Intracavity lavage and wound irrigation for prevention of surgical site infection: systematic review and network meta-analysis

Background: Surgical site infections (SSIs) are costly and associated with poorer patient outcomes. Intraoperative surgical wound irrigation and intracavity lavage may reduce the risk of SSIs through removal of dead or damaged tissue, metabolic waste, and wound exudate. Irrigation with antibiotic or antiseptic solutions may further reduce the risk of SSI because of bacteriocidal properties. Randomised controlled trials (RCTs) have been conducted comparing irrigation solutions but important comparisons (e.g. antibiotic vs antiseptic irrigation) are absent. We use systematic reviewbased network meta-analysis (NMA) of RCTs to compare irrigation solutions for prevention of SSI. Methods: We used Cochrane methodology and included all RCTs of participants undergoing surgery with primary wound closure, in which method of irrigation was the only systematic difference between groups. We used a random effects Bayesian NMA to create a connected network of comparisons. Results are presented as odds ratios (OR) of SSI, where OR<1 indicates a beneficial effect. Results: We identified 42 eligible RCTs with 11,726 participants. Most were at unclear or high risk of bias. RCTs included groups given no irrigation or nonantibacterial, antiseptic, or antibiotic irrigation. There was substantial heterogeneity and a random effects model was selected. Relative to nonantibacterial irrigation mean OR of SSI was 0.439 (95% credible interval: 0.282, 0.667) for antibiotic irrigation and 0.573 (0.321, 0.953) for antiseptics. No irrigation was similar to nonantibacterial irrigation (OR 0.959 (0.555, 1.660). Antibiotic and antiseptic irrigation were ranked as most effective for preventing SSIs; this conclusion was robust to potential bias. Conclusions: Our NMA found that antibiotic and antiseptic irrigation had the lowest odds of SSI. However, there was high heterogeneity and studies were at high risk of bias. A large RCT directly comparing antibiotic irrigation with both antiseptic and nonantibacterial irrigation is needed to define the standard of care for SSI prevention by wound irrigation.