丁羟茴香醚对衰老大鼠肾脏缺血再灌注损伤的保护作用

目的观察老年大鼠肾脏缺血再灌注（I／R）模型中。肾小管上皮细胞的损伤变化，探讨活性氧（ROS）清除剂对I／R损伤的保护作用。方法27月龄大鼠随机分为假手术组、I／R模型组、丁羟茴香醚（BHA）组和nicardipine组。夹闭双侧。肾动脉30min再灌注18h制成I／R模型。观察肾功能、肾脏病理改变、肾小管上皮细胞凋亡情况。检测肾组织半胱氨酸天冬氨酸蛋白酶（caspase）3、细胞色素C表达。测定肾组织脂质过氧化物丙二醛（MDA）含量和超氧化物歧化酶（SOD）活性。结果（1）肾脏I／R损伤时，老年大鼠肾功能明显减退，肾组织病理改变比较明显，大量肾小管上皮细胞凋亡，肾组织caspase-3、细胞色素C表达明显上调。肾组织中MDA增加、SOD活性下降（P均〈0．05）。（2）BHA或nicardipine均能明显改善肾功能。肾组织病理改变和凋亡相关指标（P〈0．05）；BHA或nicardipine均能减少组织中MDA含量，部分恢复肾组织中SOD含量。结论老年大鼠肾脏I／R损伤时肾小管上皮细胞凋亡增加，肾功能减退。ROS堆积后，线粒体损伤导致肾小管上皮细胞凋亡。清除ROS可以抑制‘肾小管上皮细胞凋亡，减轻I／R损伤。     

mito-KATP通道在缺血后处理减轻大鼠肾缺血再灌注损伤中的作用

目的 评价线粒体ATP敏感性钾通道(mito-KATP通道)在缺血后处理减轻大鼠肾缺血再灌注损伤中的作用.方法 健康成年雄性SD大鼠35只,体重250～280 g,随机分为5组(n=7):假手术组(S组)仅分离双侧肾蒂,暴露45 min不夹闭;肾缺血再灌注组(I/R组)夹闭双侧肾蒂缺血45 min,再灌注6 h制备大鼠肾缺血再灌注模型;缺血后处理组(Ipo组)夹闭双侧肾蒂缺血45 min,再灌注10 s,缺血10 s,反复3次,再灌注6 h;mito-KATP通道阻断剂5-羟葵酸+I/R组(5-HD+I/R组)缺血前30 min腹腔注射5-HD 10 mg/kg,余处理同I/R组;缺血后处理+5-HD组(5-HD+Ipo组)缺血前30 min腹腔注射5-HD 10 mg/kg,余处理同Ipo组.于再灌注6 h时采集心脏血样,取肾并分离肾小管上皮细胞,测定血清Cr和BUN的浓度、肾小管上皮细胞线粒体膜电位、细胞内活性氧(ROS)含量和游离Ca2+浓度.结果 与S组比较,I/R组、Ipo组、5-HD+I/R组和5-HD+Ipo组血清Cr和BUN的浓度、肾小管上皮细胞内游离Ca2+浓度和ROS含量升高,线粒体膜电位降低(P＜0.05);与I/R组比较,Ipo组血清Cr和BUN的浓度、肾小管上皮细胞内游离Ca2+浓度和ROS含量降低,线粒体膜电位升高(P＜0.05),5-HD+I/R组和5-HD+Ipo组上述指标差异无统计学意义(P＞0.05);与Ipo组比较,5-HD+I/R组和5-HD+Ipo组血清Cr和BUN浓度、肾小管上皮细胞内游离Ca2+浓度和ROS含量升高,线粒体膜电位降低(P＜0.05).结论 mito-KATP通道的开放参与了缺血后处理减轻大鼠肾缺血再灌注损伤的过程.     

NGAL对大鼠肾脏缺血再灌注损伤时肾小管上皮细胞凋亡的保护作用

目的探讨中性粒细胞明胶酶相关脂质运载蛋白（neutrophil gelatinase associated lipocalin,NGAL）对大鼠肾脏缺血再灌注损伤肾小管上皮细胞凋亡及凋亡蛋白fas,bcl-2表达的影响。方法建立大鼠肾脏缺血再灌注损伤模型,用HE染色观察肾组织病理变化情况;TUNEL法检测肾小管上皮细胞凋亡;免疫组织化学方法检测fas,bcl-2蛋白表达,并利用图像分析系统测量阳性表达率进行定量分析。结果①缺血再灌注模型组肾小管上皮细胞凋亡数为（20．8±3．7）个／高倍视野,NGAL组为（8．6±3．4）个／高倍视野,2组差异有统计学意义（P〈0．05）。②NGAL组较缺血再灌注模型组fas阳性表达率下降,差异有统计学意义（P〈0．05）;bcl-2阳性表达率增强,差异有统计学意义（P〈0．05）。结论NGAL对大鼠缺血再灌注损伤的肾小管上皮细胞有保护作用,其作用可能与减少细胞凋亡、改变凋亡蛋白的表达有关系。     

甘氨酸对肾缺血-再灌注损伤的保护作用及对iNOS表达的影响

目的探讨甘氨酸对急性肾缺血-再灌注损伤的保护作用及作用机制。方法将24只Wistar大鼠随机分为假手术组（A组）、对照组（B组）、甘氨酸治疗组（C组），通过夹闭大鼠双侧肾蒂30min，再灌注30min制成肾缺血-再灌注损伤动物模型，检测尿量、血尿素氮（BUN）、血肌酐（Cr），肾组织光镜及电镜检查并使用免疫组化法检测iNOS表达。结果B组比A组尿量增加，血BUN、Cr升高，肾小管上皮细胞变性坏死明显，iNOS表达明显增强（P〈0．05）。C组比B组尿量明显增加，血BUN、Cr明显下降，肾小管上皮细胞变性坏死程度减轻，iNOS表达明显减少（P〈0．05）。结论甘氨酸对大鼠肾脏缺血-再灌注损伤有明显的保护作用，其机制可能与抑制大鼠缺血-再灌注后肾脏iNOS蛋白表达有关。     

缺血预处理联合后处理对大鼠肾缺血再灌注损伤的影响

目的 评价缺血预处理联合后处理对大鼠肾缺血再灌注损伤的影响.方法 健康雄性SD大鼠30只,体重250～280 g,随机分为5组(n=6):假手术组(S组)、缺血再灌注组(I/R组)、缺血预处理组(IP组)、缺血后处理组(IPo组)和缺血预处理联合后处理组(IP+IPo组).S组仅开腹,游离双侧肾脏,分离双侧肾蒂但不夹闭.采用夹闭双侧肾蒂45 min、再灌注6 h的方法 制备肾缺血再灌注模型.IP组夹闭双侧肾蒂5 min,再灌注5 min,反复3次,余操作同I/R组;IPo组夹闭双侧肾蒂45 min后,再灌注10 8,缺血10 s,反复3次,再灌注6 h.于再灌注6 h时,经心脏抽血后迅速处死大鼠取肾,测定血清肌酐(Cr)和尿素氮(BUN)的浓度;采用硫代巴比妥酸法测定肾组织丙二醛(MDA)含量,采用黄嘌呤氧化酶法测定肾组织超氧化物歧化酶(SOD)活性;光镜下观察肾组织病理学结果 ;TUNEL法检测肾组织凋亡细胞,计算凋亡指数(AJ).结果 与S组比较,其余各组血清Cr和BUN的浓度升高,肾组织SOD活性降低,MDA含量和AI升高(P<0.05);与I/R组比较,IP组、IPo组和IP+IPo组血清Cr和BUN的浓度降低,肾组织SOD活性升高,MDA含量和AJ降低(P<0.05),肾损伤减轻;与IP组和IPo组比较,IP+IPo组肾组织SOD活性升高,AI降低(P<0.05),肾损伤减轻.结论 缺血预处理联合后处理可减轻大鼠肾缺血再灌注损伤,较单独应用时效果好.     

大鼠肾缺血再灌注后炎症反应和间质血管病变研究

目的：探讨在缺血再灌注（ischemia/reperfusion,I/R）模拟急性肾损伤的大鼠模型中间质血管损伤状况及其病变机制。方法：按随机分组将15只SD大鼠分为假手术组（sham）、肾缺血再灌注损伤（I/R）6 h组、24 h组,每组5只,测定血尿素氮水平,并观察肾脏病理改变;免疫组织化学法观察巨噬细胞浸润、促血管生成因子-血管内皮生长因子（VEGF）的表达,免疫荧光法检测肾小管间质血管的分布,原位缺口末端标记法（TUNEL）检测肾小管上皮细胞凋亡。结果：I/R 6 h、24 h组与sham组相比,BUN明显升高（P〈0.05）,巨噬细胞浸润明显（P〈0.05）,VEGF表达量下降,间质血管密度下降（P〈0.05）,上皮细胞凋亡增多（P〈0.05）。结论：I/R损伤后炎症细反应所致间质血管密度降低是肾小管上皮细胞损伤的重要机制。     

异丙酚对大鼠肠缺血再灌注时肠粘膜细胞凋亡的影响

目的评价异丙酚对大鼠肠缺血再灌注（I／R）时肠粘膜细胞凋亡的影响。方法24只SD大鼠随机分为3组（n=8），假手术组（S组）仅分离肠系膜上动脉（SMA）；肠缺血再灌注组（I／R组）阻断SMA1h；异丙酚组（P组）阻断SMA前30min腹腔注射异丙酚100mg／kg。于再灌注3h处死大鼠，取回肠末端组织，电镜及TUNEL法观察肠粘膜上皮细胞凋亡情况，并计算肠粘膜上皮细胞凋亡指数；测定肠粘膜超氧化物歧化酶（SOD）活性、丙二醛（MDA）及神经酰胺（CER）含量，RT-PCR法测定肠粘膜鞘磷脂酶（SMase）mRNA表达。结果与S组比较，I／R组肠粘膜SOD活性降低，MDA含量、CER含量、肠粘膜上皮细胞凋亡指数及SMasemRNA表达升高（P〈0．05或0．01）；与I／R组比较，P组MDA含量、CER含量、肠粘膜上皮细胞凋亡指数及SMasemRNA表达降低，S01）活性升高（P〈0．05或O．01）。I／R组肠粘膜SOD活性与CER含量呈负相关（r＝-0．775，P〈0．01），肠粘膜上皮细胞凋亡指数与CER含量呈正相关（r=0．852，P〈0．01）；P组肠粘膜上皮细胞凋亡指数与CER含量呈正相关（r=0．782，P〈0．01）。结论异丙酚可抑制大鼠肠缺血再灌注时肠粘膜上皮细胞凋亡，可能与清除氧自由基、下调SMasemRNA表达、减少CER生成有关。     

参附注射液对大鼠肠缺血再灌注损伤后肠黏膜细胞凋亡的影响

目的：研究参附注射液对大鼠肠缺血再灌注期间黏膜上皮细胞凋亡的影响，并探讨其可能机制。方法：采用大鼠肠缺血再灌注模型。24只大鼠随机分为假手术对照组（C组）、缺血再灌注组（I／R组）和参附治疗组（SF组），在规定时间检测小肠黏膜上皮细胞caspase-3、Bcl-2蛋白的表达，凋亡细胞数目，同时观察小肠黏膜病理形态学改变。结果：IR组肠黏膜上皮细胞凋亡指数（apoptosisindex,AI）、caspase-3、Bcl-2蛋白显著高于C组（P〈0．01）。SF组AI、caspase-3蛋白低于IR组（P〈0.01或P〈0．05），而Bcl-2蛋白较IR组上调（P〈0．01）。caspase-3表达与AI呈正相关（r=0，914，P〈0，01）；Bel-2的表达与AI、caspase-3呈直线负相关（r分别=-0．375，-0．367，P〈001）。SF组小肠黏膜病理损伤程度较I／R组明显减轻（P〈0.01）。结论：参附注射液通过抑制caspase-3表达和促进Bcl-2基因表达减少缺血再灌注期间肠黏膜上皮细胞的凋亡。从而一定程度上减轻肠黏膜缺血再灌注损伤。     

缺血后处理对大鼠肾缺血再灌注损伤的影响

目的探讨缺血后处理对大鼠肾缺血再灌注损伤的影响。方法SD大鼠32只,雌雄不拘,随机分为4组（n=8）,假手术组（Ⅰ组）;对照组（Ⅱ组）建立肾缺血再灌注（I/R）模型;不同时间缺血后处理组（Ⅲ组和Ⅳ组）,建立I/R模型,Ⅲ组于缺血后再灌注10s,停灌10s,反复3次;Ⅳ组缺血后再灌注2min,停灌2min,反复3次。测定再灌注24h时血清尿素氮（BUN）、肌酐（Cr）浓度、超氧化物岐化酶（SOD）活性和丙二醛（MDA）浓度,光镜下进行肾组织病理形态学观察,采用免疫组化法测定肾组织血红素氧合酶-1（HO-1）表达。结果再灌注24h时,与Ⅰ组比较,其余3组血清Cr、BUN和MDA浓度升高,SOD活性和HO-1表达降低（P〈0.01）;与Ⅱ组比较,Ⅲ组和Ⅳ组血清Cr、BUN、MDA浓度和HO-1表达降低,SOD活性升高（P〈0.05或0.01）;Ⅲ组和Ⅳ组各指标差异无统计学意义（P〉0.05）。Ⅲ组和Ⅳ组病理改变明显轻于Ⅱ组。结论缺血后处理可减轻大鼠肾缺血再灌注损伤,其机制与上调HO-1的表达和清除氧自由基有关。     

姜黄素预处理对大鼠缺血再灌注肾小管上皮细胞凋亡的影响

目的：建立大鼠。肾脏缺血再灌注损伤（IRI）模型,观察姜黄素预处理对大鼠肾脏缺血再灌注肾小管上皮细胞凋亡的影响。方法：36只SD雄性大鼠随机分为3组,分别为假手术（Sham）组、肾脏缺血再灌注模型（IR）组、姜黄素预处理（CUR）组,每组12只。CUR组在缺血前2h给予姜黄素100mg／kg剂量溶于0．1％二甲基亚砜1ml中,注入腹腔。24小时后沿原切口进入,切除左。肾。肾组织用4％多聚甲醛固定24h,常规石蜡包埋切片。采用TUNEL法检测各组缺血肾小管上皮细胞凋亡。结果：与Sham组相比,IR组肾小管上皮细胞凋亡明显增加。与IR组比较,CUR组肾小管上皮细胞凋亡减少（P＜0．05）。结论：姜黄素预处理可减轻肾脏IRI的肾小管上皮细胞凋亡。     

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.