New Insights on Early Patterns of Respiratory Disease among Extremely Low Gestational Age Newborns

Background: The analysis of early patterns of lung disease among preterm infants may help to identify predictors of pulmonary deterioration. Objectives: To analyze FIO₂ requirement in the first 14 days of life among preterm infants and to find predictors of bronchopulmonary dysplasia (BPD). Methods: Retrospective cohort study. Setting: 3 Italian level III NICUs. Population: Infants born between 24^0/7 and 27^6/7 weeks' gestational age (GA) who survived to 14 days. A consecutive sample of 588 infants was analyzed. Daily mode FIO₂ in the first 2 weeks of life were analyzed according to the criteria defined by Laughon et al. [Pediatrics 2009;123:1124-1131], who found 3 early respiratory patterns: Consistently low FIO₂ (LowFIO₂), pulmonary deterioration (PD), and early persistent pulmonary deterioration (EPPD). Factors associated with pulmonary deterioration were studied by univariate and multivariate analysis. Results: Forty percent of infants had low FIO₂, 18% had pulmonary deterioation, 21% had early persistent pulmonary deterioration, and 21% had a previously unreported pattern (pulmonary improvement, PI). The prevalence of BPD was 7% in the LowFIO₂ group, 28% in the PI group, 44% in the PD group, and 62% in the EPPD group (p = 0.000). Infants with lung deterioration were more frequently males (OR = 2.019, CI: 1.319-3.090, p = 0.001), had lower GA (OR = 0.945, CI: 0.915-0.975, p = 0.000), higher incidence of severe respiratory distress syndrome (OR = 2.956, CI: 1.430-6.112, p = 0.003), and lack of postnatal caffeine (OR = 0.167, CI: 0.052-0.541, p = 0.003). Conclusions: We report 4 distinct patterns of early respiratory disease associated with significantly different prevalence of BPD and discuss risk factors for lung deterioration.