From the Guidelines
Ceftriaxone (option B) is the most appropriate choice for prophylaxis in appendectomy. For surgical prophylaxis in appendectomy, a broad-spectrum antibiotic with coverage against both gram-negative and anaerobic organisms is recommended. Ceftriaxone is a third-generation cephalosporin that provides excellent gram-negative coverage, making it suitable for intra-abdominal procedures like appendectomy. The typical prophylactic dose is 1-2g IV given within 60 minutes before surgical incision as a single dose. While ceftriaxone alone provides good coverage, it is often combined with metronidazole (500mg IV) for enhanced anaerobic coverage, especially in cases of complicated appendicitis. This combination targets the common pathogens found in appendicitis, including Escherichia coli and Bacteroides species. Cephalexin has inadequate gram-negative coverage for intra-abdominal infections, and vancomycin is generally reserved for MRSA-risk situations or patients with severe beta-lactam allergies, making it excessive for routine appendectomy prophylaxis.
Key Points
- Ceftriaxone provides broad-spectrum coverage against gram-negative and anaerobic organisms, making it suitable for appendectomy prophylaxis 1.
- The recommended dose of ceftriaxone is 1-2g IV given within 60 minutes before surgical incision as a single dose.
- Metronidazole (500mg IV) may be added to ceftriaxone for enhanced anaerobic coverage, especially in cases of complicated appendicitis.
- Cephalexin and vancomycin are not recommended for routine appendectomy prophylaxis due to inadequate gram-negative coverage and excessive use, respectively.
Evidence-Based Recommendations
The most recent and highest quality study, published in 2024, recommends ceftriaxone as a first-line option for surgical prophylaxis in appendectomy 1. Additionally, studies from 2020 and 2022 support the use of ceftriaxone for appendectomy prophylaxis, with recommendations for combination therapy with metronidazole in certain cases 1. Overall, the evidence suggests that ceftriaxone is the most appropriate choice for prophylaxis in appendectomy, with consideration for combination therapy with metronidazole in complicated cases.
From the FDA Drug Label
The prophylactic administration of Metronidazole Injection preoperatively, intraoperatively, and postoperatively may reduce the incidence of postoperative infection in patients undergoing elective colorectal surgery which is classified as contaminated or potentially contaminated. The answer is C. Metronidazole, as it can be used as prophylaxis in surgeries that are classified as contaminated or potentially contaminated, such as appendectomy, although it is specifically mentioned for elective colorectal surgery. However, appendectomy is not explicitly mentioned in the provided drug label, but it can be considered a potentially contaminated surgery.
- Key points:
- Metronidazole can be used for prophylaxis in contaminated or potentially contaminated surgeries.
- The label specifically mentions elective colorectal surgery.
- Appendectomy can be considered a potentially contaminated surgery, but it is not explicitly mentioned in the label 2.
From the Research
Medications for Prophylaxis in Appendectomy
The following medications can be used as prophylaxis in appendectomy:
Rationale for Medication Choice
The choice of medication is based on the type of appendicitis and the presence of adverse risk factors.
- Ceftriaxone and metronidazole are effective in preventing surgical site infections in children with uncomplicated appendicitis 4
- Ceftriaxone and metronidazole are appropriate empirical therapy for patients with perforated appendicitis and cholecystitis 5
- Preoperative antibiotic prophylaxis is recommended in all patients with acute appendicitis, whereas postoperative antibiotics are only recommended in cases of perforation 7
Excluded Medications
The following medications are not specifically mentioned as prophylaxis in appendectomy:
- Cephalexin
- Vancomycin
Note: Vancomycin is mentioned in one of the studies as Vancomycin-resistant Enterococci (VRE) but it is not recommended as a prophylaxis in appendectomy.