The effects of paravertebral block with different doses of dexmedetomidine combined with ropivacaine on the emergence agitation of pediatric thoracotomy

Abstract

Objective To observe the effects of paravertebral block with different doses of dexmedetomidine(Dex) combined with ropivacaine on the emergence agitation in children subjected to thoracotomy. Methods A total of one hundred and twenty children subjected to thoracic surgery were randomly divided into four groups: Dex groups(group D1, D2, D3) and control group (group C). Group D1, D2, D3 respectively received 0.50, 0.75, 1.00 μg/kg Dex, all with 0.375% ropivacaine, group C received only 0.375% ropivacaine. The anesthesia duration, postoperative recovery time(the end of operation to wakefulness), and the time of extubation were recorded. MAP and HR were measured by the end of operation(T0), 10 min (T1) and 15 min(T2) after the operation, and after extubation(T3). Agitation scores were recorded at the time of extubation. Ramsay scores and adverse complications were recorded 5 minutes (T4) and 10 minutes (T5) after extubation, and awakening time (T6). Results ① Compared with group C, the extubation time and recovery time were longer in group D1, D2, D3, but the difference was not statistically significant. ② MAP and HR of group D1, D2, D3 were significantly lower than group C at T0-T3 (P 0.05). ③ The Agitation scores in group D1, D2, D3 were significantly lower than those in group C at T3, and the Ramsay scores in groups D1, D2, D3 were significantly higher than those in group C(P<0.05). Both the Agitation and the Ramsay scores in group D2 and D3 were significantly lower than those in group D1 (P<0.05). These parameters were not significantly different among group D1, D2 and D3. In group D3, the incidence of excessive sedation and hypotension was respectively 6% and 12%. No side effect was found in other three groups. Conclusions Dex(0.75 μg/kg) combined with 0.375% ropivacaine can effectively prevent the emergence agitation of children subjected to thoracotomy. Key words: Dexmedetomidine; Ropivacaine; Thoracotomy; Anesthesia recovery period; Agitation