the investigator modified the effect-site target concentrations by NI.If NI fall down to 46 and keep 46 more than 30 seconds,propofol and remifentanil were infused as feedback automatically to achieve the target NI of 26-46.Take blood sample before and after surgery to measure the levels of protein S100beta and NSE.

the investigator modified the effect-site target concentrations of both drugs without minimum or maximum concentration limits without using the Narcotrend monitor only depend on the experience of anesthesiologist.Take blood sample before and after surgery to measure the levels of protein S100beta and NSE.

the investigator modified the effect-site target concentrations by NI.If NI fall down to 46 and keep 46 more than 30 seconds,propofol and remifentanil were infused as feedback automatically to achieve the target NI of 26-46

The Mini-Mental State Examination (MMSE) or Folstein test is a 30-point questionnaire that is used extensively in clinical and research settings to measure cognitive impairment.It is commonly used in medicine and allied health to screen for dementia. It is also used to estimate the severity and progression of cognitive impairment and to follow the course of cognitive changes in an individual over time; thus making it an effective way to document an individual's response to treatment. The MMSE's purpose has been not, on its own, to provide a diagnosis for any particular nosological entity.We measure the patient before the operation and the first/third/seventh day after the operation.

The calcium-binding protein S100b is enriched in astroglial cells and can cross the blood-brain barrier after hypoxic damage of the central nervous system. Its routine measurement is simple and relatively inexpensive. S100b is filtrated by the kidney and has an estimated half-life of 2 h . Its serum level increases after CA, and its prognostic value has been studied . Because of mitigated results, its routine use has been, up to now, not recommended. S100bata is normally 0.2μg/L in serum or more smaller.We decide to take the blood sample before the operation and after the operation when the patient is awake.

NSE has a role in glucose metabolism. As for S100b, NSE is released from the hypoxic brain into the bloodstream, and its serum level correlates with the extent of brain injury. Also, NSE correlates with other markers of brain injury . NSE has a high specificity to predict adverse outcomes when measured in the few days post CA. A cutoff point of 33 mg/l is recommended.in our study, we take the blood sample before the operation and after the operation when the patient awake.