title: Mechanical ventilation and acute lung injury in emergency department patients with severe sepsis and septic shock: an observational study.
abstract: OBJECTIVE
  The objectives were to characterize the use of mechanical ventilation in the emergency department (ED), with respect to ventilator settings, monitoring, and titration and to determine the incidence of progression to acute lung injury (ALI) after admission, examining the influence of factors present in the ED on ALI progression.
  
  
  METHODS
  This was a retrospective, observational cohort study of mechanically ventilated patients with severe sepsis and septic shock (June 2005 to May 2010), presenting to an academic ED with an annual census of >95,000 patients. All patients in the study (n = 251) were analyzed for characterization of mechanical ventilation use in the ED. The primary outcome variable of interest was the incidence of ALI progression after intensive care unit (ICU) admission from the ED and risk factors present in the ED associated with this outcome. Secondary analyses included ALI present in the ED and clinical outcomes comparing all patients progressing to ALI versus no ALI. To assess predictors of progression to ALI, significant variables in univariable analyses at a p ≤ 0.10 level were candidates for inclusion in a bidirectional, stepwise, multivariable logistic regression analysis.
  
  
  RESULTS
  Lung-protective ventilation was used in 68 patients (27.1%) and did not differ based on ALI status. Delivered tidal volume was highly variable, with a median tidal volume delivered of 8.8 mL/kg ideal body weight (IBW; interquartile range [IQR] = 7.8 to 10.0) and a range of 5.2 to 14.6 mL/kg IBW. Sixty-nine patients (27.5%) in the entire cohort progressed to ALI after admission to the hospital, with a mean (±SD) onset of 2.1 (±1) days. Multivariable logistic regression analysis demonstrated that a higher body mass index (BMI), higher Sequential Organ Failure Assessment (SOFA) score, and ED vasopressor use were associated with progression to ALI. There was no association between ED ventilator settings and progression to ALI. Compared to patients who did not progress to ALI, patients progressing to ALI after admission from the ED had an increase in mechanical ventilator duration, vasopressor dependence, and hospital length of stay (LOS).
  
  
  CONCLUSIONS
  Lung-protective ventilation is uncommon in the ED, regardless of ALI status. Given the frequency of ALI in the ED, the progression shortly after ICU admission, and the clinical consequences of this syndrome, the effect of ED-based interventions aimed at reducing the sequelae of ALI should be investigated further.
authors.affiliation: Division of Emergency Medicine, Washington University School of Medicine in St. Louis, St. Louis, MO, USA. fullerb@wusm.wustl.edu
authors.forename: Brian M
authors.initials: BM
authors.lastname: Fuller
authors.forename: Nicholas M
authors.initials: NM
authors.lastname: Mohr
authors.forename: Matthew
authors.initials: M
authors.lastname: Dettmer
authors.forename: Sarah
authors.initials: S
authors.lastname: Kennedy
authors.forename: Kevin
authors.initials: K
authors.lastname: Cullison
authors.forename: Rebecca
authors.initials: R
authors.lastname: Bavolek
authors.forename: Nicholas
authors.initials: N
authors.lastname: Rathert
authors.forename: Craig
authors.initials: C
authors.lastname: McCammon
mesh_terms: D018806:APACHE; D000046:Academic Medical Centers; D055371:Acute Lung Injury / Q000209:etiology / Q000401:mortality / Q000503:physiopathology* / Q000628:therapy*; D000368:Aged; D015331:Cohort Studies; D018450:Disease Progression; D004636:Emergency Service, Hospital; D005260:Female; D017052:Hospital Mortality; D006785:Hospitals, University; D006801:Humans; D007362:Intensive Care Units; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012121:Respiration, Artificial / Q000379:methods* / Q000401:mortality; D012189:Retrospective Studies; D018570:Risk Assessment; D018805:Sepsis / Q000150:complications / Q000175:diagnosis / Q000628:therapy*; D012720:Severity of Illness Index; D012772:Shock, Septic / Q000150:complications / Q000175:diagnosis / Q000628:therapy; D015996:Survival Rate; D016896:Treatment Outcome