title: Length of stay by route of contrast administration for diagnosis of appendicitis by computed-tomography scan.
abstract: OBJECTIVE
  Studies show equivalent accuracy of abdominal computed tomography (CT) using rectal contrast compared with oral contrast for diagnosing appendicitis. The authors evaluated whether emergency department (ED) length of stay and satisfaction differed by route of contrast administration for abdominal CT.
  
  
  METHODS
  This before-and-after intervention evaluated adult patients in an urban academic ED who were undergoing abdominal CT to screen for suspected appendicitis. Phase 1 subjects had a CT after oral contrast. Phase 2 patients had a CT after rectal contrast infused by gravity drip. Patients were interviewed after CT scan to assess satisfaction and discomfort. The primary outcome was ED length of stay. Medians, 95% binomial confidence intervals (CI), and Wilcoxon rank sum test of differences were calculated.
  
  
  RESULTS
  One hundred twelve patients were enrolled; half received rectal contrast. There was a significant decrease in length of stay for patients who were administered rectal contrast (261 min, 95% CI = 236 to 305 min) vs. oral contrast (332 min, 95% CI = 299 to 362 min), p = 0.009. Although subjects in the rectal-contrast group waited 65 minutes longer than did oral-contrast patients before receiving contrast after the CT order, the time from contrast administration to CT was 13 minutes, vs. 150 minutes for patients receiving oral contrast (p < 0.001). Patient satisfaction and discomfort did not differ by route of contrast administration.
  
  
  CONCLUSIONS
  Rectal contrast for patients undergoing abdominal CT to rule out appendicitis reduced ED length of stay by more than an hour and did not affect patient satisfaction or discomfort. Rectal-contrast administration for abdominal CT may significantly shorten patient throughput time for individuals undergoing evaluation for appendicitis.
authors.affiliation: Department of Emergency Medicine, Boston University School of Medicine, Boston, MA, USA. evan.berg@bmc.org
authors.forename: Evan R
authors.initials: ER
authors.lastname: Berg
authors.forename: Supriya D
authors.initials: SD
authors.lastname: Mehta
authors.forename: Patricia
authors.initials: P
authors.lastname: Mitchell
authors.forename: Jorge
authors.initials: J
authors.lastname: Soto
authors.forename: Leslie
authors.initials: L
authors.lastname: Oyama
authors.forename: Andrew
authors.initials: A
authors.lastname: Ulrich
mesh_terms: D000328:Adult; D001064:Appendicitis / Q000000981:diagnostic imaging* / Q000503:physiopathology; D003287:Contrast Media / Q000008:administration & dosage*; D004636:Emergency Service, Hospital; D005260:Female; D006801:Humans; D007902:Length of Stay; D008297:Male; D017060:Patient Satisfaction; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media