title: Emergency medicine resident performed bedside ultrasonography of the gallbladder in non-fasted healthy volunteers.
abstract: BACKGROUND
  Gallbladder ultrasonography is a commonly performed test in the emergency department. It is unknown whether a non-fasting state alters the visualization of the gallbladder by emergency medicine (EM) residents.
  
  
  OBJECTIVE
  We conducted this study to determine whether EM residents are able to visualize the gallbladder in volunteers who have recently consumed a fatty meal.
  
  
  METHODS
  This study used a prospective, single-blinded, randomized controlled design. Initial scans were performed on fasting volunteers. A fatty meal was then consumed. Thirty minutes after eating, a different resident, who was unaware of whether the volunteer had eaten or fasted, performed a second scan. To control for operator bias, 10% of subjects remained fasting between scans. Student's paired-samples t-test, Pearson's chi-squared, and McNemar test were determined as appropriate.
  
  
  RESULTS
  A total of 92 scans from 46 volunteers were analyzed. EM residents were able to visualize the gallbladder in all 40 pre-prandial scans (100%) and all 40 post-prandial scans (100%). Gallbladder area as measured in the longitudinal axis decreased 20% from a mean baseline of 11.58 +/- 4.86 cm(2) (95% confidence interval [CI] 11.17-12.98) to 9.2 +/- 5.04 cm(2) (95% CI 7.74-10.66, p = 0.0009) after food intake. Total time to scan for the fasting volunteers (110.2 s, 95% CI 84.34-136) did not change significantly from non-fasting volunteers (129.7 s, 95% CI 110.29-149.01, p = 0.153).
  
  
  CONCLUSIONS
  EM residents are able to visualize the gallbladder in non-fasted healthy volunteers.
authors.affiliation: Department of Emergency Medicine, Christiana Care Health System, Newark, Delaware 19718, USA.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Breyer
authors.forename: Michael
authors.initials: M
authors.lastname: Giordano
authors.forename: Banu
authors.initials: B
authors.lastname: Tinjum
authors.forename: Leila
authors.initials: L
authors.lastname: Getto
authors.forename: Nathan
authors.initials: N
authors.lastname: Rhodes
authors.forename: Melissa
authors.initials: M
authors.lastname: Bollinger
authors.forename: Paul
authors.initials: P
authors.lastname: Sierzenski
authors.forename: Robert E
authors.initials: RE
authors.lastname: O'Connor
mesh_terms: D000328:Adult; D004635:Emergency Medicine / Q000193:education*; D004636:Emergency Service, Hospital; D005215:Fasting; D005260:Female; D005704:Gallbladder / Q000000981:diagnostic imaging*; D006801:Humans; D007396:Internship and Residency; D008875:Middle Aged; D019095:Point-of-Care Systems; D011446:Prospective Studies; D014463:Ultrasonography / Q000379:methods