复方中药对急性肝损伤大鼠血浆内皮素-1的影响

目的　研究中药对急性肝损伤大鼠血浆内皮素 1的影响。方法　采用放射免疫法测定大鼠血浆内皮素 1(endothelin 1,ET 1)水平。结果　实验组大鼠血浆ET 1水平 ( 163 98± 3 8 5 4 )pg/ml显著低于模型组 ( 2 2 2 5 9± 68 71)pg/ml,P <0 0 5。与对照组 ( 165 2 8± 3 4 13 )pg/ml相比无显著差异。结论　复方中药能显著降低急性肝损伤大鼠血浆内皮素水平。     

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     

急性等容性血液稀释对血浆ET和CGRP水平的影响

目的　探讨急性等容性血液稀释 (ANH)对血浆内皮素 (ET)和降钙基因相关肽(CGRP)水平的影响。方法　选择非心脏手术ASAⅠ～Ⅱ级患者 2 0例 ,麻醉前快速输入复方乳酸钠1 0～ 1 5ml/kg。麻醉后从桡动脉放血 1 0ml/kg ,同时经静脉输入等量的 4 %琥珀酰明胶。观察ANH麻醉前 (T0 )、血液稀释完成后 1 0min(T1 )、2 0min(T2 )、30min(T3 )的血液动力学、血浆ET和CGRP浓度的变化。结果　ANH前后MAP、HR、SpO2 和ECG均较稳定。ANH后 1 0min、2 0min血浆ET水平分别为 (1 4 4 4 7± 1 9 1 7) pg/ml和 (1 5 7 1 7± 1 2 4 5 ) pg/ml,但明显高于ANH前的 (1 2 7 6 8±2 0 92 ) pg/ml(P <0 0 5 )。ANH后 1 0min、2 0min血浆CGRP水平分别为 (5 4 72± 2 5 6 5 )pg/ml和(5 5 32± 1 7 94 )pg/ml,也明显高于ANH前的 (4 4 6 2± 1 6 90 ) pg/ml(P <0 0 5 )。而ET/CGRP比值无明显变化。结论　ANH近期血浆ET和CGRP水平均有一定的增加 ,但ET/CGRP比值的变化无统计学意义 ,同时心血管反应不明显 ,表明血浆ET和CGRP的动态平衡对ANH时的循环稳定起着重要的作用     

小鼠肝缺血再灌注后Toll样受体2在缺血肝组织中的激活及其意义

目的　探索小鼠肝缺血再灌注后缺血肝组织中Toll样受体 2 (TLR2 )的激活及其与肝功能损伤之间的关系。方法　缺血再灌注损伤组 (I/R组 ),假手术对照组 (S组 )均采用实时荧光定量多聚酶链反应检测肝组织中TLR2mRNA及TLR2蛋白的表达,同时检测门静脉血浆丙氨酸氨基转移酶(ALT)、肿瘤坏死因子α(TNF α)及门静脉血清内毒素 (endotoxin, EN)水平。结果　肝脏部分缺血1h再灌注 4h后,I/R组与S组小鼠缺血肝组织TLR2 mRNA的表达 (ΔCt值 )分别为 1. 0 6±0. 9 1和5. 0 8±1. 3 2, 两组间差异有显著性 (P < 0. 0 1 ),I/R组缺血肝组织TLR2 蛋白的表达 (OD值 )( 4 3 3. 9 1±2 5. 5 3 )水平较S组 ( 1 0 2. 8 6±1 3. 5 8 )显著升高 (P< 0. 0 1 )。I/R组门静脉血清TNF α[ ( 1 1 2. 5 2±1 4. 4 1 )pg/mL]较S组 [ ( 5. 9 6 ±4. 4 3 )pg/mL]显著升高 (P < 0. 0 1 );I/R组ALT[ ( 8 4 8. 3 3±2 7 1. 3 7 )U/L]较S组 [ ( 4 2. 3 9±1 4. 7 5 )U/L]显著升高 (P < 0. 0 1 );而门静脉血清内毒素水平组间差异无显著性 (P> 0. 0 5 )。结论　TLR2mRNA及蛋白在肝脏缺血再灌注过程中缺血肝组织的表达增强, 此变化伴有TNF α的升高及肝功能的损伤。     

肝硬化大鼠肝脏内皮素受体基因的表达与门静脉压力的关系

目的　研究四氯化碳诱导的肝硬化大鼠肝脏内皮素(endothelin, ET)受体基因的表达,并探讨其与门静脉压力的关系。方法　采用逆转录多聚酶链反应(RT PCR)测定大鼠肝组织 ETA受体和ETB受体mRNA的表达水平, 并测量门静脉压力。结果　肝硬化大鼠肝组织 ETA受体(0 4245±0 0612 vs 0 2792±0 1115,P<0 05) 和 ETB受体(0 5984±0 1047 vs 0 2938±0 1399,P< 0 05) mRNA 的表达均较对照组均显著升高;肝硬化大鼠门静脉压力较正常大鼠明显升高(16 08±2 19 vs8 25±2 56 cmH2O,P<0 05),并且ETA受体mRNA的表达与门静脉压力显著正相关(r=0 8074,P<0 05)。结论　四氯化碳诱导的肝硬化大鼠肝组织ET受体 mRNA的表达显著升高,并且 ETA受体 mRNA的表达与门静脉压力显著正相关, 表明 ET受体的高表达在门静脉高压症的发病机制中起重要作用。     

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     

肝动脉阻断对大鼠肝癌血供与VEGF、MMP表达的影响

目的　观察肝动脉阻断对大鼠移植性肝癌的血液灌流与血管内皮生长因子 (VEGF)、基质金属蛋白酶 1(MMP 1)表达的影响 ,初步探索肝动脉栓塞促进肝癌转移的机制。方法　采用大鼠肝内移植Walker 2 5 6肿瘤模型 ,以肝动脉结扎 (HAL)的方法阻断肝动脉血供 ,模拟肝动脉栓塞治疗。分为对照组、剖腹对照组、HAL组。Hoechst33342标记法检测瘤组织血液灌流 (标记细胞数代表血供情况 ) ,酶联免疫吸附试验 (ELISA)测定血清VEGF水平 ,原位杂交法检测瘤组织VEGF、MMP 1表达。结果　HAL后 2d瘤组织血供明显下降 (对照组每高倍视野Hoechst33342标记细胞数 383 6± 19 2 ,HAL组 32 9 1± 2 9 3 ,P <0 0 1)。血清VEGF水平明显升高 (对照组 5 4 9± 19 3pg ml,HAL组 92 5± 43 9pg ml,P <0 0 5 )。瘤组织VEGF、MMP 1mRNA表达水平较对照组、剖腹对照组明显升高 (P <0 0 5 )。瘤组织血供与血清VEGF水平、瘤组织VEGF表达负相关。结论　肝动脉阻断使癌组织血供减少 ,转移相关基因VEGF、MMP 1表达升高。血供减少、缺氧加重可能为其诱导VEGF表达的主要机制。     

丹参注射液对重症急性胰腺炎大鼠肾ET-1 mRNA表达的影响

目的观察丹参注射液对SAP肾脏ET-1mRNA表达的影响,以探讨SAP肾脏损伤的机制。方法45只Wistar大鼠随机等分为3组。模型组、药物组均以5%牛磺胆酸钠经胰管内逆行注射(1ml/kg)复制SAP模型。药物组则在制模后肌肉注射丹参(2ml·kg-1·d-1),每6h使用一次。对照组仅行假手术。各组动物在术后24h测血淀粉酶、ET-1和腹水量。使用原位杂交和图象分析检测肾脏ET-1mRNA的表达强度,并观察肾脏的病理变化。结果(1)血中淀粉酶和腹水量:模型组分别为(2156.05±355.87)u/L和(9.87±2.34)ml,显著高于药物组的(1439.21±332.99)u/L和(5.27±2.81)ml及对照组的(215.67±37.27)u/L和0ml(P均<0.001)。(2)血中ET-1:模型组为(185.47±20.80)pg/ml,高于药物组的(164.27±18.53)pg/ml和对照组的(72.90±17.27)pg/ml(P<0.05,P<0.001)。(3)模型组、药物组的ET-1mRNA在肾脏中表达均增高,模型组显著高于药物组(P<0.001)。(4)模型组、药物组肾脏均有病理改变,但药物组较模型组减轻。结论(1)SAP肾脏的ET-1mRNA高表达导致ET-1过度生成并与肾脏损伤有关。(2)丹参能抑制肾脏的ET-1mRNA的过度表达,从而对肾脏起保护作用。     

急性胰腺炎时促炎症因子和抗炎症因子的变化及其意义

目的研究急性胰腺炎全身炎性反应综合征 (systemicinflammatoryresponsesyndrome,SIRS)时促炎因子和抗炎因子的变化及其意义。方法本组 32例急性胰腺炎患者中轻症急性胰腺炎 (mildacutepancreatitis,MAP) 13例 ,重症急性胰腺炎 (severeacutepancreatitis,SAP) 19例。观察入院后第 1、3、5、7日急性生理和既往健康评分 (APACHEⅡ )、BalthazarCT评分、血清白细胞介素 (IL) 6、IL 8、IL 10和IL 12的变化。结果入院第 1日MAP组APACHEⅡ评分和BalthazarCT评分分别为(5 6± 2 1)和 (1 5± 0 6 ) ,SAP组为 (13 6± 4 3)和 (6 3± 1 5 ) ,2组APACHEⅡ评分和BalthazarCT评分的差异均有显著意义 (P值均 <0 0 1) ;入院第 1日MAP组患者血清IL 6、IL 8、IL 10、IL 12的水平分别为 (9± 3)pg/ml、(4 1± 16 )pg/ml、(7 9± 2 3)pg/ml、(12 9± 30 )pg/ml,SAP组分别为 (6 4± 14)pg/ml、(5 1± 18)pg/ml、(6 9± 1 7)pg/ml、(6 4± 14)pg/ml,2组IL 10 /IL 6、IL 12 /IL 6、IL 12 /IL 8的比值差异有显著意义 (P值均 <0 0 1)。结论IL 6、IL 8和IL 10、IL 12的表达水平与急性胰腺炎的严重度有关 ,综合BalthazarCT评分、APACHEⅡ评分和血清中促炎因子和抗炎因子的比值对急性胰腺炎的严重度进行评估更准确     

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     

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.     

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.     

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.     

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.