Relationship of smoking history and pulmonary function tests to tracheal mucous velocity in nonsmokers, young smokers, ex-smokers, and patients with chronic bronchitis.

Abstract

Smoking history was related to pulmonary function and tracheal mucous velocity. Groups were defined by (1) smoking history; (2) history of chronic productive cough; (3) the presence of major airway obstruction defined by 1-sec forced expiratory volume <70 per cent of predicted; and (4) signs of small airway obstruction, i.e., combinations of abnormal closing volume, abnormal volume of isoflow, and uneven N2 washout. Tracheal mucous velocity was faster in young than old nonsmokers. Five of 13 (38 per cent) young smokers had tracheal mucous velocity within the range of age-matched nonsmokers, but the remainder had markedly depressed values. Neither smoking history nor pulmonary function distinguished smokers with decreased tracheal mucous velocity from those with normal velocity. Five of 9 (56 per cent) young ex-smokers had values within the range of age-matched nonsmokers, whereas 4 of 9 (44 per cent) ex-smokers had markedly decreased tracheal mucous velocity. Neither smoking history nor pulmonary function...