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Antibiotics after Simple (Acute) Appendicitis are not Associated with Better Clinical Outcomes: A Post-Hoc Analysis of an EAST Multi-Center Study. Surg Infect (Larchmt) 2021 Jun;22(5):504-508



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Background: The post-operative management of simple (acute) appendicitis differs throughout the United States. Guidelines regarding post-operative antibiotic usage remain unclear, and treatment generally is dictated by surgeon preference. We hypothesize that post-operative antibiotic use for simple appendicitis is not associated with lower post-operative complication rates. Methods: In a post-hoc analysis in a large multi-center observational study, only patients with an intra-operative diagnosis of AAST EGS Grade I were included. Subjects were classified into those receiving post-operative antibiotics (POST) and those given pre-operative antibiotics only (NONE). Clinical outcomes examined were length of stay (LOS), 30-day emergency department (ED) visits and hospital re-admissions, secondary interventions, surgical site infection (SSI), and intra-abdominal abscess (IAA). Results: A total of 2,191 subjects were included, of whom 612 (28%) received post-operative antibiotics. Compared with the NONE group, POST patients were older (age 37 [range 26-50] versus 33 [26-46] years; p < 0.001), weighed more (82 [70-96] versus 79 [68-93] kg (p = 0.038), and had higher white blood cell counts (13.5 ± 4.2 versus 13.1 ± 4.4/103/mcL (p = 0.046), Alvarado Scores (6 [5-7] versus 6 [5-7]; p < 0.001), and Charlson Comorbidity Indices (median score 0 in both cohorts; p < 0.001). The POST patients had a longer LOS (1 [1-2] versus 1 [1-1] days; p < 0.001). There were no differences in the number who had ED visits within 30 days (9% versus 8%; p = 0.435), hospital re-admission (4% versus 2%; p = 0.165), an index hospitalization SSI (0.2% for both cohorts; p = 0.69), an SSI within 30 days (4% versus 2%; p = 0.165), index hospitalization IAA rate (0.3% versus 0.1%; p = 0.190), 30-day IAA (2% versus 1%; p = 0.71), index hospitalization interventions (0.5% versus 0.1%; p = 0.137) or 30-day secondary interventions (2% versus 1%; p = 0.155). Conclusions: Post-operative antibiotic use after appendectomy for simple appendicitis is not associated with better post-operative clinical outcomes at index hospitalization or at 30 days after discharge.

Author List

Lawless RA, Cralley A, Qian S, Vasileiou G, Yeh DD, EAST Appendicitis Study Group


Christopher M. Dodgion MD Associate Professor in the Surgery department at Medical College of Wisconsin