In the operating room (OR), the use of antibiotics is an essential practice aimed at preventing infections, which can lead to serious complications in surgical patients. Antibiotics are administered either prophylactically to prevent infection or therapeutically to treat existing infection. Understanding which antibiotics are commonly used in the OR, how they work, and their appropriate administration is crucial for both the surgical team and the patient.

Antibiotics in the OR setting are primarily used to prevent infections in patients undergoing surgery. Prophylactic antibiotics reduce the risk of postoperative infections that could result from the surgical procedure. The choice of antibiotic depends on the type of surgery, the patient’s medical history, and the most common pathogens associated with the specific procedure. In clean surgeries such as elective orthopedic procedures, first-generation cephalosporins like cefazolin are often used. In surgeries where there is a higher risk of exposure to anaerobic bacteria, such as colorectal or abdominal surgeries, antibiotics like cefoxitin or piperacillin-tazobactam may be administered. The timing of antibiotic administration is crucial to maximizing their effectiveness. Prophylactic antibiotics are typically administered within one hour prior to the incision, ensuring that the drug is at effective concentrations when the surgical site is exposed to potential bacterial contamination. In some cases, antibiotics may be continued postoperatively for a short period if the risk of infection remains elevated ^1–5.

In some surgical procedures, patients may already have an existing infection that needs to be addressed without delaying surgery. Patients undergoing emergency surgery for conditions such as appendicitis or abscess drainage may require a different antibiotic regimen than those receiving prophylaxis. Broad-spectrum antibiotics are often chosen to cover a wide range of potential pathogens. When treating an active infection, the choice of antibiotic is guided by the suspected or confirmed pathogen, which can sometimes be identified through culture and sensitivity tests taken during surgery. The selection of the right antibiotic is critical to ensuring the infection is effectively treated while minimizing the risk of resistance ^6,7.

While antibiotics are a vital tool in preventing and treating infections in the OR, their overuse or inappropriate use can lead to antibiotic resistance, a growing global concern. To combat this, many hospitals have implemented antibiotic stewardship programs. These programs aim to optimize the use of antibiotics by ensuring they are prescribed only when necessary and that the correct antibiotic is chosen based on the type of infection or surgical procedure. Antibiotic stewardship efforts also focus on adjusting the duration of antibiotic treatment. For prophylactic antibiotics, the standard practice is to limit their use to the perioperative period, typically stopping them within 24 hours after surgery. This approach minimizes the risk of complications like C. difficile infections and antibiotic resistance, both of which can result from prolonged antibiotic use ^7–9.

References

1. Contributor, W. E. What to Know About Prophylactic Antibiotics. WebMD https://www.webmd.com/a-to-z-guides/what-to-know-prophylactic-antibiotics.
2. Crader, M. F. & Varacallo, M. A. Preoperative Antibiotic Prophylaxis. in StatPearls (StatPearls Publishing, Treasure Island (FL), 2025).
3. Prokuski, L. Prophylactic antibiotics in orthopaedic surgery. J Am Acad Orthop Surg 16, 283–293 (2008). DOI: 10.5435/00124635-200805000-00007
4. Hussain, Z. et al. Prophylactic Cefazolin Dosing and Surgical Site Infections: Does the Dose Matter in Obese Patients? Obes Surg 29, 159–165 (2019). DOI: 10.1007/s11695-018-3497-0
5. Yang, Y. et al. Antibiotic prophylaxis with piperacillin-tazobactam reduces organ/space surgical site infection after pancreaticoduodenectomy: a retrospective and propensity score-matched analysis. BMC Cancer 24, 251 (2024). DOI: 10.1186/s12885-024-11955-x
6. Le Vavasseur, B. & Zeller, V. Antibiotic Therapy for Prosthetic Joint Infections: An Overview. Antibiotics (Basel) 11, 486 (2022). DOI: 10.3390/antibiotics11040486
7. CDC. Core Elements of Hospital Antibiotic Stewardship Programs. Antibiotic Prescribing and Use https://www.cdc.gov/antibiotic-use/hcp/core-elements/hospital.html (2024).
8. Tarchini, G., Liau, K. H. & Solomkin, J. S. Antimicrobial Stewardship in Surgery: Challenges and Opportunities. Clinical Infectious Diseases 64, S112–S114 (2017). DOI: 10.1093/cid/cix087
9. Campbell, K. A., Stein, S., Looze, C. & Bosco, J. A. Antibiotic stewardship in orthopaedic surgery: principles and practice. J Am Acad Orthop Surg 22, 772–781 (2014). DOI: 10.5435/JAAOS-22-12-772