Increased preoperative C-reactive protein plasma levels as a risk factor for postoperative infections

Abstract

Background. We examined the possible predictive role of preoperative C-reactive protein (CRP) levels for postoperative infections in patients who have cardiac operations. Methods. CRP levels were determined on the day before the operation and on postoperative days 1 to 4 and 6 in 593 consecutive patients. Furthermore, we documented infectious disease-related data. Results. Patients in whom an infection developed during the postoperative course ( n = 87) had significantly higher CRP levels on the day before operation (17.8 ± 3.9 mg/L compared with 7.7 ± 0.7 mg/L; p < 0.001) and on postoperative days 4 and 6. The incidence of postoperative infections was significantly higher in patients with increased preoperative CRP levels than in those with normal preoperative CRP levels (25.3% versus 11.2%, respectively; p < 0.001). Furthermore, patients with higher preoperative CRP levels had a significantly longer postoperative hospital stay than those with normal preoperative CRP levels (10.8 ± 1.2 days versus 7.8 ± 0.3 days; p < 0.001). Multivariate analysis, including classic risk factors and increased preoperative CRP levels, demonstrated that higher preoperative CRP was the most important variable predicting postoperative infection (odds ratio = 2.7; 95% confidence interval = 1.7 to 4.3; p < 0.001). Conclusions. Patients with higher preoperative CRP levels are at increased risk for postoperative infections. Therefore, preoperative measurement of CRP might be a useful, predictive marker in risk stratification for postoperative infections in patients scheduled for cardiac operations.