On measurement of the CO pulmonary diffusing capacity in each lung by a modified endtidal sampling method

　Split CO pulmonary diffusing capacity wasrneasured in 10 normal sujects and 14 caseswith pulmonaly djseases by modified endtidalsampling methhod, and the following conclusionwas obtained．

　1）　This method is very useful as clinicalfunction test to measure Dco in each lungbecause of the easiness, repeatability andreproducibility．

　2）　Distribution ratio of Dco in the rightand left lung of normal subjects is 56：44．

　3）　In patients with pulmonary tuberculosisand bronchiectasis Dco in the diseased lungdecreased with the extent of disease and asignificant correlation was found betweenDco and O₂ uptake in the diseased lung．

　4）　In patients with lung cancer, a markeddecrease of Dco was found in the diseaselung, particularly in the case whose tumoris located near the hilar region, inspite ofnearly normal ventilatory function．