What is the recommended antibiotic prophylaxis regimen for a patient with classical appendicitis undergoing surgery, specifically regarding the duration of antibiotic administration preoperatively and postoperatively?

Antibiotic Management for Classical Appendicitis

For uncomplicated appendicitis, give a single preoperative dose of broad-spectrum antibiotics (0-60 minutes before incision) and stop—no postoperative antibiotics are needed. 1

Preoperative Antibiotic Administration

A single dose of broad-spectrum antibiotics administered 0-60 minutes before surgical incision is all that is required for uncomplicated appendicitis. 1

• The 2020 WSES Jerusalem Guidelines provide a strong recommendation (Grade 1A) against postoperative antibiotics for uncomplicated appendicitis. 1
• This single preoperative dose effectively decreases wound infections and intra-abdominal abscesses regardless of whether the appendix is inflamed, gangrenous (but not perforated), or even normal. 1
• Timing beyond 60 minutes preoperatively does not affect surgical site infection rates. 1

Recommended Antibiotic Choices

Broad-spectrum coverage against enteric gram-negative organisms and anaerobes is essential: 2

• Piperacillin-tazobactam (Zosyn) 3.375g IV single dose 3
• Cefoxitin 2g IV single dose 4
• Ampicillin-sulbactam 2
• Ceftriaxone plus metronidazole (increasingly preferred to reduce broad-spectrum use) 5

Postoperative Antibiotics: When to Continue

Uncomplicated Appendicitis

Stop antibiotics after the single preoperative dose—continuing them provides no benefit and increases unnecessary antibiotic exposure. 1, 2

Complicated Appendicitis (Perforated/Abscess)

If adequate source control was achieved during surgery, limit postoperative antibiotics to 24 hours to 3-5 days maximum. 1, 2

• 24-hour postoperative therapy is safe and associated with shorter hospital stays (61 vs 81 hours) with no increase in complications compared to extended courses. 1
• A 3-5 day course is generally sufficient when adequate source control is achieved. 1, 2
• The landmark STOP-IT trial demonstrated that fixed-duration therapy (4 days) had similar outcomes to longer courses (8 days). 1
• Courses exceeding 5 days provide no additional benefit in preventing intra-abdominal abscesses and only increase hospital length of stay. 1

Critical Pitfalls to Avoid

Do not confuse gangrenous with perforated appendicitis: 2

• Gangrenous (non-perforated) appendicitis = uncomplicated = single preoperative dose only
• Perforated appendicitis with adequate source control = 24 hours to 3-5 days maximum
• Perforated appendicitis with inadequate source control = may require longer duration based on clinical response

Adequate source control means: 2

• Complete appendectomy performed
• No residual abscess or diffuse purulence remains
• If these conditions are met, prolonged antibiotics are unnecessary

The most common error is continuing antibiotics for 5-7 days in uncomplicated or adequately controlled complicated appendicitis—this increases costs, hospital stay, and antibiotic resistance without improving outcomes. 1, 2

Special Populations

Pediatric Patients

• Same principles apply: single preoperative dose for uncomplicated cases 2
• For complicated appendicitis, switch to oral antibiotics after 48 hours with total duration <7 days 2, 3

Patients ≥40 Years

• Require colonoscopy and interval CT scan if treated non-operatively due to 3-17% incidence of appendiceal neoplasms 2, 3