低温体外循环血中血管性假血友病因子浓度及循环内皮细胞的观察

目的观察先天性心脏病患者体外循环围手术期血管性假血友病因子（ｖｏｎＷｉｌｅｂｒａｎｄｆａｃｔｏｒ,ｖＷＦ）及血循环内皮细胞（ｃｉｒｃｕｌａｔｉｎｇｅｎｄｏｔｈｅｌｉａｌｃｅｌｓ,ＣＥＣ）数的动态变化过程,探讨低温体外循环对血管内皮细胞的影响。方法于肝素化后体外循环前、转流３０分钟、开放主动脉５分钟、停机、停机后４小时和术后第１天晨用酶联免疫法测定２０例先天性心脏病患者血浆中ｖＷＦ浓度,同时用Ｐｅｒｃｏｌ密度梯度离心法对患者血中ＣＥＣ进行计数和形态学观察。结果转流３０分钟、开放主动脉５分钟、停机、停体外循环后４小时、术后第１天晨ｖＷＦ水平和ＣＥＣ数较体外循环前显著升高（Ｐ＜０．０５）。结论体外循环可导致血管内皮细胞激活或损伤     

低温体外循环血中血管性假血友病因子浓度及循环内？…

目的 观察先天性心脏病患者体外循环围手术期血管性假血友病因子（ｖｏｎ Ｗｉｌｌｅｂｒａｎｄ ｆａｃｔｏｒ，ｖＷＦ）及血循环内皮细胞（ｃｉｒｃｕｌａｔｉｎｇ ｅｎｄｏｔｈｅｌｉａｌ ｃｅｌｌｓ，ＣＥＣ）数的动态变化过程，探讨低温体外循环对血管内皮细胞的影响。方法 于肝素化后体外现患者血浆中ｖＷＦ浓度，同时用Ｐｅｒｃｏｌｌ密度梯度离心法对患者血中ＣＥＣ进行计数和形态学观察。     

猪原位肝移植术中内皮素和血流动力学关系的研究

目的 探讨猪原位肝移植（ＯＬＴｘ）术中血浆内皮素（ＥＴ）与血流动力学的关系。方法 观察静脉转流组（ＶＶＢ）和无静脉转流组（ＮＶＶＢ）各６例猪ＯＬＴｘ术中ＥＴ水平和血流动力学指标改变及其相互关系。结果 复灌后ＮＶＶＢ组的ＥＴ水平比ＶＶＢ组高。血浆ＥＴ水平与ＭＡＰ、ＳＶＲ、ＰＶＰ、ＰＡＷＰ呈正相关,与ＣＯ、ＳＶ呈负相关关系。结论 ＥＴ参与猪ＯＬＴｘ术中血流动力学紊乱的病理过程,ＶＶＢ可降低ＯＬＴｘ术中血浆ＥＴ水平,有助于血流动力学稳定。     

脊髓型颈椎病患者手术前后血浆内皮素的变化

目的：通过对脊髓型颈椎病（ＣＳＭ）患者手术前后血浆中内皮素值的测定,探讨其在该病病因学的病理学中的作用。方法：采用放射免疫分析法分别对２０例正常人,４３例２和手术病人做了术后的血浆ＥＴ值测定。结果：ＣＳＭ患者血浆含量明显高于正常对照组,４１例术后患者血浆ＥＴ值明显低于术前,经统计学ｔ检验有显著性意义。结论：ＥＴ参与了ＣＳＭ发病过程,ＥＴ可能是ＣＳＭ的致损伤因子之一,寻找ＥＴ拮抗剂将为非手术治疗ＣＳ     

川芎嗪对慢性肺心病患者循环内皮细胞及血浆内皮素—1含量的影响

为观察川芎嗪对慢性肺心患者肺循环内皮细胞（ＣＥＣ）及血浆内皮素－１（ＥＴ－１）含量的影响，探讨川芎嗪治疗慢性肺心病的机制，将３４例肺心病急性发作期患者随机分为常规治疗组（１７例）及川芎嗪治疗组（１７例），分别测定各组治疗前后血浆ＥＴ－１含量及ＣＥＣ计数，结果显示，治疗前两组血浆ＥＴ－１含量及ＣＥＣ计数均较对照组显著升高（Ｐ〈０．００１），治疗后两组血浆ＥＴ－１含量及ＣＥＣ计数均较各组治疗前明显降低     

梗阻性黄疸兔血浆内毒素和内皮素1含量与血流动力学改变的关系

研究梗阻性黄疸内毒素血症对血管内皮细胞产生内皮素１（ＥＴ－１）的作用及ＥＴ－１与梗阻性黄应时血流动力学改变的关系。方法用肝总管结扎法建立梗阻性黄疸（ＯＪ）兔模型,偶氮显色法定量测定血内毒素含量,特异性放射免疫分析法测定血浆ＥＴ－１,生理记录仪和电磁血流计测定心率（ＨＲ）、平均动脉压（ＭＡＰ）、心输出量（ＣＯ）、肝动脉血流量（ＨＡＢＦ）、门静脉血流量（ＰＶＢＦ）、门静脉压力（ＰＶＰ）及内脏血管阻力（ＳＡＲ）。结果ＯＪ组血浆内毒素含量明显高于正常对照（ＮＣ）组;血浆ＥＴ－１低于ＮＣ组。ＯＪ组血浆内毒素与血浆ＥＴ－１含量呈负相关;ＯＪ组血浆ＥＴ－１含量与ＭＡＰ、ＨＡＢＦ、ＰＶＢＦ及ＳＡＲ呈正相关。结论梗阻性黄疽时血浆ＥＴ－１水平降低,内毒素血症不能刺激血管内皮细胞产生ＥＴ－１,血浆ＥＴ－１水平下降在系统血流动力学改变中起一定的作用。     

先天性心脏病心内直视手术对血浆内皮素的影响

目的　探讨先天性心脏病（ＣＨＤ） 围术期血浆内皮素（ＥＴ） 的变化。　方法　将６７ 例行心肺转流术（ＣＰＢ）的ＣＨＤ 患儿按疾病种类不同分为３ 组,室间隔缺损（ＶＳＤ） 组、肺动脉高压（ＰＨ） 组和肺动脉狭窄（ＰＳ） 组;１０ 例正常儿童为对照组。对前３ 组手术前后血浆ＥＴ 变化进行动态观测。　结果　ＰＨ 组和ＰＳ组术前ＥＴ 值即有升高,术后７ 天仍较对照组为高;ＣＰＢ３０ 分钟时各组ＥＴ 值均较术前为低;术前血浆ＥＴ 值与ＰＳ和ＰＨ 程度呈线性相关;ＰＳ组ＣＰＢ 时间和主动脉阻断时间与术后１ 小时ＥＴ 值明显相关。　结论　ＣＨＤ 患儿手术前、后血浆ＥＴ 值均有变化,血浆ＥＴ 水平可作为监测肺动脉压力变化及ＣＨＤ 手术预后的指标之一。     

小儿先心病伴肺高压围术期血浆内皮素变化机制

为应用内皮素（ＥＴ）拮抗剂及一氧化氮控制肺高压发展提供理论和临床依据。随机纳入先天性心脏病体外循环（ＣＰＢ）手术病儿４２例，其中高肺血流量肺高压（ＨＦ）组２３例，低肺血流量（ＮＦ）组１９例。采用放射免疫方法测定、比较围术期不同时间血浆ＥＴ变化。结果显示，停ＣＰＢ１５分钟和２小时后，ＨＦ组血浆ＥＴ水平均明显增高，而ＮＦ组与ＣＰＢ前比较无明显变化；停ＣＰＢ１５分钟后两组动、静脉血ＥＴ浓度差比较差异有显著性。结论：ＣＰＢ对术前高肺血流量肺高压病例可致灌注后早期血浆ＥＴ增高，从而加重了ＥＴ对肺循环系统的不良影响     

心肺转流时间对P（a—ET）CO2和肺泡死腔量的影响

观察９４例心内直视手术病人，探讨不同的心肺转流时间对Ｐ（ａ－ＥＴ）ＣＯ２和肺泡死腔量的影响。结果：停心肺转流后３０ｍｉｎ、６０ｍｉｎ时较心肺转流前Ｐ（ａ－ＥＴ）ＣＯ２和肺泡死腔量增加显著（Ｐ〈０．０５）或增加非常显著（Ｐ〈０．０１）。左向右分流两组不同心肺转流时间从Ｐ（ａ－ＥＴ）ＣＯ２和肺泡死腔量比较无显著差异（Ｐ〉０．０５）；风心病两组不同心肺转流时间的病人在停心肺转流后６０ｍｉｎ时，Ｐ（ａ－Ｅ     

血栓调节蛋白与肝细胞癌门静脉癌栓的关系

目的　了解血栓调节蛋白（ｔｈｒｏｍｂｏｍｏｄｕｌｉｎ,ＴＭ） 在肝细胞癌（ＨＣＣ） 病人血浆中的水平,探讨ＴＭ 与ＨＣＣ门静脉癌栓形成及侵袭和转移的关系。方法　采用酶联免疫吸附（ＥＬＩＳＡ） 夹心法,检测４５ 例ＨＣＣ病人和６ 例肝良性占位病人的术前和术后血浆ＴＭ 水平。结果　术前ＨＣＣ组血浆ＴＭ水平（１０±６）ｎｇ／ｍｌ 明显高于肝良性占位组（６．１ ±２．２）ｎｇ／ｍｌ,Ｐ＜ ０．０５;单发肝癌结节组（１２ ±６）ｎｇ／ｍｌ和无门静脉癌栓组（１１±６）ｎｇ／ｍｌ 明显高于多发肝癌结节组（８ ±５）ｎｇ／ｍｌ 和门静脉癌栓组（７ ±５）ｎｇ／ｍｌ,Ｐ＜ ０．０５;而ＴＭ 高低与肝癌大小、包膜是否完整、病理分化程度、ＡＦＰ值及肝癌伴肝硬化程度无关,各组比较Ｐ＞０．０５。肝良性占位组术前ＴＭ（６±２）ｎｇ／ｍｌ 与切除术后（５ ．９ ±１ ．８）ｎｇ／ｍｌ 相比差异无显著性,Ｐ＞０ ．０５ ;肝癌组术前（１０ ±５）ｎｇ／ｍｌ 与切除术后（８ ±４）ｎｇ／ｍｌ 相比差异有显著意义,Ｐ＜０ ．０５。结论　ＨＣＣ病人血浆中ＴＭ 水平可升高,ＴＭ 在抗ＨＣＣ门静脉癌栓形成过程中发挥重要作用。     

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.     

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.     

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.     

Is the recovery profile of mivacurium independent of the rate of decay of its plasma concentration in patients with normal plasma cholinesterase activity?

Background: The duration of action of muscle relaxants is poorly correlated to the rate of decay of their plasma concentration. The plasma concentration of mivacurium may rapidly decrease below its active concentration because of the extensive hydrolysis of mivacurium. By inflating a tourniquet on one upper limb for 3 min after the administration of atracurium, mivacurium or vecuronium, we studied the influence of the initial decline of their plasma concentration on their effect. Methods: In 50 patients anaesthetised with thiopental, isoflurane and fentanyl, the effect of bolus doses of 0.15 or 0.25 mg . kg^?1 mivacurium (MIV 15, MIV 25), 0.3 or 0.5 mg . kg^?1 atracurium (ATR 30, ATR 50) and 0.06 or 0.1 mg . kg^?1 vecuronium (VEC 06, VEC 10) were measured on both arms (evoked response of the adductor pollicis to train-of-four stimulation every 12 s), a tourniquet being applied on one arm just before and during 3 min after the muscle relaxant bolus. Results: Tourniquet inflation of 3 min almost abolished the neuromuscular effect of mivacurium. In the vecuronium groups and in the ATR 50 group, tourniquet inflation did not modify the maximum degree of depression of the twitch response. Also, the duration of action of vecuronium was unaffected by the tourniquet. In the ATR 30 group, times to return of the twitch response to 25% (duration 25%) and 75% (duration 75%) of control response were significantly shorter in the cuffed arm, 23 min vs 27 min, and 41 min vs 45 min, respectively. In the ATR 50 group, only duration 25% was significantly shorter in the cuffed arm (41 min vs 45 min). Conclusion: The results suggest that the rate of decline of the plasma concentration of mivacurium is so rapid, that a very low and almost clinically ineffective concentration is present as soon as 3 min after its administration. The results also indicate that the recovery from a mivacurium-induced neuromuscular blockade is not influenced by the rate of decay of its plasma concentration in patients with genotypically normal plasma cholinesterase.     

Membranes in Artificial Organs

Abstract: Membrane processes play a pivotal and enabling role in modern replacement therapy for acute and chronic organ failure and in the management of immunologic diseases. In fact, virtually all contemporary extracorporeal blood purification methods employ membrane devices, and the next generation of artificial organs and tissue engineering therapies are almost certain to be similarly grounded in membrane technology. In this short essay, we comment on the similarities and differences among synthetic membranes and their natural counterparts and also provide a critical overview of the demographics and technology of hemodialysis, hemofiltration, apheresis, oxygenation, and emerging membrane technologies and applications.     

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.