Application effect of dexmedetomidine combined with pentazocine in brachial plexus block

Objective: To investigate the effects of dexmedetomidine combined with pentazocine in the application of brachial plexus block.Methods: Sixty patients scheduled by operation were randomly divided into the simple brachial plexus group(D group),dexmedetomidine + brachial plexus group(G1 group),pentazocine + brachial plexus group(G2 group),and dexmedetomidine + spray pentazocine + brachial plexus group(G3group)(15 cases each group).D group was injected with 20 mL of 0.375% ropivacaine,G1 group was injected with 20 mL mixture of 0.375% ropivacaine and 0.5 μg/kg dexmedetomidine,G2 group was injected with 20 mL mixture of 0.375% ropivacaine and 0.5 mg/kg pentazocine,and G3 group was injected with 20 mL mixture of 0.375% ropivacaine,0.5 μg/kg dexmedetomidine and 0.5 mg/kg pentazocine.The MAP,HR and SpO₂ in four groups before anesthesia and after 5,10,30,and 60 min of operation were recorded.The onset time of sensation and duration of pain disappearance were recorded.The patients with incomplete analgesia and changing anesthesia mode,and postoperative 6 h VAS score and Ramsay score in four groups were observed.Results: At postoperative 5,10,30 and 60 min,the MAP vlaues in G3,G2,G1 and D groups gradually increased,and the difference of which was statistically significant(P<0.01).At postoperative 5 and 10 min,the HR values in G2 and G3 groups were significantly lower than that in D group(P<0.05 and P<0.01).At postoperative 30 and 60 min,the HR values in G3,G2,G1 and D groups gradually increased,and the difference of which was statistically significant(P<0.01 to P<0.05).The differences of SpO₂ values among four groups at all time-points were not statistically significant(P>0.05).The onset time of sensory block and duration of pain disappearance in G1,G2 and G3 groups were shorter than those in D group(P<0.01).The onset time of sensory block in G3 group was shorter than that in G1 group(P<0.01).The duration of pain disappearance in G3group was longer than that in G1 and G2 group (P<0.01).There was no statistical significance in the incidence rate of incomplete analgesia and changing anesthesia mode among four groups(P>0.05).At postoperative 6 h,the VAS score and Ramsay score in G3 group were significantly lower than that in D,G1 and G2 groups(P<0.01),and the differences of which among D,G1 and G2 groups were not statistically significant(P>0.05).Conclusions: The dexmedetomidine combined with pentazocine in the application of brachial plexus block anesthesia can enhance the sedative and analgesic effects,and is beneficial to the rapid recovery of postoperative patients.