The association between early tracheal colonization and bronchopulmonary dysplasia

Objective: To evaluate the relationship between early tracheal colonization and bronchopulmonary dysplasia (BPD). Study design: This is a retrospective cohort study which included 308 inborn, neonates admitted to the newborn intensive care unit at the University of Miami Jackson Memorial Medical Center between January 1997 and December 2000 with birthweight 500 to 1000 g, who required mechanical ventilation on the first day of life. Chorioamnionitis was diagnosed by maternal symptoms and histopathopathology. Tracheal cultures were obtained immediately after tracheal intubation. BPD was diagnosed in neonates who had supplemental oxygen requirement for more than 28 days. Pearson's χ² and Logistic Regression Analysis were used to evaluate the relationship between chorioamnionitis, positive initial tracheal cultures and BPD, after adjusting for confounding variables. Results: In patients with chorioamnionitis, the incidence of early positive tracheal cultures was 41% compared to 16% in those without chorioanmionitis, (P<0.0001). In patients with birthweight 700 to 1000 g, a positive early tracheal culture increased the risk of BPD (OR = 2.42, CI 1.05 to 5.62, p<0.05). Conclusion: Preterm infants exposed to chorioamnionitis have an increased incidence of early tracheal colonization. This early tracheal colonization may predispose them to develop BPD.