Abstract:Objective To detect the concentrations of choline acetyltransferase (ChAT) and cholinesterase (ChE) in cerebrospinal fluid of elderly patients and explore their relationship with postoperative delirium (POD). Methods One hundred and eighty-three patients who underwent total knee/total hip arthroplasty at Qingdao Municipal Hospital from September 2018 to August 2019 were included. All patients underwent total knee or total hip arthroplasty, using combined spinal-epidural anesthesia. After subarachnoid puncture, 2 mL of cerebrospinal fluid (CSF) was extracted. Enzyme-linked immunosorbent assay was used to detect the concentration of ChAT, ChE, tumor necrosis factor-α(TNF-α) and interleukin-6 (IL-6) in CSF, and spectrophotometry was used to detect the activity of ChAT and ChE in CSF. The occurrence of POD was assessed using the Confusion Assessment of Method (CAM) after surgery. Results Among 183 patients, 157 cases without POD were as non-POD group and 26 cases with POD were as POD group, with an incidence rate of 14.21%. In the POD group, the preoperative CSF ChE concentration ［(31.99±2.78) vs (40.89±4.19)〖LM〗 ng/mL, t=13.915, P＜0.01］ significantly reduced, while ChAT ［(1.26±0.12) vs (0.86±0.15) ng/mL, t=12.920, P＜0.01］, 〖JP2〗TNF-α［(17.19±1.32) vs (12.29±1.64) pg/mL, t=14.467, P＜0.01］, 〖JP〗and IL-6［(33.98±5.02) vs (16.98±3.41) pg/mL, t=16.643, P＜0.01］ significantly increased compared to the non-POD group. In the POD group, the preoperative CSF ChE activity significantly reduced ［(4.28±0.52) vs (5.25±0.26) u/mL, t=9.321, P＜0.01］, while ChAT activity significantly increased ［(0.36±0.05) vs (0.27±0.03) u/mL, t=8.916, P＜0.01］ compared to the non-POD group. Conclusion The high activity of ChAT and low activity of ChE in CSF are related to the occurrence of POD in elderly patients, with cholinergic degradation closely related to its occurrence.