title: Computed tomography-based clinical diagnostic pathway for acute appendicitis: prospective validation.
abstract: BACKGROUND
  Despite our regular use of CT for suspected appendicitis, a recent study at our institution demonstrated a negative appendectomy (NA) rate similar to our rate 15 years earlier. Based on analysis of this data, a diagnostic pathway was implemented prospectively for adult patients with possible appendicitis.
  
  
  METHODS
  Rates of CT, NA, and perforation for nonpregnant patients over 14 years of age undergoing appendectomy between August 2001 and August 2002 (PRE) were compared with prospectively collected pathway data (PATH, August 2004 to August 2005). All PATH patients were evaluated by a surgeon before CT. All females underwent CT. CT was obtained in male patients with low suspicion or pain for longer than 48 hours. After negative CT, patients were discharged from the emergency department or admitted for observation.
  
  
  RESULTS
  There was a substantial decrease in NA rate after implementation of the pathway (4% PATH [8 of 183] versus 16% PRE [31 of 196], p < 0.001), without a change in the rate of perforation (11% PATH [20 of 175] versus 8% PRE [13 of 165], p = 0.28) or frequency of preoperative CT (59% PATH [108 of 183] versus 60% PRE [118 of 196], p = 0.84).
  
  
  CONCLUSIONS
  Frequent appendiceal CT alone does not ensure surgical diagnostic accuracy. CT need not be used in all patients to achieve very low NA rates. An evidence-based diagnostic algorithm incorporating early surgical evaluation, objective criteria for preoperative CT, deterrence of early operation after negative CT, and use of CT to facilitate safe discharge led to substantial improvements in the care of our adult population presenting with possible appendicitis.
authors.affiliation: Department of Surgery, Naval Medical Center San Diego, San Diego, CA, USA. docantevil@yahoo.com
authors.forename: Jared L
authors.initials: JL
authors.lastname: Antevil
authors.forename: Louis
authors.initials: L
authors.lastname: Rivera
authors.forename: Bret J
authors.initials: BJ
authors.lastname: Langenberg
authors.forename: George
authors.initials: G
authors.lastname: Hahm
authors.forename: Michael A
authors.initials: MA
authors.lastname: Favata
authors.forename: Carlos V R
authors.initials: CV
authors.lastname: Brown
mesh_terms: D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001062:Appendectomy; D001064:Appendicitis / Q000000981:diagnostic imaging* / Q000601:surgery; D019091:Critical Pathways; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed