甲状腺激素对脓毒症大鼠肠屏障功能的影响

目的探讨补充甲状腺激素对脓毒症大鼠肠屏障功能的影响。方法将22只雄性SD大鼠随机分成3组:假手术组、脓毒症组、三碘甲状腺原氨酸(T3)干预组。制作盲肠结扎打孔(CLP)的脓毒症模型,应用荧光光谱分析仪检测自肠腔进入门静脉的荧光标记葡聚糖(FITC-D)的浓度,用透射电镜观察黏膜细胞间隙FITC-D颗粒的量。结果CLP后21h,假手术组血游离T3(FT3)、游离甲状腺素(FT4)浓度分别为(3.44±1.40)pmol/L和(9.53±3.39)pmol/L,脓毒症组为(1.59±0.20)pmol/L和(3.41±2.14)pmol/L,明显低于假手术组(P<0.05),干预组FT3浓度为(3.40±1.65)pmol/L,明显高于脓毒症组(P<0.05)。假手术组门静脉FITC-D浓度(0.84±0.15)μg/ml,脓毒症组为(1.73±0.39)μg/ml,高于假手术组(P<0.01),T3干预组(1.16±0.26)μg/ml,明显低于脓毒症组(P<0.01)。电镜显示T3干预后的肠黏膜细胞间隙及毛细血管的FITC-D颗粒明显减少。结论外源性甲状腺激素可降低大鼠肠黏膜的通透性,对脓毒症时肠黏膜屏障功能具有保护作用。     

脓毒症大鼠高迁移率族蛋白-1基因表达及其与内毒素血症的关系

目的观察脓毒症时高迁移率族蛋白 1(HMG 1)基因表达的变化及其与内毒素血症的关系。方法采用大鼠盲肠结扎穿孔 (CLP)造成脓毒症模型。 10 0只动物随机分为正常对照组 (10只 )、假手术组 (10只 )、CLP组 (6 0只 )及重组杀菌 /通透性增加蛋白 (rBPI2 1)治疗组 (2 0只 )。留取肝、肺及肾组织标本分别检测HMG 1mRNA表达及内毒素水平。结果CLP术后 6～ 72h肝、肺及肾组织HMG 1mRNA表达均不同程度增强 (P <0 0 5 )。rBPI2 1治疗后 12h肝、肺及肾组织内毒素水平分别为3 1± 0 8、2 6± 0 3、2 4± 0 4EU/g ,均明显低于CLP组 (5 2± 0 8、5 0± 0 8、14 2± 4 0EU/g ,P <0 0 5 ) ;同时 ,12h肝、肺、肾组织和 2 4h肝组织HMG 1mRNA表达明显受抑制 (P <0 0 5 )。CLP后肝、肺、肾组织HMG 1mRNA表达分别与相应组织内毒素水平呈显著正相关 (r =0 2 90 ,P <0 0 5 ;r =0 4 5 5 ,P <0 0 5 ;r=0 2 87,P <0 0 5 )。结论脓毒症时细菌内毒素持续侵入血循环 ,并蓄积于局部组织 ,参与了HMG 1的诱生 ,并可在基因水平调控其表达     

生长激素减轻梗阻性黄疸时肠菌及内毒素移位的实验研究

目的　探讨生长激素减轻梗阻性黄疸时肠细菌及内毒素移位的作用及其机理。方法　将 60只大鼠随机均分为假手术组 (SO组 )、梗阻性黄疸组 (OJ组 )及生长激素组 (rhGH组 ) ,rhGH组每天皮下注射Saizen 0 .75u/kg ,SO组及OJ组则用等量生理盐水作对照。检测各组血内毒素水平 ,并取腹水、血及肠系膜淋巴结、肝脏、肾脏和脾脏作细菌培养 ,同时测定末段回肠之粘膜厚度及绒毛高度。结果　OJ组血内毒素值为 (0 .77± 0 .0 3 )u/ml,较rhGH组的 (0 .40±0 .0 2 )u/ml明显增高 (P <0 .0 1) ,rhGH组接近SO组的 (0 .3 3± 0 .0 3 )u/ml水平。OJ组细菌移位率为 5 8.8% ,较rhGH组 (10 .0 % )明显增高 (P<0 .0 1) ,rhGH组与SO组 (0 )比较 ,P>0 .0 5。rhGH组绒毛高度为 (2 3 7.5 2± 13 .65 ) μm ,较OJ组的(183 .3 9± 11.0 9) μm明显增高 (P<0 .0 1) ;rhGH组粘膜厚度为 (3 2 0 .81± 14 .3 4) μm ,较OJ组的 (2 5 5 .62± 16.5 8) μm增厚(P <0 .0 1)。结论　生长激素对肠粘膜屏障具有明显的保护作用 ,可有效减轻梗阻性黄疸时肠菌及内毒素的移位。     

帕瑞昔布钠对脓毒症小鼠肠黏膜屏障的保护作用

目的研究帕瑞昔布钠对脓毒症小鼠肠黏膜屏障功能的影响及可能机制。方法 21只C57BL/6小鼠随机分为三组:假手术组(Sham组)、脓毒症模型组(CLP组)、脓毒症模型+帕瑞昔布钠2mg/kg治疗组(P组),每组7只。术后24h用襻环结扎法检测各组小鼠小肠通透性。另21只C57BL/6小鼠随机分为三组,分组及治疗同前,术后24h处死小鼠,收集小鼠回肠。小肠组织行HE染色观察肠病理损伤。采用Western bolt法检测小肠ZO-1、Occludin、Claudin-1等紧密连接蛋白的表达。采用ELISA法检测小肠黏膜IL-6、PGE2的浓度。结果与Sham组比较,CLP组小鼠小肠明显损伤,门静脉血内FD4浓度明显升高,小肠黏膜内ZO-1、Occludin、Claudin-1蛋白表达明显减少、IL-6与PGE2浓度明显升高(P0.05)。与CLP组比较,P组小鼠小肠损伤明显减轻(P0.05),门静脉血内FD4浓度明显降低(P0.05),小肠黏膜内各蛋白表达水平明显增加、IL-6与PGE2浓度明显降低(P0.05)。结论帕瑞昔布钠治疗可以明显降低脓毒症导致的肠黏膜屏障功能损伤,其机制可能与降低肠组织炎症水平,增加肠紧密连接蛋白表达相关。     

乌司他丁对脓毒症大鼠脾组织基因表达的影响

目的 应用基因芯片技术观察乌司他丁(Ulinastatin UTI)预处理脓毒症大鼠脾组织基因表达谱的变化.方法 将45只雄性Wistar大鼠按随机数字表法平均分为假手术组、脓毒症组和UTI组.采用盲肠结扎穿孔术复制脓毒症大鼠模型.UTI组于制模前1 h肌肉注射UTI10万单位/kg;脓毒症组及假手术组肌注平衡液5 ml/kg.采用RatRef-12大鼠表达谱基因芯片进行检测,用计算机软件筛选并分析比较脓毒症组、UTI组与假手术组大鼠脾组织基因表达的变化,并分析脓毒症组和UTI组表达基因的差异.结果 在22 523个基因中,与假手术组比较,脓毒症组大鼠脾组织差异表达基因共205个,占基因芯片总点数的0.910％;其中表达上调者98个,已知功能基因48个,仅在脓毒症组出现32个;表达下调者107个,已知功能基因64个,仅在脓毒症组出现34个.与假手术组比较,UTI组大鼠脾组织差异表达基因共197个,占基因芯片总点数的0.875％.其中表达上调者114个,已知功能基因35个,仅在UTI组出现19个;表达下调者83个,已知功能基因49个,仅在UTI组出现19个.结论 UTI预处理可在一定程度上纠正部分脓毒症大鼠过度炎症反应及免疫抑制所致脾组织基因表达异常,在基因水平上对脾组织有保护作用.     

帕瑞昔布钠对脓毒症大鼠肠黏膜屏障功能的影响

目的 探讨帕瑞昔布钠对脓毒症大鼠肠屏障功能的影响。 方法 采用盲肠结扎穿孔法（cecal ligation and puncture, CLP）诱导脓毒症大鼠肠损伤模型。72只Wistar大鼠按随机数字表法分为4组（每组18只）：假手术组（Sham组）、假手术＋10 mg/kg帕瑞昔布钠组（SP组）、脓毒症组（CLP组）、脓毒症＋10 mg/kg帕瑞昔布钠组（CP组）。SP组和CP组大鼠于假手术或CLP后20 min腹腔注射帕瑞昔布钠10 mg/kg,12 h后再重复注射1次。CLP组和Sham组大鼠仅经腹腔注射等量生理盐水。于假手术或CLP后24 h,检测血浆二胺氧化酶（diamine oxidase, DAO）和D-乳酸的浓度,检测各组大鼠肠组织紧密连接蛋白（zonula occludens-1, ZO-1）和Claudin-1的蛋白表达,检测肠组织髓过氧化物酶（myeloperoxidase, MPO）的活性水平。光镜检测肠组织的病理学变化。 结果 与CLP组比较,CP组脓毒症大鼠血浆中DAO和D-乳酸水平降低（P〈0.05）,MPO活性下降（P〈0.05）,CP组肠组织ZO？蛳1和Claudin-1表达上调（P〈0.05）,CP组Chiu＇s评分降低（P〈0.05）。 结论 10 mg/kg帕瑞昔布钠治疗脓毒症大鼠能够减轻肠组织损伤和炎症反应,有效降低肠黏膜的通透性,改善肠屏障功能。     

大鼠急性胰腺炎反应中脾脏对肠屏障功能的影响

目的　探讨脾脏在大鼠急性胰腺炎(AP)病程中对肠屏障功能的影响。方法　随机将大鼠分成4组:假手术组,AP组,脾切除组,脾切除+AP组。手术后2 4h检测各组血清TNF α,IL 1β,IL 6及IL 1 0水平,术后2d测肠细菌移位率,并取末段回肠行光镜及透射电镜观察肠黏膜受损情况。结果　脾切除+AP组TNF α,IL 1β,IL 6及IL 1 0值分别为3. 0 6±3. 6 1, 1 6. 4 6±5. 5 2, 19. 90±6. 8 9, 6. 9 4±3. 9 3;AP组的测得值分别为1 9. 9 3±2. 3 8, 4 2. 7 9±4. 3 1, 2 0. 1 9±3. 3 5, 3 9. 2 8±1 2. 6 9。脾切除+AP组TNF α,IL 1β及IL 1 0的值显著低于AP组(P < 0. 0 5 ),脾切除+AP组细菌移位率为4 0%显著低于AP组9 3. 3% (P< 0. 0 5 )。脾切除+AP组肠黏膜上皮仅轻微水肿,肠黏膜基本完整,而AP组肠黏膜上皮水肿明显,绒毛坏死,上皮细胞变性,炎性细胞浸润及细菌移位。结论　脾脏在急性炎症反应中,可明显促进炎性介质的产生和释放,加重炎症反应。脾脏切除后可减少促炎因子的产生和释放,肠黏膜受损减轻,细菌移位率下降。     

前列环素与门静脉高压症高动力循环的关系

目的　探讨前列环素 (PGI2 )和一氧化氮 (NO)在门静脉高压症高血流动力循环中的作用。　方法　 66只雄性SD大鼠随机分成 :肝内型门静脉高压症组 (IHPH组 )、肝前型门静脉高压症组 (PHPH组 )和假手术组 (SO组 )。模型制备 1周后再随机分为 3个亚组 ,即对照组、一氧化氮合酶抑制剂L NNA组、消炎痛组。用药 1周后测定股动脉血浆 6 酮 前列腺素F1α(6 keto PGF1α)和NO2 - /NO3- 浓度 ,应用同位素微球技术行血流动力学研究 ,并对NO、PGI2 水平与血流动力学参数行Pearson相关分析。　结果　 (1 )在基础状态下 ,血浆 6 keto PGF1α浓度 ,IHPH鼠 [(1 1 2 3 85± 1 53 64)pg/ml]和PHPH鼠 [(891 88± 83 1 1 )pg/ml]均显著地高于SO鼠 [(72 5 53± 1 0 5 54)pg/ml] ,P <0 0 5 ;血浆NO2 - /NO3- 浓度 ,IHPH鼠 [(73 34± 4 31 ) μmol/L]和PHPH鼠 [(75 2 1± 6 89) μmol/L]均显著高于SO鼠[(58 79± 8 47) μmol/L] ,P <0 0 5。 (2 )与对照组比较 ,L NNA与消炎痛均显著地降低IHPH与PHPH 2组鼠血浆 6 keto PGF1α和NO2 - /NO3- 的浓度 ,P <0 0 5 ;降低IHPH、PHPH 2组鼠的心脏指数 (CI)、门静脉压力 (FPP)和门静脉血流量 (PVI) ,P <0 0 5 ;显著地增高这 2组鼠的平均动脉压 (MAP)、总外周血管阻力 (TPR)和内脏血     

内皮素-1 mRNA在肝肺综合征大鼠肺组织中表达的研究

目的　研究内皮素 1(ET 1)及其mRNA在肝肺综合征 (HPS)大鼠肺组织中的表达。方法　 3 2只雄性SD大鼠随机分 4组 :肝前型门静脉高压症组 (PHPH)、肝内型门静脉高压症组(IHPH)、门腔端侧分流组 (PCS)和手术对照组 (SO) ,每组 8只。各组均行动脉血气分析 ;应用硝酸还原酶法和放射免疫法测定肺组织中NO2 -/NO3-及ET 1含量 ;应用原位杂交和图像分析 ,检测肺泡毛细血管内皮细胞、肺泡动脉内皮细胞和支气管上皮细胞中ET 1mRNA的表达强度。　结果　 ( 1)动脉血气分析 :动脉氧分压IHPH组大鼠 [( 73 85± 6 5 1)mmHg]较PHPH组 [( 97 3 9± 1 3 3 )mmHg]、PCS组 [( 95 2 3± 2 2 2 )mmHg]和SO组 [( 99 0 5± 0 75 )mmHg]显著下降 (P <0 0 5 ) ;肺泡 动脉氧压力梯度 :IHPH组大鼠 [( 3 4 5 3± 2 3 2 )mmHg]较PHPH组 [( 4 98± 1 69)mmHg]、PCS组 [( 6 5 1± 2 0 4 )mmHg]和SO组 [( 3 2 3± 0 81)mmHg]显著增大 (P <0 0 5 ) ,并伴轻度呼吸性碱中毒。 ( 2 )肺组织中NO2 -/NO3-含量 ( μmol/g蛋白 ) :IHPH组大鼠 ( 19 78± 5 3 3 ) μmol/g显著高于PHPH组 ( 13 2 1± 3 99)μmol/g、PCS组 ( 13 89± 3 16) μmol/g和SO组大鼠 ( 8 71± 1 68) μmol/g。肺组织中ET 1含量 (pg/g) :IHPH组大鼠 ( 195 1     

雌激素对大鼠门静脉高压性胃病的影响及其机制

目的探讨雌激素对大鼠门静脉高压性胃病的影响及其机制。方法40只SD大鼠被随机分为4组:P+E组接受门静脉主干结扎+雌激素;P组仅接受门静脉主干结扎;S+E组接受假手术+雌激素;S组仅接受假手术。所有大鼠维持相应处理14 d后处死,处死前1h予2 ml 99％乙醇灌胃。用激光多普勒仪检测胃黏膜血流量,计算胃黏膜损伤程度。用动态一氧化氮(NO)检测仪检测胃黏膜NO含量等。结果P+E组胃黏膜血流量(103±14)U显著高于其他3组(P<0．05)。胃黏膜损伤指数:P+E组(0．28±0．17)、P组(0．21±0．08)和S+E组(0．21±0．12)组均显著高于S组(0．11±0．06),P<0．05。P+E组的NO测量值(153±23)nmol／L显著高于P组(123±14) nmol／L、S+E组(116±18)nmol／L和S组(104±15)nmol／L,P<0．05。结论雌激素加重门静脉高压症大鼠胃黏膜的损伤,可能与其促进胃黏膜内NO的产生有关。     

Vasopressor hormone response following mesenteric traction during major abdominal surgery

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_1α (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.     

A Teaspoon Pump for Pumping Blood with High Hydraulic Efficiency and Low Hemolysis Potential

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.     

A comparison of the inhibitory effects of four volatile anaesthetics on the metabolism of chlorzoxazone, a substrate for CYP2E1, in rabbits

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.     

Microspheres Based Detoxification System: A New Method in Convective Blood Purification

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.     

Tissue perfusion in relation to cardiac output during continuous positive-pressure ventilation and administration of propranolol or verapamil

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.     

Bariatric Surgery in Some "Central and East-European (former Eastern bloc)"Countries - Current Status and Prediction for the Next Millennium

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.     

Volatile anaesthetics reduce adhesion of blood platelets under low-flow conditions in the coronary system of isolated guinea pig hearts

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.     

Synergistic interaction between the effects of propofol and midazolam with fentanyl on phrenic nerve activity in rabbits

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.     

Influence of dopexamine hydrochloride on haemodynamics and regulators of circulation in patients undergoing major abdominal surgery

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.     

Systemic analgesia adapted to the children's condition

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.