Persistent Ductus Arteriosus in Critically Ill Preterm Infants

Introduction: Persistent ductus arteriosus (PDA) is found with increased incidence in preterm infants, significantly affecting neonatal morbidity and mortality rates.

Aim: To evaluate the association between the presence of PDA and the severity of clinical condition at birth in critically ill preterm infants, with gestational ages (GA) ≤ 32 weeks and severe respiratory distress.

Methods: All preterm infants with GA ≤ 32 weeks admitted to the neonatal intensive care unit (NICU) of the Clinical County Emergency Hospital, Sibiu between 1 January 2010 and 31 December 2015 were included in the study. These were categorized as Group 1 [Preterm infants with PDA; n=154] and Group 2 [Preterm infants without PDA; n=186]. Epidemiological and clinical data were collected in the National Registry for Respiratory Distress Syndrome for all children, and data related to prenatal period, clinical characteristics at birth i.e GA, weight, gender, Apgar scores, and clinical features such as resuscitation at birth, surfactant administration, need and duration of respiratory support, neonatal sepsis, complications associated with prematurity, and death, were analyzed.

Results: Group 1 infants had significantly lower GA and birth weights, were more often out born (p=0.049, HR 1.69), and had significantly lower Apgar scores at 1 and 10 minutes (p=0.022, p=0.000). They presented a significantly higher need for surfactant administration (42.9% vs 24.7%, p<0.0001) and respiratory support (96.8% vs 90.3%, HR 3.19, p=0.019 for need of CPAP and 22.1% vs 10.8%, HR 2.35, p=0.004 for mechanical ventilation). Duration of respiratory support was also significantly higher in the Group 1 (7.6%±7.5 vs. 5.1±3.8 days, p<0.0001 for CPAP and 20.1±22.5 vs. 12.0±15.7 days, p<0.0001 for mechanical ventilation).

Conclusion: In very preterm infants, PDA may be associated with a critical clinical condition leading to serious complications. The presence of PDA after the seventh day of life was associated with an increased need for respiratory support, both CPAP and mechanical ventilation, increased severity of the respiratory distress syndrome, requiring a longer duration of respiratory support, and increased the hospitalization length. In very preterm infants, PDA presence was also associated with a higher rate of severe complications and death, indicating the need for a careful and proper management of these critical cases in neonatal intensive care units.