N-terminal pro-brain natriuretic peptide in the assessment of respiratory distress in term neonates.

Background: N-terminal pro-brain natriuretic peptide (NT-proBNP) is used as a biomarker to differentiate congestive heart failure from lung disease in adults and children. The clinical significance of its use in term neonates has not yet been extensively studied.

Methods: NT-proBNP level was measured in 62 term neonates admitted for respiratory distress (RD): 38 with congenital heart disease (CHD) and 24 with pulmonary disease. The control group consisted of 28 healthy neonates. Findings of auscultation, chest radiography, Silverman-Anderson score and echocardiography were recorded for each patient. Blood samples for measuring NT-proBNP were collected on admission, when blood sampling was indicated for the clinical management of the newborn.

Results: In the control group NT-proBNP was significantly higher during the first week of life compared to the rest of the neonatal period (P < 0.001). The RD group, regardless of etiology, had significantly higher NT-proBNP than the control group (P < 0.001). Neonates with more severe RD had significantly higher NT-proBNP (P = 0.002). No significant difference was found between the RD group with CHD and those with pulmonary disease. Neonates with CHD and myocardial hypocontractility had significantly higher NT-proBNP than those with normal contractility (P = 0.022).

Conclusion: Term neonates with RD have significantly higher NT-proBNP than healthy neonates. A single measurement of NT-proBNP level cannot be used as the sole biomarker for distinguishing between cardiac and pulmonary cause of RD in term neonates.