Comparative evaluation of reserve capacity of respiratory system in smokers and nonsmokers

The force and velocity parameters of respiratory system, as well as the dynamics of blood oxygen saturation in the test with a 20-second breath-hold were studied in 24 adults (12 smokers and 12 nonsmokers). Maximal inspiratory pressure (MIP), peak inspiratory flow (PIF) and peak expiratory flow (PEF), as well as the measurement of the fall in pulse oximetry saturation caused by 20-s breath-holding (dSaO 2) at the end of expiration was studied in 12 nonsmokers and 12 smokers. Our results showed significant reduction of PEF and PIF in a group of men and women smokers compared with nonsmokers. MIP had a trend to decrease in smokers, especially in women’s group. It was found that a temporary reduction in hemoglobin oxygen saturation caused by 20-sec apnea is significantly higher in smokers than non-smokers. Disturbance of ventilation-perfusion relationships during apnea because of the typical smoker disorders of the peripheral airway patency can be a major cause of severe oxygen desaturation. Smokers are at greater risk of hypoxemia during any apnea than nonsmokers.