Prophylactic Antibiotics May Not Elevate Risk of Post-Surgical Drug Resistance

Before certain medical procedures that have a high risk of antibiotic-resistance, some surgeons may choose to prescribe antibiotics. While prophylactic antibiotics have been thought to be involved in antibiotic resistance, this practice may not increase the risk of resistance after certain operations.

A new study published by the Journal of the American College of Surgeons suggests that patients who are treated with antibiotics prior to low-risk surgery do not have an increased risk of antibiotic-resistant infections.

Current guidelines outline the proper use of prophylactic antibiotics to prevent surgical infections. The study authors note that the guidelines cover major surgeries, including abdominal, neurological, and ophthalmic procedures.

However, surgeons are free to use their judgment to determine whether they prescribe antibiotics prior to other procedures, which may cause inconsistencies, according to the study.

“Guidelines don’t comment on relatively straightforward procedures, including some general surgical procedures, simple or diagnostic laparoscopy, or elective orthopedic, gynecologic, and urologic procedures because there has not been enough evidence about their benefit,” said principal author Daniel Freedberg, MD, MS. “So, some surgeons feel strongly that antibiotics are beneficial and always give them. Others never give them because of concern about the use of antibiotics and the later development of antibiotic resistance and bacterial infections that have no or almost no treatment options.”

In the current study, the authors investigated the use of prophylactic antibiotics and the development of antibiotic resistance during procedures in which there are no guidelines.

The authors reviewed data for 22,138 adults who had an operation between 2008 and 2016. Included in the study were patients who had a positive bacterial culture from any surgical site or fluid specimen within 30 days of the operation. The authors then analyzed how many patients treated with prophylactic antibiotics developed an infection.

Antibiotic-resistant infections were defined as cultured bacteria that were moderately or not susceptible to treatment with antibiotics.

The investigators found that 3.1% of patients developed an infection within 30 days of surgery. Of these patients, 80% received prophylactic antibiotics and 49% had a drug-resistant infection, according to the study.

Notably, patients were observed to have the same risk of antibiotic-resistant infections regardless of prophylactic treatment. The authors found that 47% of patients with a resistant infection did not receive antibiotics before surgery, while 49% received the drugs, according to the study.

These results remained true regardless of several factors, including when antibiotics were taken, whether the follow-up period was 30 days or 14 days, and whether patients had prior antibiotic exposure or a prior infection, according to the study.

The investigators noted that the only factor that increased the risk was previously having an antibiotic-resistant infection.

These findings suggest that prophylactic antibiotics may not drive resistant infections, according to the study.

“If you’re trying to figure out as a surgeon whether your patients may later develop a resistant infection in the postoperative period, the best clue is past history of resistant infection,” Dr. Freedberg said. “The results of this study should be reassuring for those surgeons who choose to use antibiotic prophylaxis believing that antibiotics decrease the overall risk for infection following surgery. The study shows that even if patients develop an infection, they will not be worse off because they received a single dose of an antibiotic.”