Effects of different anesthesia methods on cognitive dysfunction after hip replacement operation in elder patients.

There are many risk factors for the cause of postoperative cognitive dysfunction (POCD), however, the anesthesia selection always trigger controversy for the POCD occurrence. This study aims to explore the relationship between the anesthesia and the occurrence of POCD in elder patients, and also investigate the mechanism of the POCD. One hundred elder patients with hip replacement were included in this study, which were divided into general anesthesia (GA) and epidural analgesia (EA) group. Minimum mental state examination (MMSE) method was employed to assess the nervous and mental function (POCD) in both analgesia group patients. Aβ and tau protein levels in blood were detected by using the ELISA assay. The correlation between MMSE in POCD patients and Aβ or tau was analyzed by employing the Spearman rank correlation method. The results indicated that epidural analgesia decreases the MMSE scoring compared to general analgesia (P < 0.05). General analgesia enhanced the Aβ and tau level compared to epidural analgesia (P < 0.05). Aβ and tau level were increased in the patients with POCD. The POCD occurrence rate in GA group was significantly higher compared to EA group (P < 0.05). MMSE scores of POCD patients positively correlated with Aβ or tau level (P < 0.05). In conclusion, the epidural analgesia method was better than general analgesia method for the hip replacement in elder patients. The mechanism of the POCD may be caused by the enhancement of Aβ and Tau protein.