目的 研究右美托咪定對體外循環(huán)（CPB）下心臟瓣膜置換術(shù)患者的腦保護(hù)作用。方法 以2015年1月-2015年12月于鄭州市第七人民醫(yī)院擇期進(jìn)行CPB下心臟瓣膜置換手術(shù)的患者80例為研究對象，根據(jù)實施手術(shù)的時間順序分為觀察組和對照組，每組40例，觀察組在麻醉誘導(dǎo)前及手術(shù)中使用右美托咪定，對照組給予相同劑量的生理鹽水，比較兩組的麻醉誘導(dǎo)前（T₀）、升主動脈開放時（T₁）、CPB結(jié)束后10 min（T₂）以及術(shù)后6 h時（T₃）4個時間點的動脈-靜脈血氧含量差（Da-jvO₂）、頸內(nèi)靜脈血氧飽和度（SjvO₂）以及腦氧攝取率（CERO₂）、血漿髓鞘堿性蛋白（MBP）、血清神經(jīng)元特異性烯醇化酶（NSE）和S100β蛋白水平；手術(shù)前及手術(shù)后5 d的簡易智力量表（MMSE）評分及認(rèn)知功能障礙（POCD）發(fā)生率。結(jié)果 T₀和T₃時，兩組的SjvO₂、Da-jvO₂和CERO₂比較，差異無統(tǒng)計學(xué)意義；T₁時，兩組的SjvO₂較T₀時升高（P<0.05），Da-jvO₂和CERO₂較T₀時降低（P<0.05）；T₁和T₂時，觀察組的SjvO₂高于對照組，Da-jvO₂和CERO₂低于對照組（P<0.05）；T₂、T₃時，觀察組和對照組的MBP水平均高于T₀時（P<0.05），且觀察組MBP水平低于對照組（P<0.05）；T₁、T₂、T₃時，觀察組和對照組的NSE和S100β水平均較T₀時顯著升高（P<0.05），觀察組的NSE水平在T₁、T₂、T₃時均低于對照組（P<0.05），S-100β水平在T₂、T₃時均低于對照組（P<0.05）；術(shù)后5 d，觀察組的MMSE評分與術(shù)前比較，差異無統(tǒng)計學(xué)意義（P<0.05），對照組的MMSE評分顯著低于術(shù)前（P<0.05）；觀察組術(shù)后7 d的MMSE評分高于對照組，POCD發(fā)生率低于對照組（P<0.05）。結(jié)論 CPB下心臟瓣膜置換術(shù)患者術(shù)中使用右美托咪定可顯著改善患者的腦缺血缺氧狀態(tài)，減輕腦損傷。

Objective To investigate the cerebral protection of dexmedetomidine in patients with heart valve replacement under CPB. Methods Totally 80 cases of patients with heart valve replacement under CPB in Seventh people's hospital of Zhengzhou city from January 2015 to December 2015 were selected and divided into observation group and control group, 40 cases in each group. Patients in observation group were treated with dexmedetomidine before anesthetic induction and during the operation, and patients in control group were treated with same dose of saline solution. The arterio-venous oxygen content difference (Da-jvO₂), jugular venous oxygen saturation (SjvO₂), cerebral oxygen extraction rate (CERO₂), serum myelin basic protein (MBP), serum neuron-specific enolase (NSE), and S100β protein content before anesthetic induction (T₀) and when the ascending aorta open (T₁), After 10 min of CPB (T₂) and postoperative 6 h (T₃) were compared between two groups, and occurring rates of MMSE and POCD were also compared. Results SjvO₂ values of two groups at T₁ were significant higher than T₀ (P<0.05), Da-jvO₂, and CERO₂ were significant lower than T₀ (P<0.05), SjvO₂ values of observation group at T₁ and T₂ were significant higher than those of control group and Da-jvO₂ and CERO₂ were significant lower than those of control group (P<0.05); At T₂ and T₃, MBP levels of observation group and control group were significant higher than T₀ (P<0.05), and those in observation group were significant lower than control group (P<0.05); At T₁, T₂, and T₃ of observation group and control group were significant higher than T₀ (P<0.05), and NSE levels of observation group at T₁, T₂, T₃ were significant lower than those of control group (P<0.05), S-100β levels of observation group at T₂ and T₃ were significant lower than those of control group (P<0.05). After 7 d, MMSE score of observation group was significant higher than that of control group and POCD occurring rate was lower (P<0.05). Conclusion Dexmedetomidine can improve cerebral ischemia hypoxia state and reduce brain damage in patients with heart valve replacement under CPB.