Carbon monoxide diffusing capacity in normal male subjects, age 20–60, during exercise

¹ Cardiopulmonary Laboratory, University of Vermont College of Medicine, Mary Fletcher Hospital, Burlington, Vermont

The pulmonary diffusing capacity for carbon monoxide has been determined during steady-state treadmill exercise in 100 normal males, age 20–60 years. The method described provides a simple and acceptable technique for determination of diffusing capacity, obviating the need for arterial blood. Mean normal values and limits of normal have been established for the various age groups. Results agree closely with less extensive studies in the literature. The normal range for the Dco is seen to be quite wide, and the clinical value of the determination as a screening test is questioned.