右美托咪定对原位肝移植术患者β-淀粉样蛋白和术后认知功能障碍的影响

Effects of dexmedetomidine on β-amyloid and postoperative cognitive dysfunction in patients undergoing orthotopic liver transplantation

目的 观察右美托咪定对原位肝移植术（OLT）患者β-淀粉样蛋白和术后认知功能障碍（POCD）的影响.方法 OLT患者60例,年龄18 ～60岁,美国麻醉医师协会评分标准（ASA）分级Ⅰ～Ⅲ级,按随机数字表法随机分为两组：右美托咪定组（DX组）和对照组（NS组）,各30例.DX组患者气管插管后经静脉输注右美托咪定负荷剂量0.5 μg/kg（10 min）,继之以维持剂量0.3μg/（kg＆#183;h）输注至术毕,NS组静脉输注等量生理盐水.术前1d和术后7d使用神经心理测验评估两组患者的认知功能.分别于术前（T1）、无肝期0.5 h（T2）、新肝期2.0 h（T3）、术毕（T4）、术后1 d（T5）、术后7 d（T6）采集两组患者静脉血,用酶联免疫吸附试验（ELISA）法分析β-淀粉样蛋白含量并比较.结果 DX组患者机械通气时间少于NS组,差异有统计学意义（P＜0.05）.DX组患者POCD发生率低于NS组,分别为13.3％和40.0％,差异有统计学意义（P＜0.05）.组间比较,DX组患者T4～T6时点β-淀粉样蛋白含量显著低于NS组相应时点,差异有统计学意义（P＜0.01）;组内比较,与术前T1时点比较,两组患者T2～T5时点β-淀粉样蛋白含量均逐渐升高,于T5时点达峰后回落,DX组T6时点与T1时点比较差异无统计学意义（P＞0.05）,而NS组T6时点仍高于T1时点（P＜0.01）.结论 右美托咪定降低原位肝移植术患者β-淀粉样蛋白含量,降低术后认知功能障碍发生率.

Objective To observe the effects of dexmedetomidine on β-amyloid and postoperative cognitive dysfunction （POCD） in patients undergoing orthotopic liver transplantation.Methods Sixty patients,aged 18-60 years with USA society of anesthesiologists score standard （ASA） grade of Ⅰ-Ⅲ,scheduled for orthotopic liver transplantation between May 2013 and October 2014,were enrolled in this study.According to the random number table method,the patients were randomly divided into the dexmedetomidine group （DX group） and normal saline group （NS group）,30 cases in each.After tracheal intubation,patients in DX group were infused intravenously with a loading dose of dexmedetomidine 0.5 μg/kg in 10 min,followed by a continuous infusion of dexmedetomidine 0.3 μg/（kg＆#183;h） until the end of operation.The NS group was treated with the same volume of normal saline.Cognitive function was assessed at 1st day before operation and 7th day after operation,using a battery of neuropsychological tests.The samples of β-amyloid were collected at six time points：just before the operation （T1）,0.5 h after the start of anhepatic phase （T2）,2.0 h after the reperfusion of the new liver （T3）,the completion of operation （T4）,1 day after the operation （T5） and 7 days after the operation （T6） respectively.The samples were analyzed using a β-amyloid enzyme linked immunosorbent assay （ELISA） kit.Results The mechanical ventilation time in DX group was shorter than in NS group （P 〈 0.05）.The rate of POCD in DX group was lower than that in NS group,13.3% and 40.0% respectively （P 〈 0.05）.The concentration of β-amyloid in DX group at T4-T6 was lower than that at the corresponding time points in NS group （all P 〈 0.01）.In both two groups,the concentrations of β-amyloid were increased gradually from T2 and reached the peak value at T5,then they decreased,and in NS group the concentration at T6 was still at a higher level than that at T1 （P 〈 0.01）,but in DX group the concentration at T6 showed no significant difference as compared with that at T1 （P 〉 0.05）.Conclusion Dexmedetomidine can decrease the concentration of β-amyloid and the incidence of postoperative cognitive dysfunction in patients undergoing orthotopic liver transplantation.