Background: Increased plasminogen activator inhibitor-1 (PAI-1) concentrations are found in bronchoalveolar lavage (BAL) fluids from patients with ventilator-associated pneumonia or acute respiratory distress syndrome. The authors hypothesized that PAI-1 concentrations were associated with increased mortality in patients with either Pseudomonas aeruginosa-induced ventilator-associated pneumonia or tracheobronchial colonization.
Methods: In a prospective cohort study, daily aspirates from intubated patients were cultured for P. aeruginosa. Positive patients had blind BAL (bBAL) that was processed for biomarker concentrations. Secretion of type III secretion cytotoxins were also analyzed from the P. aeruginosa strains.
Results: Thirty-three patients were enrolled. Ten of the 33 patients died. bBAL PAI-1 concentrations were significantly increased in nonsurvivors compared with survivors (31.7 vs. 3.4 ng/ml, P = 0.001 for hospital mortality; 35.9 vs. 4.7 ng/ml, P = 0.02 for 28-day mortality). Even when acute respiratory distress syndrome patients were excluded, there was a significant difference between the survivors and nonsurvivors for bBAL PAI-1 concentrations (P = 0.005). Eighty-three percent of P. aeruginosa strains isolated from patients with high concentrations of bBAL PAI-1 also had strains that secreted cytotoxins.
Conclusions: PAI-1 concentrations in bBALs correlated with mortality in ventilated patients with positive cultures for P. aeruginosa. Elevated bBAL PAI-1 concentrations also correlated with the secretion of type III exotoxins by P. aeruginosa.