Background Surgical site infections can have a significant impact on cardiac surgical outcome. The liver plays an important role in infection prevention. This study aimed to retrospectively determine whether transient postoperative liver dysfunction after coronary bypass surgery increased surgical site infections. Methods A modified version of the Schindl scoring scale for liver dysfunction was adapted to objectively quantify transient liver dysfunction in the first 7 days after on-pump coronary artery bypass grafting. A retrospective analysis of clinical outcomes at 30 months postoperatively was performed on data of 575 patients who underwent coronary artery bypass between 2014 and 2016. The patients were categorized into a liver dysfunction group (Schindl score ≥ 4) and a non-liver dysfunction group (Schindl score < 4). Results The liver dysfunction group (47.3%) had significantly more patients who were obese, current smokers, and had diabetes, renal impairment, and peripheral vascular disease. Surgical site infections occurred predominantly in the liver dysfunction group (12.1% vs. 0.3%, p < 0.001). The independent predictors of surgical site infection were liver dysfunction, body mass index > 30 kg m-2, and coronary bypass surgery combined with other cardiac procedures. Conclusions Surgical wound infections can be precipitated by multiple factors before, during, and after coronary bypass surgery. Transient liver dysfunction in the perioperative period is associated with an increased rate of surgical infections even after adjusting for known risk factors. Considering this factor as well as other known risks may help to identify and stratify patients with a potentially higher risk of surgical site infections.
Keywords: Cardiopulmonary bypass; Coronary artery bypass; Liver diseases; Liver function tests; Risk factors; Surgical wound infection.