(5) Patent Ductus Arteriosus Is Associated with Lower Post-ductal Arterial Pressure Indices in Extremely Preterm Infants

Adrianne Rahde Bischoff, University of Iowa, United States; Regan E. Giesinger, University of Iowa, Iowa City, IA, United States; Amy H Stanford, University of Iowa Stead Family Children's Hospital, United States; Danielle R Rios, University of Iowa Stead Family Children's Hospital, United States; Patrick J. Mcnamara, University of Iowa, United States

Background: Direction and volume of patent ductus arteriosus (PDA) shunt are known to have a differential impact on pre- vs. post-ductal blood flow. Therefore, the location of arterial pressure (AP) measurement, and specific patterns of systolic, diastolic, and mean AP are important, but rarely considered, clinical considerations.

Objectives: Characterize pre- and post-ductal AP indices in extremely preterm neonates according to presence and volume of PDA shunt.

Design/Methods: Observational study of infants who underwent comprehensive targeted neonatal echocardiography (TnECHOs) (September 2019-March 2021). Studies were included for neonates born ≤28 weeks gestational age in the first 14 postnatal days. Major forms of congenital heart disease and PDAs with bidirectional/right-to-left shunts were excluded. APs were obtained immediately at the end of the TnECHO, with appropriately sized cuffs for the right arm and one of the legs. When available, invasive AP was recorded. The modified Iowa PDA score was calculated for all assessments and used to classify the different groups of PDA shunt volume(Figure 1).

Results: A total of 221 TnECHOs were included. Baseline illness severity indices were not different between the groups(Table 1). Patients with PDA had lower post-ductal AP indices overall, which was magnified in moderate to high volume shunts. Post-ductal (umbilical arterial catheter and leg oscillometric) AP indices had higher correlation, particularly in infants with no PDA; pulse pressure had poor correlation between the different modalities(Table 2).

Conclusion: A discrepancy between pre- and post-ductal AP indices may suggest the presence of a PDA in extremely preterm infants.