The prognostic value of N-terminal pro-B-type natriuretic peptide in patients with severe sepsis and septic shock

Abstract

To evaluate the prognostic value of N-terminal pro-B-type natriuretic peptide (NT-proBNP) in patients with severe sepsis and septic shock. In a prospective study, clinical data of 50 patients with severe sepsis and septic shock were analyzed. Plasma NT-proBNP level was measured at 0, 24, 48 and 72 hours after admission to the intensive care unit (ICU) of a university hospital. Patients were divided into survival group and non-survival group according to 30-day mortality rate. The dynamic variation of plasma NT-proBNP level was observed and the difference of plasma NT-proBNP levels between two groups was compared. The predictive value of NT-proBNP on mortality was evaluated by receiver operating characteristic (ROC) curves. The potential confounding factors on NT-proBNP were assessed with linear regression analysis. NT-proBNP levels (μg/L)at 0 hour after admission to ICU [20.86(14.28,23.92)] were significantly higher in non-survival group (n=20) compared with survival group [ n=30, 10.02 (5.58, 16.41), P<0.01], and the difference persisted to 72 hours [19.68 (13.90, 24.02) vs. 9.24 (4.30, 11.81), P<0.01], but there was no statistical difference of NT-proBNP levels among four time points. In the ROC curves for NT-proBNP at admission, the area under the curve(AUC) for hospital mortality was 0.842, and 95% confidence interval (CI) was 0.764-0.922, P<0.01. NT-proBNP greater than 13.30 μg/L at admission was an independent indicator of mortality (sensitivity 80.6%, specificity 70.2%). Linear regression analysis revealed that the oxygenation index (PaO(2)/FiO(2), r=-0.839, P=0.003), platelet count (PLT, r=-0.803, P=0.032), and sequential organ failure assessment (SOFA) scores at 0 hour after admission to ICU (r=0.874, P<0.001) had independent effects on NT-proBNP values at admission. Plasma NT-proBNP level is a valuable prognostic factor for severe sepsis and septic shock patients.