A Comparison of Nasal and Tracheobronchial Clearance

Abstract

Tracheobronchial clearance and nasal clearance were compared in 13 pairs of monozygotic twins and 11 nontwins. Tracheobronchial clearance was studied by having the subjects inhale, by mouth, a test aerosol of 6μmol particles tagged with technetium Tc 99m (^99mTc) and making external measurements of the radioactivity. Nasal clearance was studied with two methods: (1) a 0.6-mm anion resin particle tagged with ^99mTc was externally followed at five different points along the nasal passage and (2) a saccharine particle was placed on the mucociliary mucosa anteriorly in the nose and the time was registered until the subject noted a sweet taste. A weak positive association existed between tracheobronchial clearance and nasal clearance as studied with the saccharine particle method, but no association was found between tracheobronchial clearance and nasal clearance as tested by the tagged resin particle method.