不同脑灌注方法对深低温停循环脑组织温度、温差的影响

目的比较不同脑灌注方法对深低温停循环(DHCA)中脑组织温度、温差的影响,以及与自由基及脑皮质超微结构改变的关系,评价不同灌注方式的脑保护效果。方法健康成年杂种犬15只,随机分为3组(n=5)。Ⅰ组单纯行DHCA,Ⅱ组DHCA RCP,Ⅲ组DHCA 选择性顺行脑灌注(SACP)。转流降温至鼻咽部温18℃时停循环,期间Ⅱ、Ⅲ组分别行逆行脑灌注(RCP)及SACP,90 min后复温,再灌注90 min。结果停循环后犬脑组织温度缓慢上升,脑皮质温度(BCT)及脑深部温度(BBT)在不同时间点间差异有统计学意义(P<0.01);3组之间BCT、BBT亦有明显差异(P<0.01),停循环时间与不同脑灌注方式之间存在交互效应。停循环过程中及复温后各组脑皮质-深部温差(Dc-bT)、SOD活性及MDA含量均有明显差异(P<0.05),Ⅰ组复温30 min时Dc-bT最大,Ⅲ组停循环前Dc-bT最小。Ⅲ组脑超微结构改变轻于Ⅰ、Ⅱ组。结论DHCA中存在脑组织自然复温及较明显的脑皮质-深部温差。RCP有利于维持脑部低温,但不能有效降低脑皮质-深部温差。SACP可保持脑温低温,有效减小脑皮质-深部温差,脑保护效果优于RCP和DHCA。     

Myocardial contractility and relaxation after deep hypothermic circulatory arrest in a neonatal piglet model

Cooling before circulatory arrest or ischemic arrest has been reported to influence myocardial performance in isolated neonatal hearts. The aim of the present study was to analyze indices of myocardial contractility and relaxation in an in vivo neonatal model after deep hypothermic circulatory arrest (DHCA). DHCA (18°C; DHCA group; n = 8) or mild hypothermic cardiopulmonary bypass ([MH-CPB] 32°C; MH-CPB group; n = 10) was applied in newborn piglets. After reperfusion (60 and 120 min), left ventricular dP/dt(max) increased in DHCA and MH-CPB, while-dP/dt(max) decreased slightly in DHCA and increased in MH-CPB. Nevertheless, the differences between the two groups did not reach statistical significance. In conclusion, left ventricular contractility remained stable after reperfusion following DHCA, to some degree at the expense of the diastolic function.     

磁共振弥散加权成像和组织病理学检测深低温停循环动物术后早期脑损伤

目的 探讨磁共振弥散加权成像在术后脑损伤中应用价值并分析其与术后动物组织病理学的相关性.方法 18只3～5个月中华小型猪,体质量25～30 kg,分为3组,A组为对照组,仅行全麻,开胸,不进行体外循环;B组在20℃下停循环120 min,术后存活1天;C组20℃下停循环120 min,术后存活2天.磁共振弥散加权成像和组织病理学检测深低温停循环术后实验猪脑损伤情况.结果 深低温停循环术后动物脑组织新皮质和海马区均可发现苏木精-伊红、原位凋亡阳性细胞.弥散加权成像提示B组有5只动物出现大脑皮质高信号,3只T2WI高信号;C组6只动物均出现大脑皮质高信号,5只T2WI高信号.B、C动物海马区均未发现弥散加权成像高信号.结论 磁共振弥散加权成像是一种可靠和无创的检测深低温停循环术后早期脑损伤的方法,优于常规磁共振检查;而且这种损伤主要是大脑皮质受损为主.DHCA术后的MRI和组织病理学检测无很好的相关性.DHCA术后的MRI和组织病理学检测无很好的相关性.     

胸主动脉瘤手术中中浅低温停循环加顺行性脑灌注技术的应用

目的 评价中浅低温停循环加脑灌注技术用于Ⅰ型夹层动脉瘤手术的临床效果.方法 2007年2月至2009年8月行主动脉弓部置换术60例,按照开始停循环的最低温度分为深度低温组(DH,32例;鼻咽温18～20℃)和中浅低温组(MH,28例;鼻咽温23～25℃).观察两组患者手术及其临床预后.结果 住院病死率3.33%(2/60例),每组各有1例死于多器官功能衰竭;开始选择性脑灌注(ASCP)时MH组的鼻咽温和直肠温度[(23.8±1.9)℃和(26.6 ±2.4)℃]明显高于DH组[(19.7±3.2℃和(22.5±2.2)℃],差异有统计学意义(P<0.05).两组ASCP时间(29.4±9.3)min对(32.9±13.4)min,差异尢统计学意义(P>0.05).MH组患者的复温时间较短,(65.00±13.9)min对(90.3±27.2)min;体外循环转机时间较短,(142.8±34.2)min对(194.1±42.0)min,差异均有统计学意义(P<0.05).两组患者术后无永久性神经系统并发症(PND),暂时性神经系统并发症(TND)的发生率为6.67%(4/60例),其中MH组为7.14%(2/28例),DH组为6.25%(2/32例),差异无统计学意义(P>0.05).术后呼吸机辅助通气时间、肾脏功能衰竭发生率、监护室停留时间和住院时间差异无统计学意义(P>0.05).结论 中浅低温加选择性脑灌注用于Ⅰ型夹层动脉瘤手术可以缩短体外循环转机时间,未增加患者术后神经系统并发症.

Abstract：

Objective To compare the effects of hypothermic arrest circulation ( HAC) with moderate or deep hypothermic antegrade selective cerebral perfusion ( ASCP) technique in patients with DeBake type Ⅰ aortic dissection or aortic arch aneurysm undergoing total aortic arch replacement. Methods Between Feb. 2007 and Aug. 2009, 60 patients who underwent aortic arch replacement using HAC + SCP technique. Patients were divided into two groups according to the lowest nasopharyngeal temperature: moderate hypothermia (18 - 20℃) (group MH, n = 28), and deep hypothermia (23 -25 ℃) (group DH,n=32). The clinical and neurological outcomes were observed. Results The overall in-hospital mortality was 3. 33% (2/60) ; In-hospital mortality was 3. 6% in the MH group, while3.1% in the DH group. There were no significant differences regarding to preoperative the patients' character parameters in both groups. At the beginning of ASCP, the nasopharyngeal and rectal temperatures were significantly higher in group MH[MH group (23.8 ± 1. 9 ) ℃ ( 26. 6 ± 2. 4 ) ℃ vs. DH group group (29.4 ±9.3) min vs. DH group(32.9 ± 13.4) min]. The rewarming time and CPB time were significantly shorter in MH group[(65.0±13.9) min vs. (90.3 ±27.2) min; (142.8 ±34.2) min vs. (194.1 ±42.0) min, P <0. 05]. Temporary neurologic deficits occurred in four patients (6. 67% ) without significant differences between two groups ( MH group 7.14% vs. DH group 6. 25% ). No patient suffered from permanent neurologic dysfunction. There were no significant differences between two groups in other parameters including intubation time, kidney insufficiency, the stay times in ICU and hospital. Conclusion Our results demonstrate that moderate HCA + ASCP technique is a safe strategy for the treatment of patients who require conventional total arch replacement with individual arch-vessel reconstruction. Shorter CPB time in patients with moderate HCA + ASCP did not increase any other postoperative adverse effects.     

深低温停循环下兔脑内兴奋性氨基酸的早期变化与脑损伤研究

目的　探讨体外循环(CPB)和深低温停循环(DHCA)下脑内兴奋性氨基酸(EAA )早期变化规律,及其“兴奋毒性”作用在脑损伤中的作用。方法　建立应用脑微透析技术的兔CPB和DHCA模型。利用高效液相的电化学检测方法,测定兔脑海马CA1区脑细胞间液中EAA的连续性变化。术后利用透射电子显微镜给予组织学损伤评分。结果　谷氨酸在CPB组各阶段变化差异无统计学意义(P >0 .0 5 ) ;DHCA组在恢复循环早期明显升高(P <0 .0 5 ) ,升高程度DHCA组明显高于CPB组(P <0 .0 1)。天冬氨酸在DHCA组恢复灌注3 0～60min阶段明显升高(P <0 .0 1) ,但与CPB组的组间对照差异无统计学意义(P >0 .0 5 )。透射电镜发现两组脑细胞超微结构均明显损伤,DHCA组损伤重于C组(P <0 .0 5 )。结论　“兴奋毒性”作用与中低温CPB造成的脑损伤无关。DHCA可使再灌注早期兴奋性氨基酸升高,并导致脑损伤加重     

幼猪深低温低流量体外循环心脏手术中脑损伤的实验研究

目的 评价长时间深低温低流量体外循环( cardiopulmonary bypass,CPB)心脏手术对幼猪未成熟脑的影响及其机制.方法 北京长白幼猪15只,按随机数字表法分为实验组(10只)和对照组(5只).实验组麻醉后正中开胸,常规建立CPB,体温降至25℃后,开始低流量循环(50 ml· kg-1· min-1),主动脉阻断120 min后开放,停机后观察120 min取脑海马组织;对照组麻醉后开胸,取脑海马组织.实验组分别在麻醉诱导后即刻(T1)、停机后5 min (T2)、120 min(T3)取静脉血,酶联免疫吸附法(ELISA)检测白细胞介素-6(interleukin-6,IL-6)、肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α).实验组、对照组脑海马组织行HE染色病理检查;ELISA法测海马神经元特异性烯醇化酶(neuron-specific enolase,NSE)、S100蛋白β亚型(S100 protein beta subtypes,S100β).结果 实验组1只死于CPB停机后心脏骤停,余9只和对照组5只完成至实验结束.与T1比较,实验组T2的IL-6、TNF-α分别升高7.01％(P＜0.05)、3.52％(P＜0.05);T3的IL-6、TNF-α分别升高5.10％(P＜0.05)、1.47％(P＞0.05).与对照组比较,实验组可见脑损伤病理学改变,NSE、S100β分别升高40.08％ (P＜0.05)、29.66％( P＜0.05). 结论 深低温低流量CPB心脏手术可造成幼猪脑组织损伤,并证实炎症反应是脑损伤的可能机制之一.     

深低温停循环主动脉弓部手术后苏醒延迟危险因素分析

目的 探讨在深低温停循环(deep hypothermic circulatory arrest,DHCA)选择性脑灌注(antegrade selective cerebral perfusion,ASCP)下行主动脉弓部手术后发生苏醒延迟的危险因素. 方法 回顾性分析2006年10月至2013年6月期间南京市鼓楼医院97例行主动脉弓部手术患者的临床资料.97例患者分为两组:正常组(46例),男37例,女9例,平均年龄(48±11)岁;苏醒延迟组(51例),男40例,女11例,平均年龄(52±11)岁.观察两组患者的临床资料,采用单因素方差分析和Logistic多因素回归分析导致患者术后发生苏醒延迟的危险因素. 结果 97例患者中术后发生苏醒延迟51例(52.58％),其中11例患者(11.34％)术后一直未醒,住院死亡20例(20.62％).单因素分析结果显示:年龄(P=0.047)、高血压病史(P=0.005)、急诊手术(P=0.031)、体外循环(cardiopulmonary bypass,CPB)时间(P=0.017)、心肌阻断时间(P=0.021)、输血(P=0.001)是DHCAASCP术后发生苏醒延迟的危险因素.Logistic回归分析结果显示:急诊手术(P=0.005)、CPB时间＞240 min(P＜0.001)是导致DHCA ASCP术后发生苏醒延迟的独立危险因素. 结论 主动脉弓部手术后发生苏醒延迟是多因素共同作用的结果.     

深低温停循环中不同脑灌注方式皮层超氧化物歧化酶、丙二醛及超微结构的变化

目的观察不同脑灌注方法对深低温停循环（DHCA）中脑皮质超氧化物歧化酶（SOD）、丙二醛（MDA）及超微结构的影响，比较不同灌注方式的脑保护效果。方法健康成年杂种犬15条，随机分为3组。Ⅰ组单纯行DHCA为对照，Ⅱ组DHCA＋逆行脑灌注（RCP），Ⅲ组DHCA＋选择性顺行脑灌注脑保护（SACP）。转流降温至鼻咽部温18℃时停循环90min，然后复温再灌注90min。结果停循环期皮层SOD活性下降而MDA含量上升，复温再灌注时变化更明显，各时间点差异有统计学意义（P〈0．05）。增加或下降程度以Ⅰ组最为明显，Ⅱ组次之，Ⅲ组最小。Ⅱ、Ⅲ组与Ⅰ组比较SOD、MDA变化明显减轻（P〈0．01），Ⅱ、Ⅲ组间亦差异有统计学意义（P〈0．05），与电镜观察结果一致。结论深低温停循环期间SACP有明显脑保护作用，RCP亦可减轻DHCA中脑损害。     

乌司他丁对幼猪体外循环心脏手术脑损伤影响的实验研究

目的 评价广谱蛋白酶抑制剂乌司他丁对幼猪深低温低流量体外循环(cardiopulmonary bypass,CPB)心脏手术脑损伤的影响.方法 普通幼猪15只,采用随机数字表法分为3组(每组5只):乌司他丁组(U组)、对照组(C组)和假手术组(S组).U组和C组麻醉后正中开胸,常规建立CPB,降温至25℃后,低流量循环(50 ml·kg-1·min-1),主动脉阻断120 min后开放,调整停机后观察120 min,取海马组织.U组在CPB开始和主动脉开放即刻分别给予乌司他丁1.2万IU/kg,C组给予等量生理盐水.S组麻醉、单纯开胸,即取脑海马组织.3组在麻醉诱导后即刻(T1)、U组和C组在停机后5 min(T2)、120 min(T3)取静脉血,ELISA法测神经元特异性烯醇化酶(neuron-specific enolase,NSE)、S100蛋白β亚型(S100 protein β subtypes,S100β)、髓鞘碱性蛋白(myelinbasicprotein,MBP).光镜下观察海马病理学结果,测含水量.结果15只幼猪均完成至实验终点.与T1相比,C组在T2、T3时点NSE、S100β、MBP分别升高30.2、32.3、62.0％和33.1、29.8、57.1％,差异均有统计学意义(P＜0.05);U组在T2、T3时点NSE、S100β、MBP分别低于相应时点C组16.8、7.3、20.4％和20.4、2.7、18.5％,差异均有统计学意义(P＜0.05).C组、U组均可见脑损伤,U组较轻.含水量C组比U组升高2.2％(P＜0.05).结论 深低温低流量CPB心脏手术对幼猪存在脑损伤,乌司他丁具有对抗脑损伤(脑保护)作用.     

在深低温停循环中小预充量体外循环的脑保护效果

目的 观察在深低温停循环中小预充量体外循环的脑保护效果.方法 将实验动物分为假手术组(S组)、小预充量组(L组)、大预充量组(H组),建立联合脑微透析和体外循环(CPB)的动物模型.实验中进行微透析取样和生理指标监测,结束后取脑组织作组织学检测,用高效液相色谱法和CMA600分析仪检测微透析样品.结果 实验中,H组所用多巴胺和碳酸氢钠的量高于L组[(2.07±0.63)mg＞(1.12±0.47)mg;(14±3)ml＞(7±3)ml,P＜0.05].检测显示,H组的乳酸/葡萄糖和乳酸/丙酮酸比值在体外循环后高于L组(12.63±0.44＞3.71±1.31;13.14±1.37＞3.82±1.41,P＜0.05);H组的谷氨酸水平在实验后期高于L组(6.02±0.65＞2.21±0.72,P＜0.05);H组脑组织损伤程度明显重于L组.结论 深低温停循环时,与大预充量比较小预充量体外循环有显著的脑保护作用.     

硫喷妥钠与异丙酚在小儿心脏手术深低温停循环期间对脑缺血再灌注损伤的影响

目的 观察婴幼儿先天性心脏病心内直视手术,深低温停循环期间给予硫喷妥钠、异丙酚对脑缺血再灌注损伤的影响。方法20例室间隔缺损伴肺动脉高压(VSD+PH)患儿随机分为硫喷妥钠5mg·kg-1(A组)、异丙酚2mg·kg-1(B组)和对照(C组)三组,于转流前(Ⅰ朗)、停循环时(Ⅱ期)、再灌注始(Ⅲ期)及术后24h(Ⅳ期)分别抽取颈内静脉、桡动脉血样做血气分析,并测定乳酸含量(LAC)及肌酸激酶BB(CKBB)和神经特异性烯醇化酶(NSE)的含量;计算脑动静脉氧含量差(Ca-vO2)、脑氧摄取率(Co2ER)。结果 Ⅲ期各组LAC水平最高,并以A组较为明显;脑氧代谢在Ⅱ期各组Ca-vO2、CO2ER均较其余各期低,其中B组下降最为明显,其次为A组和C组;Ⅳ期时,各组Ca-vO2、CO2ER均有所恢复。 各组在Ⅲ期CDBB和Ⅲ、Ⅳ期NSE均有上升趋势,B组增高幅度最低。结论 异丙酚用于深低温停循环期间对脑缺血再灌注损伤有保护作用。     

血浆S100蛋白在体外循环术后脑损伤评价中的意义

目的：探讨血浆S100蛋白在体外循环术中和术后脑损伤评价中的意义。方法：体外循环下心内直视手术病人40例，在体外循环中和结束后不同时间点采血测定血浆S100浓度，并观测病人术后精神神经系统并发症。结果：体外循环可引起病人血浆S100蛋白明显升高，水平最高的3例术后均出现明显的精神神经系统症状，术后24～48h无精神神经并发症者血浆S100蛋白恢复到术前水平。结论：体外循环引起的血浆S100蛋白水平变化对体外循环术后脑损伤的评价具有重要意义。     

Antegrade selective cerebral perfusion with mild hypothermic systemic circulatory arrest during thoracic aortic surgery

Objective Antegrade selective cerebral perfusion (ASCP) and retrograde cerebral perfusion (RCP) have proven to be reliable methods of brain protection during aortic surgery. These techniques are usually accompanied by systemic circulatory arrest with moderate hypothermia (24–28°C) or deep hypothermia (18–24°C). However, hypothermia can lead to various problems. The present study therefore reports results for thoracic aorta replacement using ASCP with mild hypothermic systemic arrest (28–32°C).

Design Between 1995 and 2003, 68 consecutive patients underwent repair of the ascending aorta and/or aortic arch. Mild hypothermic ASCP was utilized in 31 cases, moderate hypothermic ASCP in 20, and deep hypothermic RCP in 17. Various parameters were compared between the mild hypothermic ASCP, moderate hypothermic ASCP, and RCP.

Results Hospital mortality was 10.3%, with no significant differences observed between any groups. Permanent neurological dysfunction was 8.8%, and no significant differences were observed between any groups. Mild hypothermic ASCP displayed significantly decreased transfusion volume, intubation time, and ICU stay.

Conclusions Use of ASCP with mild hypothermic systemic circulatory arrest during aortic surgery resulted in acceptable hospital mortality and neurological outcomes. ASCP with mild hypothermic arrest allows decreased transfusion volume and reduced duration of intubation and ICU stay.     

深低温停循环大鼠脑保护模型的建立

目的 建立一种新的深低温停循环(DHCA)大鼠脑保护模型.方法雄性SD大鼠30只,随机分为3组,即颈动脉阻断DHCA组(A组)、颈内动脉引流DHCA组(B组)和假手术组(C组).于深低温停循环后60 min时监测脑电图变化,停循环60 min后恢复循环并升温.所有大鼠于术后24 h处死,并取脑组织测脑含水量.结果 B组大鼠α波相对功率值明显低于A组(P＜0.01),而且两组大鼠α波相对功率值均明显低于C组(P＜0.01);B组大鼠θ波相对功率值明显低于A组和C组(P＜0.01),而后两组大鼠θ波相对功率差异无统计学意义.脑含水率结果 显示B组大鼠脑含水量高于A组(P＜0.05).结论 颈内动脉引流DHCA模型较颈动脉阻断DHCA模型脑缺血更完全,是一种较为理想的DHCA大鼠脑保护模型.     

The optimal flow rate for antegrade cerebral perfusion during deep hypothermic circulatory arrest

The aim of this study is to compare cerebral protection using antegrade cerebral perfusion (ACP) with various flow rates during deep hypothermic circulatory arrest (DHCA) in a piglet model. Twenty‐three piglets were randomized to five groups: the control group (n = 3), DHCA group (n = 5), ACP25 group (n = 5), ACP50 group (n = 5), and ACP80 group (n = 5). Three control piglets did not undergo operations. Twenty piglets underwent cardiopulmonary bypass (CPB) and DHCA for 60 min at 20°C. ACP was conducted at 0, 25, 50, and 80 mL/kg/min in the DHCA, ACP25, ACP50, and ACP80 group, respectively. Serum S‐100B protein and neuron‐specific enolase were monitored, and brain tissues were assayed for the activities of caspase‐3 and stained for the evidence of apoptotic cellular injury. Rise in serum S‐100B level (post‐CPB—pre‐CPB) in the ACP50 group was significantly lower than that in the ACP80 group (P = 0.001). Caspase‐3 levels were significantly elevated in the ACP80 group compared with the ACP25 (P = 0.041) and ACP50 group (P = 0.01), while positive terminal deoxyneucleotidyl transferase‐mediated biotin‐dUTP nick end labeling reaction scores in the ACP80 group were significantly higher than those in the ACP25 (P = 0.043) and ACP50 group (P = 0.023). Cerebral protection effects of ACP at 25 and 50 mL/kg/min were superior to that of ACP at 80 mL/kg/min as determined by cerebral markers, immunology, and histology.     

Anaesthesia for the treatment of a giant cerebral aneurysm under hypothermic circulatory arrest

The anaesthetic management of a patient whose giant cerebral aneurysm was clipped is described. Profound hypothermia and thiopentone were used to provide cerebral protection during circulatory arrest. Atracurium was used to provide muscle relaxation; the level of neuromuscular block and plasma concentrations of atracurium and laudanosine were measured.