门静脉分支结扎后门静脉压力变化与肝再生的关系

目的 探讨90%门静脉分支结扎后大鼠门静脉压力变化与肝再生的关系.方法 45只雄性SD大鼠行90%门静脉分支结扎术,其中5只进行假手术作为对照.观察不同时相点门静脉压力和非结扎侧肝脏质量变化,光学显微镜下观察非结扎侧肝细胞的形态学变化,免疫组织化学方法检测未结扎侧肝细胞的增殖细胞核抗原(PCNA),TUNEL法检测未结扎侧肝细胞的凋亡情况,并进行定最分析.采用Pearson相关分析和t检验分析数据.结果 95%(38/40)的大鼠存活.结扎侧肝叶进行性萎缩,非结扎侧肝叶占全肝质量的比例随时问推移而增加,12 h内增加较缓慢,仅为10.75%;而1～5 d则增加速度明显加快,达到27.57%;7～28 d达到平台期,缓慢增加到32.37%.术前门静脉压力为(9.1±1.8)cm H_2O(1 cm H_2O=0.098 kPa);结扎后立即升高,12 h达到高峰(15.8±2.7)cm H_2O,与术前比较差异有统计学意义(t=6.847,P<0.05);1～28 d由(13.6±2.3)cm H_2O逐渐下降为(9.3±2.0)cm H_2O.术前大鼠PCNA阳性细胞计数为7%±3%,术后12 h至3 d由14%±5%上升至21%±6%,第5天达到高峰为26%±7%,与术前比较差异有统计学意义(t=9.129,P<0.05),随后逐渐恢复正常.TUNEL法检测结果显示,术前大鼠肝脏和术后各时相点大鼠未结扎侧肝脏仅见极少量凋亡细胞.大鼠门静脉压力与非结扎侧肝叶肝细胞PCNA的表达在术后1、3、5 d呈正相关(r=0.913,0.896,0.908,P<0.05),在术后14 d时相点呈负相关(r=-0.926,P<0.05).结论 大鼠90%门静脉分支结扎术后,引起未结扎侧肝细胞的活跃再生,再生后的肝脏可恢复原来的质量;肝再生以肝细胞增殖加速为主,而非肝细胞凋亡减少;门静脉压力变化在肝再生过程中可能发挥重要作用.     

转化生长因子α和β1在极限门静脉结扎肝脏组织中的表达及其意义

目的探讨转化生长因子（TGF）-α和TGF-β1在90%极限门静脉分支结扎大鼠肝脏组织中的表达及其与肝脏再生的关系。方法 SD雄性大鼠96只,随机平均分成假手术组和门静脉结扎（PBL）组,观察术后0.5、1、3、5、7、14、21和28d总肝脏和未结扎侧肝脏质量变化,光学显微镜下观察未结扎侧肝细胞的形态变化,用免疫组化方法检测未结扎侧肝细胞的增殖细胞核抗原（PCNA）及TGF-α和TGF-β1的表达。结果 90%极限门静脉分支结扎后,结扎侧肝叶呈进行性萎缩、变小,未结扎侧肝叶占总肝质量的比例在术后1d内增加较缓慢,而在术后1～5d增加速度明显加快,5d以后增加变慢,于7d达＂平台期＂。与假手术组比较,PBL组术后肝组织中PCNA表达在术后0.5～3d明显增多（P〈0.01）,术后5d达高峰,7d有所减少,但仍高于假手术组（P〈0.01）,以后减少接近假手术组。假手术组术后肝脏可见少量TGF-α和TGF-β1表达,PBL组大鼠未结扎侧肝叶术后0.5d开始两者表达量增加,分别至术后3d和1d达高峰（P〈0.05）,术后7～28d下降并接近假手术组（P〉0.05）。结论大鼠90%PBL术后导致未结扎侧肝脏再生,而TGF-α和TGF-β1蛋白表达与肝脏再生启动和增殖过程密切相关。     

肝癌大鼠部分门静脉结扎术后血流动力学变化与不同肝叶肿瘤生长的关系

目的 探讨门静脉结扎术(PVL)后,肝脏血流动力学变化与荷瘤大鼠不同肝叶肿瘤生长的关系.方法 将18只雄性大鼠随机分为A、B组.均为荷瘤大鼠,A组行PVL术,B组为假手术组.分别于术后不同时间段,应用多普勒超声测量结扎肝叶与非结扎肝叶肝动脉及门静脉血流速度,正电子发射计算机断层显像(PET-CT)测算结扎与非结扎肝叶上肿瘤的体积变化,分析血流变化与肿瘤体积变化是否存在相关性.结果 A组PVL肝叶肝动脉血流速度明显高于B组[(4.34±0.53) ml/min比(2.07±0.04) ml/min,P＜0.05],且与结扎肝叶肿瘤体积增加呈正相关(r=0.908,P＜0.05).结论 PVL肝叶的肝动脉血流增加是PVL术后结扎侧肝叶肿瘤生长加速的促进因素.     

联合肝脏分割和门静脉结扎二步肝切除术大鼠模型的建立

目的:建立联合肝脏分割和门静脉结扎(PVL)二步肝切除术(ALPPS)大鼠模型。方法:将健康60只SD雄性大鼠随机均分为PVL组、ALPPS组、假手术组。PVL组行肝左外叶、左中叶、右叶门静脉分支结扎及尾状叶切除,保留肝右中叶分支;ALPPS组在PVL组手术的基础上,将肝左中叶与右中叶在缺血带处离断;假手术组仅游离出门静脉各分支,不结扎。检测大鼠术后肝再生率(HRR)、肝功能情况,以及肝左中叶病理损伤程度与肝右中叶Ki-67的表达。结果:与假手术组比较,ALPPS组、PVL组术后各时间点肝右中叶HRR均明显升高(均P0.05),且第4、7天ALPPS组肝右中叶HRR明显高于PVL组(155.96%vs.118.15%;174.86%vs.133.55%,均P0.05)。PVL组术后早期肝功能指标好于ALPPS组(均P0.05),但后期无统计学差异(均P0.05)。组织病理学检查显示,ALPPS组术后第1天肝左中叶坏死明显多于PVL组;ALPPS组肝右中叶Ki-67表达第2、4天明显高于PVL组(85.36%vs.61.84%;43.40%vs.29.06%,均P0.05)。结论:ALPPS与PVL均能促进肝再生,并且ALPPS比PVL能更快的促进肝再生;成功建立大鼠ALPPS模型,为研究ALPPS肝再生机制及相关并发症奠定了基础。     

近70%门静脉分支高位结扎对大鼠肝脏结构和功能的影响

目的 观察近70％门静脉分支高位结扎对大鼠肝脏结构和功能的影响。方法 Wistar大鼠60只，随机分成假手术对照组和门静脉结扎组。观察术后0．5、1、2、3、7和14d肝脏大体结构和血浆转氨酶的变化。用TUNEL法对结扎侧肝细胞凋亡进行定量分析，光学显微镜下观察对侧肝细胞的增殖情况，透射电子显微镜下观察结扎侧肝脏的超微结构改变。结果 70％门静脉分支高位结扎后，结扎侧肝叶呈进行性萎缩变小，对侧则成比例的代偿性增生。在整个观察过程中，全肝的总重量维持恒定，肝脏功能基本保持正常。TUNEL显示结扎侧肝细胞在术后凋亡明显增加，于第2天达高峰，同时对侧肝细胞却明显增殖。电子显微镜显示结扎侧肝脏早期出现典型的凋亡改变，晚期明显纤维化。结论 近70％门静脉分支高位结扎后，结扎侧由于肝细胞大量凋亡呈进行性萎缩，对侧则成比例的代偿性增生，全肝的总重量和肝脏功能保持正常。     

门静脉阻断对原发性肝癌荷瘤大鼠不同肝叶肿瘤生长的影响

目的 观察在门静脉阻断术(PVL)后荷瘤大鼠不同肝叶肿瘤的生长.方法 将27只雄性大鼠平均分为3组.A组为无荷瘤大鼠,B、C组为荷瘤大鼠.A组(对照组)和C组(实验组)大鼠行PVL术,B组为假手术组.分别于术后不同时段,应用正电子发射计算机断层显像(PET-CT)测算不同肝叶上肿瘤生长的体积变化及肿瘤生长率.结果 C组门静脉结扎肝叶上的肿瘤体积增生明显高于B组[ (54.90±32.17) mm3比(28.41±11.04) mm3,P＜0.05],而无门静脉结扎肝叶上的肿瘤体积增生及肿瘤生长率差异无统计学意义(P＞0.05).结论 PVL术可加速大鼠门静脉结扎肝叶上肿瘤的生长,但不会促使无门静脉结扎肝叶上肿瘤生长的加速.     

去胆管及去门静脉肝叶肝细胞功能分化的研究

目的 观察胆管结扎及门静脉结扎后肝细胞形态及功能分化现象,探讨去胆管及去门静脉肝叶的保留价值.方法 应用氰基丙烯酸酯对仅保留两个肝叶的大鼠行一叶胆道栓塞并结扎,另一肝叶行门静脉结扎,进行分肝静脉血化验检查、组织病理及超微结构观察.结果 去胆管肝叶形态及糖原染色变化不大,分肝静脉血白蛋白(30.9±1.8)g/L与对照组(31.9±2.0)g/,L比较差异无统计学意义(P>0.05).去门脉肝叶萎缩明显,但血胆红素指标维持正常,与未处理对照组比较[(7.7±3.2)比(8.7±2.3)μmol/L]差异无统计学意义(P>0.05).结论 去胆管肝叶在观察期内无明显萎缩,仍保留有蛋白质合成分泌等功能;去门脉肝叶肝细胞能够承担胆汁代谢功能.     

70%门静脉分支高位结扎大鼠肝组织细胞凋亡及相关基因Bax和Bcl-2 mRNA的表达

目的 观察70%门静脉分支高位结扎后大鼠肝组织细胞凋亡及相关基因Bax,Bcl-2的表达,以探讨肝细胞凋亡的发生机制.方法 Wistar大鼠60只,随机分成假手术对照组(n=30)和门静脉结扎组(n=30).观察术后第12小时和第1,2,3,7,14天的肝脏大体结构和血浆转氨酶的变化.用细胞凋亡原位末端标记技术(TUNEL)对结扎侧肝细胞凋亡进行定量分析,光学显微镜下观察未结扎侧肝细胞的增殖情况,采用逆转录-多聚酶链反应(RT-PCR)检测肝脏组织中Bax和Bcl-2 mRNA的表达.结果 70%门静脉分支高位结扎后,结扎侧肝叶以细胞凋亡的方式呈进行性萎缩变小,对侧则以有丝分裂的方式成比例地代偿性增生.全肝的总质量维持恒定,肝脏功能基本保持正常.结扎侧肝组织中以Bax mRNA的升高为主,而未结扎侧肝组织中以Bcl-2 mRNA的升高为主.结论 近70%门静脉分支高位结扎后,结扎侧肝脏由于Bax mRNA表达升高引起肝细胞大量凋亡,未结扎侧由于Bcl-2 mRNA表达升高引起肝细胞增殖,在维持全肝的质量和功能中具有重要意义.     

保留肝动脉血流间断门静脉阻断在肝切除术中的实验研究

目的探索新型的肝切除术中血流阻断方法。方法采用经尾状叶转流门静脉血流模型,根据阻断方式不同随机将大鼠分成3组,每组30只:对照手术组(SO)、间断完全肝门阻断组(IC)和保留肝动脉血流间断门静脉阻断组(HIC),设定阻断时间为90 min。阻断完成后切除肝左叶及尾叶,比较各组肝断面出血量,术后第0、1、3、7天共4个时相点血清谷丙转氨酶(ALP)活性、肝组织三磷酸腺苷(ATP)水平、肝组织丙二醛(MDA)水平及肝组织病理学改变情况。结果 SO组肝断面出血量[(302.6±10.2)mL]明显高于HIC组[(37.2±5.3)mL]和IC组[(35.8±4.5)mL];IC组术后1、3 d ALT[(5 455.0±424.6)U/L、(2 356.2±325.6)U/L]明显高于HIC组[(3 230.0±332.5)U/L、(1 653.5±176.7)U/L];术后IC组MDA[(7.15±1.22)nmol/mg]较HIC组[(4.16±0.89)nmol/mg]升高明显;术后HIC组ATP[(1.51±0.44)μmol/mg]明显高于IC组[(0.85±0.21)μmol/mg];以上差异均有统计学意义(P0.05)。病理形态观察,HIC组较IC组能明显减轻肝窦充血、肝细胞水肿,术后恢复快。结论与间断Pringle法相比,保留肝动脉血流间断门静脉阻断方法不会明显增加术中肝断面的失血量,但可以明显减轻肝脏缺血再灌注损伤,是值得在临床应用的一种入肝血流控制方法。     

核因子-κB在大鼠门静脉分支结扎后肝细胞凋亡中的作用

目的：探讨核因子-κB(NF-κB)在大鼠门静脉分支结扎后结扎侧肝细胞凋亡中的作用。方法：Wistar大鼠60只，随机分成对照组和门静脉分支结扎组。观察术后第12，24，48，72小时以及第168小时(第7天)和第336小时(第14天)肝脏大体结构和血浆转氨酶的变化。运用凝胶阻滞分析(EMSA)检测术后结扎侧肝脏NF-κB的活性，用TUNEL法对结扎侧肝细胞凋亡进行定量分析，电镜下观察结扎侧肝脏的超微结构改变。结果：70％门静脉分支高位结扎后，结扎侧肝叶呈进行性萎缩变小，对侧则成比例的代偿性增生。在整个观察过程中，全肝的总质量维持恒定，肝脏功能基本保持正常。结扎侧肝脏NF-κB的活性在术后明显升高，于第48小时达高峰，1w后基本恢复正常。TUNEL显示结扎侧肝细胞在术后凋亡明显增加，于第48小时达高峰。电镜显示结扎侧肝脏早期出现典型的凋亡改变，晚期明显纤维化。结论：70％门静脉分支高位结扎后，结扎侧肝脏NF-κB的活性明显升高，其可能在肝细胞凋亡中具有重要意义。     

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.