Peroral versus intravenous post-operative antibiotics after surgery for complicated appendicitis: protocol for a cluster-randomised cluster-crossover non-inferiority study

INTRODUCTION: Complicated appendicitis increases the risk of post-operative intra-abdominal abscess. Treatment of complicated appendicitis is usually a post-operative course of intravenous antibiotics. A study is needed to confirm the results of retrospective studies showing that a post-operative course of oral antibiotics is not inferior to intravenous antibiotics after laparoscopic surgery for complicated appendicitis.

METHODS: The Per oral versus Intravenous Postoperative Antibiotics after surgery for complicated appendicitis (PIPA) trial will be a prospective, multicentre, cluster-randomised cluster-crossover non-inferiority study designed to test whether a three-day post-operative course of oral antibiotics is non-inferior to a three-day post-operative course of intravenous antibiotics as standard care after laparoscopic surgery for complicated appendicitis in regards to the risk of post-operative intra-abdominal abscess formation within 30 days. Participating hospitals will either be randomised to a six-month period with an oral antibiotic regime followed by a six-month period with an intravenous antibiotic regime for the post-operative treatment after laparoscopic surgery for complicated appendicitis, or to a six-month period with an intravenous antibiotic regime followed by a six-month period with an oral antibiotic regime for post-operative treatment after laparoscopic surgery for complicated appendicitis.

CONCLUSIONS: The primary outcome will be the incidence of intra-abdominal abscess by post-operative day 30.

FUNDING: none.

TRIAL REGISTRATION: The study was approved by the Danish Data Protection Agency and by the National/Regional Committee on Health Research Ethics.