DECREASED ALVEOLARIZATION IN BABOON SURVIVORS WITH BRONCHOPULMONARY DYSPLASIA

In this study, 12 male baboons were delivered by hysterotomy at 75% of gestation. The development of a nonlethal baboon model permitted a st udy of lung growth and development in long-term survivors. Control ani mals were ventilated with clinically appropriate oxygen for the 21 d s tudy period. BPD animals were ventilated with PPV and an FIO2 of 1.0 f or 7 d, followed by an FIO2 of 0.8 for 14 d. They survived for 33 wk, at which time a right lower lobe lobectomy was performed. Controls sho wed normal well-alveolated lungs, whereas BPD lungs showed enlarged ai rspaces focally, nonclassifiable as alveoli, alveolar ducts, or respir atory bronchioles. Volume densities of alveoli were decreased signific antly (p = 0.0009), and enlarged airspaces were significantly increase d (p = 0.0003) in the BPD group compared with controls. Alveolar count s verified a significant decrease in alveoli (p = 0.004), and the inte rnal surface area was significantly decreased (p = 0.05) in BPD treate d animals compared with controls. These data document that a mild to m oderate BPD lesion results in a significant and permanent loss of alve oli and a significant increase in enlarged, unclassifiable airspaces, which together result in a decreased total internal surface area in ba boons that survive with their disease.