Rhinomanometric detection rate of rhinoscopically-assessed septal deviations.

Normal values for the flow at a transnasal pressure of 150 Pa were established with active anterior rhinomanometry (with decongestion) in a group of 33 normal subjects. These values were used to detect abnormalities in a group of 193 patients whose septum anatomy had been evaluated with rhinoscopy. About 25% of the rhinoscopically normal patients were found to have significantly low ("abnormal") flow values on one side. The same was true for patients with a small septal deviation restricted to one anatomical area. An abnormal flow was measured in about 35% of the patients with a moderate (restricted) septal deviation. In the patients whose septal deviation was not restricted to one anatomical area, about 45% had an abnormal flow. The highest detection rate was about 80% in patients with major deviations in the region of the vestibule and the valve. Such deviations were found only in a minority of the patients with complaints of nasal obstruction, which limits the importance of rhinomanometric evaluation in clinical practice.