重症急性胰腺炎患者血和腹水一氧化氮的动态变化

目的　研究诱生型一氧化氮合酶 (iNOS)活性在重症急性胰腺炎 (SAP)患者中的变化。方法　动态观察 30例重症急性胰腺炎患者发病后血性腹水和外周血一氧化氮 (NO)代谢产物NO2 - /NO3- 的变化。逆转录 聚合酶链反应 (RT PCR)检测外周血单个核细胞iNOSmRNA的变化。结果　SAP患者血性腹水NO2 - /NO3- 含量为 (385 .0± 92 .3) μmol/L与对照组 (41 .3± 1 9.5)μmol/L比较显著升高 (P <0 .0 0 1 )。起病后第 1、7、1 4天外周血NO2 - /NO3- 含量分别为(1 38.8±30 .2 ) μmol/L、(1 2 6 .4± 35 .4) μmol/L和 (77.8± 37.1 ) μmol/L ,随病情好转逐渐下降(P <0 .0 1 )。外周血单个核细胞iNOSmRNA表达在病情严重时显著增强。结论　iNOS活性增强产生过量NO参与重症急性胰腺炎全身病理生理的改变     

一氧化氮胰腺保护作用与巯基物质和氧自由基的关系

目的　探讨内源性一氧化氮 (NO)对大鼠急性坏死性胰腺炎的作用及其与巯基物质和脂质过氧化之间的关系。　方法　以 5 %牛磺胆酸钠溶液胰胆管注射 (1ml/kg)制成大鼠急性坏死性胰腺炎模型 ,以工具药L 硝基精氨酸 (L NNA)为内源性NO的阻断剂 ,观察内源性NO对胰腺损伤程度、血清淀粉酶浓度、胰腺组织内巯基物质含量和脂质过氧化终产物丙二醛 (MDA)含量的影响。　结果　牛磺胆酸钠胰胆管注射可造成胰腺组织明显的水肿和坏死 ,部分 (2 / 7)发生胰腺实质内出血 ;血清淀粉酶浓度显著升高 ,胰腺组织巯基物质含量降低 ,MDA含量增加 [(1 2 5± 0 2 8)nmol/mg蛋白质vs.(0 5± 0 0 3)nmol/mg蛋白质 ,P <0 0 5 ]。以L NNA(12 5mg/kg)阻断内源性NO ,可明显加重胰腺组织坏死 ,胰腺实质内出血率增加 (10 / 12 ,83 3 % ) ,并血清淀粉酶浓度进一步升高 ,胰腺组织MDA含量进一步增加 [(3 0± 0 40 )nmol/mg蛋白质vs.(1 2 5± 0 2 8)nmol/mg蛋白质 ,P <0 0 5 ]。但对胰腺组织内巯基物质的含量没有影响。　结论　内源性NO具有胰腺保护作用 ,其保护机制可能与抗氧自由基有关。巯基物质可能不参与NO的胰腺保护机制。     

一氧化氮(NO)合酶和NO在延迟性异种移植排斥反应中的作用

目的利用小鼠至大鼠异位心脏移植模型,研究诱导性一氧化氮合酶(iNOS)和受体血清一氧化氮(NO)在延迟性异种移植排斥反应(DXR)中的作用.方法将大鼠随机分为4组A组(6只),空白对照;B组(5只),来氟米物(Lef)+环孢素A(CsA);C组(6只),氨基胍;D组(6只),氨基胍+Lef+CsA.利用免疫组织化学染色检测CD68和NOS2,原位杂交技术检测iNOS mRNA表达.于移植前3 d和移植心脏排斥时分别采集血清检测NO含量.结果所有被排斥心脏中均见巨噬细胞(MФ)浸润,Lef+CsA显著延长移植心脏存活(与A和C组相比,P＜0.05),单用氨基胍使移植心脏存活(3 83±1.47)d(与A组比较,P＜0.05),氨基胍联用Lef和CsA使移植心脏存活(8.67±1.76)d(与A、B和C组比较,P＜0.05).发生DXR时浸润的MФ均有NOS2蛋白和mRNA阳性表达,且不受氨基胍影响.发生DXR时大鼠血清NO水平较移植前显著升高(P＜0.01),氨基胍可显著降低排斥时NO水平.结论小鼠至大鼠心脏移植发生DXR时浸润的MФ表达iNOS增多,且血清NO升高.抑制iNOS活性,降低NO水平可显著延长移植物存活时间,提示iNOS和NO是DXR发生的可能机制之一.     

肺泡巨噬细胞活化在急性坏死性胰腺炎大鼠肺损伤中的作用

目的　探讨肺泡巨噬细胞活化在急性坏死性胰腺炎 (ANP)肺损伤中的作用。　方法30只成年SD大鼠随机分为正常对照组、ANP后 1、3、6、12h组 ,每组 6只。逆行性胰胆管注射 3%牛磺酸钠建立ANP大鼠模型 ,正常对照组大鼠自胆胰管内逆行注入生理盐水。经支气管肺泡灌洗获取肺泡巨噬细胞 ,检测支气管肺泡灌洗液中蛋白含量、肺组织髓过氧化物酶 (MPO)水平、肺泡巨噬细胞分泌肿瘤坏死因子α(TNFα)及一氧化氮 (NO)水平。以反转录聚合酶链反应 (RT PCR)法测定肺泡巨噬细胞TNFαmRNA、诱导型一氧化氮合酶 (iNOS)mRNA表达情况。行肺、胰腺组织病理学检查并评分。结果　ANP大鼠肺损伤随着病情进展而逐渐加重 ;肺组织MPO及支气管肺泡灌洗液中蛋白含量逐渐升高 ,12h达最高值 ,分别为 (10 78± 0 5 8)U/g和 (2 0 11 0± 10 5 5 ) μg/ml;肺泡巨噬细胞分泌TNFα、NO水平逐渐升高 ,至 6h达到高峰 ,分别为 (16 2 4 2± 149 2 )pg/ml和 (88 8± 6 5 ) μmol/L ,12h又回落。ANP发生后 ,肺泡巨噬细胞TNFαmRNA、iNOSmRNA的表达情况与TNFα、NO的变化趋势相似。ANP大鼠各组指标与正常对照组相比差异均有显著性意义 (P <0 0 5 )。组织学评分结果表明 ,随着胰腺损伤的加重肺损伤也逐渐加重。肺泡巨噬细胞TNFαmRNA、iNOSmRNA     

氨基胍对大鼠胰岛保护作用的实验研究

目的 探讨在细胞因子与大鼠胰岛细胞共同培养过程中,诱导型一氧化氮合酶(iNOS)抑制剂氨基胍对胰岛细胞功能和存活的影响及其机理.方法 分离纯化大鼠胰岛,进行胰岛细胞培养.根据培养基中是否加入氨基胍或细胞因子IL-1β和TNF-α,按随机对照原则分为空白对照组(完全培养基)、细胞因子组(加IL-1β和TNF-α)、氨基胍组(加氨基胍)及氨基胍+细胞因子组(加氨基胍及细胞因子).检测指标包括: 培养液中NO水平、胰岛组织中iNOS活性、胰岛细胞存活情况(丫啶橙/溴乙锭染色)、胰岛细胞凋亡情况(TUNEL法)及胰岛功能(胰岛素释放试验).结果 与空白对照组比较,细胞因子组大鼠胰岛组织中iNOS的活性明显提高,培养液中NO的水平明显上升,同时胰岛细胞的存活率下降,大量细胞凋亡,胰岛素分泌明显减少(P＜0.01).与细胞因子组比较,氨基胍+细胞因子组的iNOS的活性[(3.17±0.51) U/ml比(38.93±4.72) U/ml]及NO水平[(50.5±10.4) μmol/L比(313.0±35.4) μmol/L]明显下降,胰岛细胞存活率活明显升高[(72.73±3.14)%比(57.07±5.07)%],凋亡率明显下降[(20.11±8.48)%比(41.17±6.87)%],胰岛素分泌指数明显升高(3.50±0.27比1.96±0.19),差异均有统计学意义(P＜0.01).结论 氨基胍通过抑制iNOS活性,控制NO过量产生,从而减轻细胞因子对胰岛的损害,改善胰岛的存活与功能.     

氨基胍对大鼠胰腺移植保护作用的实验研究

目的:探讨诱导型一氧化氮合酶抑制剂氨基胍对大鼠移植胰腺的保护作用。方法:糖尿病大鼠模型30只随机分成3组：（1）空白对照组（n=6），仅开腹手术，不作移植;（2）移植对照组（n=6），仅作胰腺移植;（3）氨基胍处理组（n=18），移植胰腺恢复血运前经阴茎背静脉注入盐酸氨基胍（AG）溶液，剂量分别为60，80，100 mg/kg。再灌注4h后检测血清一氧化氮（NO）水平，血糖以及淀粉酶活性，定量分析胰腺组织中的结构型一氧化氮合酶（cNOS）和诱导型一氧化氮合酶（iNOS）活性，并对胰腺进行组织形态学和组织化学检查。结果:与移植对照组比较，氨基胍处理组血NO水平及淀粉酶活性明显降低，胰腺病理损害较轻，其中以AG 80 mg/kg亚组效果更显著（P＜0.01），且该亚组血糖及iNOS活性与表达也明显低于移植对照组（P＜0.01）。结论:诱导型一氧化氮合酶选择性抑制剂氨基胍在大鼠胰腺移植中起到保护作用。其作用机制可能与抑制NO的过量产生，减轻其作为自由基的细胞毒性有关。     

一氧化氮在获得性肾囊肿癌变过程中的作用

目的　探讨一氧化氮 (NO)过多产生在获得性肾囊肿 (ACDK)发生肾癌过程中的作用。　方法　用高压液相自动分析方法测定 1 6例 1 8份ACDK和 1 2份单纯性肾囊肿囊内液体中NO的代谢产物亚硝酸盐 /硝酸盐 (NO-2 /NO-3 )的含量 ,同时测定 5份ACDK患者血浆NO-2 /NO-3 的含量。采用免疫组织化学方法 (LSAB法 )检测 1 7份ACDK和 2 0例非ACDK肾组织一氧化氮合酶 (iNOS)的表达。　结果　ACDK囊内液NO-2 /NO-3 的含量 (1 5 1 .6± 6 4.2 μmol/L)明显高于单纯性肾囊肿组(5 0 .1± 33.6 μmol/L) ,差异有极显著性 (P <0 .0 0 1 )。其中在相同的 5例ACDK患者中囊内液NO-2 /NO-3 的浓度明显的高于血浆中的浓度。在免疫组织化学染色 (LSAB法 )检测肾组织iNOS的表达中 ,1 7份ACDK中 1 4例 (82 % )为阳性。 1 3例正常肾组织和 7例非ACDK慢性肾衰的肾组织均无i NOS的表达。　结论　NO在ACDK囊内液中过多产生有可能是其囊上皮发生肾癌的原因之一。     

生育男性和异常精子症病人精浆一氧化氮水平的差异

目的 :通过研究精子正常和异常男性精浆中一氧化氮 (NO)含量及动态的差异 ,以了解NO与男性生育力的关系。　方法 :采用硝酸还原酶法 ,经Greiss试剂显色后 ,用分光光度法测定 174例生育男性和 2 17例异常精子症男性精浆中NO的含量。　结果 :① 174例精子生育男性精浆中均检测出NO ,平均含量为 (2 7.78± 5 .81) μmol/L,并随年龄增加而增高 ,40岁以后增高显著。 2 0～ 2 9岁组 [(2 6 .2 5± 5 .5 2 ) μmol/L]与 30～ 39岁组 [(2 8.11± 5 .87)μmol/L]相比 ,差异无显著性 (P >0 .0 5 ) ,但 40～ 49岁组 [(30 .17± 6 .14) μmol/L]与 2 0～ 2 9岁组相比 ,增高有统计学意义 (P <0 .0 5 )。② 9类精子异常症男性的精浆中NO含量均显著高于精子正常组。增高幅度以精子单项异常为最小 ,以精子的 3项异常为最高 ,2项精子异常的精浆中NO水平介于两者之间。　结论 :男性精浆中适度的NO可能具有调节精子发生的作用。     

一氧化氮合酶抑制剂对延缓腰椎间盘退变的影响

目的　探讨一氧化氮合酶(NOS)抑制剂L N6 亚氨乙基 赖氨酸(L NIL)和S 甲基异硫脲(SMT)对退变腰椎间盘组织代谢的影响。方法　无菌条件下,取2 0例腰椎间盘突出症患者的椎间盘组织体外培养,分别加入1mmol/L浓度的SMT和L NIL ,培养72h后,通过检测硝酸盐和亚硝酸盐的含量来观察椎间盘NO的释放量及NOS的活性;原位杂交法检测椎间盘组织iNOSmRNA和MMP3mRNA的表达。培养10d后,化学比色法观察椎间盘蛋白多糖含量和羟脯氨酸释放量的变化。结果　L NIL组髓核和纤维环NO释放量(65 .6±4.5 ,68.8±5 .7) μmol/L和SMT组髓核和纤维环NO释放量(69.5±6.5 ,69.1±6.1) μmol/L较对照组NO释放量(10 7.9±4.4,93 .1±5 .9) μmol/L明显减少(P <0 .0 1)。L NIL组和SMT组髓核组织中蛋白多糖含量(5 1.3±9.6,48.2±8.5 )kg/L ,比对照组(3 2 .1±6.4)kg/L明显增加(P <0 .0 1) ,羟脯氨酸释放量(1.1±0 .4,1.2±0 .5 )kg/L比对照组(3 .4±0 .8)kg/L显著减少(P <0 .0 1) ;同时,原位杂交法未检测到iNOSmRNA和MMP3mRNA的表达。结论　NOS抑制剂L NIL和SMT能抑制过量NO的释放,对延缓椎间盘退变具有积极的作用     

氨基胍对脊髓损伤后诱导性一氧化氮合酶表达的影响

目的　探讨氨基胍 (AG)对脊髓损伤后诱导性一氧化氮合酶 (iNOS)表达变化的影响及机制。方法　用Nystrom法 (锤重 3 5 g ,10min)制成大鼠脊髓损伤的动物模型 ,采用免疫组织化学技术和同位素标记方法检测脊髓组织iNOS蛋白及iNOS活性在脊髓损伤及应用AG后的变化。结果　脊髓未损伤时无iNOS表达 ;损伤后出现表达上调且表达量与伤后时间呈正相关 ,损伤后 2 4hiNOS蛋白及活性分别为 2 2 .60± 2 .3 6、0 .97± 0 .0 7;应用AG后两者出现抑制性改变为 17.40±2 .0 7、0 .5 2± 0 .0 3 (P <0 .0 1)。结论　iNOS是脊髓继发性损伤中可明显影响神经功能的重要因子 ,通过应用AG可明显抑制脊髓损伤后iNOS的高表达并降低其对神经组织的破坏作用。     

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.     

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.     

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.