ABSTRACT
Objective To investigate the analgesic effect of different concentrations of medetomidine and ropivacaine on knee arthroscopy in elderly patients in the orthopedics department. Methods 72 patients were di-vided into 4 groups,and from February 2016-September 2017 ,different concentrations of dexmedetomidin and ropivacaine were given to the patients after the operation,and compared the analgesic effects and adverse reactions of each group. Results The duration of analgesia in groups C and D were longer than group A and B and there were significant differences in the amount of fentanyl in the 4 groups after 24 h(F = 79.633,P < 0.05 )and there was no significant difference in the incidence of adverse reactions between the 4 groups(P > 0.05);1,3,6, 10,16,24 h after operation,The VAS scores in group C and D were significantly lower than those in group A and B(P < 0.05 ). Conclusion Dexmedetomidine plus ropivacaine can effectively improve the analgesic effect after knee arthroscopy,0.50 g/kg was the best concentration of dexmedetomidin.