Transfer factor for CO during exercise in children.

The transfer factor of carbon monoxide (TLco) has been measured in 40 normal schoolchildren by the steady state method during treadmill exercise. The fractional uptake of CO diminished with increasing oxygen consumption and the nett CO uptake was linearly correlated with oxygen consumption. The TLco at two work levels was significantly correlated with height and increased moderately with increasing work. The highest values of TLco during strenuous exercise were approximately three times those reported at rest. The pulmonary diffusing capacity or transfer factor for carbon monoxide (TLco) has been studied in adults at rest and on exercise, in health The steady state method of measuring pulmonary diffusing capacity, as modified by Bates, Boucot, and Dormer (1955) for assumed respiratory dead space, is a relatively easy test to carry out, especially on exercise. We have therefore used this method to obtain exercise values for TLco in normal children.