[Incidence of bronchopulmonary dysplasia]

The incidence of bronchopulmonary dysplasia (BPD) was retrospectively studied in all ventilated newborns at a neonatal intensive care unit of a university based hospital at Santiago, Chile along a 5 years period (1983-1987). BPD incidence among the whole sample of newborn infants requiring artificial ventilation was analysed according to birth weight (BW) and compared with that of newborns surviving after 28 days of life. The possible association of BPD with hyaline membrane disease (HMD), ductus arteriosus (DA) and pulmonary air leak (PAL) was studied. The total number of ventilated newborns was 200, incidence of BPD was 9.5% (19/200) and lethality for BPD was 5.2% (1/19). The incidence of BPD increased progressively with decreasing BW, reaching 37.5% in infants less than 1,000 g (p less than 0.001 chi 2). Among 28 day survivors incidence of BPD in the same BW group increased to 75% (p less than 0.05). These findings support the idea that the incidence of BPD increases with improved survival of low birth weight infants. A positive association of BPD with DA and PAL was seen with 10/19 versus 33/181 incidence for DA (p less than 0.01) and 6/19 versus 16/181 for PAL (p less than 0.01) among patients with and those without BPD respectively, but not with HMD.