Respiratory compliance in premature babies treated with artificial surfactant (ALEC).

In a randomised trial of artificial surfactant (ALEC) given at birth to 294 babies less than 34 weeks' gestation, the respiratory compliance was measured at 1, 6, 24, 48, and 168 hours after birth. In babies less than 29 weeks' gestation ALEC significantly improved the mean (SEM) compliance at 6 hours from 0.54 (0.06) to 0.91 (0.13) ml/cm H2O/kg and at 24 hours from 0.57 (0.04) to 0.92 (0.10) ml/cm H2O/kg. The improvements at 1, 48, and 168 hours were not significant. In babies of over 29 weeks' gestation the compliance was lower in the ALEC treated babies. This was significant only at one hour: 0.52 (0.03) compared with 0.71 (0.07) ml/cm H2O/kg and only occurred in babies who were not ventilated.