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) w ere investigated in 11 premature infants with severe respiratory distr ess syndrome. Successful closure of a PDA did not improve the short-te rm severity of pulmonary disease (24 and 48 h after treatment) as judg ed by the arterial/alveolar oxygen tension ratio or the amount of vent ilatory support. Also, pulmonary mechanics measured 24 h before, 24 an d 48 h after treatment, were not statistically different. Conclusion I nfants with severe respiratory disease requiring high ventilation pres sure and high oxygen concentration, where structural changes in the lu ngs are already established, will rarely show short-term improvement i n pulmonary disease as a result of closure of a PDA. The overall clini cal condition may, however, improve as a result of reduced cardiovascu lar strain. Earlier treatment of a PDA could reduce the ventilation pe riod and the possible risk of developing chronic lung disease.