How many days of antibiotics are recommended for a perforated appendix?

Antibiotic Duration for Perforated Appendicitis

For perforated appendicitis, antibiotics should be administered for 3-5 days postoperatively when adequate source control has been achieved. 1

Adult Patients

• A single preoperative dose of broad-spectrum antibiotics should be given 0-60 minutes before surgical incision for all appendicitis cases 1
• Postoperative antibiotics are indicated for perforated appendicitis, especially when complete source control has not been achieved 1
• Discontinuation of antibiotics after 24 hours following appendectomy with adequate source control has been shown to be safe and is associated with shorter hospital stays 1
• For adult patients with adequate source control, a fixed-duration antibiotic therapy of 3-5 days is recommended and produces outcomes similar to longer courses 1, 2
• Extending antibiotics beyond 3-5 days does not improve outcomes when adequate source control has been achieved 2

Pediatric Patients

• Children with perforated appendicitis can safely be switched to oral antibiotics after 48 hours of IV therapy 1, 2
• Total antibiotic duration for children should be less than 7 days when adequate source control is achieved 1
• A shortened course (5-8 days) of antibiotics has similar outcomes to prolonged courses (10-14 days) in pediatric patients 3
• Amoxicillin/clavulanate is recommended for oral management of perforated appendicitis in children due to better tolerance 3

Antibiotic Selection

• For non-critically ill patients, piperacillin/tazobactam is recommended as first-line therapy 2, 4
• Alternative regimens include ceftriaxone plus metronidazole or amoxicillin/clavulanate 4
• For beta-lactam allergies, ciprofloxacin plus metronidazole or moxifloxacin are recommended 4
• For patients at risk for ESBL-producing bacteria, carbapenems (ertapenem, meropenem, imipenem/cilastatin) are recommended 4

Monitoring Response to Treatment

• Antibiotics can be discontinued when the patient is:
  1. Afebrile for 24 hours (temperature < 38°C)
  2. Eating normally
  3. Has a normal WBC count with ≤3% band forms 5
• Patients with persistent signs of infection beyond the recommended antibiotic duration should undergo diagnostic investigation 2
• Monitoring should include clinical status, laboratory tests (WBC, PCT, CRP), and imaging when necessary 2

Common Pitfalls and Caveats

• Extending antibiotics beyond 3-5 days does not improve outcomes when adequate source control has been achieved 2
• Patients may develop postoperative abscesses despite initial peritoneal cultures showing organisms sensitive to treatment antibiotics 6
• Empirical addition of gentamicin to ceftriaxone and metronidazole does not reduce the risk of developing intra-abdominal abscesses 6
• Delaying antibiotic administration after diagnosis can increase morbidity and mortality 4
• Inadequate anaerobic coverage can lead to treatment failure 4