Effects of Smoking on Pulmonary Function and Arterial Blood Gas Tension in Smokers Past Middle Age

Abstract

Spirometry (%VC and FEV_1.0%) and arterial blood gas analysis (pH, PaO₂ and PaCO₂) were performed in 90 smokers (55±11 years old) and 90 non-smokers (57±15 years old) who were scheduled for general anesthesia, Although %VC did not differ significantly between smokers and non-smokers (97±17% vs 99±17%), FEV_1.0% of in smokers was signifi-cantly lower than in non-smokers (76±11% vs 83±6%, p<0.01). In arterial blood gas analysis, no significant differences in pH and PaCO₂ between smokers and non-smokers were seen (7.40±0.02 vs 7.40±0.04 in pH, and 41.4±3mmHg vs 41.1±3 mmHg in PaCO₂). PaO₂ was standardized as %PaO₂ by the equation, 100×PaO₂/(102.5-0.22×age), using the PaO₂ regression value of Conway et al. Smokers had significantly lower %PaO₂ than non-smokers (92±15% vs 99±10%, p<0.05). In addition, both FEV_1.0% and %PaO₂ in smokers decreased significantly related to Brinkman's smoking history index, the number of ciga-rette smoked per day×the duration of smoking in years. We concluded that smokers had lower PaO₂ as well as lower FEV_1.0% and need more intense respiratory care in the perioper-ative period.