Preoperative C-Reactive Protein/Albumin Ratio, a Risk Factor for Postoperative Delirium in Elderly Patients After Total Joint Arthroplasty

Postoperative delirium (POD), as an acute brain failure, is widely reported as a very common postoperative complication, and it is closely associated with increased morbidity and mortality. This study aimed to investigate potential risk factors including C-reactive protein/albumin ratio (CAR) for POD in elderly subjects after total joint arthroplasty (TJA).

A total of 272 elderly patients (aged 65∼85 years) who were scheduled to undergo elective TJA with epidural anesthesia were consecutively recruited. The data of baseline characteristics, operation-associated indexes, and preoperative laboratory tests were collected. POD assessment was performed daily within postoperative 7 days. Receiver operating characteristic curve analysis was utilized for evaluating the predictive and cut-off value of CAR for POD. Risk factors for POD were evaluated by the binary univariate and multivariate logistic regression analyses.

Within postoperative 7 days, there were 55 patients who had suffered POD with an incidence of 20.2% (55/272). The area under the curve of CAR for POD was 0.804, with the cut-off value of 2.35, a sensitivity of 66.82%, and a specificity of 80.00%, respectively (95% confidence interval [CI]: 0.737-0.872, P < .001). Age (odds ratio: 2.02, 95% CI: 1.03-3.96, P = .038) and preoperative CAR level (odds ratio: 3.04, 95% CI: 1.23-7.23, P = .016) were 2 independent risk factors for POD in elderly subjects undergoing TJA.

Preoperative CAR level may be a promising predictor for POD in elderly subjects following TJA.