Relationship between preoperative serum albumin concentrations and postoperative delirium in patients undergoing total knee/hip arthroplasty / 中华麻醉学杂志

ABSTRACT

Objective:To evaluate the relationship between preoperative serum albumin concentrations and postoperative delirium (POD) in the patients undergoing total knee/hip arthroplasty.Methods:Five hundred patients of both sexes, aged 50-90 yr, with body mass index of 50-80 kg, of American Society of Anesthesiologists Physical Status classification Ⅰ or Ⅱ, undergoing elective total knee or hip replacement under combined spinal-epidural anesthesia in our hospital from December 2021 to December 2022, were selected. Cerebrospinal fluid (CSF) samples were collected after successful subarachnoid puncture for determination of amyloid-beta 42 (Aβ42), total tau protein (T-tau) and phosphorylated tau protein (P-tau) concentrations using enzyme-linked immunosorbent assay. Confusion Assessment Method and Memorial Delirium Assessment Scale were used to evaluate the occurrence and severity of POD at 1-7 days after surgery (or before discharge), and the patients were divided into POD group and non-POD group (NPOD group). Logistic regression analysis was used to identify the risk factors for POD. The accuracy of plasma albumin concentration and CSF biomarker concentration in predicting POD was evaluated by the receiver operating characteristic (ROC) curve, and the mediating effect of CSF biomarker was analyzed.Results:A total of 343 patients were finally enrolled in the study, and the incidence of POD was 23.3%. There were statistically significant differences in age, preoperative plasma albumin concentration and Memorial Delirium Assessment Scale score in POD group as compared with NPOD group ( P<0.05). Before and after adjusting for confounding factors, decreased plasma albumin and increased concentrations of P-tau and T-tau in CSF before operation were the risk factors for POD, and increased concentrations of Aβ42, Aβ42/P-tau and Aβ42/T-tau ratio in CSF were protective factors for POD. The area under the ROC curve of preoperative plasma albumin concentrations in predicting POD was 0.668, and the area under the ROC curve of preoperative plasma albumin concentrations combined with CSF biomarker concentrations in predicting POD was 0.810 ( P<0.05). The direct effect of plasma albumin on POD was -0.009 869 2, the total effect was 0.029 443 7, and the mediating effect of P-tau accounted for 33.53% of the total effect. Conclusions:Decreased preoperative plasma albumin concentration is a risk factor for POD, and P-Tau in CSF serves as a key mediator in the relationship between serum albumin concentrations and postoperative delirium in the patients undergoing total knee/hip arthroplasty.