The importance of side difference in nasal obstruction and rhinomanometry: a retrospective correlation of symptoms and rhinomanometry in 1000 patients

Abstract

Objectives: The correlation between subjective and objective outcomes of nasal obstruction is still a matter of controversy. The aim of this study was to determine the minimal level of side difference in nasal airway resistance (NAR measured by Broms'v(2)) between the two nasal cavities, which could be discerned subjectively by the patient on a visual analogue scale (VAS). Nasal airway resistance was calculated from rhinomanometric measurements of nasal airflow and transnasal pressure after decongestion of the nasal mucosa.

Design: A retrospective study.

Setting: ENT department, Vaxjo Central Hospital, Sweden.

Participants: We studied 1000 active anterior rhinomanometries from patients with nasal obstructions.

Main outcome measures: We compared the side difference of nasal airway resistance with the side difference of VAS estimated immediately prior to the rhinomanometry. Each measurement was performed after nasal decongestion.

Results: When the difference in nasal airway resistance between the two nasal cavities was larger than 20° (Broms'v(2)) or R(2) > 0.36 Pa/cm(3) /s, we found a significant correlation between side differences of the objective measurement and the subjective assessment (VAS). With a nasal airway resistance side difference over 20°, an additional 20° difference corresponded to a 0.9 centimetre average VAS change. The more obstructed side of the nose could be determined by VAS in 823 (82.3%) of 1000 patients. Yet, 177 (17.7%) patients had a paradoxical sensation of nasal obstruction with the low resistance side of the nose experienced as the most congested side.

Conclusion: A significant correlation between the side differences of nasal airway resistance and VAS can serve as a supplement to rhinoscopy in decisions about nasal surgery. This study also showed that in 17.7% of patients, there was a negative correlation between subjective and objective evaluations of nasal airway resistance. But in this group, the nasal airway resistance side difference was mostly under 20°.