title: The Acute Respiratory Distress Syndrome (ARDS) in mechanically ventilated burn patients: An analysis of risk factors, clinical features, and outcomes using the Berlin ARDS definition.
abstract: BACKGROUND
  The Berlin definition of Acute Respiratory Distress Syndrome (ARDS) has been applied to military burns resulting from combat-related trauma, but has not been widely studied among civilian burns. This study's purpose was to use the Berlin definition to determine the incidence of ARDS, and its associated respiratory morbidity, and mortality among civilian burn patients.
  
  
  METHODS
  Retrospective study of burn patients mechanically ventilated for ≥48h at an American Burn Association-verified burn center. The Berlin criteria identified patients with mild, moderate, and severe ARDS. Logistic regression was used to identify variables predictive of moderate to severe ARDS, and mortality. The outcome measures of interest were duration of mechanical ventilation and in-hospital mortality. Values are shown as the median (Q1-Q3).
  
  
  RESULTS
  We included 162 subjects [24% female, age 48 (35-60), % total body surface area (TBSA) burn 28 (19-40), % body surface area (BSA) full thickness (FT) burn 13 (0-30), and 62% with inhalation injury]. The incidence of ARDS was 43%. Patients with ARDS had larger %TBSA burns [30.5 (23.1-47.0) vs. 24.8 (17.1-35), p=0.007], larger FT burns [20.5(5.4-35.5) vs. 7 (0-22.1), p=0.001], but had no significant difference in the incidence of inhalation injury (p=0.216), compared to those without ARDS. The % FT burn predicted the development of moderate to severe ARDS [OR 1.034, 95%CI (1.013-1.055), p=0.001]. ARDS developed in the 1st week after burn in 86% of cases. Worsening severity of ARDS was associated with increased days of mechanical ventilation in survivors (p=0.001), a reduction in ventilator-free days/1st 30 days in all subjects (p=0.004), and a strong indication of increased mortality (0% in mild ARDS vs. 50% in severe ARDS, unadjusted p=0.02). Neither moderate ARDS nor severe ARDS were significant predictors of death.
  
  
  CONCLUSIONS
  ARDS is common among mechanically ventilated civilian burn patients, and develops early after burn. The extent of full thickness burn predicted development of moderate to severe ARDS. Increasing severity of ARDS based upon the Berlin definition was associated with a significantly greater duration of mechanical ventilation and a trend toward higher mortality.
authors: Ross Tilley Burn Centre, Toronto, Canada. Electronic address: robert.cartotto@sunnybrook.ca.
authors: Robert
authors: R
authors: Cartotto
authors: Ross Tilley Burn Centre, Toronto, Canada.
authors: Zeyu
authors: Z
authors: Li
authors: Ross Tilley Burn Centre, Toronto, Canada.
authors: Steven
authors: S
authors: Hanna
authors: Ross Tilley Burn Centre, Toronto, Canada.
authors: Stefania
authors: S
authors: Spano
authors: Ross Tilley Burn Centre, Toronto, Canada.
authors: Donna
authors: D
authors: Wood
authors: Ross Tilley Burn Centre, Toronto, Canada.
authors: Karen
authors: K
authors: Chung
authors: Ross Tilley Burn Centre, Toronto, Canada.
authors: Fernando
authors: F
authors: Camacho
mesh_terms: D000328:Adult; D001830:Body Surface Area; D002056:Burns / Q000453:epidemiology* / Q000401:mortality / Q000628:therapy; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D015994:Incidence; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D012121:Respiration, Artificial; D012128:Respiratory Distress Syndrome / Q000453:epidemiology* / Q000401:mortality / Q000628:therapy; D012189:Retrospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index; D015208:Smoke Inhalation Injury / Q000453:epidemiology*; D013997:Time Factors; D015599:Trauma Severity Indices; D014481:United States / Q000453:epidemiology
keywords: Acute Respiratory Distress Syndrome; Berlin definition; Burns; Mechanical ventilation