The effect of preoperative oral nutritional supplementation on surgical site infections among adult patients undergoing elective surgery: A systematic review and meta-analysis

Introduction: Mixed findings are reported on the effect of oral nutritional supplements in reducing Surgical Site Infections (SSIs). Material and methods: PubMED, EMBASE and Cochrane were searched. Studies from inception to July 2022 were included if they involved adults undergoing elective surgery and compared preoperative macronutrient oral nutritional supplements to placebo/standard diet. Results: Of 372 unique citations, 19 were included (N = 2480): 13 RCTs (N = 1506) and 6 observational studies (N = 974). Moderate-certainty evidence suggested that nutritional supplements SSI risk (OR 0.54, 95% C.I. 0.40-0.72, N = 2718 participants). In elective colorectal surgery, this risk-reduction was 0.43 (95% C.I. 0.26-0.61, N = 835 participants) and among patients who received Impact 0.48 (95% C.I. 0.32-0.70, N = 1338). Conclusion: Oral nutritional supplements prior to adult elective surgery may significantly reduce SSIs, with an overall 50% protective effect. This protective effect persisted in subgroup analysis of colorectal surgery patients and the use of Impact.