The plasma B-type natriuretic peptide(BNP) concentration increases with the degree of pulmonary hypertension in patients with chronic respiratory disease. The aim of this study was to examine the prognostic role of BNP in the acute exacerbation of chronic obstructive lung disease (COPD).

We selected 67 patients who were admitted our hospital because of an acute exacerbation of COPD. Their BNP levels were checked on admission at the Emergency Department. Their medical records were analyzed retrospectively. The patients were divided into two groups according to their in-hospital mortality. The patients' medical history, comobidity, exacerbation type, blood gas analysis, pulmonary function, APACHE II severity score and plasma BNP level were compared.

Multiple logistic regression analysis identified three independent predictors of mortality: FEV₁, APACHE II score and plasma BNP level. The decedents group showed a lower FEV₁(28±7 vs. 37±15%, p=0.005), a higher APACHE II score(22.4±6.1 vs. 15.8±4.7, p=0.000) and a higher BNP level (201±116 vs. 77±80pg/mL, p=0.000) than the sSurvivors group. When the BNP cut-off level was set to 88pg/mL using the receiver operating characteristic curve, the sensitivity was 90% and the specificity was 75% in differentiating between the survivors and decedents. On Fisher's exact test, the odds ratio for mortality was 21.2 (95% CI 2.49 to 180.4) in the patients with a BNP level > 88pg/mL.

The plasma BNP level might be a predictor of mortality in an acute exacerbation of COPD as well as the FEV₁ and APACHE II score.