静脉注射携带人白介素-10的腺病毒载体对肝硬化大鼠肝缺血再灌注损伤的保护作用

目的探讨静脉注射携带hIL-10腺病毒载体对淤胆性肝硬化大鼠肝常温缺血再灌注损伤的保护作用。方法结扎SD大鼠的胆总管建立淤胆性肝硬化模型,4周后通过每只尾静脉注射Ad-hIL10-EGFP1×109PFU/ml,体内转染72h后,进行常温肝缺血再灌注损伤实验(缺血15min,再灌注60min)。经静脉取血,进行肝功能生化检测,再通过酶联免疫吸附法(ELISA)检测大鼠血清内hIL-10的表达情况。并取肝脏冰冻切片,用倒置荧光显微镜观察肝组织中EGFP的表达,石蜡切片HE染色观察肝脏的组织形态变化;免疫组化方法观察肝脏内hIL-10的表达情况;Tunel法检测肝脏内细胞凋亡情况。结果治疗组的肝脏冰冻切片,荧光显微镜下可见EGFP的表达;同时免疫组化有较多的hIL-10染色;ELISA检测血清中hIL-10的表达量为(723·8±301·7)ng/ml。相对应的是,治疗组的肝功能较对照两组明显改善,组织病理改变较对照两组减轻,肝细胞凋亡数量明显减少,差异有显著意义(P<0·05)。结论hIL-10肝脏基因治疗可以减轻肝硬化大鼠的肝缺血再灌注损伤,其机制可能是减少肝缺血再灌注损伤过程中肝细胞凋亡的数量。     

内质网应激分子伴侣GRP78在大鼠缺血再灌注损伤肝脏中的表达

目的:观察内质网应激相关分子葡萄糖调节蛋白78(GRP78)在大鼠缺血再灌注损伤肝脏组织中的表达水平.方法:将24只健康雄性SD大鼠随机均分为假手术组,单纯肝缺血组(肝缺血30 min+再灌注0h),再灌注6h组(肝缺血30 min+再灌注6h)和再灌注12h组(肝缺血30 min+再灌注12h).分别检测各组血清丙氨酸转氨酶(ALT)和门冬氨酸转氨酶(AST)水平;肝组织病理学、凋亡情况及GRP78 mRNA表达水平.结果:与对照组比较,各实验组大鼠肝缺血后出现明显的肝组织损伤,且随着再灌注时间的延长损伤加重,表现为血清ALT和AST水平升高,明显的肝组织病理学改变,肝细胞凋亡率增加,各组间计量指标的差异均有统计学意义(均P＜0.05).大鼠肝组织GRP78 mRNA变化趋势与上述指标一致,缺血后表达明显上调,且随着再灌注时间延长而逐渐升高,各组间差异均有统计学意义(均P＜0.05).结论:缺血再灌注损伤肝脏组织中GRP78表达上调,但其具体作用还有待于探明.     

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。     

缺血预处理对大鼠肝脏缺血/再灌注早期核因子κB活性及细胞凋亡的影响

目的 观察缺血预处理对大鼠肝脏缺血/再灌注早期核因子KB活性、促凋亡基因Fas和FasL蛋白表达以及肝细胞凋亡的影响,以进一步阐明肝脏缺血预处理的抗凋亡作用机制.方法 建立SD大鼠肝缺血(40min)再灌注(120 min)损伤及肝缺血预处理的模型.24只大鼠随机分成3组(n=8).①假手术对照组(C组),仅分离肝十二指肠韧带,不阻断肝门,不进行其他干预处理.②缺血再灌注组(IR组),在第一肝门用小血管夹阻断尾状叶及左肝叶血流40 min松开血管夹肝脏再灌注2 h,再灌注开始后关腹.③缺血预处理组(IP组),先行3个循环的缺血预处理,阻断第一肝门10 min,开放再灌注10 min为1个循环,随后操作同缺血/再灌注组.实验结束后全自动生化分析仪检测血清谷草转氨酶和血清谷丙转氨酶活性:TUNEL法检测肝组织的细胞凋亡指数(AI):EMSA法测定肝组织核因子κB的结合活性:Western blotting免疫印迹法检测Fas及FasL蛋白的表达水平.结果 IR组和IP组的ALT、AST及细胞凋亡指数(AI)均明显高于S组(P<0.01),但与IR相比,IP组则明显较低(P<0.01).与C组比较,IR组的核因子κB活性、促凋亡基因Fas和FasL蛋白表达水平明显增高,而IP组仅轻度增高.结论 缺血预处理可通过降低肝脏缺血/再灌注早期核因子κB的转录活性,并下调促凋亡基因Fas及FasL的表达,从而发挥抗细胞凋亡和损伤保护效应.     

缺血后处理对大鼠移植肝缺血再灌注损伤的保护作用

目的探讨在体条件下缺血后处理对大鼠移植肝缺血再灌注损伤的保护作用及其可能机制。方法采用SD大鼠原位肝移植模型,供肝冷保存时间100min,无肝期控制于18min以内,60只雄性健康SD大鼠随机分为3组,对照组12只,缺血再灌注损伤组和后处理组各24只。对照组开腹后仅游离肝周韧带;缺血再灌注损伤组受体大鼠供肝切除前仅以肝素化生理盐水经门静脉灌注;后处理组供肝植入后完全再灌注前,给予多次短暂复灌复停作为缺血后处理。缺血再灌注损伤组、后处理组受体一半（6只）于再灌注后2h留取血液及肝组织,另一半（6只）于再灌注后6h留取肝组织。对照组于关腹后相应时间留取血液及肝组织。各组分别检测肝功能,采用酶联免疫吸附法测定血清肿瘤坏死因子Or．和中性粒细胞弹性蛋白酶。根据酶促反应原理,利用分光光度仪测定肝脏谷胱甘肽过氧化物酶、丙二醛、髓过氧化物酶、超氧化物歧化酶。肝组织HE染色后光镜下观察组织学变化。结果缺血再灌注损伤组和后处理组血清肝功能指标、炎性细胞因子水平及肝组织过氧化物含量均高于对照组（P〈0．05）,而后处理组较缺血再灌注损伤组则明显低（P〈0．05）;缺血再灌注损伤组和后处理组肝组织抗氧化酶活力显著低于对照组（P〈0．05）,而后处理组较缺血再灌注损伤组则明显高（P〈0．05）。结论缺血后处理对大鼠移植肝的缺血再灌注损伤有明显的保护作用。提高组织的抗氧化能力和降低炎性细胞因子水平可能是缺血后处理保护作用的机制之一。     

17-β雌二醇对大鼠肝切除肝缺血再灌注损伤肝细胞凋亡和Bcl-2、Bax表达的影响

目的 观察17-β雌二醇预处理对肝切除肝缺血再灌注损伤肝脏组织细胞凋亡及Bcl2、Bax表达的影响,并探讨其肝保护的机制.方法 建立大鼠肝切除肝缺血再灌注损伤模型,75只雄性SD大鼠随机分为3组:假手术组(Sham组)、缺血再灌注组(IR组)和17-β雌二醇预处理组(E2+ IR组).检测各组大鼠再灌注后lh、3h、6h、12 h、24 h肝功能变化.光镜下观察肝组织病理学改变.TUNEL法观察再灌注后12 h大鼠肝细胞凋亡情况、流式细胞学方法测定再灌注后12h肝细胞凋亡率.Western blot法检测再灌注后12 h Bcl-2和Bax的表达情况.结果 与Sham组相比,在IR组各时间点均可见ALT和AST增高,且在再灌注后的12h达到了最高值;病理学检查可见肝细胞肿胀,肝窦变窄,嗜中性粒细胞浸润和片状坏死等变化;在再灌注后12h,凋亡细胞增多及细胞凋亡率明显升高;肝脏组织Bcl 2表达减少,Bax的表达增加.17-β雌二醇预处理组在灌注后各时间点ALT和AST值明显下降,肝脏病理损伤改善;在再灌注后12h,凋亡细胞减少及细胞凋亡率明显降低,肝脏组织Bcl-2表达增加,Bax的表达减少.结论 17-β雌二醇对大鼠肝缺血再灌注损伤有明显的保护作用,其可能通过促进Bcl-2表达及抑制Bax表达,从而抑制肝细胞凋亡.     

丙泊酚对大鼠肝脏缺血-再灌注损伤c-fos、c-jun蛋白及细胞凋亡的影响

目的 通过研究丙泊酚对大鼠肝脏缺血-再灌注损伤时c-fos、c-jun蛋白的影响,进一步探讨丙泊酚对肝脏缺血-再灌注损伤的保护机制.方法 36只健康SD大鼠(雌雄不限)随机分为三组,每组12只.肝脏缺血-再灌注组(A组):肝缺血前30min经微量泵持续输注牛理盐水10ml·kg-1·h-1至再灌注后1h;肝脏缺血-再灌注加丙泊酚组(B组):肝缺血前经微量泵持续输注丙泊酚30ml·kg-1·h-1至再灌注后1h;假手术组(C组):末予缺血处理,经微量泵持续输注生理盐水10ml·kg-1·h-1共1.5h.各组大鼠取肝脏右叶标本,免疫组化染色,显微镜下观察c-fos、c-jun蛋白的表达并进行图像分析,电镜下观察细胞凋亡情况.结果 免疫组化结果显示c-fos、c-jun蛋白在B组的表达较A组明显减少(P<0.05).图像分析结果表明积分光密度(IOD)值三组差异有统计学意义(P<0.05).电镜结果显示B组细胞凋亡不显著,明显少于A组.结论 丙泊酚对肝脏缺血-再灌注损伤的保护作用与c-fos、c-jun蛋白密切相关,可明显减少两者的表达,并且显著减轻肝脏缺血-再灌注损伤所引起的细胞凋亡.     

七叶皂甙钠对肝脏缺血再灌注损伤的保护作用

为探讨七叶皂甙对肝脏缺血再灌注损伤的作用,通过预先对大鼠肝脏缺血再灌注(ischemia—reper(?)us(?)on,I/R)模型静脉注射七叶皂甙钠,经测定肝组织内ATP、AMP、ADP含量,肝脏的细胞能荷及血清谷丙转氨酶(ALT)、谷草转氨酶(AST)、碱性磷酸酶(AKP)、γ-GT等各项指标,结果发现用药组较单纯缺血再灌注对照组肝组织内ATP含量高,肝功能损害较轻,结果表明:七叶皂甙钠对肝脏缺血再灌注造成的肝脏损伤具有明显的预防作用。     

干细胞来源外泌体对大鼠肝脏缺血再灌注损伤的保护作用

[摘 要] 目的 研究大鼠脂肪间充质干细胞来源的外泌体（exosomes,Exo）对肝脏缺血再灌注损伤（hepatic ischemia-reperfusion injury,HIRI）的保护作用。方法 胶原酶法提取SD大鼠原代脂肪间充质干细胞,超速离心法提取干细胞来源的外泌体。SD大鼠随机分为假手术组（Sham）、缺血再灌注损伤组（IR）、缺血再灌注损伤外泌体治疗组（IR+Exo）。Sham组腹部正中切口,离断肝脏周围韧带,不做其他处理;IR组用动脉夹阻断70%肝脏血流60 min;IR+Exo组70%肝脏血流阻断60 min后,尾静脉注射外泌体观察其对肝脏缺血再灌注损伤的保护作用。检测血清中谷丙转氨酶（ALT）、谷草转氨酶（AST）、肿瘤坏死因子α（TNF-α）、白介素1β（IL-1β）含量。检测肝组织中超氧化物歧化酶（SOD）与丙二醛（MDA）含量。Western blotting法检测氧化应激指标醌氧化还原酶（NQO-1）、血红素氧合酶1（HO-1）,凋亡相关指标Bcl-2、Bax,HE染色观察肝组织病理变化。结果 相比IR组,IR+Exo组血清中ALT、AST、TNF-α、IL-1β水平显著下降（P<0.05）,SOD活性显著升高（P<0.05）,MDA含量明显下降（P<0.05）。 NQO1、HO-1、Bcl-2表达量显著升高,Bax显著下降（P<0.05）,肝组织病理损伤明显改善。结论 外泌体能够减轻肝脏缺血再灌注损伤,其可能通过缓解氧化应激、抑制炎症反应、抗凋亡而发挥作用。     

姜黄素对大鼠肝缺血再灌注早期肝组织中氧自由基生成的影响

目的探讨姜黄素对大鼠肝脏缺血再灌注早期损伤的氧自由基生成的影响。方法将大鼠随机分为假手术组、对照组（肝血流阻断前30min和再灌注开始时经肠系膜上静脉各注入二甲基亚砜1ml）和实验组（姜黄素40mg／kg溶于二甲基亚砜1ml注入,余同对照组）。通过检测再灌注早期1、3h血清转氨酶水平、组织病理学改变及肝组织中超氧化物歧化酶（SOD）、过氧化氢酶（CAT）、丙二醛（MDA）的含量来评价姜黄素对大鼠肝脏缺血再灌注早期损伤氧自由基生成的影响。结果姜黄素可降低大鼠肝脏缺血再灌注早期1、3h血清转氨酶水平,可增加肝组织中SOD、CAT含量,降低肝组织中MDA含量。结论姜黄素可通过减少肝组织氧自由基生成,减少肝缺血再灌注肝实质细胞的受损。     

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.     

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.     

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.