- Target organisms (Enteric Gram-negative bacilli (Escherichia coli, Klebsiella) · anaerobes (Bacteroides fragilis group) · skin flora (Staphylococcus, Streptococcus))
- Clinical context (Non-perforated acute appendicitis undergoing appendectomy · single preoperative prophylactic dose — not therapeutic postoperative course)
First-line therapy
Cefazolin • i.v. • 30–30 mg/kg/dose • 1×/day
Max 2000 mg/dose · Duration: Single preoperative dose · Infuse within 60 minutes before surgical incision (0–60 min) · redose intraoperatively if procedure exceeds ~4 h per local protocol
Enter weight on Kids to calculate doses
Metronidazole • i.v. • 15–15 mg/kg/dose • 1×/day
Max 500 mg/dose · Duration: Single preoperative dose · Give with cefazolin within 60 minutes before incision · neonates <1200 g: 7.5 mg/kg single dose (ASHP)
Enter weight on Kids to calculate doses
Cefoxitin • i.v. • 40–40 mg/kg/dose • 1×/day
Max 2000 mg/dose · Duration: Single preoperative dose · Second-generation cephalosporin with anaerobic activity · redose intraoperatively if procedure exceeds ~2 h per local protocol
- • Cefoxitin: alternative single-agent regimen with Gram-negative and anaerobic coverage — equivalent to cefazolin + metronidazole (ASHP/SIS/IDSA, WSES, pediatric RAND consensus).
- • Cefazolin monotherapy: acceptable for uncomplicated appendectomy per some pediatric consensus statements when anaerobic coverage is deferred — verify local protocol (ESPES/RAND pediatric abdominal surgery).
- • Beta-lactam allergy (anaphylaxis, angioedema, bronchospasm): clindamycin + gentamicin OR metronidazole + aminoglycoside; aztreonam + metronidazole — avoid cephalosporins if true Type I allergy (ASHP, APSA).
- • Minor beta-lactam reactions (rash without systemic features): cephalosporins may still be used per institutional allergy protocol (APSA, ASHP).
- • Complicated or perforated appendicitis: requires therapeutic postoperative antibiotics — not covered by this prophylaxis-only card (WSES Jerusalem guidelines).
- • Amoxicillin/clavulanate: WSES-listed alternative empiric regimen for uncomplicated appendicitis NOM — acceptable narrow-spectrum option; IV form may be used initially in hospitalized children (WSES, prospective pediatric cohort studies).
- • Oral step-down (after ≥24–48 h IV if improving): amoxicillin/clavulanate 45 mg/kg/day (amoxicillin component) PO BID, or continue ceftriaxone + metronidazole PO equivalents (metronidazole 10 mg/kg TID) to complete 7–10 days total (WSES Rec. 2.3, Carilion 7–10 day pathway).
- • Piperacillin/tazobactam: clinical failure within 48–72 h, progression to complicated appendicitis, or sepsis — not routine first-line (pediatric NOM RCTs often used broad agents; current stewardship favors ceftriaxone + metronidazole or amox-clav first).
- • Beta-lactam allergy: ciprofloxacin + metronidazole per institutional protocol — consult ID/pharmacy (WSES IAI allergy pathways).
- • Appendicolith on imaging: surgery recommended over NOM — high treatment failure (~47–60% in pediatric series); do not offer antibiotics-first as primary pathway (WSES Statement 2.2, Mahida et al.).
Enter weight on Kids to calculate doses
Clinical notes
- • Perioperative antibiotic prophylaxis is indicated for all children with acute appendicitis undergoing appendectomy — single broad-spectrum preoperative dose given 0–60 minutes before skin incision reduces surgical site and intra-abdominal infection (WSES, ASHP/SIS/IDSA).
- • Postoperative antibiotics are NOT recommended after uncomplicated appendectomy in children — single preoperative prophylaxis is sufficient (WSES strong recommendation 1A; ASHP).
- • Discontinue antibiotics after the single preoperative dose for uncomplicated appendicitis; total prophylactic duration should be <24 hours even if intraoperative redosing is required for prolonged surgery (ASHP/SIS/IDSA).
- • Beta-lactam allergy alternatives: clindamycin + gentamicin, metronidazole + aminoglycoside, or aztreonam + metronidazole for Type I allergy; consult pharmacy for weight-based gentamicin dosing (ASHP, APSA).
- • If perforation, phlegmon, or abscess is found intraoperatively, switch to therapeutic postoperative regimen — typically continue IV antibiotics 24–48 h then oral step-down for complicated appendicitis (WSES; use complicated-appendicitis protocols).
- • WSES — Diagnosis and treatment of acute appendicitis: Jerusalem guidelines update (2020)
- • ASHP / IDSA / SIS / SHEA — Surgical Antimicrobial Prophylaxis Guidelines (2023)
- • RAND / ESPES — Surgical antimicrobial prophylaxis in abdominal surgery for neonates and paediatrics (2022)
+ 2 more
- • APSA — Surgical antibiotic prophylaxis recommendations (2024)
- • AAP — Perioperative antibiotic prophylaxis (principles applicable) (2024)