米力农复合一氧化氮对先天性心脏病患者体外循环后肺动脉高压的影响

目的 评价米力农复合一氧化氮(NO)对先天性心脏病(CHD)患者体外循环(CPB)后肺动脉高压(PH)的影响.方法 先天性左向右分流型心脏病经肺动脉导管确诊为PH患者24例,随机分为3组(n=8):NO组(N组)、米力农组(M组)和米力农复合NO组(NM组).CPB主动脉开放后,N组于CPB结束血液动力学平稳后,吸入20 ppm NO 45 min;M组静脉注射米力农负荷量50 μg/kg,然后持续静脉输注0.5μg/kg-1·min-1至术毕;NM组静脉注射米力农负荷量50 μg/kg,然后持续静脉输注0.5μg/kg-1·min-1至术毕,脱离CPB后,吸入20 ppm NO 30 min.分别于切皮前(T0)、CPB结束血液动力学平稳后、吸入NO15 min、30 min和停止NO吸入后15 min记录血液动力学指标.结果 N组吸入NO时平均肺动脉压(mPAP)和肺血管阻力指数(PVRI)降低(P＜0.05),停止吸入后,均出现不同程度的回升(P＜0.05),平均动脉压(MAP)、体循环阻力指数(SVRI)以及心脏指数(CI)差异无统计学意义(P＞0.05);M组静脉输注米力农期间PVRI下降,CI增加(P＜0.05),mPAP、MAP以及SVRI差异无统计学意义(P＞0.05).NM组给药期间mPAP和PVRI降低,CI增加(P＜0.05),停吸NO前后mPAP、PVRI差异无统计学意义(P＞0.05).结论 CHD合并PH患者CPB后,静脉输注米力农复合吸入NO可降低mPAP和肺循环阻力,增加CI;米力农可预防NO停用后PH反跳.     

不同速度输注异丙酚对低温体外循环期间患者麻醉深度的影响

目的 探讨不同速度输注异丙酚静脉麻醉下低温体外循环期间大脑状态指数(cerebral state index,CSI)及爆发抑制比(burst supression ratio,BS%)的变化.方法 择期行低温体外循环下心脏瓣膜置换手术患者44例,年龄(18～60)岁.随机分为两组,每组22例.麻醉诱导采用静脉注射异丙酚1mg/ks～1.5 mg/kg,芬太尼10μg/kg,维库溴铵0.1 mg/kg.麻醉维持采用持续静脉输注异丙酚4 mg·kg-1·h-1(P4组)或6 rag·kg-1·h-1(P6组),芬太尼5gμ·kg-·1h-1.记录体外循环(cardio pulmonany bypass,CPB)前5 min(T0)、CPB后2 min(T1)、CP8开始后30 min(T2)、CPB开始后60 min(T3)、停CPB后15 min(T4)时的CSI、BS%、鼻咽温度、平均动脉压(MAP)、心率(HR).结果 CPB期间两组的CSI均下降,与体外循环前比较差异有统计学意义(P<0.05或0.01),P6组CPB 30 min、60 min的CSI与P4组比较为差异有统计学意义(P<0.01).P6组在CPB 30 rain、60 min时出现爆发抑制比,与CPB前比较为差异有统计学意义(P<0.01),与P4组比较为差异有统计学意义(P<0.01).结论 低温CPB期间持续输注异丙酚6 mg·kg-1·h-1时,CSI处于较低水平,BS%明显增多,应适当减少异丙酚的输注速度,以维持合适的麻醉深度.     

前列腺素E1肺动脉途径给药对肺动脉高压患者的降压效果

目的 探讨前列腺素E1肺动脉途径给药对肺动脉高压患者的降压效果.方法 择期行非体外循环冠状动脉搭桥术合并肺动脉高压患者30例,性别不限,年龄65 ～ 82岁,体重60 ～ 88 kg,ASA分级Ⅱ或Ⅲ级,肺动脉收缩压＞40 mm Hg.采用随机数字表法,将其随机分为2组(n=15):中心静脉给药组(C组)和肺动脉给药组(P组).麻醉诱导后行右颈内静脉穿刺置入Swan-Ganz导管用于监测血流动力学指标.切皮后,C组和P组分别通过中心静脉导管和肺动脉导管输注前列腺素E120 ～ 50 ng·kg-1 ·min-1,使肺动脉收缩压降至25～ 30 mm Hg.分别于给药前5 min(To)及给药后5 min(T1)记录心率、平均动脉压、中心静脉压、肺动脉收缩压、肺毛细血管楔压和心脏指数,计算肺血管阻力和周围血管阻力.记录前列腺素E1的用量.结果 与C组相比,P组前列腺素E1用量减少,T1时肺动脉收缩压和肺血管阻力降低,平均动脉压和周围血管阻力升高(P＜0.05).结论 经肺动脉途径给药可提高前列腺素E1降低肺动脉高压的效价,且不影响体循环血流动力学.     

右美托咪定对心肺转流心内直视手术患儿血流动力学及应激反应的影响

目的观察右美托咪定连续输注对小儿先天性心脏病CPB心内直视手术期间的血流动力学及应激反应的影响。方法 CPB心内直视矫治手术患儿30例,ASAⅡ或Ⅲ级,随机均分为右美托咪定组(D组)和对照组(C组)。D组接受初始剂量为1.0μg/kg的右美托咪定(给药时间大于10min),随后以0.5～1.0μg·kg-1·h-1的速度维持直至手术结束,C组则给予相同容量的生理盐水。分别于给药前(T0)、给药后10min(T1)及15min(T2)、切皮后(T3)、锯胸骨后(T4)、停CPB后(T5)、手术结束时(T6)记录血流动力学参数,并分别于T0、T4～T6时检测血糖(Glu)、皮质醇(Cor)、去甲肾上腺素(NE)和肾上腺素(E)浓度。结果与C组比较,T1～T6时D组HR减慢,SBP、DBP及MAP明显降低,以T2时降低最为显著(P<0.05)。与T0时比较,T4～T6时两组的Glu、Cor、NE及E浓度显著增加(P<0.05),并以T5时升高最为显著,但与C相比较,D组明显降低(P<0.05)。结论右美托咪定连续输注能够缓解小儿先天性心脏病CPB心内直视手术时的血流动力学及应激激素水平的变化,从而减轻心内直视手术和CPB的应激反应。     

右美托咪定对合并肺动脉高压患者二尖瓣置换术时血流动力学和心肌损伤的影响

目的 评价右美托咪定对合并肺动脉高压患者二尖瓣置换术时血流动力学和心肌损伤的影响.方法 择期行二尖瓣置换术的肺动脉高压患者40例,年龄18 ～64岁,性别不限,体重45～75 kg,ASA分级Ⅱ或Ⅲ级.采用随机数字表法,将其分为2组(n=20):对照组(C组)和右美托咪定组(D组).气管插管后D组经10 min静脉注射右美托咪定负荷量1μg/kg,随后以0.5 μg·kg-·h-1速率输注至术毕,C组输注等容量生理盐水.麻醉诱导后气管插管,机械通气,采用静吸复合麻醉,维持Narcotrend指数值40～50.分别于给予右美托眯定前即刻、停CPB后10 min、术毕、术后6、24h时采集中心静脉血样,测定血浆CK-MB和cTnI的水平.于右美托眯定给药前后、切皮时、劈胸骨时、CPB前后及手术结束时,采用Swan-Ganz导管及VigilanceⅡ血液动力学监测系统测定HR、MAP、肺动脉平均压(MPAP)、心排量(CO)、外周循环阻力(SVR)、肺循环阻力(PVR).记录术中血管活性药物应用情况和心脏自动复跳情况.结果 D组各血流动力学指标在切皮、劈胸骨手术刺激时维持稳定,CPB后MPAP下降并维持在较低水平.与C组比较,D组血浆CK-MB及cTnI水平、术中去氧肾上腺素用量、多巴胺用量及肾上腺素使用率降低(P＜0.05),米力农用量和心脏自动复跳率差异无统计学意义(P＞0.05).结论 合并肺动脉高压患者二尖瓣置换术中,静脉注射右美托咪定负荷量1 μg/kg,随后以0.5 μg·kg-·h-1速率输注右美托咪定,有助于维持体循环和肺循环的稳定,且产生一定程度的心肌保护作用.     

右美托咪啶对体外循环心内直视手术患者脑氧代谢和糖代谢的影响

目的 评价右美托咪啶对体外循环(CPB)心内直视手术患者脑氧代谢和糖代谢的影响.方法 择期行CPB二尖瓣置换术患者58例,性别不限,ASA分级Ⅱ或Ⅲ级,年龄32～64岁,体重52～90 kg,采用随机数字表法,将其随机分为2组(n=29):对照组(C组)和右美托咪啶组(D组).气管插管后D组静脉输注右美托咪啶0.5μg·kg-1·h-1至术毕,C组给予等容量生理盐水.分别于CPB开始前鼻咽温度为36℃时、CPB期间鼻咽温度降至30℃时、心脏复跳时以及心脏复跳30 min时采集桡动脉和颈内静脉球部血样,进行血气分析,测定血糖和乳酸浓度,计算动脉血氧含量、脑动脉-静脉血氧含量差、脑氧摄取率、脑动脉-静脉血糖含量差和脑动脉-静脉乳酸含量差.结果 与C组比较,D组CPB期间鼻咽温度降至30℃时脑动脉-静脉血氧含量差和脑氧摄取率降低(P＜0.05),动脉血氧含量和糖代谢指标差异无统计学意义(P＞0.05).结论 术中静脉输注右美托咪啶0.5 μg·kg-1 ·h-1可降低CPB心内直视手术患者脑氧代谢率,有助于维持脑氧供需平衡,而对脑糖代谢无明显影响.     

不同剂量异丙酚对浅低温体外循环心内直视手术病人脑静脉血浆S-100蛋白和NSE的影响

目的 探讨不同剂量异丙酚对浅低温体外循环(CPB)心内直视手术病人脑静脉血浆S-100蛋白和神经元特异性烯醇化酶(NSE)的影响.方法 择期心内直视手术病人32例,随机分为3组:低剂量异丙酚组(Ⅰ组,n=10)、高剂量异丙酚组(Ⅱ组,n=7)和咪达唑仑组(Ⅲ组,n=15).CPB开始时,Ⅰ组经5～10 min静脉注射异丙酚1 mg/kg,然后静脉输注3 mg·kg-1·h-1至CPB结束;Ⅱ组经5～10 min静脉注射异丙酚1 mg/kg,然后静脉输注6 mg·kg-1·h-1至CPB结束;Ⅲ组静脉输注咪达唑仑0.2 mg·kg-1·h-1至CPB结束.于CPB开始前(基础值,T0)、鼻咽温(NPT)降温至32℃(T1)、NPT复温至36℃(T2)、CPB结束后30 min(T3)、4 h(T4)和24 h(T5)时采集颈内静脉球部血,测定血浆S-100蛋白和NSE浓度.连续监测平均动脉压(MAP)和颈静脉球压(JBP),并计算脑灌注压(CPP=MAP-JBP).结果 与T0时比较,Ⅰ组T2～4时NSE浓度升高,Ⅱ组T1～4时升高,Ⅲ组T1～5时升高,3组T1～3,时S-100蛋白浓度均升高(P＜0.05);3组间各时点NSE和S-100蛋白浓度比较差异无统计学意义(P＞0.05).结论 异丙酚对浅低温体外循环心内直视手术病人脑静脉血浆S-100蛋白和NSE的释放无影响.     

心肺转流后鱼精蛋白经左房给药的可行性

目的 探讨心肺转流(CPB)后经左心房给鱼精蛋白的可行性.方法 36例心内直视手术患者按鱼精蛋白给药途径随机分为三组:A组中心静脉给药、B组左房给药、C组主动脉根部给药,每组12例.CPB结束后,三组以1.5倍肝素钠的量注射鱼精蛋白,给药速度1 mg·kg-1·min-1.记录鱼精蛋白给药前(T0)和给药后1 min(T1)、3 min(T2)、5 min(T3)、10 min(T4)的MAP、CVP、气道阻力(AWR),取右房血5 ml检测血栓素B2(TXB2,TXA2稳定代谢产物)和组胺的浓度,在T3时测活化全血凝固时间(ACT).结果 与T0时比较,T1～T3时A组MAP明显下降(P＜0.05或P＜0.01),且低于B、C组(P＜0.05或P＜0.01);T1～T3时A组CVP、AWR升高,且T2、T3时A组明显高于B、C组(P＜0.05);T1时A组TXB2和组胺浓度升高,且持续至T4(P＜0.05或P＜0.01);B、C组TXB2升高延迟(P＜0.05或P＜0.01),且相应时点升高的程度小于A组(P＜0.05或P＜0.01).结论 与经主动脉根部给药一样,经左房给鱼精蛋白也可以明显减轻其对血流动力学和肺通气的影响.     

双心房输注对二尖瓣置换术患者体外循环后肺动脉压的影响

目的 评价双心房输注对二尖瓣置换术患者体外循环后肺动脉压(PAP)的影响.方法 择期行二尖瓣置换术合并肺动脉高压[平均肺动脉压(MPAP)＞50 mm Hg]的患者20例,年龄22～53岁,体重34～57kg,心功能分级Ⅱ或Ⅲ级,随机分为2组(n=10):右心房输注组(R组)和双心房输注组(B组).麻醉诱导后右颈内静脉穿刺置入Swan-Ganz三腔漂浮导管,监测CVP、PAP、肺毛细血管楔压(PCWP)和CO.R组经中心静脉输注前列腺素E130～150 ng·kg-1·min-1和去氧肾上腺素0.2～0.6μg·kg-1·min-1.B组经中心静脉输注前列腺素E130～150 ng·kg·min-1,经左心房输注去氧肾上腺素0.2～0.6μg·kg-1·min-1.分别于给药前5 min(T0)、给药后5 min(T1)、10 min(T2)、30 min(T3)和60 min(T4)时记录MAP、HR、MPAP、PCWP、CVP和CO,计算肺血管阻力指数(PVRI)、体循环血管阻力指数(SVRI)和CI.结果 与T0时比较,R组T1-4时MAP、MPAP、PCWP和PVRI降低,CI升高(P＜0.05),HR、CVP和SVRI差异无统计学意义(P＞0.05),B组T1-4时MAP、CI和SVRI升高,HR、MPAP、PCWP、CVP和PVRI降低(P＜0.05);与R组比较,B组MAP、CI和SVRI升高,HR、MPAP、PCWP、PVRI和CVP降低(P＜0.05).结论 双心房输注可降低二尖瓣置换术患者体外循环后肺动脉压和肺血管阻力.     

地尔硫䓬对心肺转流下冠状动脉旁路移植术患者左心室功能的影响

目的探究小剂量地尔硫在心肺转流(CPB)下冠状动脉旁路移植术(CABG)术中应用是否产生抗动脉痉挛作用及左心室负性肌力作用。方法选择择期行CPB下CABG患者43例,男27例,女16例,年龄45~79岁,BMI 18~30 kg/m²,ASAⅡ或Ⅲ级,NYHAⅡ或Ⅲ级,术前左心室射血分数(LVEF)≥45%。随机分为两组:地尔硫组(D组)和对照组(C组),术中均采用全凭静脉麻醉。在置入经食管超声心动图(TEE)探头后,D组静脉输注地尔硫0.5μg·kg^-1·min^-1,C组给予生理盐水,均连续静脉输注至手术结束。在置入TEE探头即刻(T 0)、置入TEE探头后30 min(T₁)、CPB断流20 min(T₂)、50 min(T₃)采用TEE探头采集心脏超声图像,通过斑点追踪技术(STI)离线处理图像,分析并记录左心室功能STI指标:整体纵向应变力(GLS)、整体环向应变力(GCS)、整体纵向达峰时间标准差(GLTSD)、整体环向达峰时间标准差(GCTSD);同时记录传统心功能指标:CI及LVEF;记录左侧乳内动脉桥(LIMA)血流及术后房颤(POAF)发生率、呼吸支持时间、ICU停留时间及总住院时间等术后恢复指标。结果两组不同时点左心室收缩功能及运动同步化指标GLS、GCS、GLTSD、GCTSD差异无统计学意义;两组CI、LVEF差异无统计学意义。D组LIMA血流量高于C组(P<0.05);D组术后6 h cTnI浓度明显低于C组(P<0.05),两组POAF发生率、呼吸支持时间、ICU停留时间及总住院时间差异无统计学意义。结论小剂量地尔硫在CABG术中应用可增加动脉桥血管血流量,同时不产生左心室负性肌力作用。     

多巴胺复合去甲肾上腺素对内毒素休克犬肾脏的影响

目的了解内毒素休克时低剂量去甲肾上腺素和多巴胺对肾血流量和肾功能的影响.方法21只犬(14-30kg)戊巴比妥钠麻醉,静脉注射内毒素2mg/kg,1h后将犬分成3组,Ⅰ组静滴去甲肾上腺素40ng.kg-1@min-1,Ⅱ组静滴多巴胺4μg.kg-1@min-1,Ⅲ组静滴去甲肾上腺素和多巴胺(剂量同上),给药1h停药并再观察2h.观察血流动力学(MAP、HR、CVP、PCWPCOSVISVR、)、肾血流量(电磁流量计)和肾功能(血清Na+、K+、肌酐、尿素氮、尿酸).结果休克后MAP显著下降(P＜0.01),CO明显减少(P＜0.01),肾血流量减少(P＜0.05),肾功能无显著改变.给予多巴胺、去甲肾上腺素和两药合用后MAP、SVI和CO增加,肾血流量无显著改变,肾功能基本无变化,仅给去甲肾上腺素2h及3h后尿素氮增加(P＜0.05),血肌酐显著增加(P＜0.01).结论低剂量去甲肾上腺素,特别是与多巴胺合用后能改善血流动力学,维持肾血流量,对肾功能无显著影响.     

右美托咪定对冠状动脉旁路移植术患者左心室内同步化的影响

目的 评价右美托咪定(dexmedetomidine,Dex)对CPB冠状动脉旁路移植术(coronary artery bypass grafting,CABG)患者左心室内同步化的影响. 方法 择期CPB下行CABG患者21例,年龄45～74岁,身高151～176 cm,体重52～85 kg,ASA分级Ⅱ、Ⅲ级,纽约心脏病协会(New York Heart Association,NYHA)分级2级或3级.采用随机数字表法分为两组:实验组(D组,10例),对照组(C组,11例).D组在停CPB 15 min后泵注0.5 μg/kg Dex,10 min输注完,继以0.5 μg·Kg-1·h-1维持至术毕;C组以相同速率静脉泵注等容量生理盐水.于锯胸骨前(To)、停止CPB后15 min泵注Dex前(T1)、泵注Dex 30 min(T2)、泵注Dex 1 h(T3)时分别记录MAP、HR、CVP、肺动脉阻塞压(pulmonary artery occlusion pressure,PAOP)和经食管超声心动图(transesophageal echocardiography,TEE)监测指标:左室射血分数(left ventricular ejection fraction,LVEF)、心排血量(cardiacoutput,CO)、每搏量(stroke volume,SV)、左室17节段整体纵向应变收缩期达峰时间的标准差(standard deviation of time tomaximum systolic velocity of the 17 left ventricular segments of longitudinal strain,Tssl-17-SD)、左室16节段环向应变收缩期达峰时间的标准差(standard deviation of time to maximum systolic velocity of the 16 left ventricular segments of circumferential strain,Tssc-1 6-SD). 结果 D组HR在T2[(71.0±5.4)次/min]、T3[(69.3±2.8)次/min]时较C组[(89.5±14.7)、(89.4±14.0)次/min]低(P＜0.05);D组CO在T2[(4.4±1.2) L/min]时低于C组[(5.8±1.5) L/min] (P＜0.05).D组Tssl-17-SD在T2时较C组明显升高(P＜0.01). 结论 CPB后泵注Dex早期能抑制CABG患者左心室心肌纵向的同步化运动.     

Blood flow velocity in the ophthalmic artery measured by doppler ultrasonography during cardiopulmonary bypass —Usefullness for cerebral perfusion monitor—

Brain blood flow is supplied from the internal carotid artery, and the ophthalmic artery is the first branch of the internal carotid artery. We studied how blood flow velocity in the ophthalmic artery (OAV) changes during cardiopulmonary bypass (CPB) and investigated whether it can be used to monitor brain blood flow during CPB. In 13 open heart surgeries in adaults, OAV and blood flow velocity in the common carotid artery (CAV) were measured with Doppler ultrasonography, and blood flow volume in the brachiocephalic artery (BA flow) was measured simultaneously with an electromagnetic flow meter. Maximal blood flow velocity in the ophthalmic artery (OAVmax) and the common carotid artery (CAVmax) were 0.27±0.13 m/ sec and 0.64 ± 0.40 m/sec, BA flow was 486 ± 226 ml/min before CPB. When CPB pump flow was varied (2.4, 2.2, 2.0, 2.2, 2.4 l/min/m²), the parameters during and after CPB changed as follows (as percentage of pre-CPB levels): OAVmax, 58.1%, 50.9%, 37.6%, 49.4%, 64.7%, 108.4%; CAVmax, 67.0%, 58.0%, 48.2%, 113.6%, 105.5%, 134.3%; and BAflow, 87.3%, 39.8%, 53.9%, 50.5%, 95.0%, 159.8%. Our results indicate that OAVmax more accurately reflects changes in pump flow than does CAVmax and BA flow. Because vessel resistance in the ophthalmic artery was small during CPB, OAVmax was thought to be determined mainly by CPB pump flow. OAVmax was useful for monitoring brain blood flow during CPB.     

控制性低中心静脉压对兔肝缺血再灌注损伤的影响

目的 评价控制性低CVP对兔肝缺血再灌注损伤的影响.方法 新西兰大白兔32只,随机分为4组(n=8):假手术组(S组)、控制性低CVP组(L组)、肝缺血再灌注组(IR组)和控制性低CVP下肝缺血再灌注组(LIR组).L组静脉输注硝酸甘油10～30μg·kg~(-1)·min~(-1)和多巴胺30～40μg·kg~(-1)·min~(-1),在5 min内使CVP降至4～5 cm H_2O且维持MAP≥90 mm Hg,持续至再灌注6 h.IR组采用夹闭肝门30 min后再开放的方法建立肝缺血再灌注模型.LIR组在控制性低CVP模型制备成功后立即进行肝缺血再灌注.分别于实施控制性低CVP前(T_0,基础状态)、再灌注即刻(T_1)、30 min(T_2)、1 h(T_3)、2 h(T_4)、4 h(T_5)、6 h(T_6)时采用彩色超声多普勒诊断仪测定门静脉、肝动脉和肝静脉的血流速度,同时采集动脉血样,测定血浆AST和ALT的活性.于再灌注6 h时,取肝组织,电镜下观察细胞超微结构.结果 与S组比较,L组各时点门静脉、肝动脉、肝静脉的血流速度、血浆AST和ALT的活性差异无统计学意义(P＞0.05),IR组T_(1～5)时肝动脉血流速度减慢,T_(5,6)时肝静脉血流速度增快,血浆AST和ALT的活性升高,LIR组T_(1～6)时肝静脉血流速度度增快,T_(1～6)时血浆AST和ALT的活性升高(P＜0.05);与IR组比较,LIR组T_(1,2)时肝动脉血流速度增快,T_1～6时肝静脉血流速度增快,T_(1,4～6)时血浆ALT和AST的活性降低(P＜0.05).与IR组比较,LIR组肝细胞线粒体及窦周间隙面微绒毛的肿胀程度减轻,肝血寞窦壁覆盖完整.结论 控制性低CVP可减轻兔肝缺血再灌注损伤,其机制可能与增加再灌注期间肝血流量,减轻肝细胞及肝血窦损伤,从而改善肝灌注有关.     

右美托咪啶对非体外循环冠状动脉旁路移植术患者心肌损伤的影响

目的 评价右美托咪啶对非体外循环冠状动脉旁路移植术患者心肌损伤的影响.方法 择期非体外循环冠状动脉旁路移植术患者46例,性别不限,ASA分级Ⅱ或Ⅲ级,年龄37～64岁,采用随机数字表法,将其随机分为2组(n=23),两组麻醉诱导及麻醉维持方法相同.右美托眯啶组(D组)于麻醉诱导后持续静脉输注右美托咪啶0.5 μg·kg-1∶h-1至术毕,对照组(C组)给予等容量生理盐水.分别于手术开始、血管吻合完毕、血管吻合完毕后30 min和术毕时记录平均肺动脉压、肺毛细血管楔压;中心静脉压和心输出量,计算每搏指数、左室每搏功指数、右室每搏功指数、周围血管阻力和肺血管阻力.分别于麻醉诱导前、术毕、术后4 h和术后24 h时采集静脉血样,采用ELISA法测定血浆心肌肌钙蛋白Ⅰ浓度.结果 与C组比较,D组术毕时每搏指数和左室每搏功指数升高,血管吻合完毕后30 min和术毕时周围血管阻力降低,术后24 h时血浆cTnI浓度降低(P＜0.05);其余血液动力学指标组间差异无统计学意义(P＞0.05).结论 术中静脉输注右美托咪啶0.5 μg·kg-1·h-1可减轻非体外循环冠状动脉旁路移植术患者心肌损伤.

Abstract：

Objective To evaluate the cardioprotective effect of dexmedetomidine in patients undergoing off-pump coronary artery bypass grafting. Methods Forty-six ASA Ⅱ or Ⅲ patients aged 37-64 yr weighing 54-81 kg undergoing off-pump coronary artery bypass grafting were randomized into 2 groups ( n = 23 each): control group (group C) and dexmedetomidine group (group D) . Dexmedetomidine was infused at 0.5 μg·kg-1·h-1 starting after induction of anesthesia until the end of operation in group D. Radial artery was cannulated and Swan-Ganz catheter placed via right internal jugular vein. HR, MAP, mean pulmonary arterial pressure, pulmonary capilary wedge pressure, central venous pressure, and cardiac output were recorded and stroke volume index, left and right ventricular stroke work index, systemic vascular resistance and pulmonary vascular resistance were calculated at the beginning of operation (T1 ), immediately (T2 ) and at 30 min after reestablishment of coronary blood flow (T3 ) and the end of operation (T4 ) . Venous blood samples were taken before induction of anesthesia (T0 , baseline) , at T4 and 4 h (T5 ) and 24 h (T6 ) after operation for determination of plasma concentration of cardiac troponin I by ELISA. Results Stroke volume index and left ventricular stroke work index were significantly higher at T4 while systemic vascular resistance was lower at T34 in group D than in group C. Plasma cardiac troponin Ⅰ concentration was significantly lower at T6 in group D than in group C. Conclusion Dexmedetomidine infusion at 0.5 μg ·kg-1·h-1 during operation can protect myocardium in patients undergoing off-pump coronary artery bypass grafting.     

不同年龄患者腹腔镜胆囊切除术中肾血流量变化的比较

目的 比较不同年龄患者腹腔镜胆囊切除术中肾血流量的变化.方法 择期行腹腔镜胆囊切除术患者60例,年龄18～75岁,ASA分级Ⅰ或Ⅱ级,性别不限,体重48～78 kg,根据年龄分为2组(n=30):中青年组(18～60岁)和老年组(61 ～ 75岁).经口气管插管后置入食管超声探头,分别于气腹前、气腹1、5、10、15、20、30 min、气腹结束后1和5 min时,采用经食管超声心动图测量左肾动脉主干内径(RAD)和血流速度时间积分(VTI),计算左肾血流量(LRAF),记录最大下降时间点,计算最大下降百分比.结果 与气腹前比较,两组气腹各时点和气腹结束后1 min时RAD、VTI和LRAF降低(P＜0.05).与中青年组比较,老年组气腹前LRAF降低,最大下降时间点延迟(P＜0.05),最大下降百分比差异无统计学意义(P＞0.05).结论 中青年患者和老年患者腹腔镜胆囊手术中肾血流量均发生可逆性下降;老年患者最大下降时间延迟.     

Pharmacokinetics of epsilon-aminocaproic acid in patients undergoing aortocoronary bypass surgery.

BACKGROUND: Epsilon-aminocaproic acid (EACA) is commonly infused during cardiac surgery using empiric dosing schemes. The authors developed a pharmacokinetic model for EACA elimination in surgical patients, tested whether adjustments for cardiopulmonary bypass (CPB) would improve the model, and then used the model to develop an EACA dosing schedule that would yield nearly constant EACA blood concentrations. METHODS: Consenting patients undergoing elective coronary artery surgery received one of two loading doses of EACA, 30 mg/kg (group I, n = 7) or 100 mg/kg (group II, n = 6) after CPB, or (group III) a 100 mg/kg loading dose before CPB and a 10 mg x kg(-1) x h(-1) maintenance infusion continued for 4 h during and after CPB (n = 7). Two patients with renal failure received EACA in the manner of group III. Blood concentrations of EACA, measured by high-performance liquid chromatography, were subjected to mixed-effects pharmacokinetic modeling. RESULTS: The EACA concentration data were best fit by a model with two compartments and corrections for CPB. The elimination rate constant k10 fell from 0.011 before CPB to 0.0006 during CPB, returning to 0.011 after CPB. V1 increased 3.8 l with CPB and remained at that value thereafter. Cl1 varied from 0.08 l/min before CPB to 0.007 l/min during CPB and 0.13 l/min after CPB. Cl2 increased from 0.09 l/min before CPB to 0.14 l/min during and after CPB. Two patients with renal failure demonstrated markedly reduced clearance. Using their model, the authors predict that an EACA loading infusion of 50 mg/kg given over 20 min and a maintenance infusion of 25 mg x kg(-1) x h(-1) would maintain a nearly constant target concentration of 260 microg/ml. CONCLUSIONS: EACA clearance declines and volume of distribution increases during CPB. The authors' model predicts that more stable perioperative EACA concentrations would be obtained with a smaller loading dose (50 mg/kg given over 20 min) and a more rapid maintenance infusion (25 mg x kg(-1) x h(-1)) than are typically employed.     

右美托咪定对心内直视手术患者炎性反应和胰岛素抵抗的影响

目的观察右美托咪定对心内直视手术患者炎性反应和胰岛素抵抗的影响。方法择期在心肺转流(CPB)下行心脏瓣膜置换术的患者50例,随机均分为观察组和对照组。观察组麻醉诱导后静注右美托咪定负荷量1.0μg/kg(给药时间15min),随后泵注0.4μg·kg-1·h-1至CPB结束;对照组静注等容量生理盐水。于麻醉诱导后切皮前(T1)、CPB开始后30 min(T2)、停CPB(T3)、CPB结束后2h(T4)采集静脉血检测血清TNF-α、IL-6、胰岛素及血糖水平,计算胰岛素敏感指数(ISI)=1/(血糖×胰岛素)。结果与T1时比较,T2~T4时两组TNF-α、IL-6、胰岛素、血糖明显升高,ISI明显降低(P0.05)。与对照组比较,观察组T2~T4时TNF-α和IL-6,T2、T3时胰岛素和血糖均明显降低(P0.05),而T2、T3时ISI明显升高(P0.05)。两组患者均未出现低血压和心动过缓等不良反应。结论右美托咪定可明显减少CPB下心内直视手术患者炎性反应,降低术中血糖,改善胰岛素抵抗。     

Pharmacokinetics of [Greek small letter epsilon]-aminocaproic Acid in Patients Undergoing Aortocoronary Bypass Surgery

Background: [Greek small letter epsilon]-Aminocaproic acid (EACA) is commonly infused during cardiac surgery using empiric dosing schemes. The authors developed a pharmacokinetic model for EACA elimination in surgical patients, tested whether adjustments for cardiopulmonary bypass (CPB) would improve the model, and then used the model to develop an EACA dosing schedule that would yield nearly constant EACA blood concentrations.

Methods: Consenting patients undergoing elective coronary artery surgery received one of two loading doses of EACA, 30 mg/kg (group I, n = 7) or 100 mg/kg (group II, n = 6) after CPB, or (group III) a 100 mg/kg loading dose before CPB and a 10 mg [middle dot] kg-1 [middle dot] h-1 maintenance infusion continued for 4 h during and after CPB (n = 7). Two patients with renal failure received EACA in the manner of group III. Blood concentrations of EACA, measured by high-performance liquid chromatography, were subjected to mixed-effects pharmacokinetic modeling.

Results: The EACA concentration data were best fit by a model with two compartments and corrections for CPB. The elimination rate constant k10 fell from 0.011 before CPB to 0.0006 during CPB, returning to 0.011 after CPB. V1 increased 3.8 l with CPB and remained at that value thereafter. Cl1 varied from 0.08 l/min before CPB to 0.007 l/min during CPB and 0.13 l/min after CPB. Cl2 increased from 0.09 l/min before CPB to 0.14 l/min during and after CPB. Two patients with renal failure demonstrated markedly reduced clearance. Using their model, the authors predict that an EACA loading infusion of 50 mg/kg given over 20 min and a maintenance infusion of 25 mg [middle dot] kg-1 [middle dot] h-1 would maintain a nearly constant target concentration of 260 [micro sign]g/ml.