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.