盐酸戊乙奎醚预先给药对大鼠内毒素性急性肺损伤的影响

目的研究盐酸戊乙奎醚预先给药对内毒素诱导大鼠急性肺损伤(ALI)的影响及其机制。方法40只雄性SD大鼠随机分为5组(n=8),对照组(C组):腹腔和尾静脉均注射生理盐水1 ml/kg;模型组(L组):腹腔注射生理盐水1 ml/kg,30 min后经尾静脉注射脂多糖(LPS)5mg/kg;盐酸戊乙奎醚低剂量组(DL组)、中剂量组(DM组)和高剂量组(DH组)分别腹腔注射盐酸戊乙奎醚0.03 mg/kg、0.1 mg/kg、0.3 mg/kg,30 min后经尾静脉注射LPS 5 mg/kg。LPS注射后4 h放血处死动物。检测肺组织湿/干重比(W/D)、肺通透性指数(LPI)、髓过氧化物酶(MPO)活性、丙二醛(MDA)水平和超氧化物歧化酶(SOD)活性;检测支气管肺泡灌洗液蛋白浓度、乳酸脱氢酶(LDH)活性和中性粒细胞数;测定血清MDA水平和SOD活性;光镜观察肺组织形态学改变;电镜观察肺组织超微结构。结果与C组比较, L组、DL组、DM组和DH组肺W/D、肺含水量、LPI、支气管肺泡灌洗液LDH活性增加,支气管肺泡灌洗液中性粒细胞数和肺组织MPO活性、肺组织和血清MDA水平升高,SOD活性降低(P<0.05);与L组相比,DL组、DM组和DH组肺W/D、肺含水量、LPI、支气管肺泡灌洗液LDH活性降低,支气管肺泡灌洗液中性粒细胞数和肺组织MPO活性以及肺组织和血清MDA水平降低,SOD活性升高(P<0.05); DL组、DM组和DH组各指标组间差异无统计学意义(P>0.05)。光镜、电镜观察:盐酸戊乙奎醚预先给药各组肺组织病理学变化较L组减轻。结论盐酸戊乙奎醚预先给药可减轻内毒素诱导的大鼠急性肺损伤。     

促红细胞生成素预先给药对大鼠内毒素性急性肺损伤的影响

目的 探讨促红细胞生成素(EPO)预先给药对大鼠内毒素性急性肺损伤的影响.方法 成年雄性SD大鼠32只,体重180～220 g,随机分为4组(n=8),C组腹腔注射生理盐水4 ml/kg(EPO溶剂对照),30 min后静脉注射生理盐水2 ml/kg[脂多糖(LP3)溶剂对照];EPO组腹腔注射EPO3 000 U/kg,30 min后静脉注射生理盐水2 ml/kg;LPS组腹腔注射生理盐水4 ml/kg,30 min后静脉注射LPS 6 mg/kg;EPO+LPS组腹腔注射EPO 3 000 U/kg,30 min后静脉注射LPS 6 mg/kg.于静脉注射LPS后4 h时处死大鼠,观察肺组织病理学结果 ,计算肺组织湿/干重(W/D)比;测定肺组织髓过氧化物酶(MPO)活性和丙二醛(MDA)、一氧化氮(NO)含量;采用Western blot法测定肺组织诱导型一氧化氮合酶(iNOS)和硝基酪氨酸(NT)的表达.结果 与C组相比,LPS组和EPO+LPs组肺组织W/D比、MPO活性、MDA和NO含量升高,iNOS和NT表达上调(P<0.01);与LPS组相比,EPO+LPS组肺组织W/D比、MPO活性、MDA和NO含量降低,iNOS和NT表达下调(P<0.01).结论 EPO预先给药可减轻大鼠内毒素性急性肺损伤,与其下调iNOS表达,减少NO生成有关.     

罗格列酮预先给药对内毒素诱导大鼠急性肺损伤的保护作用

目的 研究过氧化物酶体增殖物激活受体γ(PPARγ)激动剂-罗格列酮预先给药对内 毒素(LPS)诱导急性肺损伤(ALI)的影响。方法 36只雄性Wistar大鼠,随机分为6组,每组6只:对 照组(DMSO)、ROSI、GW组分别静脉注射10％二甲基亚砜(DMSO)2 ml／kg、罗格列酮0．3 mg／kg或 GW9662 0．3 mg／kg,30 min后静脉注射生理盐水2 ml／kg;LPS、ROSI LPS组分别静脉注射10％DMSO、 罗格列酮0．3 mg／kg,30 min后静脉注射LPS 6 mg／kg;GW ROSI组处理同ROSI LPS组,但在给予罗格 列酮前20min静脉注射GW9662 0．3mg／kg。注射LPS后4 h处死大鼠,光镜下观察肺组织病理学变化, 测定肺组织湿／干重比(W／D)、髓过氧化物酶(MPO)活性、丙二醛(MDA)和一氧化氮(NO)含量,检测肺 组织诱导型NO合酶(iNOS)和硝基酪氨酸(NT)的蛋白表达。结果 与DMSO比较,LPS组肺损伤严 重,W／D、MPO活性、MDA和NO含量升高(P<0．01),肺组织iNOS、NT的蛋白表达增加(P<0．05或 0．01)。与LPS组比较,ROSI LPS组肺损伤明显减轻,W／D、MPO活性、MDA和NO含量降低(P< 0．01),肺组织iNOS和NT的蛋白表达减弱。PPARγ拮抗剂GW9662能逆转罗格列酮的作用。结论 罗格列酮预先给药对内毒素诱导的ALI具有一定的保护作用,其机制与激活PPARγ有关。     

体温对内毒素致急性肺损伤大鼠肺微血管通透性的影响

目的探讨亚低温和高温对内毒素致急性肺损伤(ALI)大鼠肺微血管通透性的影响。方法健康雄性SD大鼠48只,体重300～350 g,随机分为4组(n=12),常温对照组(A组)静脉注射37℃生理盐水;常温内毒素组(B组)静脉注射脂多糖(LPS)5 mg·kg-1;亚低温 内毒素组(C组)静脉注射LPS 5 mg·kg-1,维持直肠温31.5～32℃;高温 内毒素组(D组)静脉注射LPS 5 mg·kg-1,维持直肠温39.5～40℃。动脉血氧合指数(PaO2/FiO2)≤300 mm Hg即ALI模型制备成功。于ALI 6 h后处死大鼠,取肺组织,清洗固定后测定肺微血管通透性指标:肺湿/干重量比(W/D)、肺泡灌洗液(BALF)蛋白(BALFpro)、肺通透性指数(PPI)、肺微血管通透性指数(PMPI)及肺组织硝基酪氨酸(NT)、髓过氧化物酶(MPO)、丙二醛(MDA)含量,观察肺组织病理学改变。结果与A组比较,B组、C组、D组PPI、W/D、BALFpro、PMPI和肺组织MPO、MDA、NT均升高(P<0.05);与B组比较,C组上述指标降低,D组上述指标升高(P<0.05);与C组比较,D组PPI、W/D、BALFpro、PMPI和肺组织MPO、MDA、NT升高(P <0.05)。结论高温加重内毒素血症大鼠ALI程度,亚低温通过抑制ONOO-生成,抑制了肺微血管通透性的升高,可减轻大鼠内毒素致ALI。     

七氟醚预处理对大鼠内毒素性急性肺损伤的影响

目的 探讨七氟醚预处理对大鼠内毒素性急性肺损伤的影响.方法 健康雄性SD大鼠24只,体重220～250 g,随机分为4组(n=6):对照组(c组)、内毒素组(LPS组)、七氟醚组(Sev组)和七氟醚预处理组(SP组).C组和LPS组机械通气30 min后分别静脉注射生理盐水和脂多糖(LPS)5 mg/kg;Sev组和SP组吸入七氟醚(呼气末浓度2.4%)30 min,洗脱5 min,然后分别静脉注射生理盐水和LPS 5 mg/kg.于给予LPS或生理盐水后6 h时,心脏放血处死大鼠,取肺组织,计算湿重/干重(W/D)比;采用弥漫性肺泡损伤(DAD)评分评价肺组织损伤程度;测定肺组织髓过氧化物酶(MPO)活性、细胞因子诱导中性粒细胞化学趋化因子-1(CINC-1)含量、CINC-1和CINC-1 mRNA的表达水平.结果 与C组比较,LPS组和SP组肺组织W/D比、DAD评分、MPO活性和CINC-1含量升高,CINC-1和CINC-1 mRNA的表达上调(P<0.01),Sev组上述指标差异无统计学意义(P>0.05);与LPS组比较,SP组肺组织W/D比、DAD评分、MPO活性和CINC-1含量降低,CINC-1和CINC-1 mRNA的表达下调(P<0.01).结论 七氟醚预处理可减轻大鼠内毒素性急性肺损伤,可能与其抑制肺组织炎性反应有关.     

氟比洛酚酯对内毒素急性肺损伤中性粒细胞肺内聚集与氧自由基损伤的抑制作用

目的 探讨氟比洛酚酯(FA)预处理对内毒素及脂多糖(LPS)所致急性肺损伤(ALI)的保护作用.方法 雄性SD大鼠40只,随机分为A1组和A2组(尾静脉注射LPS 5 mg/kg)、FA干预的F1组和F2组(注射LPS前1h,静脉注射FA 6 mg/kg)和脂微球对照组(C组),每组8只.每组给药固定容积1 ml/kg,A1、F1组和A2、F2组分别于LPS注入2、4 h后处死动物.测定动脉血氧合指数(PaO2/FiO2)、肺组织湿干质量(W/D)比值,支气管肺泡盥洗液(BALF)里中性粒细胞(PMN)百分比和乳酸脱氢酶(LDH)活性、肺髓过氧化物酶(MPO)活性,血浆及肺组织丙二醛(MDA)含量和超氧化物歧化酶(SOD)活性,计算肺细胞凋亡指数(AI),并进行肺组织病理学检查.结果 与A1、A2组比较,F1、F2组PaO2/FiO2明显升高(P＜0.05);LDH活性和W/D比值显著下降(P＜0.05);BALF中PMN百分比、肺MPO活性显著降低(P＜0.05);血浆及肺组织MDA含鼍下降,SOD活性升高(P＜0.05);AI下降(P＜0.05),但F1与F2组间差异无统计学意义.肺组织病理学检查显示F1与F2组内毒素引起的肺损伤较A1、A2明显减轻.结论 FA预处理对ALI有保护作用,其机制可能与抑制PMN聚集、减少氧自由基生成、降低肺细胞凋亡的作用有关.     

地氟醚对内毒素致急性肺损伤大鼠肺泡毛细血管膜通透性的影响

目的 研究地氟醚对内毒素致急性肺损伤鼠肺泡毛细血管膜通透性和肺泡灌洗液(BAIF)内炎性细胞的影响。方法 48只雄Wistar大鼠随机分为4组,每组12只,C组:生理盐水对照组,股静脉注射生理盐水1.2 ml后机械通气4 h;L组:股静脉注射内毒素(LPS)5 mg/kg后机械通气4 h;D1L和D2L组:股静脉注射LPS 5 mg/kg后机械通气,分别吸人1.0 MAC和1.5 MAC地氟醚4 h。每组有6只大鼠不注射伊万斯蓝,用于病理学检查及肺泡灌洗。测定肺组织病理形态学积分、肺湿/干重比(W/D)、肺水含量、肺通透指数(LPI)、伊万斯蓝(EB)含量、BALF内炎性细胞总数及百分比、大鼠死亡率。结果 与C组比较,L组病理形态学积分、W/D、肺水含量、LPI和EB含量均升高(P<0.05或0.01),D1L组病理形态学积分和LPI升高(P<0.01)。与L组比较,D1L组W/D、肺含水量和EB含量升高(P<0.05)。与D1L组比较,D2L组病理形态学积分升高(P<0.05)。与C组比较,L组、D1L组、D2L组炎性细胞总数、中性粒细胞、巨噬细胞、淋巴细胞均升高(P<0.01)。与L组、D1L组比较,D2L组死亡率升高(P<0.01)。结论 吸入大剂量地氟醚加重内毒素致急性肺损伤。     

富氢液对脂多糖致小鼠急性肺损伤的影响

目的 评价富氢液对脂多糖(LPS)致小鼠急性肺损伤的影响.方法 成年雄性C57BL/6小鼠32只,体重20 ～ 25 g,采用随机数字表法,将其分为4组(n=8):对照组(C组)、富氢液组(H2组)、急性肺损伤组(ALI组)和急性肺损伤+富氢液组(ALI+ H2组).ALI组和ALI+ H2组分别雾化吸入LPS25 μg(溶于PBS中)制备ALI模型,C组和H2组分别雾化吸入无菌PBS 50μl.H2组和ALI+H2组雾化吸入PBS或LPS后1和12 h时腹腔注射0.6 mmol/L富氢液5 ml/kg.LPS或PBS处理后24 h时,机械通气15 min,行动脉血气分析,计算氧合指数.然后收集支气管肺泡灌洗液(BALF),测定蛋白浓度,计数中性粒细胞(PMN).采用ELISA法检测BALF中TNF-α、IL-1β、IL-6和高迁移率族蛋白1(HMGB1)的浓度.然后处死小鼠,取肺组织,行病理学损伤评分,测定湿重/干重(W/D)比、髓过氧化物酶(MPO)和caspase-3的活性,计算细胞凋亡指数(AI).结果 与C组比较,H2组氧合指数、BALF总蛋白、TNF-α、IL-1β、IL-6和HMGB1的浓度和PMN计数、肺组织病理学损伤评分、W/D比、MPO和caspase-3的活性以及AI差异均无统计学意义(P＞0.05),ALI组和ALI+H2组氧合指数降低,BALF蛋白、TNF-α、IL-1β、IL-6和HMGB1的浓度、PMN计数、肺组织病理学损伤评分、W/D比、MPO和caspase-3 的活性以及AI均升高(P＜0.05);与ALI组比较,ALI+ H2组氧合指数升高,BALF总蛋白、TNF-α、IL-1β、IL-6和HMGB1的浓度、PMN计数、肺组织病理学损伤评分、W/D比、MPO和caspase-3的活性以及AI均降低(P＜0.05).结论 富氢液可减轻LPS致小鼠急性肺损伤,可能与其抗炎和抗凋亡作用有关.     

中度低温对内毒素诱导急性肺损伤大鼠肺泡毛细血管膜通透性的影响

目的探讨中度低温对脂多糖(LPS)诱导急性肺损伤(ALI)大鼠肺泡毛细血管膜通透性的影响。方法34只雄性SD大鼠,随机分为4组。腹腔注射LPS 1.0 mg·kg-1,16 h后在机械通气下气管内滴注1.5 mg·kg-1LPS(0.5 ml)方法建立ALI模型。正常对照组(C组,n=8):只给予等量的生理盐水;内毒素组(L组,n=10):给予LPS;低温组(H组,n=8):将体温降低并维持在32.5-33.0℃, 但不给予LPS;内毒素复合低温组(L H组,n=8):给予LPS,并且当氧合指数(PaO2/FiO2)≤300mm Hg 时将体温降低并维持在32.5-33.0℃。分别于ALI时、ALI后1、2、3、4 h记录平均动脉压(MAP)和中心静脉压(CVP),同时测定动脉血气的变化。于ALI后4 h处死大鼠,检测支气管肺泡灌洗液(BALF) 中白蛋白浓度、左肺湿/干重(W/D)及肺组织髓过氧化物酶(MPO)活性,电镜下观察肺泡毛细血管膜形态结构的变化。结果L组PaO2/FiO2降低(P<0.01),PaCO2在ALI后3、4 h升高(P<0.01);与L组比较,L H组PaO2,FiO2差异无统计学意义,但PaCO2在ALI后3、4 h降低(P<0.05)。与C组比较,L 组BALF中白蛋白浓度、W/D及肺组织MPO活性升高(P<0.01或0.05);而L H组上述指标则较L 组下降(P<0.01或0.05)。电镜结果:C、H组肺泡毛细血管膜结构基本正常;L组毛细血管内皮明显剥脱;而L H组毛细血管内皮剥脱程度较L组减轻。结论中度低温对ALI大鼠可通过减轻肺内PMN聚集,降低肺泡毛细血管膜通透性,在一定程度上减轻了肺损伤。     

甘草甜素对大鼠脓毒血症引起的急性肺损伤的保护作用

目的 观察甘草甜素(GL)对大鼠脓毒血症引起的急性肺损伤(ALI)的保护作用.方法 采用脂多糖(LPS)尾静脉注射诱导大鼠脓毒血症引起的AI模型.雄性SD大鼠30只,随机均分为五组:对照组(C组)、模型组(S组.静注LPS 7.5 mg/kg)、GL处理组(GL1、GL2、GL3组,分别于静注LPS 7.5 mg/kg前10 min腹腔注射GL、30、60、120 mg/kg).LPS静沣后12 h,测定各组大鼠支气管肺泡灌洗液(BALF)中自细胞总数、总蛋白的含量、肺组织髓过氧化物酶(MPO)活性和湿干重比值.并观察肺组织病理学变化.结果 与C组相比.S组BALF中白细胞计数、总蛋白含量、肺组织MPO活性和湿千重比值明显增加(P<0.05);S组肺组织切片观察见明显的炎细胞浸润、充血、水肿等.与S组相比,GL1、GL2、GL3组BALF中白细胞计数、总蛋白含量、肺组织MPO活性和肺组织湿干重比值均降低(P<0.05).病理学损伤也减轻;GL3组损伤减轻较GL1、GL2组更为明显(P<0.05).结论 GL可减轻肺泡毛细血管屏障的损伤,并随着剂量的加大损伤减轻更加明显,对脓毒血症引起的急性肺损伤具有保护作用.     

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.     

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.     

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.     

Dilemma of Membrane Biocompatibility and Reuse

Abstract: Numerous articles have been published on the multiple use of dialyzers and on the effect of different reprocessing chemicals and techniques on the dialyzer biocompatibility and performance. The results often appear contradictory, especially those comparing standard biocompatibility parameters. Despite this confusion, a discerning review of the published works allows certain limited conclusions to be drawn. Reprocessing of used hemodialyzers changes the biocompatibility profile of a dialyzer as defined by the parameters complement activation. leukopenia, and cytokine release. The effect of reprocessing depends on the chemicals and reprocessing technique applied and also on the type of membrane polymer being subjected to the reprocessing procedure. Reports of pyrogenic reactions indicate that the flux of the membrane also influences how suitable it is for safe reuse. An increased risk of allergic and pyrogenic reactions appears to be associated with dialyzer reuse. Furthermore, there has been a lack of investigations into the immunologic effect of the layer of adsorbed and chemically altered proteins that remains on the inner surface of reprocessed dialyzers. We conclude that the clinical benefit of dialyzer reuse cannot be generally accepted from a biocompatibility point of view.     

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.