Neonatal lung function in very immature infants with and without RDS

Some infants. despite bring born at low gestations(< 28 weeks gestational a ge) do not develop RDS and are not surfactant treated. The changes in lung function during the neonatal period in such infants have nor been explored, hence it is unknown whether they are similar to those of surfactant treate d infants with RDS of similar gestational age. Such data would facilitate a ssessment of the impact of surfactant administration on the lung function a bnormalities of very immature infants with RDS. We, therefore, compared the results of neonatal lung function measurements from immature infants with RDS who received surfactant to those from infants with non-RDS respiratory distress not so treated and matched to the RDS infants for gestational age and within 10 % of birthweight. Compliance and functional residual capacity (FRC) were measured daily for the first five days and then at 1, 2 and 4 w eeks in 16 infants, median gestational age 27 weeks (range 25-27 weeks). Al though exogenous surfactant administration to the immature infants with RDS was associated with improvements in lung function, the non RDS, non surfac tant treated infants had both higher compliance (p<0.05) and lung volumes ( p < 0.01)throughout the perinatal period. These results demonstrate surfact ant administration does not fully correct the perinatal lung function abnor malities of very immature infants with RDS.