title: Emergency department length of stay for patients requiring mechanical ventilation: a prospective observational study.
abstract: BACKGROUND
  Recommendations for acceptable emergency department (ED) length of stay (LOS) vary internationally with ≤ 8 h generally considered acceptable. Protracted ED LOS may place critically ill patients requiring mechanical ventilation at increased risk of adverse events as most EDs are not resourced for longitudinal delivery of critical care. Our objective was to quantify the ED LOS for mechanically ventilated patients (invasive and/or non-invasive ventilation [NIV]) and to explore patient and system level predictors of prolonged ED LOS. Additionally, we aimed to describe delivery and monitoring of ventilation in the ED.
  
  
  METHODS
  Prospective observational study of ED LOS for all patients receiving mechanical ventilation at four metropolitan EDs in Toronto, Canada over two six-month periods in 2009 and 2010.
  
  
  RESULTS
  We identified 618 mechanically ventilated patients which represented 0.5% (95% CI 0.4%-0.5%) of all ED visits. Of these, 484 (78.3%) received invasive ventilation, 118 (19.1%) received NIV; 16 received both during the ED stay. Median Kaplan-Meier estimated duration of ED stay for all patients was 6.4 h (IQR 2.8-14.6). Patients with trauma diagnoses had a shorter median (IQR) LOS, 2.5 h (1.3-5.1), compared to ventilated patients with non-trauma diagnoses, 8.5 h (3.3-14.0) (p <0.001). Patients requiring NIV had a longer ED stay (16.6 h, 8.2-27.9) compared to those receiving invasive ventilation exclusively (4.6 h, 2.2-11.1) and patients receiving both (15.4 h, 6.4-32.6) (p <0.001). Longer ED LOS was associated with ED site and lower priority triage scores. Shorter ED LOS was associated with intubation at another ED prior to transfer.
  
  
  CONCLUSIONS
  While patients requiring mechanical ventilation represent a small proportion of overall ED visits these critically ill patients frequently experienced prolonged ED stay especially those treated with NIV, assigned lower priority triage scores at ED presentation, and non-trauma patients.
authors.affiliation: Lawrence S, Bloomberg Faculty of Nursing, 155 College St, Rm 276, Toronto, ON, M5T IP8, Canada. louise.rose@utoronto.ca
authors.forename: Louise
authors.initials: L
authors.lastname: Rose
authors.forename: Sara
authors.initials: S
authors.lastname: Gray
authors.forename: Karen
authors.initials: K
authors.lastname: Burns
authors.forename: Clare
authors.initials: C
authors.lastname: Atzema
authors.forename: Alex
authors.initials: A
authors.lastname: Kiss
authors.forename: Andrew
authors.initials: A
authors.lastname: Worster
authors.forename: Damon C
authors.initials: DC
authors.lastname: Scales
authors.forename: Gordon
authors.initials: G
authors.lastname: Rubenfeld
authors.forename: Jacques
authors.initials: J
authors.lastname: Lee
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016638:Critical Illness / Q000628:therapy*; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D007902:Length of Stay / Q000706:statistics & numerical data*; D008297:Male; D008875:Middle Aged; D063087:Noninvasive Ventilation / Q000706:statistics & numerical data; D009864:Ontario; D011446:Prospective Studies; D012121:Respiration, Artificial / Q000706:statistics & numerical data*; D012131:Respiratory Insufficiency / Q000628:therapy*