title: Patient weight as a predictor of pain response to morphine in the emergency department.
abstract: OBJECTIVE
  There is little evidence that patient weight is associated with pain response to morphine in the emergency department (ED). The primary outcome of this study is to identify demographic variables including patient weight that are associated with an adequate pain reduction after the first dose of morphine.
  
  
  METHODS
  A retrospective chart review of all patients with severe nontraumatic abdominal pain receiving intravenous morphine was conducted in our ED over a 3-month time period. Pain score, using an 11-point verbal numerical pain scale (0-10), was measured before and after each dose of morphine. Adequate response was defined as a ≥ 4-point reduction from baseline pain score.
  
  
  RESULTS
  A total of 105 patients were included in the analysis. Univariate logistic regression analyses stratified by dose (2 or 4 mg) showed that patient weight was not predictive of adequate pain response after the first dose of morphine (2 mg: odds ratio = 1; 95% confidence interval 0.97-1.03; P = .88; 4 mg: odds ratio = 1; 95% confidence interval 0.97-1.03; P = .86).
  
  
  CONCLUSIONS
  Patient weight may not predict pain response to morphine in the ED. Dosing strategies based on patient weight may not be necessary in this patient population.
authors.affiliation: Department of Pharmacy Practice & Science, College of Pharmacy, University of Arizona, Tucson, Arizona 85721, USA. patanwala@pharmacy.arizona.edu
authors.forename: Asad E
authors.initials: AE
authors.lastname: Patanwala
authors.forename: Adam D
authors.initials: AD
authors.lastname: Biggs
authors.forename: Brian L
authors.initials: BL
authors.lastname: Erstad
mesh_terms: D015746:Abdominal Pain / Q000188:drug therapy* / Q000378:metabolism*; D000293:Adolescent; D000328:Adult; D001835:Body Weight / Q000187:drug effects / Q000502:physiology*; D004636:Emergency Service, Hospital; D005260:Female; D005544:Forecasting; D006801:Humans; D008297:Male; D008875:Middle Aged; D009020:Morphine / Q000493:pharmacokinetics / Q000627:therapeutic use*; D010146:Pain / Q000188:drug therapy / Q000378:metabolism; D010147:Pain Measurement / Q000187:drug effects / Q000379:methods; D012189:Retrospective Studies; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D009020:Morphine