title: Does an Acute Surgical Model increase the rate of negative appendicectomy or perforated appendicitis?
abstract: BACKGROUND
  The clinical outcomes from suspected appendicitis depend on balancing the rate of negative appendicectomy (NA) with perforated appendicitis (PA). An Acute Surgical Model (ASM) was introduced at Geelong Hospital (GH) in 2011 involving a dedicated emergency general surgery theatre list every business day giving greater access to theatre for general surgeons. The aim of this study was to evaluate the effect of the ASM at GH on the management of appendicitis, in particular the NA and PA rates.
  
  
  METHODS
  Data for 357 patients undergoing emergency appendicectomy was collected prospectively over 1 year (2011) and compared with a historical control group of 351 patients (2010). The data was analysed for patient demographics, preoperative diagnostic radiology and outcomes including NA and PA rates and complications. The negative appendicectomy rates were compared with contemporary studies.
  
  
  RESULTS
  There was no difference between the two groups in rates of negative appendicectomy 21% (ASM; 73/357) versus 21% (Control; 73/351) P = 0.98, or perforated appendicitis 17% (ASM; 61/357) versus 13% (Control; 47/351) P = 0.18. The introduction of the ASM corresponded to a significantly lower proportion of emergency appendicectomies overnight (4% [16/357] versus 12% [44/351] P = 0.005). There was no significant difference in the use of preoperative diagnostic radiology or complications. Matched contemporary studies had a NA rate of 26%.
  
  
  CONCLUSIONS
  The introduction of the ASM at GH has not significantly altered the rate of NA or PA. The NA rate at GH is comparable to other published UK and Australian series.
authors.affiliation: Department of Surgery, Geelong Hospital and Deakin University, Geelong, Victoria, Australia.
authors.forename: Stephen F
authors.initials: SF
authors.lastname: Brockman
authors.forename: Steel
authors.initials: S
authors.lastname: Scott
authors.forename: Glenn D
authors.initials: GD
authors.lastname: Guest
authors.forename: Douglas A
authors.initials: DA
authors.lastname: Stupart
authors.forename: Shannon
authors.initials: S
authors.lastname: Ryan
authors.forename: David A K
authors.initials: DA
authors.lastname: Watters
mesh_terms: D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001062:Appendectomy / Q000706:statistics & numerical data; D001064:Appendicitis / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000517:prevention & control / Q000601:surgery*; D004636:Emergency Service, Hospital / Q000458:organization & administration* / Q000706:statistics & numerical data; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017146:Models, Organizational; D011183:Postoperative Complications; D011446:Prospective Studies; D011859:Radiography; D013503:Surgery Department, Hospital / Q000458:organization & administration* / Q000706:statistics & numerical data; D014193:Trauma Centers; D016896:Treatment Outcome; D019564:Unnecessary Procedures / Q000706:statistics & numerical data*; D014739:Victoria; D055815:Young Adult
keywords: Acute Surgical Model; appendectomy; emergency surgery; negative appendicectomy; perforated appendicitis