The capnogram in the study of chronic obstructive lung disease

The purpose of this study is: 1) to emphasize the importance of the capnogram in the investigation of ventilatory disorders of the obstructive type; 2) to propose a numerical parameter representative of the capnogram; 3) to ascertain, by means of this parameter, possible correlations between capnogram changes and other tests of lung function. This parameter enables a quantitative criterion to be substituted for a descriptive one in assessment of the capnogram. The study covered 245 patients with chronic obstructive lung disease. We observed that as the capnographic tracing becomes more and more pathological, the lung function tests show progressive deterioration.