经尿道钬激光、电切及开放手术处理膀胱袖套-输尿管下段的对照研究

目的 评估钬激光、电切及开放手术在上尿路上皮性恶性肿瘤根治术中袖套状切除膀胱-输尿管下段的临床疗效. 方法 回顾性分析2000年1月至2010年12月162例肾盂癌、中上段输尿管癌患者的资料.肾及近端输尿管切除术采用开放或后腹腔镜法.袖套状切除膀胱-输尿管下段分别采用钬激光(A组)32例、电切(B组)51例及开放手术(C组)79例.经尿道手术组术中插入5F输尿管气囊导管以阻断尿流.病理诊断均为肾盂和(或)输尿管上皮癌,病理分期为T(4)NoM0 ～T4N0M0.对3组围手术期指标(手术时间、术中失血量、术中并发症、术后住院时间等)和术后随访结果(肿瘤复发率、肿瘤种植发生率、患者生存率等)进行对照研究.术后随访3个月～8年. 结果 A、B组手术时间[(203.6±31.5),(207.2±24.3) min]、术中失血量[(127.4±63.2),(135.0±82.7) ml]、术后住院时间[(5.8±1.3),(5.6±1.2)d]显著低于C组[(248.0±42.9) min,( 484.5±217.7)ml,(8.7±3.5)d,P＜0.01].B组术中发生闭孔神经反射6例,膀胱穿孔合并较大出血3例,其中中转开放手术2例.3组术后膀胱肿瘤发生率(16.3％、18.1％、21.7％)、肿瘤种植发生率(均为0)、1、3年生存率(96.3％/90.5％、98.0％/88.6％、95.7％/86.4％)比较差异均无统计学意义(P＞0.05). 结论 经尿道术式的创伤程度、手术时间、术中失血量、术后恢复时间等围手术期指标显著优于传统开放手术,膀胱肿瘤发生率、肿瘤种植发生率、生存率等与开放手术相当.袖套状切除膀胱-输尿管下段的手术方式与术后肿瘤复发率无关.钬激光袖套状切除膀胱-输尿管下段是肾盂癌和输尿管癌根治术中安全、微创的方法.     

经腹腹腔镜与后腹腔镜治疗上尿路尿路上皮癌的比较研究

目的探讨完全腹腔镜下肾输尿管全长切除、膀胱袖状切除术治疗上尿路尿路上皮癌的有效性和安全性。方法回顾性分析2010年10月~2015年10月上尿路尿路上皮癌79例资料,其中经腹完全腹腔镜下肾输尿管全长切除及膀胱袖状切除术47例(CTLNU组),后腹腔镜肾输尿管全长切除+下腹部小切口膀胱袖状切除术32例(RLNU组)。记录手术时间、术中出血量、术后肛门排气时间和术后住院时间。结果与RLNU组相比,CTLNU组手术时间短[(120.5±21.6)min vs.(145.2±29.9)min,t=-4.265,P=0.000],术中出血量少[(120.8±42.4)ml vs.(190.6±60.8)ml,t=-6.017,P=0.000],术后住院时间短[(8.2±2.5)d vs.(9.9±3.2)d,t=-2.646,P=0.010];术后肛门排气时间差异无统计学意义(P0.05)。CTLNU组和RLNU组随访发现膀胱尿路上皮癌分别为5例和3例(P0.05),行经尿道膀胱肿瘤电切术治愈,远处转移分别为2例和3例(P0.05)。结论完全腹腔镜下肾输尿管全长切除、膀胱袖状切除术是治疗上尿路尿路上皮癌的可行、安全、有效的微创方法。     

基于加速康复外科理念的输尿管软镜钬激光碎石术

目的探讨基于加速康复外科(enhanced recovery after surgery,ERAS)理念的输尿管软镜钬激光碎石术的临床疗效。方法回顾性分析2015年1月~2017年5月255例上尿路结石行输尿管软镜钬激光碎石术的资料。按经治医师不同分成2组,其中传统处理方法 134例(对照组),采用ERAS措施121例(ERAS组)。比较2组手术时间、术后下床活动时间、术后发热、术后住院时间、住院总费用、清石率等。结果 251例软镜碎石手术获得成功,对照组3例、ERAS组1例软镜手术失败。ERAS组和对照组的手术时间[(80.7±32.3)min vs.(86.3±33.6)min,t=-1.342,P=0.181]和清石率[86.7%(104/120)vs.85.5%(112/131),χ~2=0.072,P=0.789]无明显差异。ERAS组术后下床活动时间明显早于对照组[(11.3±5.2)h vs.(21.5±4.4)h,t=-16.940,P=0.000],术后住院时间明显短于对照组[(2.2±0.9)d vs.(3.4±1.9)d,t=-6.341,P=0.000],住院总费用明显低于对照组[(19.4±3.8)千元vs.(21.0±4.7)千元,t=-2.980,P=0.003],术后发热率低于对照组[25.0%(30/120)vs.37.4%(49/131),χ~2=4.468,P=0.035]。结论基于ERAS理念的输尿管软镜钬激光碎石术安全可靠,术后恢复快,住院费用低。     

一期与分期输尿管软镜治疗双侧上尿路结石的疗效比较

目的探讨一期与分期输尿管软镜下碎石术(flexible ureteroscopic lithotripsy,FURL)治疗双侧上尿路结石的临床疗效。方法我院2012年9月~2015年5月一期输尿管软镜下钬激光碎石术治疗双侧上尿路结石29例(一期手术组),分期输尿管软镜治疗双侧上尿路结石20例(分期手术组),比较2组总手术时间、总住院时间、结石清除率、并发症发生率。结果 2组患者均顺利完成手术。一期手术组总手术时间明显短于分期手术组[(71.0±19.0)min vs.(112.6±26.8)min,t=-6.366,P=0.000],2组总住院时间无统计学差异[(6.9±3.6)d vs.(8.4±2.1)d,t=-1.674,P=0.101]。2组患者术后4周结石清除率分别为79.3%(23/29)、80.0%(16/20),无统计学差异(χ~2=0.000,P=1.000);2组术后并发症发生率无统计学差异[20.7%(6/29)vs.15.0%(3/20),χ~2=0.017,P=0.896]。结论一期双侧输尿管软镜钬激光碎石术可有效、安全治疗双侧上尿路结石,但仍需严格把握手术适应证。     

经尿道电切联合后腹腔镜在上尿路肿瘤手术中的应用体会

目的:探讨应用经尿道等离子电切镜联合后腹腔镜行膀胱输尿管口袖套状切除加肾输尿管全长切除术治疗上尿路移行细胞癌的可行性及安全性。方法:选取12例上尿路移行细胞癌患者,首先取截石位,应用经尿道等离子电切镜行膀胱输尿管口袖套状切除术,再改为健侧卧位采用后腹腔镜行肾输尿管切除,术中游离出输尿管中上段,最后采取麦氏点或反麦氏点切口游离输尿管下段并取出标本。术后常规行膀胱灌注化疗。结果:手术均获成功,手术时间平均(155.3±13.3)min,出血量平均(81.3±20.8)ml,术后平均(9.1±0.9)d出院,无严重并发症发生。术后随访1.5年,1例发生膀胱移行细胞癌。结论:经尿道等离子电切镜联合后腹腔镜手术治疗肾盂输尿管上尿路移行细胞癌安全、可行,具有术后康复快、手术创伤小及并发症少等优点,具有良好的应用前景。     

后腹腔镜联合尿道电切镜根治性肾输尿管切除治疗上尿路肿瘤3例

目的探讨后腹腔镜联合尿道电切镜根治性肾输尿管切除治疗上尿路移行细胞癌的临床疗效。方法对2例肾盂癌、1例输尿管上段移行细胞癌先采用尿道电切镜行患侧输尿管口膀胱黏膜袖套状切除,而后行后腹腔镜根治性肾输尿管全切术。结果3例手术均获成功,平均手术时间190min,术中出血平均50mL,患者均于术后36~48h下床活动,术后住院时间9~11d(平均10d),术中、术后无严重并发症。结论后腹腔镜联合尿道电切镜根治性肾输尿管切除治疗上尿路肿瘤是一种安全、有效的微创手术方法,实用性较强,具有良好的应用前景。     

后腹腔镜肾输尿管全切并膀胱袖套状切除治疗上尿路移行细胞癌

目的:探讨后腹腔镜肾输尿管全切并膀胱袖套状切除治疗上尿路移行细胞癌的疗效.方法:对7例上尿路移行细胞癌患者行后腹腔镜下肾脏切除术,经同侧下腹斜切口切除输尿管肿瘤或下段输尿管并行膀胱袖套状切除,完整取出切除的肾输尿管标本.术后常规卡介苗膀胱灌注.结果:手术时间210～240 min;术中出血量80～200 ml;术后8 d出院,无严重并发症发生.随访0.5～1.5年,1例肿瘤局部复发伴肝脏转移,其余无复发.结论:后腹腔镜肾输尿管全切并膀胱袖套状切除治疗上尿路移行细胞癌,是一种安全有效的术式,具有痛苦小、并发症少及患者恢复快等优点.     

上尿路上皮癌手术中输尿管膀胱壁内段3种切除方法的疗效比较

目的比较开放式袖套状切除、经尿道电切以及经尿道铥激光切除输尿管膀胱壁内段治疗上尿路上皮癌的疗效。方法回顾性分析上海交通大学附属第一人民医院2004年5月至2009年5月利用3种不同方法切除输尿管膀胱壁内段治疗上尿路上皮癌的病例共49例。其中开放性输尿管膀胱壁内段袖套状切除术22例（A组）,经尿道电切镜切除输尿管膀胱壁内段15例（B组）,经尿道铥激光输尿管膀胱壁内段切除12例（C组）。比较3种方法的手术时间、术中失血量、导尿管留置时间、腹膜后引流管留置时间、术后住院时间以及肿瘤复发率。结果B、c两组与A组相比,手术时间明显缩短（平均分别为198、183、262rain,P〈0．05）;术中失血量明显减少（平均分别为140、135、363mL,P〈O．05）;术后住院时间明显缩短（平均10、8、12d,P〈o．05）;而B、C两组之间比较差异无统计学意义（P〉O．05）。3组术后腹膜后引流管与导尿管平均留置时间无明显差异（P〉O．05）。中位随访时间49个月（12～72个月）,其中A组术后膀胱肿瘤复发5例（2互7％）,腹膜后肿瘤复发1例（6．7％）;B组术后膀胱肿瘤复发4例（26．7％）;C组术后膀胱肿瘤复发2例（16．7％）。对比3组术后膀胱肿瘤复发率,差异无统计学意义（P=0．91）。结论与传统开放手术行输尿管膀胱壁内段袖套状切除术相比较,经尿道输尿管膀胱壁内段电切除术或激光切除术手术时间短、术后出血少、恢复快、不增加术后肿瘤种植及复发率。其中经尿道铥激光输尿管膀胱壁内段切除术更具有切割精确、手术安全性高等特点,有较好的临床应用前景。     

改进型超声引导下针状可视肾镜(Needle perc)钬激光碎石术治疗肾下盏结石的临床评价：与输尿管软镜对比

目的 比较改进型超声引导下针状可视肾镜(Needle perc)钬激光碎石术和输尿管软镜下钬激光碎石术治疗1～2 cm肾下盏结石的效果,为临床治疗方式的选择提供参考。方法 回顾性分析2022年1月—2023年5月郑州市第一人民医院收治的60例肾内单发下盏结石(最大径1～2 cm)患者的临床资料,比较行输尿管软镜钬激光碎石术的30例患者(软镜组)和改进型超声引导下Needle perc钬激光碎石术的30例患者(Needle perc组)的临床资料。结果 Needle perc组较软镜组的整体住院时间[(3.00±1.25)d vs.(4.00±1.25)d]、手术时间[(44.63±5.42)min vs.(48.50±7.24)min]和住院花费[(15 518±441)元vs.(16 872±903)元]均较少(P<0.05)。Needle perc组术后清石率高于软镜组[93.3%(28/30)vs.50.7%(15/30),P<0.001)]。术后降钙素原(PCT)上升幅度低于软镜组[(0.02±0.01)vs.(0.12±0.18),P=0.007],而并发症发生率...     

后腹腔镜与输尿管镜技术用于感染性输尿管上段结石取石碎石的比较

目的比较腹腔镜输尿管切开取石术与输尿管镜钬激光碎石术治疗有上尿路感染病史的梗阻性输尿管上段结石的疗效和安全性。方法回顾性分析189例有上尿路感染病史的梗阻性输尿管上段结石患者的临床资料,统计两种手术方式的结石清除率、术后并发症,特别是感染并发症情况,评价两种手术方式的疗效和安全性。结果腹腔镜手术组患者81例,输尿管镜手术组患者108例。两组患者的年龄、性别比例无统计学差异。腹腔镜手术组患者的结石直径[(16.1±1.4)mmvs.(10.4±1.6)mm]、手术时间[(78.5±12.6)min vs.(37.3±14.7)min,P0.05]、住院时间[(7.6±1.5)d vs.(4.7±1.8)d,P0.05)]均明显大于输尿管镜手术组患者(P0.05)。腹腔镜手术组术后1月时的结石清除率为98.8%,输尿管镜组为88.9%,差异具有统计学意义(P0.05)。腹腔镜手术组患者术后高热(38.5℃)的发生率明显低于输尿管镜手术组(4.9%vs.11.1%,P0.05)。结论对于有明确上尿路感染病史的梗阻性输尿管上段结石患者,腹腔镜切开取石术较输尿管镜手术结石清除率高,术后感染并发症少,但手术时间、住院时间较长。     

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 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.     

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.     

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.