title: The use of noninvasive positive pressure ventilation in the emergency department: results of a randomized clinical trial.
abstract: OBJECTIVE
  To determine whether the use of noninvasive positive pressure ventilation (NPPV) in the emergency department (ED) will reduce the need for tracheal intubation and mechanical ventilation.
  
  
  METHODS
  Randomized, controlled, prospective clinical trial.
  
  
  METHODS
  ED of Barnes-Jewish Hospital, a university-affiliated teaching hospital.
  
  
  METHODS
  Twenty-seven patients meeting a predetermined definition of acute respiratory distress requiring hospital admission.
  
  
  METHODS
  Conventional medical therapy for the various etiologies of acute respiratory distress and the application of NPPV.
  
  
  RESULTS
  The primary outcome measure was the need for tracheal intubation and mechanical ventilation. Secondary outcomes also assessed included hospital mortality, hospital length of stay, acquired organ system derangements, and the utilization of respiratory care personnel. Sixteen patients (59.3%) were randomly assigned to receive conventional medical therapy plus NPPV, and 11 patients (40.7%) were randomly assigned to receive conventional medical therapy without NPPV. The two groups were similar at the time of randomization in the ED with regard to demographic characteristics, hospital admission diagnoses, and severity of illness. Tracheal intubation and mechanical ventilation was required in seven patients (43.8%) receiving conventional medical therapy plus NPPV and in five patients (45.5%) receiving conventional medical therapy alone (relative risk=0.96; 95% confidence interval=0.41 to 2.26; p=0.930). There was a trend towards a greater hospital mortality rate among patients in the NPPV group (25%) compared to patients in the conventional medical therapy group (0.0%) (p=0.123). Among patients who subsequently required mechanical ventilation, those in the NPPV group had a longer time interval from ED arrival to the start of mechanical ventilation compared to patients in the conventional medical therapy group (26.0+/-27.0 h vs 4.8+/-6.9 h; p=0.055).
  
  
  CONCLUSIONS
  We conclude that the application of NPPV in the ED may delay tracheal intubation and the initiation of mechanical ventilation in some patients with acute respiratory distress. We also demonstrated that the application of NPPV was associated with an increased hospital mortality rate. Based on these preliminary observations, larger clinical investigations are required to determine if adverse patient outcomes can be attributed to the early application of NPPV in the ED. Additionally, improved patient selection criteria for the optimal administration of NPPV in the ED need to be developed.
authors.affiliation: Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA.
authors.forename: K A
authors.initials: KA
authors.lastname: Wood
authors.forename: L
authors.initials: L
authors.lastname: Lewis
authors.forename: B
authors.initials: B
authors.lastname: Von Harz
authors.forename: M H
authors.initials: MH
authors.lastname: Kollef
mesh_terms: D000208:Acute Disease; D004636:Emergency Service, Hospital; D004638:Emergency Treatment; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D007442:Intubation, Intratracheal; D008297:Male; D008875:Middle Aged; D018579:Patient Selection; D011175:Positive-Pressure Respiration / Q000379:methods / Q000706:statistics & numerical data*; D011446:Prospective Studies; D012131:Respiratory Insufficiency / Q000401:mortality / Q000628:therapy*; D013997:Time Factors; D016896:Treatment Outcome