Impact of chest radiography‐based definition of bronchopulmonary dysplasia

Abstract

Background Bubbly/cystic appearance on chest radiograph is an important factor in severe‐type bronchopulmonary dysplasia (BPD) in Japan. The aim of this study was to determine the perinatal characteristics and neonatal complications of the bubbly/cystic(+) group in extremely preterm infants with BPD, that is, oxygen dependency at day 28 after birth (BPD28). Methods This was a multicenter retrospective cohort study of population data from infants (birthweight, <1,500 g) enrolled in the Neonatal Research Network of Japan. Of the 15 480 infants born at <28 weeks’ gestational age (GA) between 2003 and 2012, 8,979 met the BPD28 criteria. The BPD28 infants were classified according to bubbly/cystic appearance on radiograph (±) at >28 postnatal days. Results The bubbly/cystic(+) group had lower GA and birthweight and required longer mechanical ventilation and oxygen dependency than the bubbly/cystic(−) group. After adjustment for confounding factors, bubbly/cystic appearance was an independent risk factor for home oxygen therapy at discharge. Conclusion Bubbly/cystic appearance on chest radiograph was a predictor of short‐term respiratory outcomes in infants with BPD28, which is diagnosed much earlier (≥28 postnatal days), and has a potentially different etiology to BPD36 (oxygen and/or positive pressure respiratory support dependency at 36 weeks’ postmenstrual age).

Bubbly and cystic appearance on chest radiograph of extremely preterm infants with bronchopulmonary dysplasia is associated with wheezing disorder

“…Moreover, BPD28 infants were classified based on the bubbly/cystic appearance on CXR at ≧28 days postnatal age, as previously described. 12 The bubbly/cystic appearance was defined as diffuse, streaky infiltrates with small cystic areas (diameter, 1-10 mm) 6,7 (Figure 1). The diagnoses based on the CXR findings were made after postnatal day 28 by the neonatologists of each institution.…”

“…Although BPD is associated with worse respiratory outcomes, whether the bubbly/cystic ± BPD28 classification is associated with long‐term respiratory outcomes remains unclear. We aimed to determine whether the CXR classification was associated with long‐term respiratory or neurological outcomes in the same cohort group as examined previously …”

“…In addition, it is possible that the bubbly/ cystic ± BPD28 classification could be diagnosed at an earlier stage (≧28 days postnatal). 12 One of the purposes of defining BPD is to provide a prognosis for respiratory outcomes. 1 Although BPD is associated with worse respiratory outcomes, 13 whether the bubbly/cystic ± BPD28 classification is associated with long-term respiratory outcomes remains unclear.…”

“…We aimed to determine whether the CXR classification was associated with long-term respiratory or neurological outcomes in the same cohort group as examined previously. 12…”

“…We showed an association between extremely preterm infants with bubbly/cystic+ BPD28 and a higher rate of home oxygen therapy in a Japanese population‐based cohort study. In addition, it is possible that the bubbly/cystic ± BPD28 classification could be diagnosed at an earlier stage (≧28 days postnatal) …”