The Role of Perioperative Statin Use in the Prevention of Delirium After Total Knee Replacement Under Spinal Anesthesia

Background: The relationship between statin use and incidence of postoperative delirium (POD) is controversial. We investigated the association between perioperative statin use and occurrence of delirium after total knee arthroplasty (TKA) under spinal anesthesia. Methods: We retrospectively reviewed the electronic medical records of patients who underwent TKA under spinal anesthesia at a single tertiary care hospital between January 2005 and October 2017. POD incidence was recorded for patients who received statins continuously from 1 month before surgery until discharge and for patients who did not receive any statins. Univariable and multivariable logistic regression analyses were conducted to investigate an association between occurrence of POD and perioperative statin use. Results: In total, 6020 procedures were included, and 992 (16.4%) were associated with perioperative statin use. POD was confirmed for 304 (5.0%) procedures. The statin group showed a 1.7% significant lower incidence (P = .017) of POD (35/992, 3.5%) than the no statin group (1420/5,028, 5.4%). In multivariable logistic regression analysis, the POD incidence in the statin group was 34% lower than that in the no statin group (odds ratio [OR] 0.66, 95% confidence interval [CI] 0.45-0.97, P = .036]. Moreover, the POD incidence was decreased by 37% (OR 0.63, 95% CI 0.40-0.99, P = .047) and 79% (OR 0.21, 95% CI 0.05-0.88, P = .033) respectively, when atorvastatin and simvastatin were administered. Conclusion: Continuous perioperative statin use may be associated with a significantly lower risk of delirium after TKA under spinal anesthesia; simvastatin was the most effective statin for POD prevention. (C) 2018 Published by Elsevier Inc.