The analgesic effect of dexmedetomidine on the ultrasonic guidance brachial plexus block / 中国医师进修杂志

ABSTRACT

Objective To evaluate the analgesic effect of dexmedetomidine on the ultrasonic guidance brachial plexus block.Methods Sixty patients who underwent elective for one-side upper limb or forearm surgery were selected,they were received ultrasonic guidance brachial plexus block.The patients were divided into observation group and control group by random digits table method with 30 cases each.The observation group received 0.5％ ropivacaine 100 mg and dexmedetomidine 0.75 μg/kg,and the control group received 0.5％ ropivacaine 100 mg alone.The heart rate,mean arterial pressure (MAP),pulse oxygen saturation (SpO2) at the time of entering operating room,brachial plexus block completed,incision and the end of surgery were recorded.After brachial plexus block completed,the visual analogue score (VAS) at the time of incision,1 h during surgery and 1,2,6,12,24,48 h after surgery was recorded.Morphine was given the patients when VAS ＞ 4 scores,and the time to first prescription of morphine and total morphine consumption dose within 48 h after surgery were also detected.The adverse reaction was recorded.Results There were no statistical differences in heart rate and MAP at the time of entering operating room and brachial plexus block completed between the 2 groups (P ＞ 0.05).The heart rate and MAP at the time of incision and the end of surgery in observation group were significantly lower than those at the time of entering operating and the same time of control group,there were statistical differences (P ＜ 0.05).There was no statistical difference in SpO2 between the 2 groups (P ＞0.05).The VAS at the time of 6,12,24 and 48 h after surgery in observation group were significantly lower than those in control group [(3.0 ± 0.9) scores vs.(4.9 ± 0.5) scores,(3.0 ± 0.7) scores vs.(5.6 ± 1.2) scores,(2.2 ± 0.9) scores vs.(4.8 ± 1.8) scores,(1.7 ± 0.5) scores vs.(3.2 ± 1.0) scores],there were statistical differences (P ＜ 0.05).The time to first prescription of morphine in observation group was significantly longer than that in control group [(450 ± 37) min vs.(368 ± 42) min],the total morphine consumption dose was significantly lower than that in control group [(8.3 ± 2.8) mg vs.(15.5 ± 4.5) mg],there were statistical differences (P ＜ 0.05).There was no adverse reaction found.Conclusion Ropivacaine plus 0.75 μ g/kg dexmedetomidine for ultrasonic guidance brachial plexus block may prolong the duration of analgesia,thus reduce morphine consumption within 48 h after surgery without severe adverse reaction.