HEMODYNAMIC PREDICTION OF COMPLICATIONS IN NEONATAL RESPIRATORY-DISTRESS SYNDROME

Objectives. We hypothesized that the absence of an increase in the Dop pler-derived aortopulmonary pressure gradient (APPG) across the ductus arteriosus, which reflects pulmonary artery pressure during the first day of rife, can predict clinical complications in preterm infants wi th neonatal respiratory distress syndrome (RDS). Study design. Twenty- nine healthy preterm infants weighing 2210 +/- 244 gm (mean +/- SEM) a nd 63 infants with RDS weighing 1645 +/- 86 gm were studied with the D oppler ultrasound technique for measurement of the mean APPG at 2, 24, 48, and 72 hours of age. Of infants with RDS, 67% were treated with s ynthetic surfactant. Results. Spontaneous closure of the ductus arteri osus on the first day of life led to exclusion of 11 infants with RDS and 17 control subjects from the study. Of the remaining 52 infants wi th RDS, 26 had an increase in the APPG from 2 to 24 hours of age, and APPG values remained tow in the other 26 infants. Neonatal complicatio ns appeared more frequently (p <0.001) in distressed infants with litt le change in APPG values (Delta APPG) (22/26) than in infants with hig h Delta APPG (6/26). Six of the infants with high Delta APPG values (2 3%) needed medical or surgical closure of the ductus, but no other acu te neonatal complications occurred; 14 ((54%) of the infants with low Delta APPG required ductal closure. Between the ages of 24 and 58 hour s, five of the latter 26 infants had severe pulmonary hemorrhage, whic h was fatal in two cases. Severe (grade II or IV) intraventricular hem orrhage was seen in three infants with RDS and a low Delta APPG; one o f these infants also had severe pulmonary breeding. Pneumothorax occur red in six infants with a low Delta APPG. Infants without an increase in the APPG value during the first day of life required a significantl y higher fraction of inspired oxygen. Conclusions. Noninvasive measure ment of the change in APPG during the first day of life may provide a useful method for identifying infants with RDS at high risk of neonata l complications.