TLR4和NF-κB在大鼠肾缺血再灌注损伤中的表达及意义

目的：观察大鼠肾缺血再灌注损伤后Toll样受体4（TLR4）和核因子-κB（NF-kB）的表达变化及其关系.方法：将40只SD大鼠随机等分为假手术组（S组）和肾缺血再灌注损伤组（I/R组）,建立肾缺血再灌注模型.在肾缺血再灌注后24 h切取肾脏.采用免疫组织化学法观察TLR4蛋自及NF-κB蛋白在肾脏组织中的表达变化及其相关性 采用半定肇逆转录-聚合酶链反应（RT-PCR）检测两组肾组织中TLR4、NF-κB的mRNA水平表达变化.结果：TLR4蛋白在S组大鼠肾小管细胞中有少量表达,在I/R组24 h后肾组织中表达明显增加,与S组比较,差异有统计学意义（P〈0.05）.NF-κB P65蛋白在S组大鼠肾小管细胞胞浆和少量胞核中有表达.在I/R组24 h后肾小管细胞胞浆和胞核均可见NF-κB P65明显表达.差异有统计学意义（P〈0.01）.TLR4和NF-κB在肾缺血再灌注损伤组织中的表达具有明显的相关性.I/R组中的TLR4 mRNA、NF-κB mRNA表达均较S组上调,差异有统计学意义（P〈0.05）.结论：大鼠肾缺血冉灌注损伤后,肾组织TLR4和NF-κB P65的表达明显上调,且有明显的相关性.TLR4有可能通过激活NF-κB继而引起下游的炎症因子募集,介导肾缺血再灌注损伤.     

雷公藤内酯醇对大鼠肾缺血再灌注损伤时Toll样受体4表达的影响

目的 观察雷公藤内酯醇(TRI)对大鼠肾缺血再灌注损伤时肾组织中Toll样受体4(TLR4)表达的影响.方法 随机将51只Wistar大鼠分为3组.(1)阴性对照组(n=15):游离双侧肾脏,切除右肾,缝合腹壁.(2)缺血再灌注组(n=18):实验过程与阴性对照组相同,但在切除右肾和游离左肾之后,将左肾动、静脉夹闭45 min,然后开通.(3)TRI处理组(n=18):肾缺血再灌注前3 d经大鼠腹腔注射TRI 0.4 mg/kg,每天1次,连续3 d,其他实验过程与缺血再灌注组相同.肾缺血再灌注1、3、5 d后,分别采用全自动生化分析仪检测血清尿素氮(BUN)和肌酐(Cr)的含量;逆转录聚合酶链反应(RT-PCR)方法检测肾组织中TLR4 mRNA的表达水平;免疫印记法(Western blot)检测肾组织中TLR4表达水平.结果 肾缺血再灌注1、3、5 d后,缺血再灌注组和TRI处理组血清BUN及Cr均明显高于阴性对照组(P＜0.01),肾组织中TLR4 mRNA和TLR4的表达也明显高于阴性对照组(P＜0.05);但与缺血再灌注组比较,TRI处理组血清BUN和Cr明显降低(P＜0.01),肾组织中TLR4 mRNA和TLR4的表达也显著降低(P＜0.05).结论 雷公藤内酯醇可以减轻肾缺血再灌注损伤,其机制可能是通过抑制TLR4的表达而发挥作用的.     

党参皂甙减轻大鼠移植肾缺血再灌注损伤中细胞凋亡的作用及其机制

目的 探讨党参提取物皂甙减轻移植肾缺血再灌注损伤中细胞凋亡的作用及其机制.方法 将雌、雄各半SD大鼠随机分成三组,每组20只,即假手术组、缺血再灌注组和皂甙干预组.假手术组不进行肾移植,仅切除右肾,游离左肾动静脉,暴露左肾1 h后关闭腹腔.缺血再灌注组和皂甙干预组建立大鼠移植肾缺血再灌注损伤模型.皂甙干预组分别于肾移植前48、24和0.5 h经腹腔注入皂甙溶液(每千克体重80 mg).移植肾再灌注后24 h,取大鼠外周血和移植肾组织待测.检测各组血尿素氮(BUN)和肌酐(Cr)水平;采用脱氧核糖核苷酸末端转移酶介导的缺口末端标记(TUNEL)法检测各组肾组织原位细胞凋亡指数(AI);采用逆转录聚合酶链反应(RT-PCR)检测与细胞凋亡有关的基因Bcl-2和Bax mRNA在各组肾组织中的相对表达量.结果 与假手术组相比,缺血再灌注组和皂甙干预组血BUN和Cr水平都显著升高(P＜0.05);移植肾细胞凋亡指数也显著增高(P＜0.05);移植肾组织中Bcl-2 mRNA表达显著降低,Bax mRNA表达显著增高(P＜0.05).与缺血再灌注组比较,皂甙干预组血BUN和Cr值明显下降(P＜0.05);移植肾细胞凋亡指数明显下降(P＜0.05);移植肾组织中Bcl-2 mRNA表达显著增加,Bax mRNA表达明显下降(P＜0.05).结论 党参皂甙在移植肾缺血再灌注损伤中能显著减轻细胞凋亡.其机制可能是通过对Bcl-2基因表达的上调和对Bax基因表达的下调,从而抑制细胞的凋亡.     

TLR2/4蛋白在小鼠全肝缺血再灌注损伤肝脏的表达及意义

目的观察Toll样受体2／4蛋白在小鼠全肝缺血再灌注损伤中肝脏的表达，并分析其与肝功能损伤的关系。方法通过夹闭BALB／c小鼠肝门，复制小鼠全肝缺血再灌注损伤模型。采用Western blot方法定量检测缺血肝叶中TLR2／4蛋白的表达变化，并检测门静脉血浆丙氨酸氨基转移酶（pALT）、肿瘤坏死因-α（TNF-α）及门静脉血清内毒素（endotoxin，EN）水平。结果与假手术组（sham-operated group，SH组）相比：（1）全肝缺血20min并行再灌注后，缺血再灌注组（ischemic／reperfusion group，I／R组）血清ALT在再灌注1h即明显升高，且在再灌注3h时较1h时明显升高；（2）I／R组缺血肝脏TLR2／4蛋白的表达（OD值）明显升高，TLR2蛋白的表达在再灌注3h较1h明显高；而TLR4蛋白的表达以再灌注1h时水平最高。（3）I／R组中门静脉血清TNF-α在再灌注1h即开始高，在再灌注3h达高峰。（4）门静脉血清内毒素水平明显升高（与SH相比，P〈0．01），但I／R组在不同灌注时间点之间无显著性差异（P〉0．05）。结论TLR2／4蛋白表达的上调参与了小鼠全肝脏缺血再灌注中肝脏的损伤。     

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。     

缺血预处理对缺血再灌注损伤大鼠肾组织TLR2表达的影响

目的观察缺血预处理对缺血／再灌注损伤大鼠肾组织Toll样受体2（TLR2）表达的影响。方法将24只雄性SD大鼠随机分为3组：假手术对照组（SHAM组）、单纯缺血再灌注组（I／R组）和缺血预处理组（IPC组）,每组8只。于术后24h留取各组大鼠血标本和肾组织。检测各组大鼠血肌酐（SCr）和尿素氮（BUN）,肾组织切片行HE染色后观察其病理学改变,酶联免疫吸附法（ELISA）检测肾组织肿瘤坏死因子-α（TNF-α）含量,实时荧光定量多聚酶链反应检测肾组织TLR2mRNA表达,Westernblot检测肾组织TLR2蛋白表达。结果与SHAM组相比,I／R组大鼠SCr和BUN升高,肾组织TNF-α含量和TLR2蛋白表达升高,差异均有统计学意义（P〈0．01）;与I／R组相比,IPC组大鼠SCr和BUN降低,肾组织TNF-α含量和TLR2蛋白表达降低,差异均有统计学意义（P〈0．05）。结论缺血预处理可能通过抑制大鼠。肾组织TLR2表达及其信号通路,下调TNF-α的表达,发挥其肾脏保护作用。     

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。     

大鼠肾脏缺血再灌注损伤中垂体中叶素及降钙素受体样受体的表达

目的 观察垂体中叶素（IMD）及其受体降钙素受体样受体（CRLR）在大鼠肾脏缺血再灌注损伤中的表达变化。 方法 将健康雄性Wistar大鼠随机分为假手术组和手术组,夹闭大鼠双侧肾动脉制作肾脏缺血再灌注损伤（IRI）模型,于缺血再灌注后0、6、12、24、48、72 h 6个时间点各取6只大鼠,留取血清及肾组织标本,对肾脏病理损伤评分并行半定量分析; Western印迹法半定量分析肾组织IMD及其受体CRLR的表达变化;放射免疫法检测血浆中IMD的表达变化。 结果 手术组大鼠发生了急性肾小管坏死（ATN）,以缺血再灌注48 h时病理损伤最重。与假手术组比较,IMD及CRLR在缺血再灌注12、24、48、72 h表达显著增高（均P < 0.01）;血浆中IMD在缺血再灌注12、48、72 h表达显著增高（均P < 0.05）。 结论 IMD及受体CRLR在大鼠肾脏缺血再灌注损伤中表达增加,血浆中IMD表达上调,提示其可能在肾脏缺血再灌注损伤病理生理过程中发挥作用。     

阿托伐他汀对大鼠肾缺血再灌注损伤中TLR4及NF-κB p65的影响

目的：探讨阿托伐他汀对大鼠肾缺血再灌注损伤（ischemia-reperfusion injury,IRI）中Toll样受体4（toll like receptor4,TLR4）及细胞核因子κB p65（nuclear factor kappa Bp65,NF-κB p65）表达的影响。方法：雄性wistar大鼠54只随机分为假手术组、手术组和干预组,每组又分为（6h、24h、48h）3个时相组。用动脉夹夹闭大鼠双侧肾动脉制成肾IRI模型;干预组：术前灌胃阿托伐他汀10mg·kg-1.d-1,1周,其余处理同手术组。再灌注达相应时间点时,检测Scr,进行肾组织病理学观察并采用免疫组织化学法测定TLR4和NF-κB p65蛋白的表达水平。结果：较手术组,干预组中肾组织损伤明显缓解,Scr水平、TLR4、NF-κB p65阳性表达在相应时间点明显下降。结论：阿托伐他汀预处理可减轻IRI,其机制可能是通过抑制TLR4及NF-κB p65的表达,发挥其肾脏保护作用。     

TLR4表达在大鼠小肠缺血再灌注损伤中的改变及意义

目的:观察大鼠小肠缺血再灌注（I/R）损伤后小肠组织TLR4的表达及其与炎症因子水平变化的关系。方法:雄性SD大鼠90只,随机分为正常对照（N）组、假手术（S）组、小肠部分缺血/再灌注损伤（肠I/R）组。分别于缺血再灌注后6，12，24,48 h检测各组小肠组织TLR4mRNA的表达，门静脉血清中TNF-α和IL-6水平，并进行相关性分析。用免疫组化法观察TLR4在小肠组织中的表达和分布。结果:（1）肠I/R组TLR4mRNA表达上调,于I/R12 h最强,阳性细胞主要是小肠黏膜细胞;（2）I/R组门静脉血清中IL-6及TNF-α浓度与N组相比各时点均明显增高（P<0.01）;在I/R24 h后达到峰值，与S组比较差异亦有显著性 (P< 0.01);（3） 肠I/R组门静脉IL-6及TNF-α浓度的增高与小肠TLR4mRNA表达的上调呈正相关（r=0.752，r=0.812;均P<0.01）;（4）免疫组化法显示小肠黏膜细胞表面TLR4表达明显增强。结论:大鼠小肠I/R损伤后,小肠组织TLR4的表达上调可能是导致肠黏膜免疫屏障功能下降的机制之一，也可能是系统性炎症反应的始动环节。     

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.