Pulmonary effects of closure of patent ductus arteriosus in premature infants with severe respiratory distress syndrome

The pulmonary effects of closure of a patent ductus arteriosus (PDA) were investigated in 11 premature infants with severe respiratory distress syndrome. Successful closure of a PDA did not improve the short-term severity of pulmonary disease (24 and 48 h after treatment) as judged by the arterial/alveolar oxygen tension ratio or the amount of ventilatory support. Also, pulmonary mechanics measured 24 h before, 24 and 48 h after treatment, were not statistically different.Conclusion Infants with severe respiratory disease requiring high ventilation pressure and high oxygen concentration, where structural changes in the lungs are already established, will rarely show short-term improvement in pulmonary disease as a result of closure of a PDA. The overall clinical condition may, however, improve as a result of reduced cardiovascular strain. Earlier treatment of a PDA could reduce the ventilation period and the possible risk of developing chronic lung disease.