The Comparative Effectiveness of Perioperative Antibiotic Regimens to Prevent Surgical Site Infections in Pediatric Liver Transplant Recipients

Introduction: Surgical site infections (SSIs) are a common complication in liver transplant(LT) recipients. Lack of pediatric prophylaxis guidelines results in variation in preventative antibiotic regimens.

Methods: We performed a retrospective observational study of LT recipients under 18 years using a merged dataset that included data from PHIS and UNOS between 2006 and 2017. The exposure was defined as the antibiotic(s) received within 24 hours of LT; with 6 categories, ranging from narrow (category 1: cefazolin), to broad). The primary outcome was presence or absence of SSI in the index admission. Mixed-effects logistic regression compared the effectiveness of each category relative to category 1 in preventing SSI.

Results: Of the 2586 LT, 284 (11%) met SSI criteria. SSI rate was higher (16.2%) in the younger sub-cohort compared to older (8.6%), necessitating a stratified analysis. Antibiotics from category 5 were most commonly used. In the younger sub-cohort, the adjusted risk was increased in all categories compared to the reference, most notably in category 3 (OR 2.58; 0.69-9.59) and category 6 (OR 2.76; 0.66-11.56). In the older sub-cohort, estimated ORs were also increased for each category, most notably in category 4 (2.49; 0.99-6.27). None of the ORs suggested benefit from broader-spectrum prophylaxis. Our E value assessment suggests it's unlikely there is unmeasured confounding by indication to the degree necessary to revert ORs to protective.

Conclusion: There was wide variation in antibiotic prophylaxis. Adjusted analyses did not reveal a protective benefit of broader-spectrum prophylaxis in either sub-cohort, suggesting that narrower regimens may be adequate.