Changing incidence of bronchopulmonary dysplasia

Abstract

APART FROM RARE AND ISOLATED CASESOfpulmonary fibrosis occurring in very small infants, b ronchopu l monary dysplasia was first noted at the Babies Hospital , New York City, when artificial vent i la t ion for the treatmen t of respiratory distress syndrome was insti tuted. Over the past eight years, the incidence of BPD has fal len as techniques of neona ta l care have been improved and greater experience with artificial vent i la t ion has been gained. The lower incidence occurred despite an increase in survival rate and more frequent use of vent i la tory support on very small infants. We consider that the diagnosis of BPD canno t be m a d e without a history and wi thout a s tudy of sequent ia l films. With the changing techniques of assisted venti lat ion, we now rarely see the typical stages of the disease as described by Northway. In our lnsn tunon , we have seen two types of chronic lung disease in neonates : the first in the smallest in fant with little or no respiratory distress syndrome, and the second in infants surviving severe RD S (Table I). The changing survival rates according to weight group for the period 1972 to 1977 are presented in the Figure. The improved survival rate in very small infants has occurred concurrent ly with changes in bo th obstetr ic pracnce and newborn care. There have been more l iberal indicat ions for cesarean section for p remature b reech deliveries and for the very immatu re infant with fetal distress, as well as an earlier inst i tut ion of CPAP using nasal prongs and an increased use of mechan ica l venti lation for the very immatu re infant with respiratory difficulty. The changing incidence of BPD is presented in Table II. In 1970-1971. the condi t ion was seen in only four of 85 patients with RDS. two of whom were normal at seven months and two years, respectively; two died. A s t h m a and wheezing dur ing the first four years of life were seen in