[Comparison in patients with chronic bronchitis of the data offered by the output-volume loop and the transfer capacity of CO]

The present study concerns 78 cases of chronic bronchitis (mean age : 55,3 years) submitted to a complete enough functional respiratory study (spirometry, RV, blood gases) and distributed into three groups:--Group I: 78 cases, mean age : 55 years. All these patients were submitted to spirometry, blood gases determination and determination of the transfer capacity of CO (by making use of the method under single breath : 54 cases,--or the method with steady state : 24 cases).--Group II : 15 cases, mean age 54 years. All these patients were submitted to spirometry, blood gases determination, determination of the transfer capacity of CO with the method under single breath and to a determination of the V (60-70%) CT output on the output-volume loop.--Group III : 13 cases, mean age 53,9 years. All these patients were submitted to spirometry, blood gases determination, determination of the transfer capacity of CO with the method under steady state and a determination of the V (60-70%) CT output on the output-volume loop. The comparison of the data and the study of the eventual correlations between the various parameters determined suggests that the determination of the V (60-70 %) CT on the V/V loop is a more reliable parameter of the obstructive ventilatory syndrome than the determination of the disorders in the transfer capacity of CO. This latter method of study under steady state appears often modified when there exists an alveolar (as yet mentioned by other authors); however, this is not the case when the test is performed under single breath. In the detection of chronic bronchitis, the informations obtained with the determination of the V (60-70 %) CT output appear thus to assume a great value, but these results necessitate to be verified in a greater number of patients.