Abstract: Objective To study and observe the effect of nerve block in ward and postoperative patient controlled intravenous analgesia（PCIA） on pain degree， pain mediators and stress state of elderly orthopedic patients during perioperative period. 
Methods A total of 90 elderly orthopedic patients were selected as the research subjects， and they were randomly divided into group A（postoperative PCIA group）， group B（“Cocktail” local injection analgesia and PCIA group） and group C（nerve block in ward and postoperative PCIA group）, with 30 cases in each group. Then the visual analogue scale(VAS) score at 2 h， 4 h， 6 h， 12 h， 24 h and 48 h after operation， serum pain mediators and stress state（stress hormones and oxidative stress）indexes at admission and at 12 h， 48 h after operation of three groups were compared. 
Results The VAS scores of three groups at 2 h， 4 h， 6 h， 12 h， 24 h and 48 h after operation increased initially and decreased afterwards， and the VAS scores of group C were significantly lower than those of group A and group B，and the scores of group B were significantly lower than those of group A，suggesting significant differences（P＜0.05）. There was no significant difference in the serum pain mediators and stress state indexes of three groups （P＞0.05）. The serum pain mediators and stress hormones of three groups at 12 h and 48 h after operation increased initially and decreased afterwards; the serum pain mediators and stress hormone indexes of group C were all significantly lower than those of group A and group B, and the results of group B were significantly lower than those of group A. The serum pain mediators and stress hormones of three groups at 12 h and 48 h after operation increased initially and decreased afterwards; serum oxidative stress indexes of group C were all significantly higher than those of group A and group B， and the results of group B were significantly higher than those of group A，with significant differences（P＜0.05）.  
Conclusion The nerve block in ward and postoperative PCIA can effectively control the pain degree of elderly orthopedic patients during perioperative period， and its influence on pain mediators and stress state are relatively better. Therefore, its application value is higher in elderly patients undergoing orthopedic surgery.

Key words: autonomic nerve block, perioperative period , pain