LUNG COMPLIANCE AND LUNG VOLUME MEASURED CONCURRENTLY IN NORMAL FULL-TERM AND PREMATURE INFANTS

Abstract

Lung compliance and functional residual capacity have been measured simultaneously, using a body plethysmograph, in 35 full-term and 29 premature infants. The results suggest the following conclusions: 1. Lung compliance increases in the early hours of life, while no significant change of FRC is demonstrated. This may reflect a true alteration of lung tissue properties. 2. Specific lung compliance in full-term infants older than 24 hours of age is similar to that of older children and young adults. 3. Premature infants have a larger FRC/kg of body weight than full-term infants, but, when lung weight is used as the basis for comparison, the FRC in infants of all weights is similar. 4. In evaluating infants with the respiratory distress syndrome, one should be aware of the small specific lung compliance noted in full-term infants younger than 3 hours of age.