Cefazolin, Beta-Lactam Allergy Linked to Decreased Surgical Site Infections

Cefazolin is associated with a significantly reduced frequency of surgical site infections (SSIs) compared with clindamycin and/or vancomycin without an increased risk for hypersensitivity reactions (HSRs) among patients with a β-lactam allergy who had a total knee or hip arthroplasty. These are among the study findings published in Open Forum Infectious Diseases.

Researchers conducted a retrospective chart review of all patients who underwent total knee or hip arthroplasty within a university health system from January 2020 to July 2021. Using patient data from electronic health records, eligible participants were aged 18 years and older, underwent a primary total knee arthroplasty (TKA) or total hip arthroplasty (THA), and were allergic to a penicillin or cephalosporin antibiotic.

The participants were assigned to 2 groups based on perioperative antibiotic received — cefazolin vs clindamycin and/or vancomycin. The primary outcome was surgical site infection, including periprosthetic joint infection or superficial infection, within 90 days of surgery.

The analysis included 1128 surgical procedures in 1047 participants: 809 surgeries (71.7%) used cefazolin as the perioperative antibiotic regimen, and the other 319 (28.3%) surgeries used clindamycin and/or vancomycin as the perioperative antibiotic regimen. The participants who received cefazolin were a mean age of 68.1±9.6 years (71% women), and those who received clindamycin and/or vancomycin were a mean age of 67.2±10.4 years (68% women). Cephalosporin allergy history and allergic reactions associated with immediate hypersensitivity were more common in the clindamycin and/or vancomycin group.

The rate of SSIs was lower among those in the cefazolin group compared with those in the clindamycin and/or vancomycin group (0.9% vs 3.8%; P <.01; relative risk, 4.3; 95% CI, 1.7-10.9). The cefazolin group had fewer superficial incisional infections (0.7% vs 1.9%) and fewer prosthetic joint infections (0.1% vs 1.9%). The mean (SD) time from surgery to an SSI was 24.3 (10.2) days for the cefazolin group and 21.6 (11.0) days for the clindamycin and/or vancomycin group.

The interoperative HSR frequency was not different between the 2 groups (cefazolin 0.2% vs clindamycin and/or vancomycin 1.3%, P =.06). The cefazolin group had 2 HSRs, 1 participant with skin involvement and 1 with an allergic reaction without supporting symptoms. The clindamycin and/or vancomycin group had 4 HSRs, with 2 involving the skin and 2 involving hemodynamic instability.

In the cefazolin group, the most common pathogens isolated from SSIs were methicillin-susceptible Staphylococcus spp, Streptococcus canis (group G), Cutibacterium avidum, and Proteus mirabilis. In the clindamycin and/or vancomycin group, the most common pathogens were methicillin-susceptible Staphylococcus aureus, Enterococcus spp, and Klebsiella pneumoniae.

Study limitations include the retrospective design and lack of randomization. Determining the presence of HSR was difficult due to the nature of medication administration in the operating room, and participants in the cefazolin group received more topical antibiotics.

“The lack of safety concerns regarding the potential of cross-reactivity between cefazolin and other beta-lactams combined with the increased risk [for] SSI associated with second-line antibiotic regimens should encourage surgeons, anesthesiologists, and other clinicians involved in the selection of perioperative antibiotic selection to use cefazolin for SSI prophylaxis,” the study authors conclude.