右美托咪定不同用药方式对全膝关节置换术患者术后镇痛的影响

Effects of dexmedetomidine applied in different methods on postoperative analgesia in patients with total knee arthroplasty

目的观察右美托咪定不同用药方式对全膝关节置换术患者术后镇痛的效果,并探讨右美托咪定在周围神经发挥作用的机制。方法选择在气管插管全麻下行单侧全膝关节置换术患者90例,ASAⅠ~Ⅱ级,随机分为三组(n=30):右美托咪定混合罗哌卡因行股神经阻滞组(A组),肌内注射(肌注)右美托咪定联合罗哌卡因行股神经阻滞组(B组),单纯用罗哌卡因行股神经阻滞组(C组)。术后当患者静息VAS评分≥3分时使用舒芬太尼患者自控静脉镇痛泵,并维持患者术后VAS评分≤5分。观察并记录术后第一次使用镇痛泵时间、术后24 h镇痛泵内舒芬太尼用量及镇痛泵按压次数,记录患者术后24 h内不良反应发生情况。结果与B、C组比较,A组患者术后第一次使用镇痛泵的时间延长,术后24 h镇痛泵内舒芬太尼用量以及镇痛泵按压次数减少,差异有显著意义(P<0.05);B组和C组比较,患者术后第一次使用镇痛泵时间、术后24 h镇痛泵内舒芬太尼用量及镇痛泵按压次数无显著差异(P>0.05)。三组术后24 h内高血压、低血压、心动过缓等发生率比较差异均无显著意义(P>0.05)。结论与肌注右美托咪定相比,右美托咪定混合罗哌卡因行股神经阻滞能延长术后镇痛的作用时间,减少术后静脉镇痛药物的使用量,适合用于全膝关节置换术患者的术后镇痛。

AIM To observe the effects of dexmedetomidine applied in different methods on postoperative analgesia in patients with total knee arthroplasty, and to investigate the mechanisms of dexmedetomidine on peripheral nerves. METHODS Ninety patients, ASA grade Ⅰ - Ⅱ , undergoing unilateral total knee arthroplasty were enrolled and randomly divided into three groups （n = 30） ： femoral nerve block by dexmedetomidine combined with ropivacaine （group A）, intramuscular injection of dexmedetomidine combined with femoral nerve block by ropivacaine （group B）, femoral nerve block by ropivacaine （group C）. When the pain VAS score ≥ 3 postoperative, the sufentanil patient controlled intravenous analgesia （PCIA） pump would be used to control VAS score ≤ 5. The first time to use analgesia pump was observed and recorded. The sufentanil consumption and the data of pump pressing frequencies were recorded within postoperative 24 hours. At the same time, the adverse reactions were recorded within postoperative 24 hours. RESULTS Compared with the group B and C, the duration for the first time to use the PCIA pump was prolonged, while the sufentanil consumptions and the PCIA pump pressing frequencies were decreased in the group A within postoperative 24 hours （P 〈 0.05）. There were no significant difference in the duration for the first time to use the PCIA pump, sufentanil consumptions and the pump pressing frequencies between the group B and group C （P 〉 0.05）. And there were no significant difference in the incidence of hypertension, hypotension, bradycardia among three groups within postoperative 24 hours （P 〉 0.05）. CONCLUSION Compared with intramuscular injection of dexmedetomidine, femoral nerve block by dexmedetomidine combined with ropivacaine can prolong the duration of postoperative analgesia, and reduce postoperative analgesic consumptions, which is suitable for postoperative analgesia in patients with total knee arthroplasty.