Abstract:Objective To compare the effect of epidural and intravenous application of dexmedetomidine (DEX) on epidural anesthesia in abdominal hysterectomy. Methods Altogether 66 patients undergoing abdominal hysterectomy from January to December 2017 were enrolled for the study and randomly divided into epidural group and intravenous group by random number table, 33 cases for each group. Patients in epidural group were injected with 15 ml 0.75% ropivacaine and 2 ml 1 ug/kg DEX into the epidural space. Patients in intravenous group were injected with 15 ml 0.75% ropivacaine and 2 ml saline into the epidural space, and 1 ug/kg DEX through intravenous infusion. Preoperative baseline data, intraoperative data, nerve block and adverse reactions were compared between two groups. Results ① There were no significant differences between the two groups in preoperative baseline data and intraoperative data (P > 0.05). ② The highest block plane of both groups was T5. The onset time of anesthesia and the time to reach the highest anesthesia plane were lower in the epidural group than those in the intravenous group (P < 0.05); the duration of anesthesia was longer than that in the intravenous group (P < 0.05). There were no significant difference between the two groups in terms of modified Bromage classification, Ramsay sedation score and traction response classification (P > 0.05). ③ The mean arterial pressure and heart rate indexes of the two groups analyzed by two-factor repeated measures of variance showed no significant difference between the groups, time difference and interaction (P > 0.05). ④ There were 7 cases of hypotension, 6 cases of nausea and vomiting, 2 cases of chills and 2 cases of bradycardia. There was no significant difference in the incidence of adverse reactions between two groups. (P > 0.05). Conclusions Compared with intravenous administration, epidural administration of DEX could significantly improve the effect of epidural anesthesia of ropivacaine, including faster effect-acting and longer lasting, and it did not increase the incidence of adverse reactions, so it is safe, reliable and worthy of clinical application.