Perforated Appendicitis and Postoperative Antibiotics Pilot Trial

Perforated Appendicitis and Postoperative Antibiotics Pilot Trial

The goal of this clinical trial is to learn if not giving antibiotics is as effective as giving antibiotics after surgery for patients who have surgery for a perforated (burst) appendix. This pilot study will also help determine whether a larger, multi-centre study can be successfully conducted. The main questions it aims to answer are:

• Do patients who do not receive antibiotics after surgery have similar rates of infection after surgery as patients who do?
• Is it feasible to enroll and randomize patients and collect complete health data for a larger multi-centre study?

Researchers will compare patients who do not receive antibiotics after surgery to patients who do to see whether avoiding antibiotics is as effective as using antibiotics for preventing infections after surgery.

Participants will:

• Be randomly assigned to either receive or not receive antibiotics after surgery for their perforated (burst) appendix.
• Be contacted 30 and 90 days after surgery to check for infections and other health outcomes.

Acute appendicitis, a sudden and severe inflammation of the appendix, is the most common emergency general surgery condition worldwide. In some cases, the appendix perforates, leading to contamination or infection within the abdominal cavity. Complicated appendicitis is associated with higher morbidity and mortality, including a higher risk of surgical site infections (SSIs). Approximately 20% of patients with complicated appendicitis develop an SSI, compared to about 5% of patients with uncomplicated appendicitis.

The use of antibiotics before surgery is well established and standard practice to reduce SSI risk. However, there is limited evidence to guide the use of antibiotics after surgery in patients with complicated appendicitis. Antibiotics carry potential risks, including allergic reactions, gastrointestinal side effects, and secondary infections, and their overuse contributes to antimicrobial resistance, which is a growing global health concern. As a result, there is a considerable variation in clinical practice, with some surgeons routinely prescribing post-operative antibiotics and others choosing not to.

Large, high-quality randomized controlled trials (RCTs), the gold-standard in clinical research, are needed to understand if post-operative antibiotics are necessary in this population. The current study will evaluate the impact of post-operative antibiotics on SSIs in patients with perforated appendicitis. This pilot specifically aims to determine the feasibility of a larger, multi-centre RCT, and will assess our ability to enroll and randomize patients, and to collect complete health data using an existing framework. Patients will be randomly assigned to receive post-operative antibiotics or no post-operative antibiotics after surgery for perforated appendicitis, and will be followed until 30 days after surgery to assess incidence of SSIs, with additional outcomes collected up to 90 days post-surgery.

Inclusion Criteria:

• Adults aged 18 years or older
• Scheduled to undergo an open or laparoscopic appendectomy
• Complicated appendicitis confirmed intra-operatively (AAST Appendicitis Grade III or IV)

Exclusion Criteria:

• Patients demonstrating signs of septic shock for whom the omission of systemic antibiotics is contraindicated
• Patients with positive blood cultures for whom antibiotics are required for treatment of the bacteremia
• Immunosuppressed patients
• AAST Appendicitis Grade V