Patent ductus arteriosus: pathophysiology and management

Abstract

Patent ductus arteriosus (PDA) in preterm newborns prior to 28 weeks of gestation has led to many challenges regarding the type and timing of treatment regimens. A PDA results in increased pulmonary blood flow and redistribution of flow to other organs. Several co-morbidities (i.e., necrotizing enterocolitis, intracranial hemorrhage, pulmonary edema/ hemorrhage, bronchopulmonary dysplasia, and retinopathy) are associated with the presence of a PDA, but whether or not a PDA is responsible for their development is still unclear. The prostaglandin inhibitor, indomethacin, is effective in the treatment of PDA. Questions regarding the optimal timing of the intervention -early prophylaxis or treatment, once signs and symptoms become evident -have challenged physicians for decades. Both evidence and experience are explored in this article. Comparative physiology between the full-term and preterm newborn and the barriers preventing the necessary cascade of events leading to permanent constriction of the PDA are reviewed.

Ibuprofen lysine administration to neonates with a patent ductus arteriosus: effect on platelet plug formation assessed by in vivo and in vitro measurements

“…Hemorrhagic complications among ELBW neonates can be significant and therefore medications that do not impair platelet function might be considered preferentially above alternative medications that do. 17,20 In this study we assessed platelet plug formation of 20 NICU patients where ibuprofen dosing had been ordered by the clinician in order to close a PDA. We assessed platelet plug formation using two tests: the template bleeding time and the PFA-100 closure time.…”

Indomethacin prophylaxis or expectant treatment of patent ductus arteriosus in extremely low birth weight infants?

“…1 A hemodynamically significant sPDA is associated with serious co-morbidities such as congestive heart failure, pulmonary hemorrhage, necrotizing enterocolitis, bronchopulmonary dysplasia and retinopathy of prematurity. 1,2 Although spontaneous closure of the ductus arteriosus can occur, the majority of ELBW infants with sPDA require pharmacological treatment or surgical ligation.…”

Fluid regimens and the risk of patent ductus arteriosus in extremely low birth weight infants

“…2 The authors mention that fluid intake did not predict the development of bronchopulmonary dysplasia when controlling for other known risk factors. Did any infants in the study develop pulmonary hemorrhage?…”

“…The incidence of a symptomatic PDA among extremely low birth weight (ELBW) infants is reported to be 55 to 70%. 2 A large multicenter randomized control trial (TIPP trial) of infants <1000 g birth weight showed that indomethacin prophylaxis reduced the incidence of symptomatic PDA from 50% (placebo) to 24%. 3 The low PDA incidence in the study by Stephens et al 1 may have been secondary to indomethacin prophylaxis and/or because they only included infants that survived to discharge, which might limit the ability to generalize their findings to initial fluid management.…”

“…2 As the study by Stephens et al 1 suggests, fluid regimens at critical periods of development certainly could play a role in PDA closure. However, without having randomized infants to different fluid regimens, it is difficult to comment on the true impact of fluid management on the PDA.…”