Efficacy of different doses of dexmedetomidine for prevention of shivering after combined spinal-epidural anesthesia in patients undergoing caesarean section

Abstract

Objective To evaluate the efficacy of different doses of dexmedetomidine for prevention of shivering after combined spinal-epidural anesthesia in the patients undergoing caesarean section. Methods A total of 120 patients, of ASA physical statusⅠ or Ⅱ, aged 20-40 yr, with body mass index≤35 kg/m2, scheduled for elective caesarean section under combined spinal-epidural anesthesia, were randomly divided into 4 groups (n=30 each) using a random number table: control group (group C) and dexmedetomidine 0.1, 0.3 and 0.5 μg/kg groups (D1, D2 and D3 groups). Combined spinal-epidural anesthesia was performed at L3, 4 interspace with isobaric 0.5% bupivacaine 2 ml. In D1, D2 and D3 groups, dexmedetomidine 0.1, 0.3 and 0.5 μg/kg (in 50 ml of normal saline) were infused intravenously, respectively. In group C, normal saline 50 ml was infused at a rate of 5 ml/min. The development of shivering, bradycardia, hypotension, nausea and vomiting was recorded during the period from the end of dexmedetomidine infusion to PACU discharge time. Results Compared with group C, the incidence and degree of shivering and incidence of nausea and vomiting were significantly decreased in D2 and D3 groups, and no significant change was found in the parameters mentioned above in group D1. Compared with group D2, the incidence and degree of shivering and incidence of nausea and vomiting were significantly decreased in D3 group. Conclusion Dexmedetomidine 0.3 and 0.5 μg/kg can prevent shivering after combined spinal-epidural anesthesia in the patients undergoing caesarean section, and 0.5 μg/kg provides better efficacy. Key words: Dexmedetomidine; Shivering; Anesthesia, spinal; Anesthesia, epidural