The Influence of Surgical Stress and Inflammatory Biomarkers on the Occurrence of Postoperative Delirium

Research focusing on hypothermia has established a relationship between surgical stress and inflammatory biomarkers on delirium incidents in critically ill non-cardiac surgical patients. Unfortunately, postoperative delirium is a common complication after surgery and results in acute brain failure. Though the cause of delirium is still relatively unknown, systemic inflammation with neurological involvement is one of the leading etiologic theories. Another common complication in surgical patients is the occurrence of unplanned hypothermia during non-cardiac surgeries. For our study, we will be looking at two inflammatory biomarkers: C-reactive protein (CRP), and Interleukin 6 (IL-6). CRP is produced in the liver and is an index of overall inflammation in the body and is found elevated in postoperative delirium. IL-6, a pro-inflammatory cytokine, promotes a variety of cell functions that stimulate and enhance inflammation and is also known as a brain-active interleukin. IL-6 is a biomarker identified as a predictor of postoperative delirium when compared to those that do not experience postoperative delirium. Delirium assessments, surgical temperatures, and blood samples will be obtained from at least 100 non-cardiac surgical intensive care patients at a local hospital for the first three postoperative days. Our role in the project is to separate the serum from the blood and perform enzyme-linked immunosorbent assays (ELISAs) for CRP and IL-6. We will be assaying the separated serum to identify the levels of the two previously established inflammatory biomarkers. Through the comparison of inflammatory biomarker levels and surgical temperatures in non-cardiac patients with and without postoperative delirium, we hope to establish the influence of inflammatory stress and unplanned hypothermia on postoperative delirium. It is hoped that the findings from this study will further the understanding of how to assess, treat, and prevent postoperative delirium. Presently, this is a work in progress and our findings will be shared at the symposium