Respiratory compliance of newborns after birth and its prognostic value for the course and outcome of respiratory disease.

The compliance of the respiratory system was determined at an average of 2.89 h (range 45 min - 8 h) after birth in 82 newborns who were retrospectively divided into group 1: healthy newborns (mean gestational age 37.1 weeks, range 30 - 41 weeks); group 2: newborns with respiratory distress (RD) needing no ventilatory support (mean gestational age 37.3 weeks, range 35--40 weeks); group 3: newborns with RD needing ventilatory support and surviving (mean gestational age 34.3 weeks, range 30--39 weeks), and group 4: newborns with RD who needed ventilatory support and died (mean gestational age 30.8 weeks, range 28--37 weeks). Respiratory compliance was measured by the airway occlusion technique in spontaneously breathing babies and by injecting a known volume of gas into the closed airway system and measuring airway pressure in intubated babies. The difference in postnatal compliance was statistically significant (p less than 0.01) in those four groups and was correlated with the severity of the disease in groups 2 and 3. In infants with RD, compliance was highly predictive for the need for ventilatory support (93% correct and 7% erroneous) and in infants with ventilatory support, for the mortality (83% correct and 17% erroneous). We conclude that postnatal compliance measurements are very useful to predict the course and outcome as well as to classify the severity of RD.