Postoperative Antibiotic Use Provides No Benefit

Although routinely prescribed after surgery, a new meta-analysis of studies on antibiotics and surgery finds there is no need for post-surgery antibiotics if best practices are followed.

One of the biggest risks of surgery is infection. According to the World Health Organization (WHO), surgical-site infections are the most common hospital-acquired infection in low- and middle-income countries, affecting 11.8% of all surgeries by 1 estimate. Although less common in more developed countries, surgical-site infection occurs with regularity; as of 2010-2011, colon surgery topped the risk list, with 9.5% of procedures resulting in infection. Coronary artery bypass surgery carried an infection risk of 3.5%, with cesarean sections clocking in at a 2.9% risk.

Recognizing the infection risk posed by surgery, clinicians have often prescribed antibiotics pre- and post-procedure, sometimes for several days after surgery. However, given the growing awareness of antibiotic resistance and potential toxicities, in 2016 WHO issued in its “Global Guidelines for the Prevention of Surgical Site Infection” a strong recommendation not to continue administering antibiotics after surgery. The recommendation calls for antibiotics to be administered before surgery--up to 2 hours prior--in order to reduce the risk of surgical-site infection.

Given WHO guidelines on the discontinuation of antibiotics after surgery, as well as similar guidelines put forth by the US Centers for Disease Control and Prevention (CDC) and Britain’s National Institute for Health and Care Excellence (NICE), a team of investigators at the University of Amsterdam conducted a meta-analysis of randomized clinical trials focusing on postoperative antibiotic prophylaxis.

The analysis, published in The Lancet, incorporated 83 trials published between 1990 and 2018, 52 of which specifically examined the effects of continuing antibiotics from 1 to 5 days post surgery compared with the effects of ceasing antibiotics immediately after surgery. Based on rates of surgical-site infection, these 52 trials--encompassing a total of 19,273 patients —demonstrated no conclusive evidence that taking antibiotics after surgery provides any benefit, the investigators found.

When the team conducted a subgroup analysis, it did find an indication that post-surgery antibiotic use mitigated the incidence of surgical-site infections; however, when looking at only the 24 trials in which best practice standards were adhered to regarding dose and timing of antibiotics pre- and during surgery, the investigators concluded that the continuation of antibiotics after surgery provided no benefit.

Possible exceptions for which post-surgery antibiotics may be warranted include maxillofacial surgery and cardiac surgery, but the team noted that none of the studies in the cardiac surgery subgroup followed best practices, and just 3 in the maxillofacial group did so.

“Antibiotic use is associated with important adverse effects in a duration-dependent manner,” the investigators wrote in their report. “In turn, these adverse effects are associated with a substantial economic burden that adds to additional acquisition and administration costs related to postoperative continuation of antibiotic prophylaxis. Such costs are particularly consequential in developing countries with limited resources, where this practice is most prevalent.”

The scientists noted that in resource-poor settings, antibiotics may be taken after surgery because of a dearth of best practices before and during surgery. This points to the need for antibiotic stewardship programs to help clinicians in these locales use antibiotics safely and efficiently.

According to the investigators, the strengths of the meta-analysis include its wide-ranging geographic parameters (participating studies took place in 28 countries) and the fact that patients were of all ages and had undergone a variety of surgical procedures. Limitations are that less than half of included studies encompassed best practices, as well as the potential for bias due to a lack of reporting standards prior to 2010.