Pharmacological closure of ductus arteriosus in preterm infants using indomethacin.

Patent ductus arteriosus (PDA) was diagnosed in 27 (21%) of 129 infants weighing [unk] 1500 g at birth presenting over 1½ years. The incidence of PDA in infants with pulmonary disease, particularly hyaline membrane disease, was higher than that in infants without such disease (31% compared with 16%). 16 (59%) infants with PDA developed congestive cardiac failure (CCF), of whom 12 were [unk] 1000 g at birth. Eight of these infants had persistent CCF despite aggressive antifailure treatment, and 8 were ventilator-dependent although stable on medical management. Pharmacological ductal closure with indomethacin was attempted in these 16 infants according to clinical and echocardiographic criteria. Complete or partial ductal closure with clinical and echocardiographic improvement was achieved in 75% of infants. Treatment with indomethacin failed in 4 infants all of whom were [unk] 1000 g at birth and had gestational ages [unk] 26 weeks. Two of these infants had surgical ligation of the PDA and recovered. No morbidity was attributed to indomethacin except for transient oliguria. Overall survival was 76%; this ranged from 50% in infants weighing 501-750 g, to 91% in infants weighing 1251-1500 g. Results suggest that (1) extremely preterm infants are less likely to respond to indomethacin, (2) success is more likely in the first 10 days of life, (3) a total dose greater than 0·6 mg/kg will not increase the success rate, (4) selective morbidity from indomethacin is unlikely if the contraindications of bleeding tendency, hyperbilirubinaemia, and renal dysfunction are followed, although urinary output must be monitored carefully, (5) indomethacin is a useful alternative to surgical ligation although long-term prognosis from clinical trials has yet to be established.