ABSTRACT
With the increasing survival of extremely premature infants there is a large number
of them who are developing chronic lung disease (CLD), but the severity of the lung
damage is considerably less than that observed in the classic form of bronchopulmonary
dysplasia (BPD). Because many of these infants have only a mild initial respiratory
distress and therefore do not receive aggressive ventilation, it is clear that factors
other than oxygen toxicity and barotrauma are involved in the pathogenesis of this
new milder type of CLD. CLD results from the interaction of multiple factors that
can injure the immature lung. For this reason the prevention must be based on the
elimination of all the factors implicated in its pathogenesis. Clinical and epidemiological
data strongly suggest that infections, either prenatal or nosocomial, and the presence
of a patent ductus arteriosus (PDA) play a major role in the development of CLD in
these infants. For this reason, efforts to prevent CLD in extremely low birth weight
infants should include an aggressive approach to the prevention and treatment of prenatal
and neonatal infections and an early closure of the PDA.
KEYWORD
Prematurity - chronic lung disease - bronchopulmonary dysplasia - lung injury - mechanical
ventilation - patent ductus arteriosus - inflammation
