Primary observation indices : ( @ ) postoperative time and additional amount of morphine ; ( @ ) rate of postoperative delirium ( POD ) and postoperative cognitive dysfunction ( POCD ) at @ days , @ week , @ months and @ months postoperation ( T@-T@ ) ; ( @ ) se rum levels of NSE and S-@ were measured at the timepoints of before analgesia ( t@ ) , before anesthesia ( t@ ) , end of surgery ( t@ ) and @ hours , @ hours , @ hours postoperation ( t@-t@ ) ; ( @ ) other serious complications .