甲状腺激素对体外循环脑损伤保护作用的研究

Protective effect of thyroid hormone on neurological damage in cardiopulmonary bypass

摘要:

目的  探讨体外循环（CPB）心脏手术中，甲状腺激素（TH）对患者脑损伤的保护作用。方法  152例CPB心脏瓣膜置换术患者随机分为干预组和对照组，每组76例，干预组于术前7 d开始口服左甲状腺素钠片（优甲乐）50μg/d至手术日早晨。检测术前（T1）、CPB开始后30 min（T2）、CPB结束时（T3）、CPB结束后6 h（T4）和CPB结束后24 h（T5）的血清S100-β蛋白、神经元特异性烯醇化酶（NSE）、白细胞介素6（IL-6）、C反应蛋白（CRP）、游离三碘甲腺原氨酸（FT3）水平，并于术晨、术后1、3和7 d对患者进行简易智能状态检查量表（MMSE）评分。结果  在T2、T3、T4时，干预组S100-β蛋白水平低于对照组（P <0.05）；在术中及术后24 h内，干预组NSE、IL-6、CRP水平显著低于对照组（P <0.05），干预组FT3水平显著高于对照组（P <0.05）。术后1周内，干预组MMSE评分高于对照组（P <0.05）。结论  CPB术前应用TH，可有效地提高围手术期血清TH水平，通过抑制炎症因子，产生一定的脑保护作用。

Abstract:

Objective To explore the protective effect of thyroid hormone (TH) on neurological damage in cardiopulmonary bypass (CPB). Methods Totally 152 patients performed with heart valve replacement were randomly divided into treatment group (n = 76) and control group (n = 76). In the treatment group, 50 μg levothyroxine sodium (Euthyrox) was given daily from a week before surgery to the morning of surgery. Serum levels of S100-β protein, neuron specific enolase (NSE), interleukin 6 (IL-6), C-reactive protein (CRP) and free triiodothyronine (FT3) were detected at the time before opearation (T1), 30 min after beginning of CPB (T2), when CPB was ended (T3), 6 h (T4) and 24 h (T5) after CPB. The patients' cognitive function was assessed with mini-mental state examination (MMSE) before operation and 1, 3 and 7 d after operation. Results The concentrations of plasma S100-β protein at T2, T3 and T4 were significantly lower in the treatment group than those in the control group (P < 0.05). During operation and within 24 h after operation the concentrations of plasma NSE, IL-6 and CRP were significantly lower in the treatment group than those in the control group (P < 0.05), and the concentration of plasma FT3 was significantly higher in the treatment group than that in the control group (P < 0.05). The MMSE score was higher in the treatment group than that in the control group within 1 w after operation (P < 0.05). Conclusions Preoperative application of TH can effectively improve the perioperative serum TH level and produce certain cerebral protection by inhibiting the inflammatory factors in cardiopulmonary bypass.