Perforated Appendicitis and Postoperative Antibiotics Pilot Trial

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.

• Postoperative antibiotico-prophylaxis (Drug): Patients receive oral antibiotics following surgery for perforated appendicitis. The dose, duration, and type are at the discretion of the treating physician.
• No postoperative antibiotics (Other): Patients do not receive antibiotics following surgery for perforated appendicitis.

Primary outcomes

• Average number of participants enrolled per month across multiple sites. [First to last day of each month of recruitment phase (1 year).]: Assessment of accrual: feasible if 10 or more overall.
• Percentage of participants who receive the correct intervention. [From beginning to end of recruitment phase (1 year).]: Assessment of ability to accurately deliver the intervention that participants were randomized to receive: feasible if >90% of participants receive the assigned intervention.
• Percentage of patient-reported outcomes collected. [Duration of the study (1 year). For each participant, data collected 30 and 90 days after surgery.]: Assessment of ability to collect complete data for patient reported outcomes. Feasible if >80% of data is collected directly from patients with an additional 10% collected from patient health records.

Secondary outcomes

• Quality of Life, as assessed by EQ-5D-5L. [30 and 90 days after surgery for perforated appendicitis.]: Level Sum Score can be calculated, ranging from 5 to 25, with higher scores representing a worse health status.
• Post-operative pain, as assessed by PROMIS Pain Inventory. [30 days after surgery for perforated appendicitis.]: 5-point Likert scale, with higher scores (i.e., 5 or "very much") indicating higher levels of pain.
• Percentage of patients with surgical site infections, as assessed by Participant Assessment of Surgical Wound questionnaire. [30 days after surgery for perforated appendicitis.]: 5 questions (4 yes/no answers, 1 check all that apply).
• Percentage of participants prescribed systemic antibiotics. [Within 30 days after surgery for perforated appendicitis.]: Collected from Participant Assessment of Surgical Wound questionnaire or patient health records.
• Post-operative complications, as assessed by Health Resource Utilization questionnaire. [Within 90 days after surgery for perforated appendicitis.]: 6 questions (5 yes/no, 1 check all that apply).
• Healthcare utilization, as assessed by Health Resource Utilization questionnaire. [Within 90 days after surgery for perforated appendicitis.]: Healthcare utilization, including number of: reinterventions, all-cause reoperations, emergency department visits, all-cause unplanned family physician or walk-in clinic visits, and all-cause readmissions and length of stay of each readmission.

Sex: All, ages: 18 Years to any

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