Clinical impact of interleukin 6 as a predictive biomarker in the early diagnosis of postoperative systemic inflammatory response syndrome after major thoracic surgery: A prospective clinical trial

Background: Postoperative systemic inflammatory response syndrome and sepsis are associated with high morbidity and mortality rates. Early detection of postoperative systemic inflammatory response syndrome improves the outcome. The aim of this study was to evaluate the feasibility of interleukin 6 as a predictive biomarker in the early diagnosis of postoperative systemic inflammatory response syndrome after a major thoracic operation.

Methods: A total of 94 patients were enrolled in this prospective, clinical, single-center study. The enrolled subjects underwent either lung resection or esophageal operation. Interleukin 6, procalcitonin, C-reactive protein, and leucocytes were measured sequentially before, during, and after the operation. These levels were compared between patients who developed postoperative systemic inflammatory response syndrome and those who did not.

Results: The enrollees who completed the study included of 55 males (79.7%) and 14 females (20.3%) with a mean age of 60.9 years. Twenty patients (29.0%) developed systemic inflammatory response syndrome at a median time of 33.0 hours postoperatively. In cases of postoperative systemic inflammatory response syndrome, interleukin 6 was the most predictive biomarker, showing a striking increase on the day of operation and preceding the median onset of postoperative systemic inflammatory response syndrome, which occurred the next day (P ≤ .001). Peak procalcitonin and C-reactive protein occurrence were significantly delayed at 24 hours (P = .012) and 48 hours (P = .012). There was no mortality 30 days postoperatively.

Conclusion: Interleukin 6 is a reliable predictor of postoperative systemic inflammatory response syndrome, and it is able to detect postoperative system inflammatory response syndrome before the onset of related clinical symptoms. When identifying patients at high risk, it would be beneficial to include interleukin 6 in conventional postoperative monitoring, particularly after extended surgical resection.