Habitual tea consumption and postoperative delirium after total hip/knee arthroplasty in elderly patients: The PNDABLE study

Abstract

Purpose: To clarify the effects of habitual tea consumption on postoperative delirium (POD) in elderly patients undergoing total hip/knee arthroplasty. Patients and Methods: A prospective cohort study was carried out at Qingdao Municipal Hospital Affiliated to Qingdao University between June 2020 and June 2021. A total of 332 patients aged 65–85 years undergoing total hip/knee arthroplasty under combined spinal and epidural anesthesia were enrolled from the Perioperative Neurocognitive Disorder and Biomarker Lifestyle (PNDABLE) study in the final analysis, consisting of 168 patients with habitual tea consumption and 164 patients with infrequent tea consumption. The primary endpoint was the effects of habitual tea consumption on POD and the incidence of POD, which was assessed by the Confusion Assessment Method (CAM) twice daily during the first 7 postoperative days, and POD severity was measured by the Memorial Delirium Assessment Scale (MDAS). The secondary endpoints were the concentrations of caffeine and tea polyphenols in plasma and cerebrospinal fluid (CSF), which were detected by the enzyme-linked immunosorbent assay. Results: POD occurred in 61 of 332 patients (18.37%), among whom 19 had habitual tea consumption (5.72%) and 42 had infrequent tea consumption (12.65%). Habitual tea consumption (odds ratio [OR] = 0.370, 95% confidence interval [CI]: 0.205–0.670, P =.001) was significantly associated with POD in the logistic analysis, and then after adjusting for age and American Society of Anesthesiologists (ASA) physical status (OR = 0.353, 95% CI: 0.190–0.655, P =.001). Furthermore, caffeine in T0 plasma (OR = 0.834, 95% CI: 0.752–0.924, P =.001), T1 plasma (OR = 0.818, 95% CI: 0.738–0.908, P