Asymmetry in the nasal mucociliary transport rate.

Several methods have been devised for measuring the nasal mucociliary transport rate (N-MTR), but only one side of the nose has usually been studied. This study was conducted to determine whether there are side-to-side differences in N-MTR. A radioisotopic method was used to investigate 185 patients with various respiratory symptoms. Bilateral measurements were performed in the 111 patients with an N-MTR of under 7 mm per minute. In 16 healthy control subjects, the N-MTR ranged from 5.0 to 14.6 mm per minute (mean: 7.8 mm per minute) in the better nostril and from 1.2 to 11.0 mm per minute (4.3 mm per minute) in the poorer nostril (P<.001). In the 111 patients, the N-MTR ranged from 0.0 to 12.0 mm per minute (3.5 mm per minute) in the better nostril and from 0.0 to 9.5 mm per minute (1.7 mm per minute) in the poorer nostril (P<.001). In the control subjects, the mean N-MTR was better (P=.011) in the decongested nostril. Even when the N-MTR was less than 5 mm per minute on the first measured side, it was normal on the opposite side in 18.9% of patients and in 18.8% of control subjects. The author concluded that if the N-MTR is impaired in one nostril, it should also be measured in the opposite nostril.