PDA management in preterm infants: keep your hands off the ductus!

Abstract

The current management of a patent ductus arteriosus (PDA) in preterm infants is fundamentally aimed at the closure of ductus through the cyclooxygenase (Cox)-inhibitors or surgical ligation in case of failure. Although the role of surgical approach to morbidity and mortality remains unclear, measures avoiding it appear entirely justified.

During the last two years, 8 newborns were admitted to our intensive care unit for surgical ligation of a hemodynamic significant PDA, after a two ineffective Cox-inhibitor courses. The mean gestational age was 26 5/7 weeks (24 6/7 - 28 3/7 w.), the mean birth weight 1,000 g (800-1,300 g) and the mean age at admission 20 days (9-29 d.) at a mean post-conceptional age (PCA) of 29 3/7 weeks (27 5/7 - 31 5/7 w.). We have submitted these newborns to an approach consisting in a continuous monitoring of cerebral and renal oxygenations, time-scheduled ultrasound controls, monitoring of blood pressure and of urine output and continuous aEEG registration. All were treated with dopamine infusion. Under dopamine, ranging from 5 to 10 μg/kg/min, the stabilization criteria (see text) were reached in 7/8 infants. Afterwards a new cycle of Cox-inhibitors has been tried with the result of closing the ductus in 4/8 and obtaining a flow closing pattern in other three. None of the seven infants has shown in the following weeks a reapparence of ductal reopening signs. In this way we avoided the surgical intervention in 7/8 newborns.

An attempt with Cox-inhibitors (ibuprofen) has also been proved in the single newborn who didn’t reach the stabilization but resulted ineffective. This newborn has been submitted to surgical ligation immediately thereafter.

Moreover, the clinical conditions observed in all the newborns at admission testify that the duration of the exposure to left-to-right shunt is a crucial factor of the organ damage. This aspect is often not considered, waiting for the Cox-inhibitor effects.

The contribution of the aEEG recordings is, in this context, considerable, having shown a background pattern of burst suppression in four subjects and a discontinuous pattern not in line with reached PCA in other three.

On the basis of these results we think that the therapy of PDA in preterm infants must be mainly aimed at the containment of the ductal shunt and of its effects on pulmonary and systemic flow.

In this way the objective of the ductal closure stops to be primary, being possible, under conditions of hemodynamic stability, waiting during the first week of life for the physiologic events of closure or resorting in selected cases to the Cox-inhibitors or to the surgical intervention.

This limited experience requires more consistent proofs of effectiveness, while the impact of this approach on the outcomes needs to be evaluated.

Proceedings of the 10^th International Workshop on Neonatology · Cagliari (Italy) · October 22^nd-25^th, 2014 · The last ten years, the next ten years in Neonatology

Guest Editors: Vassilios Fanos, Michele Mussap, Gavino Faa, Apostolos Papageorgiou