Patent ductus arteriosus in the neonate

Early ductal shunting in preterm infants has traditionally been viewed as insignificant because of pulmonary hypertension. Doppler echocardiography has given us a window on preterm haemodynamics that questions the current relevance of this thinking. It has been shown that early postnatal ductal constriction is very variable and that the shunt direction is usually left to right. Where constriction fails, the adverse haemodynamic influence of the duct might may be most significant in the first 12-24 h. Failed ductal constriction in the early hours after birth predicts haemodynamic significance at the time and also predicts later persisting patency requiring treatment. The only approach to the treatment of patent ductus arteriosis (PDA) that has been shown to make a difference to any outcome is prophylactic early indomethacin. However, the short-term benefits of reduced major IVH and PDA ligation have not been demonstrated to translate into better neurodevelopmental outcome. More research is needed into the role of targeting indomethacin on the basis of early ductal constriction as a refinement of the prophylactic approach.