Lung transfer for carbon monoxide during the first three years of life.

Lung transfer for CO (TLCO) was measured in 35 healthy infants. A steady state, non-invasive method using a technique of alveolar sampling was employed [3]. During the first three years of life, TLCO expressed as mmol.min-1.kPa-1 increased linearly with height (cm): y = 0.036x - 1.15 (r = 0.91); with body weight (kg): y = 0.18x - 0.005 (r = 0.85); with body surface area (m2): y = 3.48x - 0.375 (r = 0.88); and with logn of age (months): y = 0.406x + 0.184 (r = 0.88). FRC was also measured in 29 of these infants by the helium dilution technique. FRC expressed in ml increased linearly with logn of age: y = 62.24x + 62.4 (r = 0.86) and was correlated with TLCO: y = 0.05x + 0.084 (r = 0.8). TLCO and FRC were correlated with the number of alveoli [7, 9]. Thus, in the first three years of life, lung volume and lung gas transfer seem to progressively adapt in order to satisfy energetic needs during growth.