To determine if there is a specific postnatal (PNA) or postconceptional age
(PCA) at which ventilated preterm infants respond to β-agonists, we evaluated 15 infants
with a mean gestational age of 26.5 ± 1.5 weeks and mean birth weight of 0.89 ± 0.23 kg
who required mechanical ventilation at 10 days of age. Weekly pulmonary function testing
(PFT) was performed before and 1 h after administration of albuterol. Taking the group as a
whole, as well as individual babies, regression analysis showed no relationship between positive
response and either PNA or PCA. Evaluation of individual infants, however, showed
that some consistently responded to ß-agonists whereas others did not. We recommend
individual PFT to identify those infants who will benefit from use of β-agonists.