B-type natriuretic peptide concentrations to guide treatment of patent ductus arteriosus

Objective: To determine whether b-type natriuretic peptide (BNP) concentrations can guide treatment of patent ductus arteriosus (PDA) to reduce the number of indomethacin doses without increasing morbidity. Design: Prospective, randomised, controlled trial. Setting: Single-centre referral neonatal intensive care unit. Patients: Infants with echocardiographic diagnosis of PDA. Infants with congenital heart disease or renal insufficiency were excluded. Interventions: BNP measurement and echocardiography were performed in all subjects before and after indomethacin treatment. The investigational group had BNP concentrations measured 12 and 24 h after the first dose (before the 2nd and 3rd doses of indomethacin). Indomethacin dosing was withheld in the BNP-guided group if the 12 or 24 h BNP concentrations were found to be <100 pg/ml. Main outcome measures: Number of doses of indomethacin given during the primary course of treatment (three doses every 12 h). Results: Sixty patients were randomly assigned to control In = 30) and BNP-guided (n = 30) treatment groups. There was no difference between the groups with respect to gestational age (26(+3) vs 25(+5) weeks, respectively), Apgar scores, delivery method, gender or indomethacin prophylaxis. Median baseline and 48 h BNP concentrations did not differ between the groups (0 h: 500 vs 542 pg/ml: 48 h: 85 vs 126 pg/ml; control and BNP-guided groups, respectively). During primary indomethacin treatment, the BNP-guided group received fewer doses of indomethacin than controls (70 vs 88 doses, p<0.05). The rate of PDA ligation, intestinal perforation and chronic lung disease did not differ between groups. Conclusions: BNP-guided treatment reduced the number of primary indomethacin doses. There was no increase in PDA persistence or associated morbidity.