Objective:To evaluate the effect of dexmedetomidine mixed with dexamethasone on efficacy of ropivacaine for popliteal sciatic nerve block in the patients undergoing ankle surgery.Methods:A total of 120 patients of either sex, aged 30-64 yr, with body mass index of 19.6-29.7 kg/m 2, of American Society of Anesthesiologists physical status Ⅰ or Ⅱ, undergoing elective ankle surgery, were divided into 4 groups ( n=30 each) by a random number table method: control group (group C), dexmedetomidine group (group DD), dexamethasone group (group DM), and dexmedetomidine plus dexamethasone group (group DD+ DM). In group C, 0.5% ropivacaine 30 ml was injected around the popliteal sciatic nerve guided by ultrasound combined with a nerve stimulator.Dexmedetomidine 1 μg/kg, dexamethasone 10 mg and dexmedetomidine 1 μg/kg plus dexamethasone 10 mg were added to 0.5% ropivacaine in group DD, group DM and group DD+ DM, respectively.The analgesic time, consumption of sufentanil and adverse reactions were recorded after popliteal sciatic nerve block. Results:Compared with group C, the analgesic time was significantly prolonged, the consumption of sufentanil was reduced, and the incidence of nausea and vomiting was decreased in group DD, group DM and group DD+ DM ( P<0.05). Compared with group DD and group DM, the analgesic time was significantly prolonged, and the consumption of sufentanil was reduced in group DD+ DM ( P<0.05). No itching, drowsiness, hypotension, bradycardia or respiratory depression occurred in each group. Conclusion:Dexmedetomidine mixed with dexamethasone can effectively enhance the efficacy of ropivacaine for popliteal sciatic nerve block in the patients undergoing ankle surgery.

Objective To investigate the effect of compound betamethasone adjuvant on break-through pain after unicompartmental knee arthroplasty under sciatic nerve combined with femoral nerve block.Methods A total of 100 patients underwent unicondylar knee arthroplasty,32 males and 68 females,aged 55-75 years,BMI 18.5-35.0 kg/m2,ASA physical status Ⅰ-Ⅲ,were divided into three groups according to random number table method:no adjuvant group(group C,n=34),dexamethasone adjuvant group(group D,n=33)and compound betamethasone adjuvant group(group B,n=33).The patients in the three groups received sciatic nerve block and 0.4％ropivacaine 15 ml before anesthesia in-duction,then femoral nerve block,0.4％ropivacaine 15 ml in group C,0.4％ropivacaine 15 ml in group D(containing dexamethasone 5 mg),and 0.4％ropivacaine 15 ml in group B(containing compound beca-methasone 4 mg).The occurrence of breakthrough pain,the number of effective analgesic pump compres-sions,opioid dosage,and the number of remedial analgesia cases were recorded.The ground movement dis-tance was recorded 0-24 hours,24-48 hours,and 48-72 hours after operation.The sleep quality scores and adverse events were also recorded.Results Compared with group C,the incidence rate of breakthrough pain was lower(P＜0.05),the number of effective analgesia pump compressions,the dosage of opioid,and the sleep quality score on the first night after operation were significantly decreased in group B(P＜0.05).Compared with group D,the incidence rate of breakthrough pain and breakthrough pain score were lower(P＜0.05),the number of effective analgesia pump compressions,the dosage of opioid,and the sleep quality score on the 1 st night after operation were significantly decreased in group B(P＜0.05).There was no significant difference in the ground movement distance of in different time periods and inci-dence of adverse events among the three groups.Conclusion Compound betamethasone adjuvant can reduce the incidence of breakthrough pain after unicompartmental knee arthroplasty under sciatic nerve com-bined with femoral nerve block,provide perfect analgesic effect,reduce postoperative opioid consumption,and improve the sleep quality of patients on the first night after surgery.