不同剂量右美托咪定对脑膜瘤切除术患者术后认知功能的影响

The neuroprotective effect of dexmedetomidine during periopererative period in patients with meningioma

目的评价不同剂量右美托咪定(Dex)对脑膜瘤切除术患者术后早期认知功能及血清S100β、胶质纤维酸性蛋白(GFAP)、神经元特异性烯醇化酶(NSE)浓度的影响。方法选择择期行脑膜瘤切除术患者45例,年龄45～65岁,体重55～65kg,ASAⅡ或Ⅲ级,术前简易智能量表(mini mental state exam,MMSE)评分>23分,采用随机数字表法,将患者均分为三组:生理盐水组(C组)、低剂量Dex组(D1组)和高剂量Dex组(D2组),D1和D2组于常规诱导前10min静脉输注Dex负荷量1μg/kg,继之分别以0.2和0.5μg·kg-1·h-1持续输注至术毕前30min,C组给予等容量的生理盐水。维持患者术中BIS在40～49之间,分别于麻醉诱导前(T1)、取出肿瘤时(T2)、拔管时(T3)、术后24h(T4)采集静脉血,测定血清中S100β、GFAP及NSE的浓度,于术前24h和术后24h采用MMSE评分评定患者术后早期的认知功能。结果与T1时比较,T2～T4时三组患者血清S100β、GFAP、NSE浓度升高(P<0.05);与C组比较,T2～T4时D2组血清S100β、GFAP、NSE浓度降低(P<0.05)。与C组比较,D2组术后24hMMSE评分升高(P<0.05);C、D1组术后24hMMSE评分差异无统计学意义。D2组术后认知功能障碍(POCD)发生率降低明显低于C、D1组(P<0.05)。结论术中持续静脉输注高剂量Dex可升高术后早期MMSE评分,降低POCD的发生率,其机制可能与降低S100β、GFAP及NSE浓度有关。

Objective To evaluate the effects of different doses of dexmedetomidine （Dex） on the cognitive function and the concentration of S100β. GFAP and NSE in serum in patients with meningioma. Methods Forty-five ASA Ⅱ or Ⅲ patients with meningioma and mini mental state exam （MMSE） score〉23, aged 45-65yr, weighing 55-65 kg, scheduled for elective intracranial tumor resection were enrolled and randomly divided into 3 groups （n= 15 each）： control group （group C）; low dose Dex group （group D1 ）; high dose Dex group （group D2 ）. Dex 1 μg/kg was infused intravenously over 10 rain before anesthesia induction, and then was infused at a rate of 0. 2μg·kg-1·h-1 （group D1 ）and 0.5μg·kg-1·h-1 （group De ） until 30 rain before the end of the operation. Group C received the equal volume of normal saline. BIS was maintained at 40-49 throughout the surgery. Venous blood samples were taken at 4 time points： before induction （T1）, while the tumor was resected （T2）, extubation （Ta） and 24 h after operation （T4） for determination of serum concentrations of S100β, Neuron-specific enolase （NSE） and glial fibrillary acidic protein（GFAP）, cognitive function was evaluated at 24 h before and 24 h after surgery using MMSE, results of MMSE were recorded. Results Compared with T1, the concentration of S100β, GFAP and NSE in serum were significantly increased at T2-T4 in the three groups （P〈0.05）. Compared with group C, the concentration of S100β, GFAP and NSE were significantly decreased at T2-% in group De （P〈0. 05）, there was no significant difference in the indexes mentioned above between group C and group Eh. The incidence of postoperative cognitive dysfunction were lower in group De than in group C and group D1 （P〈O. 05）. Compared with group C, the postoperative MMSE scores were significantly increased in group D2 （P 〈 0. 05 ）, there was no significant difference between group C and group Eh. Conclusion Continuous infusing high dose Dex intraoperative can impact on MMSE score during early postoperative period, its mechanism may be associated with the decrease of the concentration of S100β, GFAP and NSE in serum.