Determination of diffusing capacity by modeling the dynamics of C18O uptake in newborns.
Dynamic modeling of lung C18O diffusion is used to measure the C18O transfer factor (TLCO) of 14 newborns aged 1-4 mo. The model equation is based on the alveolar fractions of C18O and on changing alveolar ventilation induced by the rebreathing conditions. The model does not involve the volume of the rebreathing bag which is usually needed when applying rebreathing technique and which is a source of error. The equation is discretized and solved for recorded data obtained with equipment adapted to use in newborns. A least-square parameter calculation technique is applied to estimate TLCO. Results show a strong relationship between this index and the biometrical ones and confirm those found in the literature featuring that the measurement duration can be considerably shortened.
Bouferrache
B
B
U.R.A.P.C., Faculté de Médecine, Amiens, France. urapc@burotec
Krim
G
G
Mejdoub
N
N
Quanjer
P H
PH
Freville
M
M
Libert
J P
JP
D000704:Analysis of Variance; D002248:Carbon Monoxide / Q000378:metabolism*; D004867:Equipment Design; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D016018:Least-Squares Analysis; D016014:Linear Models; D008168:Lung / Q000378:metabolism*; D008176:Lung Volume Measurements; D013058:Mass Spectrometry; D008954:Models, Biological; D011653:Pulmonary Diffusing Capacity; D012119:Respiration; D014692:Ventilation-Perfusion Ratio
D002248:Carbon Monoxide