Increased N-terminal Pro-B-Type Natriuretic Peptide during Extracorporeal Life Support Is Associated with Poor Outcome in Neonates with Congenital Diaphragmatic Hernia

Abstract

Objectives: To evaluate the prognostic information derived from the daily measurements of N-terminal pro-B-type natriuretic peptide (proBNP) in neonates with congenital diaphragmatic hernia undergoing extracorporeal life support (ECLS).

Study design: Plasma proBNP was prospectively measured daily during the first week of ECLS using an electrochemiluminescence immunoassay. Patients (n = 63) were allocated according to outcome: survivors (group 1, n = 35); nonsurvivors with successful weaning (defined as survival for >12 hours after ECLS discontinuation) (group 2, n = 16); nonsurvivors with unsuccessful weaning (group 3, n = 12). ProBNP kinetics were compared using Kruskal-Wallis testing and correlated with pulmonary hypertension and cardiac dysfunction on echocardiography using the Spearman correlation coefficient.

Results: Infants in group 3 presented significantly higher proBNP values from day 3 to day 6 compared with group 1 and 2. Overall mortality among patients with the highest proBNP values on day 1 was 30.6% compared with 63% in those patients with at least 1 higher value on day 2 to day 7. In patients with a late increase (day 4 to day 7) in proBNP the mortality was 70%, compared with 32.6% in those with proBNP below the value on day 1. Weaning failure was 35% in patients with a late increase and 11.6% in those without a late increase. ProBNP correlated significantly with pulmonary hypertension and cardiac dysfunction before and during ECLS.

Conclusions: Absolute proBNP values are associated with weaning failure but not overall mortality in neonates with congenital diaphragmatic hernia undergoing ECLS. Echocardiographic findings correlate well with proBNP values.

Keywords: BNP; cardiac dysfunction; extracorporeal life support; natriuretic peptides; pulmonary hypertension.