局部使用右美托咪定对老年患者髋部手术术后认知功能Toll样受体4表达的影响

目的 探讨右美托咪定局部用药对老年患者髋部手术术后认知功能和单核细胞Toll样受体4表达的影响。方法 择期股骨上段骨折行动力髋螺钉植入系统内固定术60例，采用随机数字表法分为罗哌卡因组（R组）和右美托咪定混合罗哌卡因组（RD组），每组30例。所有患者均采用神经刺激仪引导腰丛+坐骨神经阻滞法麻醉，R组注射0.5%罗哌卡因，RD组注射含右美托咪定1.5 μg/kg的0.5%罗哌卡因，腰丛20 ml、坐骨神经10 ml。于术前1 d（T0）、术毕即刻（T1）、术后1 d（T2）、术后3 d（T3）取静脉血，观察单核细胞TLR4的表达，并于T0、T1、T2、T3、术后7 d（T4）测定白细胞介素-1β、肿瘤坏死因子-α水平。于T0、T2、T3、T4应用MoCA评估认知功能，记录术后认知功能障碍的发生情况。结果 与T0比较，两组患者T2~T3时MoCA评分降低，T1~T3时血浆TNF-α、IL-1β水平升高（P＜0.05）；与R组比较，RD组T2~T3时MoCA评分均高于R组， T1~T2时TLR4表达下调，T1~T3时TNF-α、IL-1β水平降低（P＜0.05）。RD组术后认知功能障碍发生率低于R组（P＜0.05）。结论 右美托咪定局部用药可能预防老年患者术后认知功能障碍的发生，机制可能与抑制TLR4蛋白的表达，减少炎性因子释放有关。

Effects of Local Use of Dexmetomidine on Cognitive Function and Expression of Toll Like Receptor 4 after Hip Surgery in Elderly Patients

Objective To investigate the effects of dexmetomidine on cognitive function and monocyte Toll like receptor 4 expression in elderly patients after hip surgery.Methods 60 patients with elective upper femoral fractures were treated with hip screw fixation system. They were randomly divided into ropivacaine group (R group) and dexmedetomidine mixed ropivacaine group (RD group). 30 cases in each group. All patients underwent a lumbar plexus + sciatic nerve block anesthesia with a neurostimulator, 0.5% ropivacaine in the R group, and 0.5% ropivacaine containing dexmedetomidine 1.5 μg/kg in the RD group.20 ml of lumbar plexus and 10 ml of sciatic nerve. Venous blood was taken 1 d(T0),venous blood was taken immediately after surgery(T1), 1 day after surgery (T2), and 3 days after surgery(T3). The expression of TLR4 in monocytes was observed at T0, T1, T2, T3, and 7 days after surgery (T4). The levels of interleukin-1β and tumor necrosis factor-α were measured. MoCA was used to evaluate cognitive function at T0, T2, T3, and T4, and the incidence of postoperative cognitive dysfunction was recorded.Results Compared with T0, the MoCA scores decreased in T2~T3, and the levels of plasma TNF-α and IL-1β in T1~T3 increased(P<0.05).Compared with R group, the MoCA scores of T2~T3 in RD group were higher than those in R group. The expression of TLR4 was down-regulated at T1~T2, and the levels of TNF-α and IL-1β were decreased at T1~T3 (P<0.05). The incidence of postoperative cognitive dysfunction in the RD group was lower than that in the R group(P<0.05). Conclusion The local administration of Dexmetomidine may prevent the occurrence of cognitive dysfunction in elderly patients after operation, and the mechanism may be related to the inhibition of TLR4 protein expression and the reduction of inflammatory factor release.