Effect of early targeted indomethacin on the ductus arteriosus and blood flow to the upper body and brain in the preterm infant.

Author(s): Osborn DA, Evans N, Kluckow M

Affiliation(s): Department of Neonatal Medicine, Royal Prince Alfred Hospital and University of Sydney, Sydney, NSW, Australia. david.osborn@email.cs.nsw.gov.au

Publication date & source: 2003-11, Arch Dis Child Fetal Neonatal Ed., 88(6):F477-82.

Publication type: Clinical Trial; Multicenter Study; Randomized Controlled Trial

OBJECTIVE: To determine if indomethacin given to preterm infants with a large ductus arteriosus (DA) in the first hours of life results in maintained or improved brain and upper body blood (superior vena cava (SVC)) flow. STUDY DESIGN: A randomised, double blind trial of indomethacin v placebo. Echocardiography was performed on 111 infants born at < 30 weeks gestation at 3 and/or 10 hours after birth. Infants were eligible if the DA diameter was > 1.6 mm. Infants were randomised to receive indomethacin 0.2 mg/kg or placebo. Crossover occurred if the DA was still > 1.6 mm. Echocardiography was performed one hour after each treatment. RESULTS: Seventy (63%) infants had a DA > 1.6 mm, with 35 randomised to receive indomethacin and 35 to receive placebo. At one hour there was no difference in DA constriction (indomethacin -20% v placebo -15%), change in SVC flow (-1% v -9%), for right ventricular output (RVO). Two hours after indomethacin, 62 infants had uncontrolled observations, at which time significant ductal constriction had occurred. At this time, infants of > or = 27 weeks gestation had significantly greater increases in SVC flow and RVO than infants of < 27 weeks gestation. Infants with failed ductal constriction had significantly lower initial SVC flow and developed more late grade 3/4 peri/intraventricular haemorrhage (P/IVH). Initial SVC flow, but not ductal constriction, was a significant predictor of late grade 3/4 P/IVH in adjusted analysis. CONCLUSIONS: Indomethacin had minimal effect on ductal constriction and blood flow at one hour compared with placebo. Failure of ductal constriction is associated with low SVC flow and subsequent late severe P/IVH.