Efficacy of dexmedetomidine mixed with ropivacaine for epidural anesthesia

Abstract

Objective To evaluate the efficacy of dexmedetomidine mixed with ropivacaine for epidural anesthesia in the patients. Methods Forty-six patients, of ASA physical status Ⅰ or Ⅱ, aged 36–58 yr, weighing 48–77 kg, scheduled for elective hysterectomy under epidural anesthesia, were randomly divided into 2 groups(n=23 each)according to the random number table: normal saline + ropivacaine group(R group)and dexmedetomidine + ropivacaine group(DR group). Epidural anesthesia was performed at L2, 3 interspace.The catheter was inserted into the epidural space.A mixture of 0.75% ropivacaine 15 ml and dexmedetomidine 1 μg/kg was injected epidurally in DR group.A mixture of 0.75% ropivacaine 15 ml and normal sline 2 ml was injected epidurally in R group.The onset time of sensory block, maximum level of sensory block, and duration of sensory block were recorded.The modified Bromage scale, Ramsay sedation score and intraoperative traction reaction were assessed.The occurrence of dexmedetomidine-related cardiovascular events and respiratory depression, and epidural anesthesia-related adverse events within 2 h after operation was recorded. Results Compared with R group, the onset time of sensory block was significantly shortened, the duration of sensory block was prolonged, the maximum level of sensory block and Ramsay sedation score were increased, the degree of intraoperative traction reactions was lessened, and the incidence of shivering was decreased in DR group(P<0.05). No patients developed dexmedetomidine-related adverse events. Conclusion Epidural dexmedetomidine 1 μg/kg significantly optimize the efficacy of ropivacaine when used for epidural anesthesia in the patients. Key words: Dexmedetomidine; Amides; Anesthesia, epidural