Increased plasma concentrations of brain natriuretic peptide in patients with acute lung injury

This study was performed to elucidate the pathophysiological role of brain natriuretic peptide (BNP) and atrial natriuretic peptide (ANP) in acute lung injury.

We sequentially measured plasma concentrations of immunoreactive BNP and ANP in 10 patients (mean age, 63 years (with acute lung injury and compared those with hemodynamic parameters and pulmonary functions.

Plasma concentrations of immunoreactive BNP and ANP were markedly elevated at entry into the study. Plasma BNP concentrations during the early course (3 days) showed significant (P < .01) positive correlations with systemic vascular resistance index (r = .708) and pulmonary vascular resistance index (r = .573), but a negative correlation with cardiac index (r = .608). Plasma ANP concentrations showed a significant (P < .05) positive correlation with pulmonary capillary wedge pressure (r = .398). Plasma BNP in 4 patients who died and 1 patient with acute renal failure remained elevated during the entire hospital length of stay (12 days).

These findings suggest that circulating BNP plays an important role in acute lung injury along with ANP as a compensatory mechanism for cardiac dysfunction accompanied by increased systemic vascular resistance index and pulmonary vascular resistance index. Circulating BNP may be a sensitive humoral marker for the degree of ventricular dysfunction associated with acute lung injury.