answer to a rhinologic controversy?

The purpose of this article was to study the impact of external dilation on nasal airway dimensions, sleep architecture , and snoring. Eighteen heavy snorers without severe obstructive sleep apnea syndrome (mean apnea-hypopne a index (AHI) 9.3) reporting nocturnal nasal obstruction were enrolled in a randomized (controlled) cross-over study, evaluating subjective and object ive effects of external nasal dilation (Breathe Right, 3M). The active dila tor was also worn during a one-week pretrial nln-in period. Polysomnography , recording of snoring sounds, and repeated acoustic rhinometry were perfor med on two consecutive nights, one with the active dilator and one with a p lacebo strip. The significant subjective improvement reported during the ru n-in period compared to the preceding period without dilator (p < 0.01), re mained only for nasal patency (p < 0.05) when comparing the two nights in t he sleep laboratory. The nasal dimensions increased significantly (p < 0.00 1) with the active dilator compared to placebo, both in the evening and the next morning. In a subgroup (n = 6) of habitual snorers (AHI < 10) with se vere morning obstruction (combined minimal cross-sectional area < 0.6 cm(2) ), external dilation significantly improved the mean sleep PaSO2 (92.4 --> 96.7) and the percentage of sleep with a PaSO2 < 95% (49.9% --> 4.9%).(p < 0.05). In this subgroup there was a trend toward reduction in (7.4 --> 5.4) (p = 0.06), whereas the AHI increased significantly in the group of 12 wit h larger nocturnal nasal dimensions (p < 0.05). Duration and intensity of s noring remained unchanged regardless of the subgrouping. Objective benefici al effects were restricted to nocturnal oxygen saturation and AHI in a subg roup of habitual heavy snorers identified by repeated acoustic rhinometry, in whom external dilation objectively relieved marked nocturnal nasal obstr uction This Sinning may provide a logical explanation for the conflicting r esults of medical, surgical, and mechanical expansion of the nasal dimensio ns on snoring and sleep disturbances.