Abstract
The variability of measurements of steady state DLCO (diffusing capacity of the lungs for CO) according to Filley-Linderholm, during exercise, was studied in 14 healthy subjects. PacO2 was measured with a PCO2-electrode. The variability in the DLCO measurements was 7. 2%. The introduction of the correction for the pulmonary mean capillary CO-pressure eliminated the influence of the CO-accumulation in blood when measuring DLCO repeatedly. The corrected values were systematically higher, 3. 8 ml/min/mm Hg, than those not corrected. The repro-ducibility of the analytical methods employed is reported as well as the variability of a number of data measured or calculated in connection with the DLCO determinations.