Optimal Duration of Antibiotics Following Appendectomy for Patients With Complicated Appendicitis

Complicated appendicitis patients typically undergo appendectomy followed by antibiotics. The optimal course of antibiotics for complicated appendicitis is poorly defined.

Data were collected from patients presenting with acute appendicitis and underwent appendectomy at the index hospitalization (2015-2017). Primary outcomes were readmission rate, superficial surgical site infection (SSI), deep space infection (DSI), which includes abscess. Length of post-operative antibiotic use was recorded and an average intent-to-treat (ITT) by operative grade was calculated.

Two hundred seventy-two patients (23%) were diagnosed with complicated appendicitis. SSI occurred in 4% of patients (n = 11); SSI rates ranged from 0% to 14.6% by ITT group with 3-4 days being the lowest (0%) and <3 days the highest (14.6%) (P = .008). DSI including abscesses occurred in 27 (9.9%) patients; least frequently in the 5-6 day ITT group (7.4%). Length of stay (LOS) was significantly related to longer antibiotic use (P < .001) and increasing operative grade (P < .01).

Given the lower incidence of postoperative complications between 3 and 6 days and no added benefit for ITT >6 days, we recommend limiting antibiotic treatment to 3-6 days for all complicated appendicitis cases with additional workup warranted if infectious symptoms persist.