Hyperinflation in premature infants at preschool age

Functional residual capacity was measured by helium gas dilution in 12 children born very preterm (gestational age 25-29 weeks). The children were studied at between 4.0 and 4.6 years of age. Their results were compared to those of 12 control children who were born at term without neonatal problems. The controls were matched to the children born preterm for age, race and gender. The children born preterm had significantly increased functional residual capacity values when compared to the control subjects (p less than 0.01). Eight children born preterm were hyperinflated (functional residual capacity greater than 120% of that predicted for height) compared to only one control subject (p less than 0.01). Five children born preterm and one control had a positive response to bronchodilator administration. These results suggest infants born very preterm may suffer from chronic hyperinflation.