贲门癌根治术后丙氨酰-谷氨酰胺双肽强化的肠外营养的支持作用

目的评价添加丙氨酰-谷氨酰胺双肽(Ala-Gln)的肠外营养(PN)对贲门癌根治术后病人的治疗作用。方法将贲门癌根治术后病人80例随机分为研究组(Ala-Gln强化的PN)及对照组(常规PN),每组40例。术后第1~7 d予以营养支持治疗,比较两组病人的体重变化、术后平均住院日,并测定血浆谷氨酰胺(Gln)、血浆白蛋白、血清内毒素水平。结果手术前后,研究组体重无明显变化,对照组体重平均下降(4.8±2.5)kg;研究组术后平均住院日为(10.5±3.1)d,与对照组(15.2±2.4)d比较差异显著(P<0.01);术后研究组血浆Gln水平下降不明显,而对照组显著下降,二者差异显著(P<0.01);研究组术后7 d血浆白蛋白浓度明显回升(39.76±4.32)g/L,与对照组(32.87±3.85)g/L比较,有显著性差异(P<0.01);研究组术后血清内毒素水平增加不明显,而对照组明显增加,两者差异显著(P<0.01)。结论Ala-Gln强化的PN能显著提高贲门癌根治术后病人的血浆Gln水平,有效改善手术导致的负氮平衡,提高血浆白蛋白水平,保护肠黏膜屏障,减轻高内毒素血症,改善预后,促进病人的康复。     

谷氨酰胺和生长激素对门静脉高压症患者术后营养、免疫和炎症反应的影响

目的 评价谷氨酰胺和生长激素对肝硬化门静脉高压症手术患者术后营养、免疫状态和急性炎症反应的影响.方法 选择42例接受门静脉高压症手术的肝硬化患者,随机分为两组:添加谷氨酰胺和人重组生长激素组(实验组,n=22)和标准营养组(对照组,n=20),两组术后第3天开始进行等氮等热最(125 kJ·kg-1·d-1)营养支持,持续7 d.手术当天(0 d)、第3和第10天清晨分别抽取静脉血,检测血清前白蛋白、转铁蛋白、T细胞亚群CD4、CD8、CD4/CD8、IgG、IgA、IgM、IL-2、TNF-α和CRP.结果 实验组在术后第10天血清前白蛋白:(193.84±39.78)mg/L、转铁蛋白:(2.07±0.51)mg/L、CD4:(33.7±5.5)%、CD4/CD8:(1.17±0.32)、IgG:(13.94±1.09)g/L和IL-2:(368.12±59.25)pg/mL均显著高于对照组(P<0.05),TNF-α:(321.12±81.42)pg/mL和CRP:(32.2±15.2)mg/mL均显著低于对照组(P<0.05).结论 谷氨酰胺和生长激素能够改善门静脉高压症患者手术后营养状态和免疫功能,调节急性炎症反应,作用优于标准胃肠外营养.     

谷氨酰胺颗粒对创伤患者蛋白代谢的影响

目的　观察服用谷氨酰胺颗粒对创伤、烧伤及大手术患者蛋白代谢的影响及可能发生的不良反应。方法　采用随机、双盲对照法 ,将受试患者分为谷氨酰胺 (glutamine,GLN)组和安慰剂对照(placebo,P)组 ,每组 6 0例 ,两组患者采用等氮、等热卡的营养支持。GLN组口服或管饲GLN 0 5 g·kg-1·d-1,对照组使用同等剂量的安慰剂 (甘氨酸 ) ,疗程为 7d。比较各组患者血浆GLN浓度、蛋白代谢、肝肾功能及不良反应发生率 ,对烧伤患者还观察了创面愈合情况和住院时间。结果两组患者血浆GLN浓度、血浆蛋白含量均明显低于正常值 ,而尿氮排量则明显增高。两组比较 ,GLN组患者使用谷氨酰胺颗粒 7d后血浆GLN浓度明显增高 (5 92 5 0± 185 2 3μmol/Lvs.4 0 7 4 1± 190 2 2 μmol/L) ,增幅达4 5 4 3% (P <0 0 1)。与之对应 ,血浆前白蛋白 (0 2 9± 0 10 g/Lvs.0 2 4± 0 0 7g/L)、转铁蛋白 (5 4 4±3 0 3g/Lvs.3 6 0± 2 0 2 g/L)含量均显著高于P组 ,升幅分别为 2 0 83%、5 1 11% (P <0 0 1) ,而尿氮排量则明显低于P组 (6 78± 4 78g/dvs.9 38± 6 0 2g/d) ,降幅为 2 7 78% (P <0 0 1)。血浆总蛋白、白蛋白含量、血尿常规及肝肾功能两组差异无显著意义 (P >0 0 5 )。少数患者出现轻微不良反应 ,如恶心、腹     

丙氨酰-谷氨酰胺对外科危重患者术后免疫功能的影响

目的　研究丙氨酰 谷氨酰胺 (Ala Gln)对外科危重患者术后免疫功能的影响。方法　将 3 0例外科急症大手术后APACHEⅡ评分大于 12分的患者随机分成实验组和对照组。两组均于术后给予常规外科治疗并于术后第 1～ 3天输入全营养混合液 ,其中实验组的部分氮量由 2 0 %L 丙氨酰 L 谷氨酰胺双肽注射液按每天 0 .5 g/kg体重提供 ,余部分氮量由氨基酸溶液供给。对照组仅用氨基酸溶液为氮源。分别取治疗前 (术后第 1天 )及治疗后第 7天的外周血标本测量CD3 、CD4、CD8、CD4/CD8、IgG、IgA、IgM、总淋巴细胞计数 (TLC)。 结果　实验组IgG、IgA治疗后 ( 14 .12± 3 .70 ) g/L、( 3 .5 1± 1.10 ) g/L较治疗前 ( 9.19± 4.10 )g/L、( 2 .49± 1.2 0 ) g/L显著升高 (P <0 .0 1) ;TLC( 1.13±0 .87)× 10 9/L较治疗前 ( 1.0 3± 0 .79)× 10 9/L显著升高 (P <0 .0 5 )。结论　丙氨酰 谷氨酰胺强化的肠外营养能提高外科危重患者术后免疫球蛋白和淋巴细胞计数 ,提高免疫功能。     

谷氨酰胺和生长激素对门静脉高压症术后营养状态和肠黏膜屏障的影响

目的 观察谷氨酰胺和生长激素联合肠外营养对肝硬化门静脉高压症手术患者术后营养状态和肠黏膜屏障的影响.方法 选择58例接受门静脉高压症手术的肝硬化患者,随机分为两组:实验组(添加谷氨酰胺和重组人生长激素,n=30)和标准营养组(对照组,n=28),两组术后第3天开始进行等氮等热量(每天125kJ/kg体重)营养支持,持续7d.术前、术后第3和第10天清晨分别抽取静脉血检测血清前白蛋白、转铁蛋白,并对手术前、后的尿乳果糖/甘露醇排泄率比值(L/M)、十二指肠黏膜绒毛高度、陷窝深度及肠黏膜增殖细胞核抗原(PCNA)指数进行对比.结果 实验组在术后第10天血清前白蛋白:(199.81±8.77)mg/L、转铁蛋白:(2.28±0.19)mg/L均显著高于对照组(P<0.05),L/M值升高小于对照组(P<0.05),肠黏膜绒毛高度(375.15±23.64)μm和陷窝深度(128.53±16.42)μm均大于对照组(P<0.05)及术前(P<0.05),肠黏膜上皮PCNA指数(24.27±4.25)大于对照组(P<0.05). 结论谷氨酰胺和生长激素联合肠外营养能够改善门静脉高压症手术后营养状态,降低小肠黏膜通透性,并维护肠黏膜形态学完整性,作用优于标准胃肠外营养.     

联合应用谷氨酰胺和重组人生长激素对严重烧伤患者蛋白代谢的影响

目的　探讨联合应用谷氨酰胺 (Gln)和重组人生长激素 (rhGH)对严重烧伤患者蛋白代谢的影响。　方法　将 6 0例严重烧伤患者随机分为对照组、Gln组及Gln rhGH组 ,每组 2 0例。对照组患者于伤后 1～ 14d口服甘氨酸作为安慰剂 ,并行常规治疗 ;Gln组于伤后 1～ 14d口服Gln 0 5g·kg-1·d-1;Gln rhGH组患者口服Gln(剂量、时间同Gln组 ) ,且伤后 7～ 14d皮下注射rhGH 0.2U·kg-1·d-1。3组患者于伤后 1、7、14d检测其血浆Gln浓度 ,伤后 14、2 1d检测血浆白蛋白水平 ,记录伤后 30d创面愈合率和总住院日。　结果　Gln rhGH组伤后 7d血浆Gln浓度为 ( 4 5 2 .2 8± 2 1.72 )μmol/L,高于对照组 ( 32 5 .12± 2 5 .34) μmol/L(P <0.0 5)。伤后 2 1dGln rhGH组血浆白蛋白水平为( 31.37± 4 .31) g/L,高于对照组 ( 2 6 .16± 3.12 ) g/L及Gln组 ( 2 8.2 6± 3.2 9)g/L( P <0 0 5 )。伤后 30dGln rhGH组创面愈合率高于对照组及Gln组 ,而总住院日少于对照组及Gln组 (P <0.0 5或 0 .0 1)。　结论　联合应用Gln和rhGH能显著提高严重烧伤患者血浆Gln水平 ,促进机体蛋白的合成 ,提高创面愈合率。     

阿斯匹林联合西米替丁调理感染大鼠蛋白质代谢的观察

目的　观察联合使用环氧化酶抑制剂阿斯匹林 (Asp)和组织胺H2受体阻滞剂西米替丁 (Cim)对腹腔感染大鼠全肠外营养 (TPN )时蛋白质分解的调理作用。方法　采用 2 8只成年腹腔感染大鼠 ,随机分成对照组 (TPN组 )和实验组 (Asp Cim组 )。对照组给予常规TPN ,实验组在TPN溶液中加入注射用赖氨匹林 15mg/kg·d-1和西米替丁注射液每天 80mg/kg体重 ,实验持续 4d。测定实验前后体重、血清总蛋白、白蛋白、尿素氮和肌苷的浓度 ;测定每日氮平衡和尿 3 甲基组氨酸 (3 MH)的排出量 ,计算累积氮平衡和累积尿 3 甲基组氨酸排出量。结果　实验组血清学指标实验前后变化的差值比对照组显著减少 ;累积氮平衡显著优于对照组 (P <0 .0 1) ;累积尿 3 甲基组氨酸排出量比对照组显著减少 (P <0 .0 1)。结论　环氧化酶抑制剂阿斯匹林 (Asp)联合组织胺H2受体阻滞剂西米替丁 (Cim )可以调理腹腔感染大鼠全肠外营养 (TPN)时的蛋白质代谢 ,减少蛋白质丢失。     

益生菌对慢性肾衰竭血液透析患者血红蛋白影响的随机临床研究

目的:本研究旨在评估补充益生菌对提高慢性肾衰竭血液透析患者的血红蛋白的临床价值。方法:对64例慢性肾衰竭血液透析合并贫血的患者进行随机分组,其中实验组(32例)口服补充益生菌、对照组(32例)口服安慰剂,为期12周。通过t检验和方差检验比较两组患者治疗12周内的血红蛋白和血清C-反应蛋白(CRP)水平的改变。结果:实验组患者血红蛋白水平随用药时间增加而升高(P 0. 001)、血清CRP水平降低(P 0. 001),在用药第4周后的血清CRP水平显著低于对照组患者[(13. 3±3. 9) mg/L vs (16. 4±4. 2) mg/L,P=0. 003]、第8周后的血红蛋白水平显著高于对照组患者[(108. 4±10. 3) g/L vs (93. 8±10. 7) g/L,P 0. 001]。但对照组患者在12周安慰剂治疗下的血红蛋白和血清CRP水平无明显改变(P 0. 05)。Pearson相关系数提示血清CRP与血红蛋白水平呈显著负相关(r=-0. 67,P=0. 014)。结论:补充益生菌能够有效提高慢性肾衰竭血液透析患者的血红蛋白水平并改善并改善贫血症状。     

全胃切除术后肠内营养支持

目的对比全胃切除术后肠内营养(EN)与标准肠外营养(PN)支持的效果。方法30例患者随机分为EN和PN组,两组患者从术后1d到术后10d进行等氮、等热量的营养支持。术前和术后11d测量体重,检测血中白蛋白、免疫球蛋白(Ig)A、IgG、IgM、淋巴细胞计数、T淋巴细胞亚群分类和血中谷氨酰胺含量及计算累积氮平衡。结果术后11d与术前比较,PN组的体重、白蛋白下降较EN组明显(P<0.05);血中谷氨酰胺下降也明显,与术前及与EN组相比,差异有非常显著性意义(P<0.01)。PN组累积氮平衡为(114.6±19.5)mg·kg-1·(11d)-1,而EN组为(203.6±31.8)mg·kg-1·(11d)-1,EN组明显优于PN组。体液免疫指标和T淋巴细胞亚群,EN组术后11d基本恢复到术前水平,而PN组与术前相比,尚有差异。结论全胃切除术后EN支持比标准PN支持有更好的代谢效果,能更好地恢复患者术后的免疫功能。     

两种脂肪乳对老年胃肠肿瘤患者术后营养疗效的比较

目的比较中长链脂肪乳及长链脂肪乳对老年胃肠肿瘤患者术后营养的疗效。方法29例老年胃肠肿瘤手术患者分为中长链脂肪乳组(MCT组,15例)和长链脂肪乳组(LCT组,14例),术后第2～7天共进行6d的肠外营养支持。除脂肪乳不同外,均给予等氮、等热卡的肠外营养,观察累积氮平衡、血浆蛋白、脂质代谢及与感染有关的并发症和术后住院天数等。结果术后经肠外营养MCT组获得正氮平衡,为(27.3±24.0)mg·kg-1·(6d)-1,而LCT组为(-17.5±16.2)mg·kg-1·(6d)-1。术后血浆蛋白水平均降低,LCT组前白蛋白的降幅为(-0.06±0.03)g/L,明显高于MCT组的(-0.02±0.03)g/L,差异有显著性意义(P<0.05)。两组患者的各项血脂水平手术前后变化均不明显。术后感染性并发症MCT组2例,LCT组3例。结论中长链脂肪乳对老年胃肠肿瘤患者术后的营养疗效比长链脂肪乳好。     

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 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.     

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.     

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.     

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.     

Is the recovery profile of mivacurium independent of the rate of decay of its plasma concentration in patients with normal plasma cholinesterase activity?

Background: The duration of action of muscle relaxants is poorly correlated to the rate of decay of their plasma concentration. The plasma concentration of mivacurium may rapidly decrease below its active concentration because of the extensive hydrolysis of mivacurium. By inflating a tourniquet on one upper limb for 3 min after the administration of atracurium, mivacurium or vecuronium, we studied the influence of the initial decline of their plasma concentration on their effect. Methods: In 50 patients anaesthetised with thiopental, isoflurane and fentanyl, the effect of bolus doses of 0.15 or 0.25 mg . kg^?1 mivacurium (MIV 15, MIV 25), 0.3 or 0.5 mg . kg^?1 atracurium (ATR 30, ATR 50) and 0.06 or 0.1 mg . kg^?1 vecuronium (VEC 06, VEC 10) were measured on both arms (evoked response of the adductor pollicis to train-of-four stimulation every 12 s), a tourniquet being applied on one arm just before and during 3 min after the muscle relaxant bolus. Results: Tourniquet inflation of 3 min almost abolished the neuromuscular effect of mivacurium. In the vecuronium groups and in the ATR 50 group, tourniquet inflation did not modify the maximum degree of depression of the twitch response. Also, the duration of action of vecuronium was unaffected by the tourniquet. In the ATR 30 group, times to return of the twitch response to 25% (duration 25%) and 75% (duration 75%) of control response were significantly shorter in the cuffed arm, 23 min vs 27 min, and 41 min vs 45 min, respectively. In the ATR 50 group, only duration 25% was significantly shorter in the cuffed arm (41 min vs 45 min). Conclusion: The results suggest that the rate of decline of the plasma concentration of mivacurium is so rapid, that a very low and almost clinically ineffective concentration is present as soon as 3 min after its administration. The results also indicate that the recovery from a mivacurium-induced neuromuscular blockade is not influenced by the rate of decay of its plasma concentration in patients with genotypically normal plasma cholinesterase.     

Membranes in Artificial Organs

Abstract: Membrane processes play a pivotal and enabling role in modern replacement therapy for acute and chronic organ failure and in the management of immunologic diseases. In fact, virtually all contemporary extracorporeal blood purification methods employ membrane devices, and the next generation of artificial organs and tissue engineering therapies are almost certain to be similarly grounded in membrane technology. In this short essay, we comment on the similarities and differences among synthetic membranes and their natural counterparts and also provide a critical overview of the demographics and technology of hemodialysis, hemofiltration, apheresis, oxygenation, and emerging membrane technologies and applications.     

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.