Evaluation of Laboratory Markers for the Detection of Infections in Open-heart Surgery Patients

This study compared the efficiency of interleukin-6 (IL-6), human neutrophil lipocalin (HNL), C-reactive protein (CRP) and white blood cell (WBC) count for the early detection of postoperative bacterial infections after open-heart surgery. These laboratory markers were determined preoperatively and monitored daily during the first 6 postoperative days. Postoperative bacterial infections were diagnosed in 17 of 54 studied patients needing at least 3 d of intensive care. Patients with less than 3 d of intensive care were not studied. HNL and WBC count showed no significant differences between infected and non-infected groups, whereas both IL-6 and CRP were significantly higher in the infected group. IL-6 levels were higher (p<0.01) in the infected patients on the first postsurgical day, although with considerable interindividual variation. CRP levels rose on the second postsurgical day and showed less variation (p<0.01). Calculation of the differences between preoperative and postoperative levels of IL-6 an...