Efficacy of patient-controlled brachial plexus block with different concentrations of dexmedetomidine mixed with ropivacaine for analgesia after elbow joint surgery / 中华麻醉学杂志

ABSTRACT

Objective To evaluate the efficacy of patient-controlled brachial plexus block with different concentrations of dexmedetomidine mixed with ropivacaine for analgesia after elbow joint surgery.Methods One hundred patients of both sexes,aged 18-64 yr,weighing 45-75 kg,of American Society of Anesthesiologists physical status Ⅰ or Ⅱ,undergoing elbow joint surgedyy,were divided into 4 groups (n =25 each) using a random number table method:different concentrations of dexmedetomidine mixed with ropivacaine groups (DR1-3 groups) and ropivacaine group (group R).An analgesia pump was connected at the end of surgery and patient-controlled brachial plexus block was performed.The patient-controlled analgesia (PCA) solution contained 0.5 μg/ml dexmedetomidine and 0.2％ ropivacaine in group DR1,0.75 μg/ml dexmedetomidine and 0.2％ ropivacaine in group DR2,1 μg/ml dexmedetomidine and 0.2％ ropivacaine in group DR3 and 0.3％ ropivacaine in group R.All the drugs were diluted to 400 ml in normal saline in each group.The PCA pump was set up to deliver 3 ml bolus dose with a 20-min lockout interval and background infusion at 5 ml/h.Parecoxib 0.6 mg/kg was intravenously injected as a rescue analgesic.The visual analogue scale (VAS) scores at rest and during movement (voluntary and continuous passive movement) were recorded at the end of surgery and 12,24,36,48 and 72 h after surgery.The number of successfully delivered doses,the number of attempt and postoperative consumption of parecoxib were recorded.The elbow flexion angle during voluntary and continuous passive movement was recorded.The development of motor block and drug-related adverse reactions was also recorded.Results There was no significant difference in VAS scores at rest at each time point among the four groups (P＞0.05).Compared with group R,the VAS scores during movement,the number of attempts,the number of successfully delivered doses and parecoxib consumption were significantly increased in DR1 and DR2 groups,the elbow flexion angle during voluntary and continuous passive mnovement was significantly decreased in group DR1,the elbow flexion angle during continuous passive movement was significantly decreased in group DR2,and the elbow flexion angle during voluntary movement was significantly increased (P＜0.05),and no significant change was found in the other parameters in group DR3 (P＞0.05).Compared with group DR1,the VAS scores during movement were significantly decreased,the number of attempts,the number of successfully delivered doses and parecoxib consumption were decreased,and the elbow flexion angle during voluntary and continuous passive movement was increased in DR2 and DR3 groups (P＜0.05).Compared with group DR2,the VAS scores during movement were significantly decreased,the number of attempts,the number of successfully delivered doses and parecoxib consumption were decreased,and the elbow flexion angle during voluntary and continuous passive movement was increased in group DR3 (P＜0.05).No motor block was found in DR1,DR2,and DR3 groups,and the incidence of motor block was significantly higher in group R than in the other three groups (P＜0.05).The hemodynamics was stable and no drug-related adverse reactions were found in the perioperative period in the four groups.Conclusion Patient-controlled brachial plexus block with dexmedetomidine 1 μg/ml mixed with 0.2％ ropivacaine can provide satisfactory analgesia and is helpful in improving prognosis for the patients undergoing elbow joint surgery.