Studies on the pulmonary diffusing capacity of carbon monoxide at two different levels of the inspired carbon monoxide concentrations

　1）　The modified Filley’s steady statemethod were done to assess the pulmonary dif—fusing capacity of carbon monoxide in variouspulmonary diseases．

　2）　14 cases with chronic pulmonary emphy—sema,6cases with manifested bronchial as—thma,6cases with diffuse bronchiectasis, 4cases with essential pulmonary fibrosis, 4cases with pulmonary tuberculosis,4 caseswith diffuse sclerodermia, and 4 normalhealthy were used for the study．

　3）　The duplicated measurements of thepulmonary diffusing capacity at differentcarbon monoxide concentrations of 800 PPMand l500 PPM were done．

　4）　The deviatioll of the pulmonary dif—fusing capacity at two different levels wascalculated．12 cases out of 42 Patients re—vealed their deviation exぐeeding 30％　and 6cases among those 12 cases showed the devia—tion exceding 50％．

　5）　The effects of the ventilatory functions，of the intrapulmonary distribution of inspiredgas, or of the arterial blood gases on causingthe referring deviations were discussed．

　6）　From the data presetted in this paperany definite conclusion to cause the referringdeviation of the pulrnonary diffusing capacitywas not introduced．

　7）　The importance to make the simulta—neous measurements of the pulmonary bloodvolume, cardiac output, or of the contact timewas emphasized as for the next steps of thispresented investjgations．