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1.
目的 了解二氮嗪预处理对未成熟兔心脏有无保护作用,并探讨其机制。方法 大耳白幼兔(小于28 d)21只随机分成三组:对照组(Ⅰ组n=8):K-H缓冲液灌注30 min后St.ThomasⅡ号停跳液(STH)停跳;二氮嗪预处理组(Ⅱ组n=8):二氮嗪(100μmol/L)灌注5 min,再K-H液灌注10min后STH停跳;二氮嗪+5-HD组(Ⅲ组n=5):二氮嗪和5-HD(均100μmol/L)共同灌注5 min后停跳。在LangendOrff模型上进行离体心脏常温缺血/再灌注(I/R)实验。观察再灌后血液动力学恢复、冠脉流出液心肌酶、心肌组织内ATP含量及心肌超微结构变化。结果 再灌后Ⅱ组左室发展压(LVDP)、左室压力上升和下降最大速率(±dp/dtmax)的恢复率在多个时间点上均高于Ⅰ组,再灌末心肌组织ATP含量也高于Ⅰ组(P<0.01),冠脉流出液中的三种心肌酶值均较Ⅰ组降低(P<0.01)。Ⅱ组的线粒体评分低于Ⅰ组(P<0.01),Ⅲ组线粒体评分回到Ⅰ组水平(P>0.05)。结论 二氮嗪能通过开放线粒体ATP敏感性通道而发挥对幼兔心肌的保护作用。  相似文献   

2.
目的 探讨二氮嗪预处理对大鼠离体心脏缺血再灌注时心肌线粒体通透性转换孔(PTP)的影响.方法 健康SD大鼠72只,体重250~300 g,雌雄不拘,随机分为4组(n=18),建立离体心脏Langendorf再灌注模型,K-H液平衡灌注20 min后,对照组(C组)持续灌注K-H液100 min不停搏;缺血再灌注组(IR组)持续灌注K-H液30 min;二氮嗪预处理组(D组)依次灌注K-H液15 min、二氮嗪50 μmol/L 10 min和K-H液5 min;5-羟葵酸组(5-HD组)依次灌注5-HD 100 μmol/L 10 min、K-H液5min、二氮嗪50 μmol/L 10 min和K-H液5 min.除C组外其余组于平衡后30 min灌注4℃ St.Thomas停搏液,全心停搏40 min,再灌注30 min.各组于平衡末、缺血前即刻及再灌注末随机取6个心脏测定心肌线粒体PTP半开放时间(T1/2)和线粒体膜电位.结果 与平衡末、缺血前即刻相比,各组再灌注末心肌线粒体PTP T1/2缩短,膜电位降低(P《<0.05或0.01);与C组比较,其余组心肌线粒体PTP T1/2缩短,膜电位降低(P<0.01);与IR组比较,D组心肌线粒体PTP T1/2延长,膜电位升高(P<0.01),5-HD组差异无统计学意义(P>0.05);与D组比较,5-HD组心肌线粒体PTP T1/2缩短,膜电位降低(P<0.05).结论 二氮嗪50 μmol/L预处理可减少大鼠离体心脏缺血再灌注时心肌线粒体PTP开放,减少线粒体膜电位的丢失,维持心肌线粒体膜的完整性.  相似文献   

3.
目的 评价线粒体心磷脂在二氮嗪预处理减轻大鼠离体心脏缺血再灌注损伤中的作用.方法 清洁级SD大鼠72只,体重200~280 g,雌雄各半,随机分为对照组(C组)、缺血再灌注组(I/R组)、二氮嗪预处理组(DZ组)和5-羟葵酸拮抗二氮嗪组(HD组),每组18只.采用Langendorff灌流装置建立大鼠离体心脏缺血再灌注模型,C组平衡灌注20 min,持续灌注100 min;I/R组平衡灌注20 min,持续灌注30 min,缺血40 min,再灌注30 min;DZ组平衡灌注20 min后,依次灌注K-H液15 min、50 μmol/L二氮嗪10 min和K-H液5 min,其余缺血再灌注同I/R组;HD组二氮嗪预处理前给予含5-羟葵酸100 μmol/L K-H液10 min,其余处理同DZ组.各组分别于平衡灌注末(T1)、缺血前即刻(T2)、再灌注末(T3)时随机取6只大鼠,监测心率(HR)、左心室发展压(LVDP)和左心室舒张末压(LVEDP),采用高效液相色谱仪测定心肌线粒体心磷脂含量.结果 与T1,2时比较,各组T3时HR、LVDP降低,LVEDP升高,心肌线粒体心磷脂含量降低(P<0.05);与C组比较,其余3组T3时HR、LVDP降低,LVEDP升高,心肌线粒体心磷脂含量降低(P<0.05);与I/R组比较,DZ组T3时HR、LVDP升高,LVEDP降低,心肌线粒体心磷脂含量升高(P<0.05);与DZ组比较,HD组T3时HR、LVDP降低,LVEDP升高,心肌线粒体心磷脂含量降低(P<0.05).结论 二氮嗪预处理可减轻大鼠离体心脏缺血再灌注损伤,与维持心肌线粒体心磷脂含量有关.  相似文献   

4.
线粒体ATP敏感性钾通道对缺血性脑损伤的保护作用   总被引:2,自引:1,他引:1  
目的 应用线粒体ATP敏感性钾通道 (mitoKATP)特异性的开放剂二氮嗪和阻断剂5 HD观察mitoKATP对缺血性脑损伤的影响。方法 成年健康雄性SD大鼠 32只 ,随机分成四组 :假手术组 (n =8) ,行大脑中动脉栓塞 (MCAO)的手术操作 ,但不插线 ;脑缺血组 (n =8) ,MCAO前给予同等量生理盐水 ;二氮嗪组 (n =8) ,MCAO前 30min二氮嗪 5mg/kg腹腔注射 ;5 HD复合二氮嗪组 (n =8) ,5 HD 10mg/kg静脉注射 ,15min后二氮嗪 5 0mg/kg腹腔注射 ,30min后再行MCAO。各组MCAO 2h再灌注 2 4h后 ,应用Garcia评分法观察大鼠神经精神系统表现 ,大脑切片并行TTC染色 ,计算大脑梗死容积以及透射电镜观察线粒体超微结构的变化。结果 应用二氮嗪后 ,相对脑缺血组大鼠的神经功能评分显著提高 (P <0 0 1) ,大脑梗死容积明显减小 (P <0 0 1)。电镜下见脑缺血组线粒体肿胀混浊 ,呈空泡化 ,内嵴断裂 ,膜破损 ;二氮嗪组线粒体仅有轻度肿胀 ,基本结构完好 ,内膜间隙清晰。 5 HD复合二氮嗪组表现与脑缺血组近似 ,二氮嗪的保护作用被取消。结论 mitoKATP的开放可以对缺血性脑损伤产生保护作用。  相似文献   

5.
缺血预处理对肢体缺血再灌注损伤的影响   总被引:1,自引:0,他引:1  
目的 观察缺血预处理 (IPC)对肢体缺血再灌注损伤的影响。方法 选择 2 0例需充气止血带止血进行手术的患者 ,随机分为对照组 (n =10 )和IPC组 (n =10 )。IPC组患者术前应用 3次 5min循环缺血 ,间隔 5min再灌注预处理后在止血带下进行手术 ;对照组直接在止血带下进行手术。在肢体缺血前和再灌注 30min、90min、180min分别取静脉血检测血清肌酸磷酸激酶 (CPK)、谷草转氨酶(AST)、乳酸脱氢酶 (LDH)、丙二醛 (MDA)和过氧化物歧化酶 (SOD)水平。结果 随着肢体缺血再灌注时间的延长 ,血中CPK、AST、LDH、MDA含量逐渐升高 ,而SOD活性逐渐降低。IPC组在缺血前及再灌注同时间 ,血中CPK、AST、LDH、MDA含量低于对照组 (P <0 0 5 ,P <0 0 1) ;而SOD活性高于对照组 (P <0 0 5 ,P <0 0 1)。结论 IPC能有效地减轻肢体缺血再灌注损伤程度 ,减轻脂质过氧化反应 ,提高肢体缺血耐受性  相似文献   

6.
目的 评价二氮嗪后处理对大鼠离体心脏缺血再灌注损伤的影响.方法 雄性SD大鼠,体重250~300 g,成功建立Langendorff再灌注模型的64个心脏随机分为4组(n=16):正常对照组(C组)、缺血再灌注组(I/R组)、二氮嗪后处理组(D组)和线粒体ATP敏感性钾通道阻断剂5-羟葵酸+二氮嗪后处理组(5-HD+D组).采用K-H液平衡灌注20 min时,C组继续灌注K-H液70 min;I/R组、D组和5-HD+D组进行心肌缺血40 min,I/R组缺血前灌注4 ℃ ST.Thomas停跳液10 ml/kg;D组再灌注5 min时灌注含50μmol/L二氮嗪的K-H液5 min,然后再灌注20 min;5-HD+D组灌注二氮嗪前灌注含100 μmol/L 5-羟葵酸的K-H液5 min,再灌注20 min.分别于平衡灌注末与再灌注末时取8个心脏,记录心功能指标,然后提取线粒体,测定心肌细胞线粒体膜电位(MMP)、氧自由基(ROS)生成量和呼吸功能指标.结果 各组平衡灌注末时各指标差异无统计学意义(P>0.05).与C组比较,再灌注末时其余3组心功能和线粒体呼吸功能减退,MMP降低,ROS生成量增加(P<0.05或0.01);与I/R组和5-HD+D组比较,D组心功能和线粒体呼吸功能改善,MMP升高,ROS水平降低(P<0.01).结论二氮嗪后处理可减轻大鼠心肌缺血再灌注损伤,其机制与开放线粒体ATP敏感性钾通道而改善线粒体功能有关.  相似文献   

7.
目的研究缺血预处理(IP)对大鼠离体心脏缺血再灌注损伤的保护作用机制。方法 Wistar大鼠48只,其中40只随机分为缺血再灌注组(I/R组)、IP组、二氮嗪组(DZ组)、5-羟葵酸(选择性线粒体ATP敏感性钾通道阻滞剂)拮抗IP组(5-HD IP组)、5-羟葵酸拮抗二氮嗪组(5-HD DZ 组),每组8只,另外8只用作正常心肌线粒体电镜检查对照组。应用Langendorff离体心脏灌注系统建立心脏缺血再灌注模型,平衡灌注20 min后,30 min预处理期间各组进行以下处理,IP组进行2次缺血再灌注,灌注压8.5 kPa,灌注速率8.5 ml/min。每次IP缺血5 min再灌注5 min;DZ组灌注50 μmol ·L-1二氮嗪;5-HD IP组灌注100 μmol·L-1 5-羟葵酸10 min,然后给予2次IP;5-HD DZ组灌注5-羟葵酸100μmol-L-1 10min,再灌注二氮嗪50μmol·L-1 10min。然后各组全心缺血40min,再灌注30min。持续测定心功能指标[心率、左心室发展压(INDP)、左心室舒张末压(INEDP)和冠脉流量(CF)],再灌注末取心肌,提取线粒体,电镜下观察其病理学改变,并进行线粒体Flameng评分。结果与I/R组比较,IP和二氮嗪预处理能明显提高再灌注期间LVDP,降低LVEDP,降低心肌线粒体Flameng评分(P< 0.01),减轻心肌病理学损伤;5-羟葵酸能部分拮抗IP、完全拮抗二氮嗪预处理对心肌缺血再灌注损伤的保护作用。结论 IP对心肌缺血再灌注损伤的保护作用与线粒体ATP敏感性钾通道的激活有关。  相似文献   

8.
目的研究缺血预处理(IPC)对大鼠离体心脏心肌线粒体功能的影响。方法SD大鼠72只,随机分为4组(n=18):对照组(CON组)、缺血再灌注组(IR组)、缺血预处理组(IPC组)和5-羟葵酸(5-HD)拮抗IPC组(5-HD+IPC组)。采用Langendorff装置建立大鼠离体心脏缺血再灌注模型,IPC组在全心停灌前,给予2次缺血预处理,每次缺血5min,间隔5min;5-HD+IPC组预处理前灌注5-HD 10min。各组于平衡末、缺血前、再灌注30min各取6个心脏,分离心肌线粒体并测定线粒体呼吸控制率(RCR)、磷氧比(ADP/O2)、NADH氧化酶(NADH-OX)、琥珀酸氧化酶(SUC-OX)、细胞色素C氧化酶(CYTC-OX)的活性。结果与CON组比较,IR组、IPC组和5-HD+IPC组再灌注30min RCR、ADP/O2、NADH-OX、SUC-OX和CYTC+OX的活性降低(P〈0.05);与IR组比较,IPC组和5-HD+IPC组再灌注30min上述各指标升高(P〈0.05);与IPC组比较,5-HD+IPC组再灌注30min上述各指标降低(P〈0.05)。结论缺血预处理可改善大鼠离体心脏缺血再灌注时心肌线粒体的功能,其机制与mitoKATP的激活有关。  相似文献   

9.
目的 评价c-Jun氨基末端激酶(JNK)在瑞芬太尼预处理(RPC)减轻大鼠心肌缺血再灌注损伤中的作用.方法 成年雄性SD大鼠126只,体重300-350 g,随机分为5组:缺血再灌注组(I/R组)(n=38)、缺血预处理组(IPC组)(m=38)、RPC组(n=38)、SP+IPC组(n=6)和SP+RPC组(n=6).采用结扎左冠状动脉30 min再灌注120 min的方法制备心肌缺血再灌注模型.IPC组在缺血前30min行IPC:缺血5 min,再灌注5 min,重复3次;RPC组在缺血前30 min 行RPC:静脉输注瑞芬太尼6 ug·kg-1·min-1 5 min,停止5 min,重复3次;SP+RPC组和SP+IPC组分别于RPC或IPC前5 min腹腔注射JNK选择性阻滞剂SP600125 6 mg/kg.I/R组、IPC组和RPC组于缺血前即刻、缺血5.30 min和再灌注5、30、60 min时随机处死5只大鼠,测定左心室磷酸化JNK(p-JNK)的表达.于再灌注末处死其余大鼠,取心肌,计算左心室(LV)与右心室(RV)体积之和(LV+RV)、梗死区(IS)面积占缺血危险区(AAR)面积的百分比(IS/AAR).结果 与I/R组相比,IPC组和RPC组IS/AAR降低(P<0.01),SP+PRC组和SP+IPC组IS/AAR差异无统计学意义(P>0.05);缺血前即刻IPC组心肌p-JNK表达增加,缺血5min时RPC组和IPC组心肌p-JNK表达均降低,再灌注期间RPC组和IPC组心肌p-JNK表达均增加(P<0.01).结论 JNK参与了瑞芬太尼预处理减轻大鼠心肌缺血再灌注损伤.  相似文献   

10.
Liang L  Li S  Huang J 《中华外科杂志》2002,40(4):265-267
目的 探讨缺血预处理 (IPC)对肝硬化肝癌患者入肝血流阻断肝切除的保护作用及其机理。 方法 将近期手术切除的 2 9例原发性肝癌 (HCC)随机分为 2组 :IPC组 (n =14 ) :肝门阻断切肝前先给予缺血 5min ,灌注 5min的缺血预处理 ;对照组 (n =15 ) :单纯肝门阻断切肝。比较 2组术前后肝功能的变化和肝灌注 1h时肝组织caspase 3活性和细胞凋亡的情况。 结果 术后 1、3、7d ,IPC组的天门冬氨酸氨基转移酶 (AST)、丙氨酸氨基转移酶 (ALT)明显低于对照组 (t =4 2 38,P <0 0 5 ) ;术后 3、7d ,IPC组的总胆红素 (TBIL)明显低于对照组 (t=2 2 96 ,P <0 0 5 ) ;术后 1d ,IPC组的ALB高于对照组 ,但无统计学差异 (t=2 0 2 9,P >0 0 5 )。术后 1h ,IPC组肝组织caspase 3活性和凋亡的内皮细胞均明显低于对照组 (t=2 349,P <0 0 5 )。 结论 IPC对肝硬化肝癌患者入肝血流阻断肝切除术后肝功能有良好的保护作用 ,其保护机理是通过抑制caspase 3的活性 ,从而抑制肝窦内皮细胞来实现的。  相似文献   

11.
Background : We investigated the vasopressor hormone response following mesenteric traction (MT) with hypotension due to prostacyclin (PGI2) release in patients undergoing abdominal surgery with a combined general and epidural anesthesia. Methods : In a prospective, randomized, placebo-controlled study we administered 400 mg ibuprofen (i.v.) in 42 patients scheduled for abdominal surgery. General anesthesia was combined with epidural anesthesia (T4-L1). Before as well as 5, 15, 30, 45, and 90 min after MT we recorded plasma osmolality, hemodynamics and measured 6-keto-PGFlα (stabile metabolite of PGI2), TXB2 (stabile metabolite of thromboxane A2) active renin, and arginine vasopressin (AVP) plasma concentrations by radioimmunoassay. Catecholamine levels were assessed by high-pressure liquid chromatography (HPLC) with electrochemical detection. Results : Following MT, arterial hypotension occurred along with a substantial PGI2 release. This was completely abolished by ibuprofen administration. Although plasma levels of 6-keto-PGF (1133 (708) vs. 60 (3) ng/L, median (median absolute deviation), P=0.0001, placebo vs. ibuprofen) remained significantly elevated, blood pressure was restored within 30 min after MT in the placebo group. At the same point in time plasma concentrations of TXB2 (164 (87) vs. 58 (1) ng/L, P=0.0001), epinephrine (46 (33) vs. 14 (6) ng/L, P=0.001), AVP (41 ± (18) vs. 12 (7) ng/L, P=0.0004), and active renin (27 (12) vs. 12 (4) ng/L, P = 0.001) were significantly higher in placebo-treated patients. Conclusion : Under combined general and epidural anesthesia arterial hypotension following MT due to endogenous PGI2 release is associated with enhanced release of AVP, active renin, epinephrine and thromboxane A2, presumably contributing to hemodynamic stability within 30 min after MT.  相似文献   

12.
Don Dame 《Artificial organs》1996,20(5):613-617
Abstract: Virtually all blood pumps contain some kind of rubbing, sliding, closely moving machinery surfaces that are exposed to the blood being pumped. These valves, internal bearings, magnetic bearing position sensors, and shaft seals cause most of the problems with blood pumps. The original teaspoon pump design prevented the rubbing, sliding machinery surfaces from contacting the blood. However, the hydraulic efficiency was low because the blood was able to "slip around" the rotating impeller so that the blood itself never rotated fast enough to develop adequate pressure. An improved teaspoon blood pump has been designed and tested and has shown acceptable hydraulic performance and low hemolysis potential. The new pump uses a nonrotating "swinging" hose as the pump impeller. The fluid enters the pump through the center of the swinging hose; therefore, there can be no fluid slip between the revolving blood and the revolving impeller. The new pump uses an impeller that is comparable to a flexible garden hose. If the free end of the hose were swung around in a circle like half of a jump rope, the fluid inside the hose would rotate and develop pressure even though the hose impeller itself did not "rotate"; therefore, no rotating shaft seal or internal bearings are required.  相似文献   

13.
Abstract: A variety of protein-bound or hydrophobic substances, accumulating as a result of pathologic conditions such as exogenous or endogenous intoxications, are removed poorly by conventional detoxification methods because of low accessibility (hemodialysis), insufficient adsorption capabilities (hemosorption), low efficiency (peritoneal dialysis), or economic limitations (high-volume plasmapheresis). Combining advantages of existing methods with microspheric technology, a module-based system was designed. Major operating parameters of the latter can be modified to allow for adjustment to individual clinical situations. An extracorporeal blood circuit including a plasmafilter is combined with a secondary high-velocity plasma circuit driven by a centrifugal pump. Different microspheric adsorbers can be combined in one circuit or applied in sequence. Thus, a prolonged treatment can be tailored using specially designed selective adsorber materials. Comparing this system with existing methods (high-flux hemodialysis, molecular adsorbent recycling system), results from our in vitro studies and animal experiments demonstrate the superior efficiency of substance removal.  相似文献   

14.
Background: Halothane inhibits in vitro and in vivo activity of cytochrome P-450 (CYP) 2E1. There are several fluorinated volatile anaesthetics besides halothane, and most of them are defluorinated by CYP2E1. It is unclear whether other fluorinated anaesthetics inhibit the in vivo activity of CYP2E1.
Methods: We compared the inhibitory effects of therapeutic concentrations of four inhalational anaesthetics, halothane, enflurane, isoflurane, and sevoflurane, on chlorzoxazone metabolism in rabbits receiving artificial ventilation.
Results: All four inhalational anaesthetics decreased arterial blood pressure and increased plasma chlorzoxazone concentration. However, no significant differences in the plasma chlorzoxazone concentration were found between the four anaesthetics. The estimated chlorzoxazone clearance increased after beginning inhalation with all four agents, but no significant difference in clearance was noted between agents.
Conclusions: At therapeutic concentrations, the in vivo inhibitory effect on chlorzoxazone metabolism was similar for all four inhalational anaesthetics examined, even though their chemical characteristics and extent of hepatic metabolism differ considerably.  相似文献   

15.
Background : Our objective was to determine whether administration of propranolol or verapamil modifies the hemodynamic adaptation to continuous positive-pressure ventilation (CPPV), in particular the regional distribution of cardiac output (CO).
Methods : General hemodynamics and regional blood flows assessed by microsphere technique (15 (μm) were recorded in 16 anesthetized pigs during spontaneous breathing (SB) and CPPV with 8 cm H2O end-expiratory pressure (CPPV8) before and after intravenous administration of propranolol (0.3 mg · kg−1 followed by 0.15 mg · kg−1 · h−1, n=8) or verapamil (0.1 mg · kg−1 followed by 0.3 mg · kg−1 · h−1, n=8).
Results : CPPV8 depressed CO by 25% without shifts in its relative distribution with the exception of a noteworthy increase in adrenal perfusion. Propranolol increased arterial blood pressure, and due to a fall in heart rate, CO dropped by 25%. The kidneys and, to a lesser extent, the splanchic region and central nervous system received increased fractions of the remaining CO at the expense of skeletal muscle flow. Similar patterns were seen during SB and CPPV8 such that the combination of propranolol and CPPV8 depressed CO by 50%. The circulatory effects of verapamil were less evident but myocardial perfusion tended to increase.
Conclusions : The combination of propranolol or verapamil with CPPV does not result in any specific hemodynamic interaction in anesthetized pigs, except that the combined effect of propranolol and CPPV may severely reduce CO.  相似文献   

16.
Background: Obesity is increasing globallly, including in the formerly "Eastern Bloc" countries. Methods: A survey was made of obesity and bariatric surgery. Results: In the 8 East and Central European countries studied, with total population 300 million, roughly 43% of the population was overweight (BMI 25-30), 23% obese (BMI > 30), with about 15 million people morbidly obese (BMI > 40). From 0-10 morbidly obese individuals/100,000/year undergo bariatric surgery. Conclusion: Most countries were found to provide inadequate treatment for obesity.The majority of the morbidly obese are not treated effectively. However, health-care awareness of obesity and bariatric surgeons are slowly increasing.  相似文献   

17.
Background : Inhibitory effects of volatile anaesthetics on platelet aggregation have been demonstrated in several studies. However, the influence of volatile anaesthetics on intracoronary platelet adhesion has not been elucidated so far.
Methods : Isolated hearts of guinea pigs were perfused with buffer in the absence or presence of volatile anaesthetics (0.5 and 1 MAC) at constant coronary flow rates of 5 ml/min for 25 min, then 1 ml/min for 30 min and again 5 ml/min for 10 min. Before, during and after low-flow perfusion, a bolus of human platelets was applied into the coronary system. To simulate thrombogenic conditions, 0.3 U/ml human thrombin was infused during low-flow perfusion and reperfusion. The number of platelets sequestered to the endothelium was calculated from the difference between coronary in- and output of platelets. The myocardial production of lactate and consumption of pyruvate and coronary perfusion pressure were also determined.
Results : At a flow rate of 5 ml/min only about 3% of the applied platelets did not emerge from the coronary system, in any group. In contrast, 13.1±1.2% (mean±SEM) of infused platelets became adherent in low-flow perfusion in the control group without anaesthetic. The adherence was reduced with each 1 MAC isoflurane (to 6.2±1.2%), sevoflurane (to 4.4±0.9%) or halothane (to 3.2±1.5%) (each P <0.05 vs. control). Volatile anaesthetic, 0.5 MAC, did not inhibit platelet adhesion to a statistically significant extent in any case. Perfusion pressure and metabolic parameters were not statistically different between the control and the hearts exposed to anaesthetics.
Conclusion : Volatile anaesthetics in a concentration of 1 MAC can reduce the adhesion of platelets in the coronary system under reduced flow conditions. This action does not arise from vasodilation or inhibition of ischaemic stress.  相似文献   

18.
Background: It has been shown that the depressive effects of both propofol and midazolam on consciousness are synergistic with opioids, but the nature of their interactions on other physiological systems, e. g. respiration, has not been fully investigated. The present study examined the effect of propofol and midazolam alone and in combination with fentanyl on phrenic nerve activity (PNA) and whether such interactions are additive or synergistic. Methods: PNA was recorded in 27 anaesthetised and artificially ventilated rabbits. In three groups, propofol, fentanyl and midazolam were administered intravenously in incremental doses to construct dose-response curves for the depressant effects of each one on PNA. In another two groups, the effect of pretreatment with either fentanyl 1 μg · kg?1 i. v. or midazolam 0.05 mg · kg?1 i. v. on the effects of propofol and fentanyl respectively on PNA were studied. Results: Propofol and fentanyl caused a dose-dependent depression of PNA with complete abolition at the highest total doses of 16 mg · kg?1 i. v. and 32 μg · kg?1 i. v., respectively. In contrast, midazolam in incremental doses to a total of 0.8 mg · kg?1 reduced mean PNA by 63%, but approximately 12% of PNA remained at a total dose as high as 6.4 mg · kg?1. The mean ED50s, calculated from dose-response curves, were 5.4 mg · kg?1, 3.9 μg · kg?1 and 0.4 mg · kg?1 for propofol, fentanyl and midazolam, respectively. Initial doses of either fentanyl 1 μg · kg?1 i. v. or midazolam 0.05 mg · kg?1 i. v. acted synergistically with subsequent doses of either propofol or fentanyl to abolish PNA at total doses of 8 mg · kg?1 and 8 μg · kg?1, respectively. Conclusion: Fentanyl has a synergistic interaction with both propofol and midazolam on PNA and hence potentially on respiration.  相似文献   

19.
Background: Catecholaminergic support is often used to improve haemodynamics in patients undergoing major abdominal surgery. Dopexamine is a synthetic vasoactive catecholamine with beneficial microcirculatory properties. Methods: The influence of perioperative administration of dopexamine on cardiorespiratory data and important regulators of macro- and microcirculation were studied in 30 patients undergoing Whipple pancreaticduodenectomy. The patients received randomized and blinded either 2 μg · kg?1 · min?1 of dopexamine (n=15) or placebo (n=15, control group). The infusion was started after induction of anaesthesia and continued until the morning of the first postoperative day. Endothelin-1 (ET-1), vasopressin, atrial natriuretic peptide (ANP), and catecholamine plasma levels were measured from arterial blood samples. Measurements were carried out after induction of anaesthesia, 2 h after onset of surgery, at the end of surgery, 2 h after surgery, and on the morning of the first postoperative day. Results: Cardiac index (CI) increased significantly in the dopexamine group (from 2.61±0.41 to 4.57±0.78 1 · min?1 · m?2) and remained elevated until the morning of the first postoperative day. Oxygen delivery index (DO2I) and oxygen consumption index (VO2I) were also significantly increased in the dopexamine group (DO2I: from 416±91 to 717±110 ml/m2 · m2; VO2I: from 98±25 to 157±22 ml/m2 · m2), being significantly higher than in the control group. pHi remained stable only in the dopexamine patients, indicating adequate splanchnic perfusion. Vasopressive regulators of circulation increased significantly only in the untreated control patients (vasopressin: from 4.37±1.1 to 35.9±12.1 pg/ml; ET-1: from 2.88±0.91 to 6.91±1.20 pg/ml). Conclusion: Patients undergoing major abdominal surgery may profit from prophylactic perioperative administration of dopexamine hydrochloride in the form of improved haemodynamics and oxygenation as well as beneficial influence on important regulators of organ blood flow.  相似文献   

20.
A concept of balanced analgesia using nonsteroidal anti-inflammatory drugs (NSAIDs), paracetamol (acetaminophen), opioids, and corticosteroids can also be used in patients with pre-existing illnesses. NSAIDs are the most effective treatment for acute pain of moderate intensity in children; however, these drugs should be avoided in patients at increased risk for serious side effects, e.g. patients with renal impairment, bleeding tendency, or extreme prematurity. NSAIDs can be given with minimal risks to the younger child with mild to moderate asthma, and, in these patients, the use of steroids can be encouraged; in addition to their antiemetic and analgesic action, a beneficial effect on asthma symptoms can be expected. In the non-intubated child with cerebral trauma, exaggerated sedation caused by opioids and increased bleeding tendency caused by NSAIDs must be avoided. In neonates and small infants, the oral administration of sucrose or glucose is helpful to minimize pain reaction during short uncomfortable interventions.  相似文献   

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