Effect of Cigarette Smoking on the Tidal Carbon Dioxide Profile

ABSTRACT

Four indices have been tested for quantitative description of the form of the expiratory partial pressure carbon dioxide curves within a group of 80 male smokers with normal routine spirometry. The control group consisted of 60 healthy nonsmokers whose age and residence matched those of the smokers. The tests demonstrated statistically significant differences between smokers and the control group. Gamma angle index and planimetric index displayed high sensitivity to the quantitative description of the capnographic curves, whereas the concomitant cough and sputum production or the smoking index did not. The data produced show that capnographic indices provide valuable data on ventilation-perfusion ratio dysfunction and also, indirectly, on small airways in smokers with normal conventional spirometry.