The modern method of prenosological diagnosis of respiratory function abnormalities in smokers

The study was performed for measuring the fall in pulse oximetry saturation caused by 20-s breath-holding (dSO2) at the end of expiration in nonsmokers and smokers with normal spirometry parameters. Ventilation perfusion ratio unevenness at apnea because of peripheral airways abnormalities in smokers may be the main reason of great arterial oxygen desaturation. Our date indicate that during apnea of different genesis, smokers may suffer greater risks of hypoxemia compared with nonsmokers. Breath-holding test may reveal an early stage of gas-exchange abnormalities of the lung in smokers. It may be useful to help subjects recognize potentially severe lung disorders and to promote more effective behavioral intervention.