Postoperative infections after cardiac surgery with cardiopulmonary bypass – incidence, performance of diagnostic procedures, and predictive factors

OBJECTIVES: Cardiac surgery using cardiopulmonary bypass (CPB) induces a systemic inflammatory response that affects common inflammatory markers, including C-reactive protein (CRP), white blood cell count (WBC), and body temperature, complicating postoperative diagnosis of infections. The objective of this study was to assess the incidence of postoperative infections and evaluate the performance of clinically used biomarkers. DESIGN: of September 2021. Patients with postoperative infection were compared to patients without. Multivariable logistic regression was used to identify independent predictors of postoperative infections. Receiver operating characteristic (ROC) curves evaluated the diagnostic ability of current biomarkers to detect infection. RESULTS: A total of 1,222 patients were included. The incidence of postoperative infections (during hospitalisation and/or late infection) was 17.3%. Patients with postoperative infection had more comorbidities, underwent more complex procedures, and had higher mortality (90-day mortality 3.8% vs 1.5%, p = 0.045; 1-year mortality 5.7% vs 2.7%, p = 0.032). CRP, WBC, and temperature performed poorly in detecting postoperative infection, although peak CRP (OR 1.069, p < 0.001) and peak temperature (OR 2.408, p = 0.005) were independent predictors of postoperative infection. Peak temperature occurred on postoperative day 5 in infected patients versus day 2 in those without infection. CONCLUSION: Postoperative infections following cardiac surgery with CPB remain common and are associated with increased postoperative complications and mortality. Common inflammatory biomarkers perform poorly in detecting infection. Improved diagnostic tools are needed to facilitate early detection and treatment.