title: Stress ulcer prophylaxis in mechanically ventilated patients: integrating evidence and judgment using a decision analysis.
abstract: OBJECTIVE
  Stress ulcer prophylaxis with a histamine-2 receptor antagonist can reduce the risk of gastrointestinal bleeding in mechanically ventilated patients but may also increase the risk of ventilator-associated pneumonia. We sought to clarify the tradeoffs involved in selecting a prophylactic strategy.
  
  
  METHODS
  Decision analysis.
  
  
  METHODS
  A decision tree was constructed for a hypothetical cohort of patients receiving mechanical ventilation for an expected duration of longer than 48 h, using probabilities estimated from the published literature.
  
  
  METHODS
  Patients in the model could receive either prophylaxis with a histamine-2 receptor antagonist or no prophylaxis. Sensitivity analyses were preformed varying the estimated probabilities over their plausible ranges.
  
  
  RESULTS
  Both strategies were associated with approximately the same baseline expected mortality (16.6% for histamine-2 receptor antagonists and 16.9% for no prophylaxis, risk difference 0.3%). Varying the estimated probabilities resulted in only small changes in both the expected mortality and the absolute risk reduction associated with the preferred treatment. At the extremes of assumptions the absolute mortality reduction ranged from 0.1% to 3.3%.
  
  
  CONCLUSIONS
  No single strategy of stress ulcer prophylaxis is preferred when mortality is used as the outcome. In the absence of a clinical trial demonstrating survival benefit the individual clinician's assumptions regarding the effect of prophylaxis on gastrointestinal bleeding and pneumonia and the attributable mortality of pneumonia vs. gastrointestinal bleeding will have a significant effect on the decision.
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Harborview Medical Center, 325 Ninth Avenue, Seattle, WA 98119, USA,
authors.forename: Jeremy M
authors.initials: JM
authors.lastname: Kahn
authors.forename: Jason N
authors.initials: JN
authors.lastname: Doctor
authors.forename: Gordon D
authors.initials: GD
authors.lastname: Rubenfeld
mesh_terms: D003663:Decision Trees; D006635:Histamine H2 Antagonists / Q000627:therapeutic use*; D006801:Humans; D010437:Peptic Ulcer / Q000209:etiology* / Q000517:prevention & control*; D012121:Respiration, Artificial / Q000009:adverse effects*; D012680:Sensitivity and Specificity; D013312:Stress, Physiological / Q000209:etiology* / Q000517:prevention & control*
chemical_list: D006635:Histamine H2 Antagonists