Prolonged low-dose indomethacin therapy for patent ductus arteriosus in very low birthweight infants

Objective: To determine the efficacy and side-effects of prolonged low-dose indomethacin therapy in very low birthweight (VLBW; <1500 g) infants with a haemodynamically significant patent ductus arteriosus (hsPDA). Methodology: Very low birthweight infants admitted over a 16 month period were studied (6 months, retrospectively and 10 months, prospectively). Cross-sectional and M-Mode echocardiograms with pulsed-wave and colour Doppler were performed to assess the significance of ductal patency. Results: Forty-one (28%) of 148 VLBW infants were diagnosed to have hsPDA. Indomethacin therapy was successful in 90% after the first course, increasing to 95% after the second course. The recurrence rate after the first course was 3%. Minor and transient complications included oliguria, urea retention, hyponatraemia and thrombocytopenia. Although three infants had focal bowel perforation and the fourth had bowel perforation associated with necrotizing enterocolitis, the incidence of gastrointenstinal pathology was not significantly different from infants without hsPDA and not given indomethacin. Conclusions: Very low birthweight infants with hsPDA have a high response rate and low recurrence rate to prolonged low-dose indomethacin therapy. Side-effects were mild and transient. However, it is prudent to be cautious when administering indomethacin in critically ill infants <1000 with hsPDA who manifest clinical features of bowel ischaemia.