Prognostic value of assay of brain natriuretic peptide in patients with acute respiratory distress syndrome

Abstract

To explore the prognostic value of brain natriuretic peptide (BNP) level in patients with acute respiratory distress syndrome (ARDS). Eighty-six patients with ARDS who had normal left ventricular ejection fraction (LVEF), from January 2004 to May 2009, were studied retrospectively. The baseline characteristics of the patients were recorded. The plasma concentration of BNP and Murray lung injury score (LIS) of the patients with their outcomes, and the relationship between the BNP concentration and LIS were analyzed. The prediction results of death and survival of patients using the cut off points of concentration of BNP and LIS were also analyzed. Eighty-six patients were diagnosed as ARDS.Among those patients with ARDS, 55 patients were dead and 31 patients were survival in 14 days. The proportion of pulmonary hypertension (25.8% vs. 72.7%) and that of using large dose of intravenous norepinephrine (38.7% vs. 94.5%), the time without using mechanical ventilation in 14 days [(8.63+/-3.26) days vs. (0.38+/-0.02) days], BNP concentration [(179.5+/-84.5) ng/L vs. (550.8+/-337.1) ng/L] and LIS (1.37+/-0.65 vs. 2.29+/-0.46) differed significantly between the survivors and the nonsurvivors (P<0.05 or P<0.01). The plasma concentration of BNP had a significant correlation with LIS (r=0.786, P<0.001). By using the threshold value of 329.5 ng/L for BNP, the specificity for the prediction of mortality was 96.8%. The threshold value for LIS of 1.875 showed sensitivity of 80.0%. BNP concentration and LIS were significantly elevated in nonsurvivors than survivors in patients with ARDS who have normal LVEF. High BNP level can predict mortality.