右美托咪定改善老年患者术后认知功能及脑氧代谢适宜剂量的研究

Study of appropriate dose of Dexmedetomidine on improving postoperative cognitive function and cerebral oxygen metabolism in elderly patients

摘要:

目的 探讨右美托咪定（Dex）对老年髋部手术患者术后认知功能及脑氧代谢影响的适宜剂量。方法 选取择期行全髋关节置换术老年患者120例。年龄≥62岁，体重54～79?kg，ASA分级Ⅰ、Ⅱ级，随机分为4组：右美托咪定组（D1、D2、D3组）和对照组（R组），D1、D2、D3组在给予1?μg/kg负荷量的Dex后分别继续维持泵注0.2、0.5和0.8?μg/（kg·h）至手术结束前30?min，R组给予等量生理盐水。于麻醉诱导前（T0）、术毕即刻（T1）、术后1?d（T2）、术后3?d（T3）、术后7?d（T4）测定血清S100β蛋白及神经元特异性烯醇化酶（NSE）水平，并于T0、T1和T2时计算脑氧摄取率（CERO2）。利用蒙特利尔认知功能评分量表（MoCA）对患者术前1?d、术后1、3、7?d时实施评分，观察患者术后认知功能障碍（POCD）的发生率。结果 与T0时比较，4组T1～T3时血清S100β与NSE浓度均升高（P?<0.05）；与R组比较，D1、D2、D3组T1～T4时血清S100β与NSE浓度均降低（P?<0.05）。与T0时比较，4组T1、T2时CERO2降低（P?<0.05），与R组比较，D1、D2、D3组T2、T3时CERO2降低（P?<0.05）。D1、D2、D3组术后1、3和7?d MoCA评分均高于R组（P?<0.05）；与D1组比较，D2、D3组术后1、3?d和D2组术后7?d MoCA评分均升高（P?<0.05）。R组、D1、D2和D3组POCD发生率分别为40%、23%、10%和17%。结论 持续静脉输注Dex可有效降低POCD的发生率，其机制可能与降低S100β、NSE浓度及脑代谢率相关，其中以0.5?μg/（kg·h）维持剂量最佳。

Abstract:

Objective To observe the appropriate dose of Dexmedetomidine (Dex) to improve the postoperative cognitive function and cerebral oxygen metabolism in elderly patients with hip surgery. Methods Totally 120 cases undergoing hip replacement with ASA physical status I or II, age ≥ 62 years and weight 54 to 79?kg were randomly divided into Dex group (D1, D2, D3 group) and control group (R group), The D1-D3 groups were given 1?μg/(kg?h) Dex by infusion first and continued infusion of respectively 0.2?μg/(kg?h), 0.5 μg/(kg?h) and 0.8?μg/(kg?h) to 30?mins before the end of surgery, R group received the same amount of normal saline. Serum S100β protein and Neuron-specific enolase (NSE) levels were measured before anesthesia induction (T0), immediately after operation (T1), 1 day after surgery (T2), 3 days after surgery (T3) and 7 days after surgery for (T4); and the cerebral oxygen extraction rate (CERO2) was calculated at T0, T1 and T2. The patients were assessed with the Montreal cognitive function assessment (MoCA) 1 day before surgery, 1, 3 and 7 days after surgery. The occurrence of postoperative cognitive dysfunction (POCD) was recorded. Results Compared with T0, the concentrations of S100β and NSE in serum increased significantly at T1-T3 in the 4 groups (P?