Postnatal Corticosteroid to Prevent or Treat Chronic Lung Disease in Preterm Infants

Bronchopulmonary Dysplasia (BPD) is a pathological diagnosis, as a result of lung injury caused by either oxygen or mechanical ventilation in premature infants with Respiratory Distress Syndrome (RDS). The “classic “or “old” BPD described by Northway four decades ago occurred in relatively large premature infants (birth weight 1500-2000 g) and occurs less nowadays. Instead a new type of chronic lung disease (CLD), often described as new “BPD” has emerged. The so called “new BPD” occurs in very immature infants who initially may have RDS or have minimal or even absent signs of RDS and subsequently develop oxygen and ventilator dependency over the first several weeks of life. The diagnosis of so called “new BPD” was also redefined. A workshop organized by NICHD/NHLBI/ORD in 2000 set diagnostic criteria based on the clinical findings (Table 1) 1 BPD now is defined only clinically as the need for supplemental O 2 for at least 28 days after birth, and its severity is graded according to respiratory support at near term. With the advance of neonatal care, more tiny infants who previously would have died now survive and remain oxygen /ventilator dependent at 28 days of age. Rate of severe BPD increases inversely with gestation age at 20% among 27 weeks to 44% at 24 weeks or less. 2