PAEA Surgery End Of Rotation (EOR) Practice Exam

For colorectal surgeries, what is the recommended antibiotic regimen?

1. Cefazolin alone

2. Cefazolin and metronidazole

3. Metronidazole alone

4. Amoxicillin

The correct answer is: Cefazolin and metronidazole

The recommended antibiotic regimen for colorectal surgeries typically includes a combination of cefazolin and metronidazole. This combination provides broad-spectrum coverage against both gram-positive and certain gram-negative bacteria, as well as anaerobes, which are common in the gastrointestinal tract. Cefazolin is a first-generation cephalosporin effective against gram-positive cocci, including Staphylococcus and Streptococcus species, which are commonly found on the skin and can contribute to surgical site infections. Metronidazole is key in covering anaerobic bacteria and also some protozoa, making it particularly valuable in the context of surgeries involving the colon, where anaerobic flora are abundant. Using this dual regimen reduces the risk of postoperative infections significantly compared to using a single antibiotic. It ensures a more comprehensive prophylactic approach, accounting for the varied microbial flora present in the intestinal environment during colorectal procedures. Other options provide insufficient coverage: cefazolin alone does not adequately address the anaerobic bacteria that are typically present in the colon, while metronidazole alone lacks coverage for gram-positive cocci. Amoxicillin, while a penicillin antibiotic, is not typically used for surgical prophylaxis in these cases due to its narrower spectrum of activity and less efficacy against the