Outcome of respiratory distress syndrome at 28 days: a prospective longitudinal study.

Fifty eight newborn infants with respiratory distress syndrome (RDS) were prospectively studied, in order to determine clinical variables prognostic of poor outcome at 28 days. Twenty six infants survived without bronchopulmonary dysplasia (BPD), 13 had Type 1 BPD, 4 had Type 2 BPD and 15 infants died before 28 days. Survivors without BPD had higher birthweights and gestational ages. Among the other infants, severity of initial lung disease was the best discriminator between outcome groups: Type 1 BPD infants had the best lungs at onset, and the nonsurvivors had the worst lungs. Stepwise multiple logistic regression identified gestational age and the ventilatory index number 1 (VI1) (= respirator frequency x maximal inspiratory pressure) at day 3 as the most useful variables to predict "poor outcome" (nonsurvival or Type 2 BPD). Ninety five percent of the infants were correctly classified using a cut-off probability of 0.5. We conclude that RDS outcome at 28 days is determined at a very early stage and that poor outcome can be predicted with reasonable accuracy at three days of age.