title: Prehospital aspirin use is associated with reduced risk of acute respiratory distress syndrome in critically ill patients: a propensity-adjusted analysis.
abstract: OBJECTIVE
  Platelet activation plays an active role in the pathogenesis of acute respiratory distress syndrome. In our prior study of 575 patients at high risk for acute respiratory distress syndrome, concurrent statin and aspirin use was associated with reduced acute respiratory distress syndrome. However, the largest study (n = 3,855) to date found no significant benefit of prehospital aspirin in a lower-risk population when adjusted for the propensity for aspirin use. We aimed to determine whether prehospital aspirin use is associated with decreased acute respiratory distress syndrome in patients at high risk for acute respiratory distress syndrome after adjusting for the propensity to receive aspirin.
  
  
  METHODS
  Secondary analysis of patients enrolled prospectively in the Validating Acute Lung Injury Markers for Diagnosis study.
  
  
  METHODS
  A total of 1,149 critically ill patients (≥40 years old) admitted to the medical or surgical ICUs of an academic tertiary care hospital including 575 previously reported patients as well as additional patients who were enrolled after completion of the prior statin and aspirin study.
  
  
  METHODS
  None.
  
  
  RESULTS
  Of 1,149 patients, 368 (32%) developed acute respiratory distress syndrome during the first 4 ICU days and 287 (25%) patients had prehospital aspirin use. Patients with prehospital aspirin had significantly lower prevalence of acute respiratory distress syndrome (27% vs 34%; p=0.034). In a multivariable, propensity-adjusted analysis including age, gender, race, sepsis, and Acute Physiology and Chronic Health Evaluation score II, prehospital aspirin use was associated with a decreased risk of acute respiratory distress syndrome (odds ratio, 0.66; 95% CI, 0.46-0.94) in the entire cohort and in a subgroup of 725 patients with sepsis (odds ratio, 0.60; 95% CI, 0.41-0.90).
  
  
  CONCLUSIONS
  In this selected cohort of critically ill patients, prehospital aspirin use was independently associated with a decreased risk of acute respiratory distress syndrome even after adjusting for the propensity of prehospital aspirin use. These findings support the need for prospective clinical trials to determine whether aspirin may be beneficial for the prevention of clinical acute respiratory distress syndrome.
authors.affiliation: 1Division of Allergy, Pulmonary, and Critical Care Medicine, Vanderbilt University School of Medicine, Nashville, TN. 2Division of Pulmonary and Critical Care Medicine, Chia-Yi Christian Hospital, Taiwan, Republic of China. 3Department of Life Science, National Chung Hsing University, Taiwan, Republic of China. 4Department of Respiratory Therapy, China Medical University, Taiwan, Republic of China. 5Section of Pulmonary and Critical Care Medicine, Louisiana State University School of Medicine New Orleans, New Orleans, LA. 6Department of Surgery, Vanderbilt University School of Medicine, Nashville, TN. 7Department of Pathology, Microbiology, and Immunology, Vanderbilt University School of Medicine, Nashville, TN.
authors.forename: Wei
authors.initials: W
authors.lastname: Chen
authors.forename: David R
authors.initials: DR
authors.lastname: Janz
authors.forename: Julie A
authors.initials: JA
authors.lastname: Bastarache
authors.forename: Addison K
authors.initials: AK
authors.lastname: May
authors.forename: Hollis R
authors.initials: HR
authors.lastname: O'Neal
authors.forename: Gordon R
authors.initials: GR
authors.lastname: Bernard
authors.forename: Lorraine B
authors.initials: LB
authors.lastname: Ware
mesh_terms: D000368:Aged; D001241:Aspirin / Q000008:administration & dosage*; D015331:Cohort Studies; D016638:Critical Illness; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012128:Respiratory Distress Syndrome / Q000517:prevention & control*
chemical_list: D001241:Aspirin