Methods:Forty elderly patients were randomly divided into two groups: ropivacaine group(GR,n=20)and physiological saline control group(GS,n=20).

• 方法:病人分为罗哌卡因组(GR；n=20)和对照组(GS；n=20)；分别采用0.；5%25罗哌卡因和生理盐水硬膜外给药。