Chronic lung disease following neonatal ventilation. II. Changing incidence in a geographically defined population

Abstract

The objective of this study was to examine the change in incidence of chronic lung disease following neonatal ventilation in a geographically defined population. Prospective data were collected over two 1-year periods (1987-1988 and 1990-1991) in the Trent Health Region, England. All infants were < or = 32 weeks gestation and/or < or = 1500g birthweight, born to mothers normally resident in the Trent Health Region. The principal outcome measures were mortality rate, presence of chronic lung disease, days of ventilation, and oxygen used by each infant. The proportion of low gestation, low birthweight babies was 1.5% in each period, made up of 897 and 925 babies from 61,050 and 63,350 births, respectively. There was a significant fall in mortality in infants of 750-1500g birthweight. However, the incidence of chronic lung disease (using either of two definitions) rose significantly between the two periods, with a corresponding large rise in the amount of respiratory care required. The contribution of various antenatal factors previously thought to be related to the development of chronic lung disease was examined. Birthweight and gestation were shown to be of overwhelming significance. We concluded that improvements in neonatal care, including the introduction of surfactant therapy, improved survival for some infants at the expense of an increased incidence of chronic lung disease. Clearly the hoped-for cost saving following the introduction of surfactant therapy has not occurred.