姜黄素预先给药对内毒素诱导大鼠急性肺损伤的作用

目的 研究姜黄素预先给药对内毒素诱导大鼠急性肺损伤的作用及其可能机制。方法 48只雄性Wistar大鼠，随机分为4组（n=12），对照组（S组）、姜黄素组（C组）分别静脉注射10％二甲基亚砜（DMSO）2 ml／kg、姜黄素40 mg／kg（溶于DMSO），30 min后静脉注射生理盐水2 ml／kg;内毒素组（L组）、姜黄素预先给药组（C-L组）分别静脉注射10％DMSO 2 ml／kg、姜黄素40 mg／kg，30 min后静脉注射脂多糖（LPS）6 mg／kg。注射LPS后4 h处死动物。每组中6只大鼠在处死前15 min静脉注射伊文思蓝（EB）20mg／kg，用于测定肺组织EB含量，每组的其余大鼠用于测定支气管肺泡灌洗液（BALF）中髓过氧化物酶（MPO）活性和中性粒细胞（PMN）计数及肺组织湿干重比（W／D）、MPO活性、PMN趋化因子-1（CINC-1）mRNA、CINC蛋白表达，并在光镜下观察肺组织病理学改变。结果 与S组比较，L组BALF中MPO、PMN计数和肺组织W／D、EB及MPO、CINC-1 mRNA、CINC蛋白水平升高（P〈0．05或0．01），C组上述指标差异均无统计学意义（P〉0．05）;与L组比较，C-L组上述指标均降低（P〈0．05或0．01）。C-L组肺组织病理学损伤较L组减轻。结论 姜黄素40mg／kg预先给药对内毒素诱导急性肺损伤大鼠肺产生一定的保护作用，与下调肺组织CINC-1的表达进而抑制PMN在肺组织的聚集、激活有关。     

内毒素性肺损伤外周血中性粒细胞CD11b表达的意义

目的：探讨内毒素血症大鼠外周血中性粒细胞（PMN）表面CD11b表达与内毒素性肺损伤的关系。方法：大肠杆菌E-Coli O111B4 4mg／kg尾静脉注射制备大鼠内毒素血症动物模型。112只大鼠随机分为对照组（静脉注射等量生理盐水）及内毒素注射后1h组、2h组、4h组、8h组、12h组、24h组,每组16只动物。在相应时间点放血处死动物,分别取股静脉血、肺组织及进行支气管肺泡灌洗,测定肺组织湿／干重（W／D）比值、肺组织髓过氧化物酶（MPO）活性和支气管肺泡灌洗液（BALF）总蛋白定量等肺损伤指标。流式细胞仪测定外周血PMN表面CD11b表达。另取16只大鼠,内毒素注射后2h时测定外周血PMN表面CD11b表达,24h时放血处死,测定上述指标。结果：①大鼠内毒素血症可以造成明显的急性肺损伤,表现为肺组织W／D比值、MPO活性和BALF总蛋白明显增高,分别在2h、8h和2h显著高于对照组（P〈0．05或P〈0．01）,峰值分别出现在内毒素注射后12h、24h和12h;②大鼠内毒素性肺损伤时,外周血PMN表面CD11b表达水平在早期（1h）明显升高（与对照组比较,P〈O．05）,在2h达到峰值,之后逐渐降低;③外周血CD11b表达峰值明显早于肺组织W／D比、MPO和BALF总蛋白等肺损伤指标的峰值出现时间;④同一动物2h时外周血PMN表面CD11b的表达水平与其24h时肺组织W／D比、MPO和BALF总蛋白含量呈显著正相关（r分别为0．78、0．77和0．73,P〈0．05）。结论：内毒素性肺损伤中,外周血CD11b表达升高可能有助于内毒素性肺损伤的早期诊断,并可能预示以后的肺损伤程度。     

阿米洛利预先给药对大鼠内毒素性急性肺损伤的影响

目的 探讨阿米洛利预先给药对大鼠内毒素性急性肺损伤的影响.方法 清洁级雄性SD大鼠32只,体重200～250 g,随机分为4组(n=8):对照组(C组)、急性肺损伤组(ALI组)、阿米洛利组(A组)和阿米洛利预先给药组(AL组).C组股静脉输注生理盐水3 ml,ALI组股静脉输注生理盐水1 ml、内毒素6 mg/kg,A组股静脉输注阿米洛利10 mg/kg、生理盐水2 ml,AL组股静脉输注阿米洛利10 mg/kg、内毒素6 mg/kg,输注速率均为0.05 ml/rain,给药间隔均为30 min.于输注内毒素结束后6 h时处死大鼠取肺,观察肺组织病理学,并行病理学评分,称重后计算肺湿干重比,检测髓过氧化物酶(MPO)活性,测定支气管肺泡灌洗液总蛋白、TNF-α和巨噬细胞炎性蛋白-2(MIP-2)的浓度,采用Western blot法检测肺组织钠氢交换体1(NHE1)、p38丝裂原活化蛋白激酶(p38MAPK)和细胞外信号调节激酶(ERK)的表达水平.结果 与C组比较,ALI组和AL组肺组织病理学评分、肺湿干重比、MPO活性、支气管肺泡灌洗液总蛋白、TNF-α和MIP-2浓度、肺组织NHE1、p38MAPK和ERK的表达水平明显升高(P＜0.01),A组上述指标差异无统计学意义(P＞0.05);与ALI组比较,AL组肺组织病理学评分、肺湿干重比、MPO活性、支气管肺泡灌洗液总蛋白、TNF-α和MIP-2浓度、肺组织NHE1和ERK的表达水平明显降低(P＜0.01),p38MAPK表达差异无统计学意义(P＞0.05).结论 阿米洛利预先给药可减轻大鼠内毒素性急性肺损伤,其机制可能与抑制ERK信号转导通路激活有关.     

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。     

N-乙酰半胱氨酸对大鼠急性胰腺炎肺损伤的治疗保护作用

目的探讨急性坏死性胰腺炎(ANP)大鼠肺损伤与肺组织细胞问粘附分子-1(ICAM-1)、肿瘤坏死因子-α(TNF-α）mRNA表达的关系及N-乙酰半胱氨酸(NAC)对肺损伤的作用。方法26只Wistar大鼠随机分为正常对照、盐水对照、胰腺炎和胰腺炎 NAC四组。以3．5％牛磺胆酸钠逆行注入胰胆管制作ANP模型，并将NAC(300mg／kg)于造模后1h用于ANP模型，造模后12h取材。采用RT-PCR法检测肺组织ICAM-1及TNF-α mRNA表达，同时观察血脂肪酶、胰腺组织湿／干重比率、肺组织髓过氧化物酶(MPO)及病理改变。结果ANP有肺组织学损伤改变，同时伴有肺组织ICAM-1、TNF-α mRNA高表达及MPO活力升高。胰腺炎 NAC组与胰腺炎组比较，胰腺湿／干重比率、肺组织ICAM-1、TNF-α mRNA的表达及MPO均降低。肺组织病理损伤程度与ICAM-1、TNF-α mRNA表达及MPO均呈正相关，相关系数分别为0．92、0．68及0．92(P＜0．01)。肺MPO与ICAM-1、TNF-α mRNA表达也呈正相关，相关系数为0．87及0．77(P＜0．01)。结论NAC可能通过抑制肺ICAM-1、TNF-a mRNA的产生及中性粒细胞的聚集，减轻AP所致的肺损伤；对胰腺本身的损伤也可能有一定的保护作用。     

丹参对大鼠内毒素休克性肺损伤的保护作用

目的　探讨丹参对内毒素休克性肺损伤的防治作用。方法　选用SD大鼠 5 4只 ,随机分成对照组、肺损伤组和丹参防治组。三组动物根据注入内毒素后时间不同分为 1、2和 4小时三小组。丹参防治组按 8g/kg体重经颈静脉注入丹参 ,30分钟后 ,再按 5mg/kg体重经颈静脉注入大肠杆菌内毒素 ;肺损伤组以生理盐水代替丹参 ;对照组中 ,丹参和内毒素均以等量生理盐水代替。实验结束后 ,取血和肺组织行血浆P 选择素、肺组织MPO活性、肺毛细血管通透性和血液流变学检测。结果　 (1)肺损伤组各时相点血浆P 选择素、肺组织MPO活性、肺毛细血管通透性均较对照组显著增高 (P <0 0 1) ;丹参防治组较肺损伤组有所下降 ,以 4小时为甚 (P <0 0 1)。 (2 )肺损伤组血液流变学指标较对照组明显升高 (P <0 0 1) ;丹参防治组与肺损伤组比较 ,血液流变学指标有不同程度的降低 ,以高中切变率 ηb和ERI差异有显著 (P <0 0 5或P <0 0 1)。 结论　丹参通过改善血液流变性 ,抑制P 选择素介导的PMN的浸润发挥对肺损伤的保护作用     

金雀异黄素预先给药对大鼠机械通气所致肺损伤的作用

目的 研究特异性蛋白酪氨酸激酶抑制剂金雀异黄素预先给药对大鼠机械通气所致肺损伤（VILI）的作用。方法 30只健康SD大鼠，随机分为3组，每组10只，A组采用8ml／kg潮气量机械通气；B组采用40ml／kg潮气量机械通气；C组采用40ml／kg潮气量机械通气，并在机械通气前30min腹腔注射金雀异黄素50mg／kg。3组呼吸频率均为80次／min，吸／呼比（I：E）为1：1，PEEP为0，吸人气体为室内空气。机械通气2h后处死大鼠，取肺组织，光镜下观察病理学，测定髓过氧化物酶（MPO）活性、磷酸化p38（p-p38）、p38水平；收集支气管肺泡灌洗液，测定总蛋白、肿瘤坏死因子-α（TNF-α）水平，并进行白细胞（WBC）计数。结果与A组比较，B组支气管肺泡灌洗液总蛋白、WBC计数、TNF-α及肺组织MPO、P—p38／p38水平升高（P〈0．05或0．01），肺组织病理学改变严重；与B组比较，C组上述指标降低（P〈0．01或0．05），肺组织病理学改变明显减轻。结论 金雀异黄素50mg／kg预先给药可减轻大鼠VILI，其机制与抑制了p38通路的激活有关。     

血红素加氧酶-1对TNF-α引起内皮细胞炎症损伤的保护作用

目的探讨血红素加氧酶-1(HO-1)在肿瘤坏死因子-α(TNF-α)导致肺微血管内皮细胞损伤中的保护作用。方法采用TNF-α刺激人肺微血管内皮细胞(HPMECs)模拟重症急性胰腺炎肺损伤的体外模型,锌原卟啉-IX(ZNPP-IX)作为HO-1抑制剂预处理细胞。试验分为对照组、TNF-α组、ZNPP-IX组。CCK8比色法检测细胞活性,采用Western blotting法及RT-PCR法检测HO-1、细胞间黏附分子-1(ICAM-1)的表达,黏附试验检测HPMECs对多形核细胞(PMN)的黏附力。结果 1与对照组相比,TNF-α组(78.69%±5.54%)、ZNPP-IX组(62.00%±4.27%)细胞活性明显降低(P0.01);2与对照组相比,TNF-α组(1.59±0.19)HO-1表达增高(P0.05),ZNPP-IX组(0.01±0.01)比TNF-α组显著降低(P0.01);3与对照组相比,TNF-α组(32.72±0.95)、ZNPP-IX组(85.33±2.37)ICAM-1表达明显升高(P0.01),且ZNPP-IX组比TNF-α组更显著(P0.01);4TNF-α引起HPMECs对PMN黏附力增高,抑制HO-1表达后,黏附作用增强。结论 HO-1可能通过下调ICAM-1的表达降低炎症时HPMECs对PMN的黏附,从而改善重症急性胰腺炎引起的肺损伤。     

虫草多糖预先给药对大鼠内毒素性急性肺损伤的影响

目的 评价虫草多糖预先给药对大鼠内毒素性急性肺损伤的影响.方法 雄性成年SD大鼠40只,体重190～220 g,随机分为5组(n=8):虫草多糖预先给药组(CP1-3,组)采用灌胃法分别给予虫草多糖1、2、3 g/ks,1次/12 h,连续6次,于最后1次给药后2 h时经股静脉注射内毒素5 mg/kg;急性肺损伤组(ALI组)以生理盐水1ml/100 g代替虫草多糖,其余方法同CP组;对照组(C组)以生理盐水1 ml/100 g代替虫草多糖和内毒素,其余方法同CP组.静脉注射内毒索后6 h时处死大鼠,计算肺湿干重比(W/D)、肺渗透指数(PPI);行支气管肺泡灌洗,对支气管肺泡灌洗液(BALF)行白细胞(WBC)和多形核白细胞(PMN)计数;测定肺组织及BALF肿瘤坏死因子α(TNF-α)水平,并行肺组织病理学评分.结果 与C组比较,ALI组和CP1～3组肺W/D、PPI、WBC和PMN计数、肺组织病理学评分、肺组织和BALF TNNF-α水平均升高(P<0.05或0.01);与ALI组比较,CP1组上述指标差异无统计学意义(P>0.05),CP2,3组上述指标降低(P<0.05);与CP2组比较,CP3组PMN计数、肺组织病理学评分、肺组织和BALFTNF-α水平降低(P<0.05).结论 虫草多糖预先给药可减轻大鼠内毒素性急性肺损伤,且呈剂量依赖性,其机制可能与虫草多糖降低肺组织炎性反应有关.     

谷氨酰胺对内毒素性急性肺损伤大鼠肺组织肿瘤坏死因子-α表达的影响

目的评价谷氨酰胺对内毒索性急性肺损伤(ALI)大鼠肺组织肿瘤坏死因子-α(TNF-α)表达的影响。方法静脉注射脂多糖(LPS)5 mg·kg-1复制大鼠ALI模型。雄性SD大鼠50只随机分为5组(n=10):A组为对照组;B组为LPS组;C组、D组、E组为谷氨酰胺+LPS组,分别于LPS注射前1h时、LPS注射同时、LPS注射后1 h静脉注射谷氨酰胺0．75 g／kg。所有动物于注射LPS或生理盐水后4 h颈动脉放血处死,采用逆转录聚合酶链反应方法检测肺组织TNF-αmRNA表达,免疫组织化学方法检测肺组织TNF-α蛋白表达,HE染色,光镜下观察肺组织病理学变化。结果与A组相比,B组TNF-αmRNA表达上调(P<0．01),肺泡巨噬细胞、中性粒细胞、上皮细胞表达增强(P<0．01);与B组相比,C组和D组肺组织TNF-αmRNA及TNF-α蛋白水平均降低(P<0．01),肺组织的炎症反应减轻。结论在静脉注射LPS前或同时给予谷氨酰胺可通过抑制ALI大鼠肺组织TNF-α的过度生成,减轻肺损伤。     

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.