Atypical chronic lung disease patterns in neonates

Objective. To determine, in the postsurfactant era, the incidence and clini cal characteristics of infants with atypical versus traditionally defined b ronchopulmonary dysplasia (BPD) among premature infants with birth weights <1251 g. Design. Retrospective cohort study. Setting. A single regional neonatal intensive care unit Patients. Two hundred thirty-two premature infants <1251 g at birth consecu tively admitted during a 2-year period. Main Outcome Measure. Incidence of classic BPD and atypical chronic lung di sease (CLD) (occurring without preceding respiratory distress or after reco very from respiratory distress). Results. Among 177 infants <1251 g who survived to 28 days, 27 (15%) had at ypical CLD and 61 (34.5%) had classic BPD. Atypical CLD infants were signif icantly heavier and more mature than classic BPD infants (mean birth weight s, 922 +/- 152 g vs 854 +/- 173 g; and mean gestational age, 26.8 +/- 1.3 w eeks vs 26.1 +/- 1.6 weeks). Median duration of ventilator support (31 days ; range, 2 to 127 vs 42 days; range, 4-145 days) and oxygen therapy (30 day s; range, 11 to 163 vs 48 days; range, 19-180 days) were shorter in atypica l CLD infants than in classic BPD infants. Conclusion. Atypical CLD comprised 31% of total cases of CLD. Atypical CLD appears to be less severe than classic BPD. These data suggest that initial , acute lung injuries are not the sole antecedents of neonatal CLD.