Combined effects of a mechanical nasal dilator and a topical decongestant on nasal airflow resistance

The goal of this stud was to compare the isolated and combined effects of t wo treatments being used to reduce nasal airflow resistance (NR): an intern al nasal mechanical dilator (Nozovent; Prevancure; St Pouret, Paris, France ) and a topical decongestant, fenoxazoline hydrochloride (Aturgyl; Synthela bo; Le Plessis-Robinson, France). The study was performed in 17 healthy sub jects. NR was estimated by active posterior rhinometry at a 0.5 L/s flow un der four conditions: in the basal state, with the internal nasal mechanical dilator, after treatment wit fenoxazoline hydrochloride, and wit both feno xazoline hydrochloride and the mechanical dilator. The mean NR (+/- SD) dec reased from 1.65 +/- 0.54 cm H2O/L/s in the basal state to 1.02 +/- 0.27 cm H2O/L/s with the mechanical dilator (p < 0.001), 1.03 +/- 0.47 cm H2O/L/s with fenoxazoline hydrochloride (p < 0.001), and 0.48 +/- 0.15 cm H2O/L/s w ith both the mechanical dilator and fenoxazoline hydrochloride (p < 0.001). The decreases in NR observed after using either the mechanical dilator (De lta NRN) or fenoxazoline hydrochloride (Delta NRA) were not significantly d ifferent. The decrease in NR observed wit both (Delta NRN + A) was not sign ificantly different from the sum Delta NRN + Delta NRA: 1.16 +/- 0.53 cm H2 O/L/s vs 1.25 +/- 0.63 cm H2O/L/s, respectively (p > 0.05). Delta NRN + A s trongly correlated wit Delta NRN + Delta NRA: Delta NRN + A = 0.80 (Delta N RN + Delta NRA) + 0.15 (r = 0.96; p < 0.0001). However, the slope of the re gression line of Delta NRN + A vs Delta NRN + Delta NRA was significantly l ower than unity (p < 0.003). These results demonstrate that, although not t otally additive, the effects of using the mechanical dilator and fenoxazoli ne hydrochloride are cumulative. Further studies that include patients with nasal obstruction would allow us to better evaluate the benefit of a thera py combining both treatments.