title: Alveolar plasminogen activator inhibitor-1 predicts ARDS in aspiration pneumonitis.
abstract: OBJECTIVE
  To test the hypothesis that alveolar plasminogen activator inhibitor-1 (PAI-1) can identify patients with witnessed aspiration at risk for progression to acute respiratory distress syndrome (ARDS).
  
  
  METHODS
  Prospective observational study.
  
  
  METHODS
  Medical intensive care unit in a tertiary care center.
  
  
  METHODS
  Fifty-one patients with witnessed aspiration who had a PaO2/FIO2<300 for a period no less than 4 h from admission.
  
  
  METHODS
  Alveolar fluid sampling was performed within 8 h of intubation via luminal suction of the distal airways using a 13-Fr catheter. Plasma levels were collected simultaneously by venipuncture.
  
  
  RESULTS
  Alveolar PAI-1 antigen levels were more than five times higher in those who progressed to ARDS than in those with uncomplicated aspiration pneumonitis (2687+/-1498 ng/ml vs. 587+/-535 ng/ml, respectively; p<0.001), while plasma levels of PAI-1 antigen were not significantly different between the two groups. The measured activity of PAI-1 antigen paralleled the levels observed in both media. A cut-off level of alveolar PAI-1 >1518 ng/ml was found to be 82.4% (56.6%-96.0%) sensitive and 97.1% (84.6%-99.5%) specific in predicting progression to ARDS. There was also a significant inverse relationship between elevation of PAI-1 antigen levels and the degree of lung injury as assessed by the days of unassisted ventilation (r2=0.37; p<0.001).
  
  
  CONCLUSIONS
  Elevation of alveolar PAI-1 antigen levels postaspiration is the consequence of local rather than systemic activation of the fibrinolytic system. Measurement of alveolar PAI-1 antigen levels can be a useful clinical marker in predicting progression to ARDS after gastric aspiration.
authors.affiliation: Division of Pulmonary, Critical Care, and Sleep Medicine, Erie County Medical Center, 462 Grider Street, Buffalo, NY 14215, USA. solh@buffalo.edu
authors.forename: Ali A
authors.initials: AA
authors.lastname: El Solh
authors.forename: Milapchand
authors.initials: M
authors.lastname: Bhora
authors.forename: Lilibeth
authors.initials: L
authors.lastname: Pineda
authors.forename: Alan
authors.initials: A
authors.lastname: Aquilina
authors.forename: Laurie
authors.initials: L
authors.lastname: Abbetessa
authors.forename: Eileen
authors.initials: E
authors.lastname: Berbary
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D008297:Male; D017395:Plasminogen Activator Inhibitor 1 / Q000276:immunology / Q000378:metabolism*; D011015:Pneumonia, Aspiration / Q000175:diagnosis* / Q000378:metabolism; D011446:Prospective Studies; D011650:Pulmonary Alveoli / Q000378:metabolism*; D012372:ROC Curve; D012128:Respiratory Distress Syndrome / Q000517:prevention & control*; D012680:Sensitivity and Specificity
chemical_list: D015415:Biomarkers; D017395:Plasminogen Activator Inhibitor 1