[State of the ventilatory function of the lungs in heavy smokers].

Computed spirography, He/O test and capnography evaluation of external respiration has been carried out for 52 subjects. Of these 27 were nonsmokers, 25 smoked but had no history of respiratory diseases. The integral criteria of external respiration obstruction (MOCmax, MOC50, MOC75) proved inadequate diagnostic tool for early detection of ventilatory alterations in smokers who are at risk to develop chronic nonspecific pulmonary diseases. Pharmacological tests, He/O investigation and capnography did reveal defects in small bronchi permeability in all the smokers. Problems of pathogenesis of obstructive affections of distal regions of the bronchial tree are under consideration.