BACKGROUND Postoperative delirium (POD) and postoperative neurocognitive disorder (NCD) are frequently seen in the elderly. Development of biomarkers for preoperative risk prediction is of major relevance. As inflammation present before surgery might predispose to POD and postoperative NCD development, we aim to determine associations between preoperative C-reactive protein (CRP) and the incidence of POD and postoperative NCD. METHODS In this observational study, we analyzed 314 patients enrolled in the SuDoCo trial, who had a preoperative CRP measurement the day before surgery. Primary outcomes were POD assessed according DSM-4 from day 1 until day 7 after surgery and postoperative NCD assessed 3 months after surgery. We conducted multivariable logistic regression analysis adjusted for age, sex, randomization, body mass index, MMSE, ASA status, infection/autoimmune disease/malignoma and types of surgery to determine associations between CRP with POD and postoperative NCD, respectively. RESULTS Preoperative CRP was independently associated with POD [OR 1.158 (95%CI 1.040, 1.291); p=0.008]. Patients with CRP values ≥ 5 mg/L had a 4.8-fold increased POD risk [OR 5.771 (95%CI 1.765, 12.899; p=0.002)] compared to patients with lower CRP values. However, no association was seen between preoperative CRP and postoperative NCD [OR 0.552 (95%CI 0.193, 1.581); p=0.269]. CONCLUSIONS Preoperative CRP levels were independently associated with POD but not postoperative NCD after three months. Moreover, higher preoperative CRP levels showed higher risk for POD. This strengthens the role of inflammation in the development of POD. Assessment of CRP before surgery might allow risk stratification of POD. This article is protected by copyright. All rights reserved.
C-Reactive Protein for Risk Prediction of Postoperative Delirium and Postoperative Neurocognitive Disorder.