Comparison of N-terminal Pro-B-Type Natriuretic Peptide Levels in Critically Ill Children With Sepsis Versus Acute Left Ventricular Dysfunction

OBJECTIVE: N-terminal pro-B-type natriuretic peptide has been shown to be a marker for cardiac dysfunction. The peptide level is also elevated in patients with sepsis. The purpose of this study was to assess whether N-terminal pro-B-type natriuretic peptide levels can differentiate pediatric patients with sepsis from patients with acute left ventricular dysfunction. PATIENTS AND METHODS: Pediatric patients admitted to an ICU with sepsis or acute left ventricular dysfunction were evaluated clinically, and the grade of systemic inflammatory-response syndrome was determined. Echocardiography was performed, and their levels of N-terminal pro-B-type natriuretic peptide were measured. The N-terminal pro-B-type natriuretic peptide level was also measured in patients with simple febrile illness. RESULTS: There were 10 patients with sepsis and 10 with acute left ventricular dysfunction. The age of the patients was similar, and systemic inflammatory-response syndrome grading was not different (sepsis: 2.8 +/- 0.4; acute left ventricular dysfunction: 2.6 +/- 0.7). N-terminal pro-B-type natriuretic peptide levels were elevated in patients with sepsis (median: 6064 pg/mL; range: 495-60,417 pg/mL) but were significantly higher in patients with acute left ventricular dysfunction (median: 65,630 pg/mL; range: 15,125-288,000). The area under the receiver operating characteristics curve for the diagnosis of acute left ventricular dysfunction was 0.9. N-terminal pro-B-type natriuretic peptide levels of patients with sepsis and impaired systolic function were not different from those of patients with sepsis and normal systolic function. The N-terminal pro-B-type natriuretic peptide levels of 20 patients with simple febrile illness were significantly lower. CONCLUSIONS: N-terminal pro-B-type natriuretic peptide levels are elevated in pediatric patients with sepsis but are higher in some, but not all, patients with acute left ventricular dysfunction. The overlap between N-terminal pro-B-type natriuretic peptide levels in sepsis and acute left ventricular dysfunction precludes the use of the peptide's level as a sole means to differentiate between these conditions. Excessive elevation in N-terminal pro-B-type natriuretic peptide levels, however, suggests cardiac etiology for acute hemodynamic deterioration in infants and children.