The early diagnostic value of C-reactive protein (CRP) in deep sternal wound infection after cardiac surgery

BackgroundThis study aimed to evaluate the early diagnostic value of C-reactive protein (CRP), procalcitonin (PCT), white blood cell count (WBC), neutrophil ratio (NEUT%), and neutrophil-to-lymphocyte ratio (NLR) in patients with deep sternal wound infection (DSWI).MethodsA retrospective case-control study was conducted on 241 patients who underwent cardiac surgery (30 patients with DSWI and 211 patients without DSWI). The differences in inflammatory markers were compared between the two groups at 5 time points (days 1, 4, 7, 10, and 14 after cardiac surgery), and the optimal cut-off values of the inflammatory factors independently correlated with DSWI were determined.ResultsUnivariate and multivariate logistic regression analyses showed that CRP on days 10 and 14, and PCT on day 10, were independently correlated with the occurrence of DSWI. The ROC curve showed the optimal cut-off value of them (CRP on day 10: AUC = 0.786, optimal cut-off point = 170.205 mg/L, sensitivity = 50.0%, specificity = 95.7%; CRP on day 14: AUC = 0.800, optimal cut-off point = 64.36 mg/L, sensitivity = 83.3%, specificity = 70.1%; PCT on day 10: AUC = 0.728, optimal cut-off point = 2.359 ng/mL, sensitivity = 43.3%, specificity = 97.6%). There was no correlation between WBC, NEUT%, NLR, and the occurrence of DSWI.ConclusionsFor patients who underwent sternotomy, CRP levels from the 10th postoperative day were correlated with the occurrence of DSWI. Early diagnosis of DSWI using CRP may be effective and can be used as a focused indicator to detect the presence of DSWI in patients as early as possible.