The role of preoperative blood parameters to predict the risk of surgical site infection

Routine preoperative blood work is not recommended but selected biochemical markers may predict the risk of surgical site infection (SSI). This study examines the association between preoperative biochemical markers and the risk of SSI. This observational cohort study, nested in a randomized controlled trial, was conducted at two tertiary referral centers in Switzerland. 122 (5.8%) of 2093 patients experienced SSI. Preoperative increasing levels of albumin (OR 0.93), CRP (OR 1.34), hemoglobin (OR 0.87) and eGFR (OR 0.90) were significantly associated with the odds of SSI. The same accounts for categorized parameters. The highest area under the curve from ROC curves was 0.62 for albumin. Positive predictive values ranged from 6.4% to 9.5% and negative predictive values from 94.8% to 95.7%. The association of CRP, mildly and moderately decreased eGFR and hemoglobin with the odds of SSI remained significant on multivariate analysis. Our results do not support generally delaying elective surgery based on preoperative blood results. However, it may be considered in situations with potentially severe sequelae of SSI.