Relationship between nasal patency and clearance.

Nasal airway patency and nasal clearance were measured bilaterally on six different test days in ten subjects. Nasal patency was evaluated using anterior rhinomanometry and clearance was measured using a dyed saccharin method. The results showed large intra- and inter-subject variances in the clearance times. Clearance times determined by the saccharin taste method were shorter than those determined by the dye method, but these measures were positively correlated. Also, the mean clearance rate was directly related to the mean nasal conductance. In seven of ten subjects, the clearance rate for a given side of the nasal passage was relatively faster when that side was the more patent. These results suggest that the clearance rate is a function of the patency of the nasal passage and may also exhibit alternating cyclic fluctuations.