The relationship between mild cognitive impairment and postoperative delirium undergoing total knee arthroplasty: The PNDABLE study

Bin Wang; Chuanlin Mu; Xinhui Tang; Fei Wang; Gaofeng Zhang; Jiahan Wang; Rui Dong; Xu Lin; Yanlin Bi

doi:10.3389/fnagi.2022.959510

The relationship between mild cognitive impairment and postoperative delirium undergoing total knee arthroplasty: The PNDABLE study

Front Aging Neurosci. 2022 Sep 29:14:959510. doi: 10.3389/fnagi.2022.959510. eCollection 2022.

Authors

Bin Wang¹, Chuanlin Mu¹, Xinhui Tang², Fei Wang³, Gaofeng Zhang¹, Jiahan Wang¹, Rui Dong⁴, Xu Lin¹, Yanlin Bi¹

Affiliations

¹ Department of Anesthesiology, Qingdao Municipal Hospital Affiliated to Qingdao University, Qingdao, China.
² Department of Anesthesiology, Dalian Medical University, Dalian, China.
³ Department of Anesthesiology, Nanjing Medical University, Nanjing, China.
⁴ Department of Anesthesiology, Drum Tower Hospital Affiliated to Nanjing University Medical School, Nanjing, China.

Abstract

Background: Patients undergoing surgery are at a higher risk of developing postoperative delirium (POD) as a result of anesthesia and surgical procedures. This study examined the association between POD and mild cognitive impairment (MCI) and whether MCI influences POD through the core pathology of POD.

Methods: We enrolled Chinese Han patients undergoing unilateral total knee arthroplasty (aged 50-90, weighing 50-80 kg, and using ASAI-II), combined with epidural anesthesia between October 2020 and June 2021. All the participants were assessed using Winblad's criteria for diagnosing MCI on pre-operation and using the Confusion Assessment Method (CAM) and the Memorial Delirium Assessment Scale (MDAS) postoperative 1-7 days (or before discharge) for diagnosing POD by an anesthesiologist. Cerebrospinal fluid (CSF) biomarkers of POD were measured by enzyme-linked immunosorbent assay (ELISA). To examine the mechanism by which POD pathologies affect cognition, causal mediation analyses were performed.

Results: POD incidence was 20.2%, including 32.5% in the MCI group and 12.4% in the non-mild cognitive impairment (NMCI) group. The MCI and CSF levels of T-tau and P-tau were risk factors, and the CSF levels of Aβ₄₂, Aβ₄₂/ T-tau, and Aβ₄₂/ P-tau were protective factors in POD (p < 0.05). Part of the effects of MCI on cognition can be attributed to amyloid pathology and tau.

Conclusion: MCI may be a reasonably good prognostic factor in POD development. Overall, amyloid pathology and tau protein might partially mediate the influence of MCI on POD.

Clinical trial registration: www.clinicaltrials.gov, identifier: ChiCTR2000033439.

Keywords: biomarkers; geriatric; mild cognitive impairment; neurodegeneration; postoperative delirium.