依达拉奉对大鼠心肌缺血再灌注诱发肺损伤的影响

目的 探讨依达拉奉对大鼠心肌缺血再灌注诱发肺损伤的影响.方法 健康清洁级雄性Wistar大鼠24只,体重250～300 g,随机分为4组(n=6):假手术组(S组)、心肌缺血再灌注组(IR组)和不同剂量依达拉奉组(E1组和E2组).IR组、E1组和E2组采用结扎冠状动脉左前降支(LAD)45 min,再灌注3 h的方法制备心肌缺血再灌注模型.S组仅LAD下穿线不结扎;IR组阻断LAD45 min后再灌注3 h;E1组和E2组分别于再灌注前1 min经右股静脉注射依达拉奉3或10 mg/kg.于再灌注3 h时放血处死大鼠,取肺组织、支气管肺泡灌洗液和动脉血样,测定血清肌酸激酶同工酶(CK-MB)活性,计算肺通透性指数(PPI),采用Western blot法检测肺组织β-防御素-2(BD-2)和TNF-α蛋白的表达,PCR法测定肺组织BD-2 mRNA表达.结果 与S组比较,IR组、E1组和E2组血清CK-MB活性和PPI升高,肺组织BD-2 mRNA、BD-2和TNF-α蛋白表达上调(P＜0.01).与IR组比较,E1组和E2组血清CK-MB活性和PPI降低,肺组织BD-2 mRNA、BD-2和TNF-α蛋白表达下调(P＜0.01).与E1组比较,E2组血清CK-MB活性和PPI降低,肺组织BD-2 mRNA、BD-2和TNF-α蛋白表达下调(P＜0.01).结论 依达拉奉可减轻大鼠心肌缺血再灌注诱发的肺损伤,其机制不仅与清除氧自由基有关,还与抑制肺组织炎性反应有关.     

依达拉奉对大鼠急性肺损伤的干预作用

目的 探讨依达拉奉(EDA)和地塞米松(DXM)对脓毒症大鼠肺损伤的干预作用.方法 50只SD大鼠随机分为假手术组(sham组)、手术对照组(CLP组)、依达拉奉治疗组(EDA组)、地塞米松治疗组(DXM组)和依达拉奉联合地塞米松治疗组(E+D组).采用盲肠结扎穿刺法造脓毒血症大鼠肺损伤模型,药物治疗组造模后立即经阴茎背静脉注射EDA(5mg/kg),DXM(5mg/kg)或EDA(5mg/kg)+DXM(5mg/kg);另两组均以等量生理盐水代替.结果 与 sham组相比,CLP组大鼠病理评分,肺干湿重比(W/D),肺泡通透指数(LPI),肺组织中MPO,MDA,IL-6,TNF-α,肺组织中凋亡细胞数量明显增加,而肺组织中T-AOC活性明显减轻.应用地塞米松,依达拉奉药物干预后,上述指标均有不同程度的改善.两种药物联合应用与单个药物应用相比,这些指标有更明显的改善.结论 依达拉奉预处理对脓毒症诱导的肺损伤有明显的防治效果,减轻急性肺损伤的机制可能是通过减少氧自由基产物,减少炎性细胞因子浓度.依达拉奉和地塞米松联合应用对肺损伤有更好的治疗效果.     

依达拉奉减轻大鼠小体积肝移植物缺血再灌注损伤

目的 探讨依达拉奉减轻大鼠小体积肝移植物缺血再灌注损伤的作用及其可能机制.方法 采用成年雄性SD大鼠作为肝移植的供、受者,随机将受者分为依达拉奉组和对照组,每组8只.依达拉奉组受者移植前30 min经阴茎背静脉注射依达拉奉3 mg/kg,对照组受者仅给予等量生理盐水.采用改良的二袖套法建立大鼠40%(供肝重量与受者全肝重量比)小体积供肝肝移植模型.术后6 h时,处死两组受者,使用全自动生化分析仪检测血清天冬氨酸转氨酶(AST)和丙氨酸转氨酶(ALT)水平,采用酶联免疫吸附试验(ELISA)法检测移植肝组织中肿瘤坏死因子α(TNF-α)含量,使用相应的检测试剂盒检测移植肝组织中MDA含量以及SOD和MPO的活性.同时,取移植肝组织进行病理学检测,观察肝组织病理损伤情况.结果 术后6h,依达拉奉组受者血清AST和ALT水平分别为(825.50±72.87)U/L和(687.40±72.21)U/L,对照组分别为(1188.03±124.04)U/L和(988.66±91.07)U/L,依达拉奉组明显低于对照组,两组间比较,差异均有统计学意义(P<0.01).与对照组比较,依达拉奉组受者移植肝组织中MDA和TNF-α含量明显下降,MPO活性也明显下降,而SOD活性则明显增加,两组间比较,差异均有统计学意义(P<0.01).移植肝组织病理学检查发现,对照组肝细胞发生明显的空泡样变性伴局部坏死灶,肝小叶结构破坏,门脉周围水肿、充血,炎症细胞浸润明显;依达拉奉组肝损伤明显减轻,小叶结构保存完整,肝细胞变性、坏死轻微,炎症细胞浸润明显减少.结论 依达拉奉能够明显减轻大鼠小体积肝移植物缺血再灌注损伤,其机制可能与增强抗氧化能力、抑制脂质过氧化以及减轻炎症反应密切相关.     

舒芬太尼预处理对大鼠肢体缺血-再灌注肺损伤的影响

目的观察舒芬太尼预处理对大鼠肢体缺血-再灌注肺损伤的影响。方法成年雄性SD大鼠60只,随机分为五组:假手术组(Sham组)、缺血-再灌注组(IR组)和舒芬太尼1、5、10μg/kg预处理组(S1组、S5组和S10组),每组12只。采用大鼠肢体缺血2h再灌注3h肺损伤模型。观察肺组织病理学改变,测定肺组织湿/干重比(W/D)、髓过氧化物酶(MPO)活性、细胞因子诱导的中性粒细胞化学趋化因子-1(CINC-1)含量及核因子-κB p65(NF-κB p65)的蛋白表达。结果与Sham组比较,IR组肺泡壁增厚,肺间质和肺泡水肿,大量炎性细胞浸润,呈局限性肺不张;与IR组比较,S1组、S5组和S10组肺组织损伤逐渐减轻,S10组只有少量渗出及肺泡隔轻度增宽,基本接近于正常肺组织。与Sham组比较,IR组、S1组和S5组W/D、MPO活性、CINC-1含量和IR组、S1组、S5组和S10组NF-κB p65蛋白表达明显升高(P0.01)。与IR组比较,S1组、S5组和S10组W/D、MPO活性、CINC-1含量及NF-κB p65蛋白表达明显降低(P0.01)。且S5组和S10组明显低于S1组(P0.01),S10组明显低于S5组(P0.01)。结论舒芬太尼预处理能减轻肢体缺血-再灌注大鼠的肺损伤,其机制可能与抑制NF-κB激活,从而减少CINC-1介导的中性粒细胞聚集有关。     

依达拉奉对大鼠肝脏缺血再灌注时线粒体膜电位的影响

目的 探讨依达拉奉对大鼠肝脏缺血再灌注时线粒体膜电位的影响.方法 成年健康雄性SD大鼠30只,体重250 ～ 300 g,采用随机数字表法,将其随机分为3组(n=10):假手术组(S组)、缺血再灌注组(I/R组)及依达拉奉组(E组),I/R组和E组采用肝脏缺血60 min进行再灌注的方法制备70％肝脏缺血再灌注损伤模型.E组于再灌注前15 min静脉注射依达拉奉3 mg/kg,I/R组给予等容量生理盐水.于再灌注2h时采集静脉血样,测定血清谷丙转氨酶(ALT)和谷草转氨酶(AST)的活性;然后处死大鼠,取肝组织,测定肝细胞凋亡情况,计算肝细胞凋亡指数;制备肝组织单细胞悬液,测定线粒体膜电位;光镜下观察肝组织病理学结果.结果 与S组比较,I/R组及E组血清ALT活性、AST活性和肝细胞凋亡指数升高,线粒体膜电位降低(P＜0.05或0.01);与I/R组比较,E组血清ALT活性、AST活性和肝细胞凋亡指数降低,线粒体膜电位升高(P＜0.05).E组肝组织病理学损伤轻于I/R组.结论 依达拉奉可减轻大鼠肝脏缺血再灌注损伤,其机制与升高线粒体膜电位,抑制肝细胞凋亡有关.     

依达拉奉对肝缺血再灌注损伤逆转作用的研究

目的研究依达拉奉影响肝脏缺血再灌注过程中TNF-α的表达情况,探讨依达拉奉对肝脏缺血再灌注损伤的逆转作用。方法将80只Wistar大鼠编号,根据计算机产生随机数字,前40为一组,后40为一组,分为实验组和对照组2组,建立常温下部分肝缺血再灌注损伤动物模型。在肝脏缺血再灌注损伤开始前1 h和开始时对实验组大鼠给予依达拉奉注射液10 ml,对照组则给予同等容量的生理盐水。分别于再灌注后0、1、2及4 h测定肝脏脂质过氧化物酶(LPO)和肝脏谷草转氨酶(AST)浓度;应用RT-PCR法检测肝组织TNF-αmRNA含量,并测定肝组织和血清中TNF-α水平;应用TUNEL染色法检测缺血肝组织的细胞凋亡情况。结果再灌注后1、2及4 h,实验组大鼠肝脏LPO及AST浓度均明显低于对照组(P<0.001);实验组再灌注后1 h时肝组织TNF-αmRNA表达量、肝组织和血清TNF-α含量均明显升高且达峰值,但均明显低于对照组(P<0.05);再灌注后各时相实验组肝细胞凋亡率明显升高,但均明显低于对照组(P<0.05)。结论依达拉奉能抑制氧化应激反应,从而降低肝缺血再灌注损伤;并显著减少炎性细胞因子TNF-α的产生,抑制炎性反应的发生,减少肝细胞的凋亡。     

依达拉奉对深低温停循环肺的保护作用

目的 观察深低温停循环(DHCA)肺缺血期间经肺动脉灌注含依达拉奉保护液对术后肺组织及肺功能的影响,并探讨其可能的机制. 方法 24只健康新西兰大耳白兔随机分为3组,对照组:建立DHCA体外循环(CPB)模型;低钾右旋糖酐(LPD)组:在DHCA开始后经肺动脉灌注LPD保护液;依达拉奉组:在DHCA开始后经肺动脉灌注含依达拉奉(5 mg/kg)的LPD保护液.观察3组基础状态、恢复通气时、恢复通气1h、2h的肺氧合指数和肺顺应性变化,比较3组术后肺功能的变化,并检测肺静脉血中丙二醛(MDA)、超氧化物歧化酶(SOD)含量.3组兔均于术后处死,取肺组织行HE染色、免疫组化检测,观察肺组织结构、炎症反应情况,采用透射电子显微镜观察肺组织超微结构改变. 结果 3组肺氧合指数、肺顺应性、MDA和SOD在基础状态下差异均无统计学意义(P＞0.05),恢复通气后3组氧合指数和肺顺应性均有不同程度恶化,对照组和LPD组氧合指数和肺顺应性于恢复通气时、恢复通气1h、2h均明显低于依达拉奉组[恢复通气时氧合指数对照组与依达拉奉组比较:(198.25±11.02)mm Hg vs.(244.87±13.05) mm Hg;恢复通气1h肺顺应性对照组与依达拉奉组比较:(45.88±1.64) ml/cm H2O vs.(59.75±2.38) ml/cm H2O;P＜0.05].CPB结束后3组MDA浓度均有不同程度上升,对照组和LPD组血MDA浓度于CPB结束、CPB结束1h、2h均明显高于依达拉奉组(P＜0.05).CPB结束后3组SOD活性均有不同程度降低,对照组和LPD组血SOD活性于CPB结束、CPB结束1h、2h均明显低于依达拉奉组(P＜0.05).HE染色显示依达拉奉组肺组织结构清晰、红细胞渗出少、炎症细胞浸润较少、肺泡内液体聚集少;免疫组化检测显示依达拉奉组IL-6的光密度积分(IOD)值与LPD组(14.44±1.75 vs.20.18±2.22,P＜0.05)和对照组比较明显降低.电子显微镜观察依达拉奉组基膜结构完整,血气屏障结构清晰,Ⅱ型上皮细胞数量明显增多,胞质内线粒体及板层小体丰富,未见肿胀;而LPD组和对照组肺组织均有不同程度的破坏. 结论 采用肺动脉灌注低温肺组织保护液可明显减轻DHCA CPB中的肺组织损伤,在低温保护液中加入依达拉奉可进一步减轻肺组织损伤,保护肺氧合功能.     

依达拉奉联合肢体远隔缺血后处理对大鼠心肌缺血-再灌注损伤的影响

目的评价依达拉奉后处理联合肢体远隔缺血后处理(RIP)对大鼠心肌缺血-再灌注损伤的影响。方法健康雄性SD大鼠60只,8周龄,体重250~300g,采用随机数字表法将其分为四组:缺血-再灌注组(C组)、依达拉奉后处理组(E组)、肢体RIP组(R组)、联合处理组(ER组),每组15只。采用结扎冠状动脉左前降支(LAD)30min、再灌注180min制备心肌缺血-再灌注模型。在再灌注前15min,E组和ER组静脉注射依达拉奉5mg/kg,C组和R组静脉注射生理盐水0.5ml;R组和ER组在结扎LAD 20min后用止血带结扎大鼠双后肢,持续10min实施RIP。再灌注后180min采集颈静脉血样,测定血浆肌酸激酶MB同工酶(CK-MB)活性、丙二醛(MDA)含量及血清心肌肌钙蛋白I(cTnI)浓度,采用伊文蓝+1%氯化三苯基四氮唑双重染色法分离坏死区与缺血区心肌评估心肌梗死面积(IS)。结果与C组比较,E组、R组及ER组各时点ST段抬高程度明显降低,IS、血清CK-MB活性、MDA含量及cTnI浓度明显降低(P<0.05)。与E组和R组比较,ER组各时点ST段抬高程度明显降低,IS、血清CK-MB活性、MDA含量及cTnI浓度明显降低(P<0.05)。结论依达拉奉后处理或肢体远隔缺血后处理对缺血-再灌注后心肌损伤有一定的保护作用,且联合应用的保护效果优于两者单独应用。     

异氟醚对大鼠肺缺血再灌注损伤的保护作用

目的 探讨异氟醚对大鼠肺缺血再灌注损伤的保护作用。方法 120只SD雄性大鼠，随机分成4组（n=30）：假手术组（S组）、缺血再灌注组（IR组）、异氟醚-缺血再灌注组（ISO-IR组）和异氟醚组（ISO-S组）。IR组、ISO-IR组建立肺缺血再灌注模型，ISO-IR组吸入1MAC异氟醚30min时行肺缺血再灌注，ISO-S组吸入1MAC异氟醚，不进行肺缺血再灌注。分别在缺血45min、再灌注30、60、120min处死6只大鼠，测定肺组织湿干比（W／D）、髓过氧化物酶（MPO）活性、中性粒细胞（PMN）膜表面CD18和肺组织ICAM-1mRNA表达、支气管肺泡灌洗液（BALF）中自细胞计数、沉渣白细胞分类和总蛋白（TP）浓度，并进行肺组织病理学检查。结果 再灌注期间IR组肺组织W／D、MPO活性、CDl8和ICAM-1mRNA表达、BALF中PMN百分比、TP浓度及PMN膜表面CD18表达均升高。而异氟醚预先给药减弱了缺血再灌注诱导的上述指标的升高。肺组织病理学检查显示异氟醚预先给药减轻了肺缺血再灌注损伤。结论 通过抑制PMN浸润和肺组织ICAM-1mRNA及CD18表达上调，缺血前吸入异氟醚对肺缺血再灌注损伤有一定的保护作用。     

依达拉奉后处理联合远隔缺血后处理对大鼠心肌缺血再灌注损伤的影响

目的 评价依达拉奉后处理联合远隔缺血后处理对大鼠心肌缺血再灌注损伤的影响.方法 健康雄性SD大鼠40只,8周龄,体重250～300 g,采用随机数字表法,将其分为5组(n=8):假手术组(S组)、缺血再灌注组(I/R组)、依达拉奉后处理组(E组)、远隔缺血后处理组(P组)、依达拉奉联合远隔缺血后处理组(EP组).采用结扎左冠状动脉前降支30 min,再灌注180 min制备心肌缺血再灌注模型.E组和EP组再灌注前1 min静脉注射依达拉奉3mg/kg;P组和EP组左冠状动脉结扎20 min时实施远隔后处理:用止血带结扎大鼠双后肢,持续10 min.于心肌缺血再灌注期间记录左心室峰压(LVSP)、左心室舒张末压(LVEDP)、左室内压最大上升速率(+dp/dtmax)、左室内压最大下降速率(-dp/dtmax).结果 与S组比较,其它各组再灌注期间LVSP、+dp/dtmax、-dp/dtmax降低,LVEDP升高(P＜0.05);与I/R组比较,E组、P组及EP组再灌注期间LVSP、+dp/dtmax、-dp/dtmax升高,LVEDP降低(P＜0.05);与E组和P组比较,EP组再灌注期间LVSP、+dp/dtmax、-dp/dtmax升高,LVEDP降低(P＜0.05).结论 依达拉奉后处理联合远隔缺血后处理可减轻心肌缺血再灌注损伤,且效果强于两者单独应用.     

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.     

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.     

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.