门静脉高压症患者肝外血管平增肌细胞凋亡及其相关基因表达的研究

目的 观察门静脉高压症患者肝外血管平滑肌细胞凋亡及相关基因表达,探讨其对门静脉高压症时内脏高动力循环形成的作用。方法 采用原位DNA片断末端标记(TUNEL)法和免疫组织化学法,检测28例门静脉高压症患者脾静脉和12例正常血管的平滑肌细胞凋亡及其相关基因bax、bcl-2的表达。结果 门静脉高压症患者脾静脉平滑肌细胞TUNEL阳性细胞数为(24.3±2.6)％,正常对照组仅为(0.8±0.2)％,差异有非常显著性(P<0.01),bax与bcl-2阳性表达率分别为(22.06±3.20)％和(18.61±2.00)％,与对照组比较差异有非常显著性(P<0.01)。结论 门静脉高压症患者肝外血管平滑肌细胞可产生凋亡,bax和bcl-2蛋白参与血管平滑肌细胞凋亡的调节,凋亡与增殖失衡导致血管结构重塑,促进门静脉高压症时内脏高动力循环的形成和发展。     

局部肾素与血管紧张素原mRNA在肝硬化门静脉高压症患者中的表达及其意义

目的探讨肝硬化门静脉高压症 (PH)对局部肾素血管紧张素系统 (LRAS)活性的影响。方法采用逆转录聚合酶链反应方法检测肝硬化门静脉高压症患者肝脏、脾脏动、静脉组织局部肾素与局部血管紧张素原mRNA的表达情况。结果　对照组内局部肾素mRNA在肝脏中最低(0 19± 0 12 ) ,显著低于脾脏动、静脉组织 [(0 4 5± 0 12 )及 (0 39± 0 12 ) ],P <0 0 5 ;局部血管紧张素原mRNA以肝脏最高 (0 6 4± 0 2 1) ,显著高于脾脏动、静脉组织 [(0 32± 0 15 )及 (0 4 1± 0 18) ],P <0 0 5。肝硬化门静脉高压症组肝脏、脾动脉、脾静脉局部肾素mRNA分别为 (0 78± 0 2 8)、(0 86± 0 35 )、(0 81± 0 2 2 ) ,显著高于对照组 ,P <0 0 5 ;肝硬化门静脉高压症组肝脏、脾动脉、脾静脉局部血管紧张素原mRNA量分别为 (0 96± 0 2 5 )、(0 83± 0 18)、(0 79± 0 2 3) ,亦显著高于对照组 ,P<0 0 5。结论肝硬化门静脉高压患者局部肾素与血管紧张素原mRNA表达增强 ,并可能促进肝硬化门静脉高压症时内脏血管病变的形成。     

肝海绵状血管瘤内皮细胞凋亡与增殖活性的研究

目的　探讨肝海绵状血管瘤 (CHL)的发生、发展与内皮细胞凋亡及增殖的关系。方法　以 2 2例肝海绵状血管瘤石蜡标本为研究对象 ,以草莓状血管瘤和正常肝脏汇管区小血管为对照 ,采用免疫组化ABC法检测增殖细胞核抗原 (PCNA )的表达 ,采用TdT介导的脱氧核苷酸原位末端标记法(TUNEL法 )检测细胞凋亡。结果　CHL组内皮细胞增殖指数 (13 .2 7± 5 .79)与正常肝脏汇管区小血管组 (10 .85± 4.79)差异无显著性 (t =1.15 ,P >0 .0 5 ) ,而显著低于草莓状血管瘤组 (2 9.3 1± 8.5 5 ,t =6.2 4,P <0 .0 1)。CHL组内皮细胞凋亡指数 (3 .49± 1.3 6)与正常肝脏汇管区小血管组 (2 .65± 1.0 6)差异无显著性 (t =1.72 ,P >0 .0 5 ) ,显著低于草莓状血管瘤组 (11.3 8± 2 .66,t=11.18,P <0 .0 1)。结论　CHL的发生、发展与内皮细胞的增殖及凋亡无关 ,此亦可能是CHL未见癌变的生物学基础。     

Fas/FasL表达和细胞凋亡在大鼠同种异体肝移植免疫中的作用

目的探讨Fas和Fas配体 (fasligand ,FasL)与细胞凋亡在大鼠肝移植免疫中的作用。方法分别用免疫组织化学法及原位杂交法 ,在移植后不同的时间点 (1、3、5、7d)检测Fas FasL、Bcl 2 Bax和细胞凋亡在不同的大鼠肝移植模型中的表达情况。结果肝急性排斥组与自发耐受组相比 ,肝细胞凋亡多 ,汇管区FasL表达高而肝细胞FasL表达低 [(2 1 5± 2 5 )个细胞vs.(39 5± 0 5 )个细胞 ,P <0 0 5 ],并且Fas[(47 0± 8 1)个细胞vs.(14 5± 0 8)个细胞 ,P <0 0 5 ]和Bax[(2 1 4± 1 1)个细胞vs.(9 4± 0 9)个细胞 ,P <0 0 5 ]表达高。子代组与肝急性排斥组各指标表达类似 ,半肝组与自发耐受组各指标表达类似。在移植后第 5天 ,汇管区凋亡指数与肝细胞FasL的表达呈正相关 (r =0 76 0 ,P <0 0 1) ,而与肝细胞Fas(r =- 0 75 9,P <0 0 1)、Bax的表达呈负相关 (r =- 0 840 ,P <0 0 1)。结论肝实质细胞的凋亡与肝急性排斥反应有关 ,而其Fas、Bax的高表达可能介导了肝实质细胞凋亡的发生 ;汇管区浸润细胞凋亡与肝自发耐受有关 ,肝细胞FasL的高表达可能介导了浸润细胞凋亡的发生。     

肝阻抗血流图评价门静脉高压症患者贲门周围血管离断术前后肝血流灌注的改变

目的利用肝阻抗血流图探讨肝硬化门静脉高压症患者的肝脏血流灌注改变和贲门周围血管离断术对肝血流灌注的影响.方法选取22例肝硬化门静脉高压症患者,分别在术前1周、术后2周检测其肝血流阻抗的改变,同时用Doppler彩超检测门静脉血流动力学的变化.结果肝阻抗血流图测定结果表明,门静脉高压症患者的肝动脉、门静脉向肝血流灌注明显下降,总肝灌注血流降低[(0.053±0.011)比(0.031±0.009)、(0.033±0.011)比(0.018±0.008)、(7.7±3.0)比(3.5±1.7),P<0.05];断流术后门静脉高压症患者的门静脉向肝灌注增加[(0.018±0.008)比(0.026±0.006),P<0.05],肝动脉向肝灌注无显著改变.结论肝硬化患者肝动脉、门静脉向肝有效血流灌注都降低,肝脏总血流量下降;贲门周围血管离断术能增加大部分患者的门静脉向肝血流灌注,但对肝动脉的向肝灌注无显著影响;肝阻抗血流图对于评价肝硬化患者的肝脏血流及手术对肝脏血流动力学的影响有一定的价值.     

PDGF mRNA及TGF-β在门静脉高压症病人内脏血管重构中的表达及意义

目的　研究门静脉高压症病人脾动脉血小板源性生长因子 (PDGF)mRNA及转化生长因子 β(TGF β)的表达并探讨与门静脉高压血管病变的关系。方法　肝硬化门静脉高压病人 37例及外伤性脾破裂病人 17例 ,取脾门处脾动脉。原位杂交法检测PDGFmRNA的表达 ,免疫组化法检测TGF β的表达 ,经计算机图像处理后行统计学分析。 结果　对照组PDGFmRNA及TGF β表达为阴性或弱阳性 ,门静脉高压组PDGFmRNA及TGF β表达均明显增强 ,为中到强阳性 ,平滑肌层有明显表达。图像光密度值有显著性差异 (PDGFmRNA :73 2 6± 12 35vs 18 2 7± 5 86 ,P <0 0 5 ;TGF β:6 5 36± 9 74vs 12 17± 6 5 5 ,P <0 0 5 )。结论　门静脉高压内脏血管PDGFmRNA及TGF β的表达增加可能为高动力循环、毒血症等引起的血管损伤所诱导 ,并可加重平滑肌细胞过度增生及纤维化 ,在门静脉高压血管病变及细胞表型转化过程中有一定意义。     

血管紧张素转换酶抑制剂对肝硬化门静脉高压症患者门静脉血流动力学的影响

目的：观察血管紧张素转换酶抑制对肝硬化门静脉高压症门静脉血流动力学的影响，探讨血管紧张素转换酶抑制剂治疗肝硬化门静脉高压症的有效性及机制。方法：肝硬化门静脉高压症患者80例，在服用血管紧张素转换酶抑制剂后不同时期，用彩色多普勒超声测量门静脉最大血流速度和门静脉血流量。用放射免疫法测定血浆肾素活性和醛固酮浓度。结果：脾切除加断流术的肝硬化患者16例，应用血管紧张素转换酶抑制剂后30分钟、60分钟、1周时，门静脉压力分别下降0．45±0．34kPa(P<0.05)、0.52±0.32kPa(P<0.05)、0．43±0.24kPa(P<0.05)，门静脉血流量、最大血流速度较用药前略有增加，但无统计学意义。因浆肾素活性从4±2mg/ml·h升高到14±6mg/ml·h(P<0.05)，血浆醛固酮浓度从125±5ng/L下降到45±4ng/L(P<0.05)，未见明显副作用。结论：血管紧张素转换酶抑制剂能快速降低门静脉压，不减少门静脉血流量，长期应用降低门静脉压力效果明显。     

断流联合附加限制环的门腔分流治疗门静脉高压症

目的　评价贲门周围血管离断术 (pericardial devasuclarization,PCDV )联合附加限制环的门腔分流术 (limitedside- to- side portacaval shunt,PCS- SS)治疗门静脉高压症的效果。方法　总结我院 1996年 4月至 2 0 0 1年 7月采用 PCDV联合 PCS- SS(放限制环 )治疗 13例门静脉高压症的经验。结果　择期手术 10例 ,预防性手术 3例 ,均无手术死亡。术前自由门静脉压力 (free portal pressure,FPP)平均为 (3.6 8± 0 .16 ) k Pa,术后为 (3.18± 0 .11) k Pa (P<0 .0 5 )。术前门静脉平均流速为(15 .2 5± 4 .18) cm / s,术后为 (14 .33± 3.75 ) cm / s。术前门静脉平均流量为 (16 2 5 .4 2± 384 .5 0 ) m l/ min,术后平均为 (10 86 .11±2 5 5 .5 1) m l/ min (P<0 .0 5 )。出院病例均随访至今 ,无手术后再出血 ,发生肝性脑病 2例。结论　该联合手术具有断流和合理口径分流的特点 ,手术简单可行 ,是目前治疗门静脉高压症的较为理想术式     

肝硬变门静脉高压症患者门体分流术前后血中内皮素,血栓素与前列？…

目的　了解肝硬变门静脉高压症患者、液递物质代谢紊乱及其血流动力学后果。方法　对 30例肝硬变门静脉高压症患者门体分流术前后门脉血中内皮素 (ET)、血栓素 (TXA2 )和前列环素 (PGI2 )进行了水平变化动态临床观察。结果　在门静脉高压症患者门脉血中无论是缩血管物质 (ET、TXA2 )还是扩血管物质 (PGI2 )浓度均比胃肠对照者明显升高 (ERT:10 7.86± 2 5 .92 pg/ml,48.11± 9.40 pg/ml,P=0 .0 0 0 ;TXA2 :34 9.6 7± 198.41pg/ml,15 6 .2 7± 5 4.0 1pg/ml,P=0 .0 0 0 ;PGI2 :46 3.14± 10 8.2 5 pg/ml,2 2 7.2 3± 46 .19pg/ml,=0 .0 0 0 ) ,且二者浓度在门体分流术后均下降 (P=0 .0 0 2 )。结论　门静脉血中内皮素水平的增高对肝硬变患者门脉血管阻力的增加有重要影响 ,并对门静脉高压症的发病机理起重要作用。在肝硬变门静脉高压这一特殊病理生理状态下 ,缩血管物质与扩血管物质之间可能达成一种新的动态平衡。     

门静脉高压症病人肠道通透性、NO和内毒素的研究

目的　观察门静脉高压症病人的门静脉压力、肠道通透性、NO和内毒素水平 ;并分析它们之间的相互关系。方法　门静脉高压症病人 2 0例 ,分别检测肠道通透性、门静脉压力和外周血中NO和内毒素浓度。另有 2 0位健康志愿者作对照。结果　门静脉高压症病人较健康志愿者的肠道通透性 (0 132± 0 110vs 0 0 32± 0 0 18,P <0 0 1) ,外周血的NO浓度 (38 77± 13 71vs 2 1 77±3 0 1μmol/L ,P <0 0 0 1)和内毒素浓度 (0 5 7± 0 18vs 0 11± 0 0 5EU/ml,P <0 0 0 1)均非常明显的升高。研究还发现门静脉压力和这三者均有显著相关性 (r >0 45 ,P <0 0 5 ) ,另外肠道通透性与内毒素浓度 (r=0 5 2 9,P <0 0 5 )也存在相关性 ,而与NO浓度则无相关性 ;内毒素和NO之间没有发现相关性。结论　研究表明门静脉高压症病人肠道通透性、NO和内毒素水平显著升高。门静脉压力和这三者的显著相关说明门静脉压力升高是导致肠道通透性升高的直接因素 ,而内毒素和NO的升高维持了门静脉的高动力循环。     

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.     

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.     

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.