title: Incidence, risk factors, and mortality associated with acute respiratory distress syndrome in combat casualty care.
abstract: BACKGROUND
  The overall incidence and mortality of acute respiratory distress syndrome (ARDS) in civilian trauma settings have decreased over the past four decades; however, the epidemiology and impact of ARDS on modern combat casualty care are unknown. We sought to determine the incidence, risk factors, resource utilization, and mortality associated with ARDS in current combat casualty care.
  
  
  METHODS
  This was a retrospective review of mechanically ventilated US combat casualties within the Department of Defense Trauma Registry (formerly the Joint Theater Trauma Registry) during Operation Iraqi Freedom/Enduring Freedom (October 2001 to August 2008) for ARDS development, resource utilization, and mortality.
  
  
  RESULTS
  Of 18,329 US Department of Defense Trauma Registry encounters, 4,679 (25.5%) required mechanical ventilation; ARDS was identified in 156 encounters (3.3%). On multivariate logistic regression, ARDS was independently associated with female sex (odds ratio [OR], 2.62; 95% confidence interval [CI], 1.21-5.71; p = 0.02), higher military-specific Injury Severity Score (Mil ISS) (OR, 4.18; 95% CI, 2.61-6.71; p < 0.001 for Mil ISS ≥25 vs. <15), hypotension (admission systolic blood pressure <90 vs. ≥90 mm Hg; OR, 1.76; 95% CI, 1.07-2.88; p = 0.03), and tachycardia (admission heart rate ≥90 vs. <90 beats per minute; OR, 1.53; 95% CI, 1.06-2.22; p = 0.02). Explosion injury was not associated with increased risk of ARDS. Critical care resource utilization was significantly higher in ARDS patients as was all-cause hospital mortality (ARDS vs. no ARDS, 12.8% vs. 5.9%; p = 0.002). After adjustment for age, sex, injury severity, injury mechanism, Mil ISS, hypotension, tachycardia, and admission Glasgow Coma Scale score, ARDS remained an independent risk factor for death (OR, 1.99; 95% CI, 1.12-3.52; p = 0.02).
  
  
  CONCLUSIONS
  In this large cohort of modern combat casualties, ARDS risk factors included female sex, higher injury severity, hypotension, and tachycardia, but not explosion injury. Patients with ARDS also required more medical resources and were at greater risk of death compared with patients without ARDS. Thus, ARDS remains a significant complication in current combat casualty care.
  
  
  METHODS
  Prognostic/epidemiologic study, level III.
authors: From the Division of Acute Care Surgery, Dept of Surgery, University of Michigan, Ann Arbor, Michigan (P.K.P., L.M.N.); School of Public Health, University of Michigan, Ann Arbor, Michigan (W.Y.); US Army Institute of Surgical Research, Fort Sam Houston, Texas (L.H.B., J.B.H.); Pulmonary/Critical Care Medicine, Wilford Hall Medical Center, Lackland AFB, Texas (W.B.); and Department of Surgery, Wilford Hall Medical Center, Lackland AFB, Texas and Department of Surgery, Uniformed Services University of the Health Sciences, Bethesda, Maryland (J.W.C.).
authors: Pauline K
authors: PK
authors: Park
authors: Jeremy W
authors: JW
authors: Cannon
authors: Wen
authors: W
authors: Ye
authors: Lorne H
authors: LH
authors: Blackbourne
authors: John B
authors: JB
authors: Holcomb
authors: William
authors: W
authors: Beninati
authors: Lena M
authors: LM
authors: Napolitano
mesh_terms: D000293:Adolescent; D000328:Adult; D000068337:Armed Conflicts; D005260:Female; D006801:Humans; D007022:Hypotension / Q000150:complications; D015994:Incidence; D015601:Injury Severity Score; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D008889:Military Personnel; D012128:Respiratory Distress Syndrome / Q000453:epidemiology* / Q000209:etiology / Q000401:mortality; D012189:Retrospective Studies; D012307:Risk Factors; D013610:Tachycardia / Q000150:complications; D014481:United States; D055815:Young Adult