B-type natriuretic peptide levels predict outcomes for children on extracorporeal life support after cardiac surgery.

Objective: Extracorporeal life support is used in 3% to 8% of infants and children after cardiac surgery. B-type natriuretic peptide may have utility as a biomarker in these patients. The objective of this study was to investigate potential associations between changes in B-type natriuretic peptide during trials off extracorporeal life support and clinical outcome.
Methods: Ten infants and children requiring extracorporeal life support after cardiac surgery were studied prospectively. Before separation from extracorporeal life support, a shunt was placed in the circuit, allowing for temporary trials off life support. Serum lactate, arterial-venous oxyhemoglobin saturation difference, and B-type natriuretic peptide levels were determined before each trial off life support and at the end of each trial off life support, and the ability to predict postoperative outcome from these data was evaluated.
Results: During trials off extracorporeal life support, lactate, the arterial-venous oxyhemoglobin saturation difference, and B-type natriuretic peptide levels increased above pre-trial values (P < .05). Only the arterial-venous oxyhemoglobin saturation difference predicted successful separation from extracorporeal life support after a trial (P < .05). There were no associations between long-term outcome and alterations in lactate and the arterial-venous oxyhemoglobin saturation difference during the final trials off life support. However, an increase in B-type natruiretic peptide levels during the final trial off life support (trial/pre-trial ratio of >1) had a sensitivity of 80% and a specificity of 100% for predicting the need for an unplanned operation or death within 3 months (P < .05).
Conclusion: B-type natriuretic peptide determinations may be a useful tool for clinicians caring for infants and children requiring extracorporeal life support after cardiac surgery.