Patent Ductus Arteriosus in Preterm Infants: Do We Have the Right Answers?

Abstract

Patent ductus arteriosus (PDA) is a common clinical condition in preterm infants. Preterm newborns with PDA are at greater risk for several morbidities, including higher rates of bronchopulmonary dysplasia (BPD), decreased perfusion of vital organs, and mortality. Therefore, cyclooxygenase (COX) inhibitors and surgical interventions for ligation of PDA are widely used. However, these interventions were reported to be associated with side effects. In the absence of clear restricted rules for application of these interventions, different strategies are adopted by neonatologists. Three different approaches have been investigated including prophylactic treatment shortly after birth irrespective of the state of PDA, presymptomatic treatment using echocardiography at variable postnatal ages to select infants for treatment prior to the duct becoming clinically significant, and symptomatic treatment once PDA becomes clinically apparent or hemodynamically significant. Future appropriately designed randomized controlled trials (RCTs) to refine selection of patients for medical and surgical treatments should be conducted. Waiting for new evidence, it seems wise to employ available clinical and echocardiographic parameters of a hemodynamically significant (HS) PDA to select patients who are candidates for medical treatment. Surgical ligation of PDA could be used as a back-up tool for those patients who failed medical treatment and continued to have hemodynamic compromise.

Persistent Ductus Arteriosus in Critically Ill Preterm Infants

“…An almost similar risk was reported by Marshall et al in VLBW infants (BW <1500 g) [69]. In preterm infants with RDS, PDA induces an interstitial and alveolar pulmonary edema, decreases pulmonary compliance, increases the need and length of mechanical ventilation and oxygen needs, thus increasing the risk for BPD [5,42].…”

“…Functional closure of DA in preterm infants with GA≥30 weeks gestation occurs towards the fourth day of life, while in those with GA<30 weeks or with RDS the incidence of PDA is about 65% [5,19,51]. Instead of analyzing only infants with significant PDA we have chosen to define and analyze PDA only if the ductus was seen on echocardiography after the first week of life.…”

“…[6,11,43,45,47,63]. In the short term, PDA is associated with arterial hypotension, myocardial dysfunction and systemic perfusion [5,8,38], renal functional disturbances [5,19,39], and pulmonary hemorrhage [40,64,65].…”

“…After birth, as part of the transition to extra uterine life, the ductus closes due to increased arterial oxygen pressure, decreased pressure of the pulmonary blood flow, decreased concentration of prostaglandin E2, and decreased the number of the prostaglandin E2 receptors [3,4]. At term, spontaneous functional closure of DA occurs in 50% of the infants at 24 hours, in 90% of the cases at 48 hours, and in 100% of the cases at 72 hours of life [5,6]. Anatomical closure of the ductus occurs in 2-3 weeks [2].…”

“…In the short term, PDA is associated with decreased blood pressure [5,8], decreased renal function [5], cardiac congestive failure [18,37,38], pulmonary haemorrhage [8,39], apnea and ventilator-dependency [6,38], bronchopulmonary dysplasia (BPD) [5,14,20,21,25,34,41,42], necrotizing enterocolitis (NEC) [8,9,11,19,20,34,39,43,44], intraventricular hemorrhage (IVH) [5,19,20,39,42,45,46], periventricular leukomalacia (PVL) [5], retinopathy of prematurity (ROP), cerebral palsy [24], delayed growth [11], and increased mortality rate [6,34,45,[47][48][49][50].…”