骨质疏松性椎体空腔样骨折对椎体后凸成形术疗效的影响

目的 评估骨质疏松性椎体空腔样骨折对椎体后凸成形术疗效的影响.方法 自2004年3月～2009年8月对157例因骨质疏松性单椎体压缩骨折行椎体后凸成形术,以27例伤椎星空腔样改变作为A组,选取27例伤椎无空腔样改变作为B组,两组年龄、性别构成及骨折压缩程度均相近.术后常规拍摄脊柱正侧位X线片及CT,比较两组椎体高度的恢复、后凸畸形的矫正、骨水泥的注入量及渗漏情况.采用疼痛视觉模拟评分(VAS)和Oswestry功能障碍指数评估两组的临床疗效.结果 所有患者均顺利完成手术,两组术后VAS、ODI均得到明显改善,组间比较差异无统计学意义(P＞0.05);A组椎体高度的恢复和后凸畸形的矫正优于B组,差异有统计学意义(P＜0.05);A组骨水泥注入量大于B组,差异有统计学意义(P＜0.05);两组间骨水泥渗漏率分别为11.1％和7.4％,差异无统计学意义(P＞0.05).结论 椎体空腔样骨折与无空腔样骨折相比,术后腰背痛、生活能力的改善及骨水泥渗漏的发生率相近,但是椎体高度的恢复和后凸畸形的矫正更明显.     

骨水泥椎间渗漏与椎体成形术术后再发椎体压缩骨折相关性研究

目的 评估骨水泥椎间渗漏与椎体成形术（percutaneous vertebroplasty,PVP）术后再发椎体压缩骨折风险的相关性.方法对2009年6月～2011年6月行PVP手术治疗的153例骨质疏松性椎体压缩骨折患者进行回顾性研究,根据椎体再发骨折情况分为再发骨折组与对照组,记录2组患者骨密度、骨水泥注射量与骨水泥椎间隙渗漏情况.结果共124例患者（148个椎体）获得完整随访,平均随访18个月;24例患者（32个椎体）再发椎体压缩骨折.再发椎体压缩骨折患者骨水泥椎间渗透率为25.0%（6/24）与对照组的21.0%（21/100）差异无统计学意义（P＞0.05）.再发椎体压缩骨折患者骨密度低于对照组,差异有统计学意义（P＜0.05）.结论 骨水泥椎间渗漏并不增加PVP术后再发椎体压缩骨折风险,低骨密度是再发椎体骨折的危险因素.     

骨水泥在椎体骨折线内弥散情况对椎体成形术治疗效果的影响

【摘要】 目的：探讨经皮椎体成形术（PVP）中骨水泥在椎体骨折线内弥散情况对疗效的影响。方法：回顾性研究2009年9月~2011年12月因骨质疏松性椎体压缩骨折（OVCF）住院并行PVP治疗的45例患者,男14例,女31例,年龄53~88岁,平均72.18岁,病程2h~4个月,平均17.36d。均为胸腰段（T10~L2）单一椎体骨折。根据术前多平面重建CT或MRI评估椎体骨折线位置,参考术后X线、多平面重建CT判断骨水泥在椎体骨折线内的弥散情况,将患者分成两组,A组（n=30）：骨水泥充分弥散在骨折线内,B组（n=15）：骨水泥在骨折线内弥散不佳。记录术前、术后3d及末次随访时的疼痛视觉模拟评分（visual analogue scale,VAS）、Oswestry功能障碍指数（Oswestry disability index,ODI）及局部后凸Cobb角,末次随访时与术后3d局部Cobb角之差定义为后凸纠正丢失量,对比分析两组上述指标的差异,并记录相关并发症。结果：所有患者均顺利完成椎体成形术,无严重并发症出现。除骨密度外两组患者术前基线特征无显著性差异,术后3d及末次随访时的VAS评分、ODI均较术前明显改善（P<0.05）,术后3d时的VAS评分、ODI相比术前值的改善程度（术前-术后）A组优于B组（VAS：5.03±1.33 vs 3.53±1.13,ODI：26.17±2.10 vs 24±2.03,P<0.05）,末次随访时的VAS评分、ODI两组无显著性差异（P＞0.05）。两组术后3d局部Cobb角均较术前明显纠正（P＜0.05）,A组术后3d时的Cobb角与末次随访时无显著性差异（P＞0.05）,B组末次随访时的后凸Cobb角较术后3d时显著增大（P＜0.05）。A组后凸纠正丢失量显著小于B组（1.08°±0.38° vs 3.58°±0.37°,P＜0.05）。A组8例出现骨水泥渗漏,B组6例出现骨水泥渗漏,总体渗漏率为31.1%,骨水泥渗漏均未引起临床症状。结论：PVP可有效缓解胸腰段骨OVCF患者的疼痛,改善功能障碍;骨水泥在骨折线内弥散不佳会影响近期疗效,也可能是骨折椎体接受PVP术后仍发生进展性后凸畸形的危险因素。     

骨水泥分布形态对经皮椎体成形术疗效的影响

目的 探讨骨水泥分布形态对经皮椎体成形术(PVP)治疗骨质疏松性椎体压缩骨折(OVCF)疗效的影响。方法 将156例采用PVP治疗的OVCF患者依据骨水泥分布形态不同分为A组(骨水泥分布呈H型，91例)、B组(骨水泥分布呈T型，49例)和C组(骨水泥分布呈O型，16例)。比较3组手术时间、术中出血量、骨水泥注入量、骨水泥渗漏率、邻近椎体骨折发生率、疼痛VAS评分、伤椎后凸Cobb角。结果 患者均获得随访，时间17～36(25.1±7.6)个月。手术时间、术中出血量及骨水泥渗漏率3组比较差异均无统计学意义(P>0.05)。骨水泥注入量A组>B组>C组(P<0.01)。邻近椎体骨折发生率A组0.05)。3组伤椎后凸Cobb角术后1年、2 d与术前比较均明显减小(P<0.05),术后1年与术后2 d比较差异均无统计学意义(P>0.05),组间比较差异均无统计学意义(P>0.05)。结论 3种骨水泥...     

骨质疏松性椎体压缩性骨折椎体强化术后再骨折相关因素研究

目的探讨骨质疏松性椎体骨折椎体强化术(椎体成形PVP和椎体后凸成形PKP)术后椎体再骨折发生的临床特点和危险因素。方法回顾性分析2008年8月～2011年8月在我院行经皮椎体强化术的171例患者,其中再发椎体骨折19例27个椎体(A组),未再发骨折152例作为对照(B组)。所有患者获得随访6～16个月,平均13个月。记录患者临床资料、骨水泥注入量、测量椎体前缘椎体高度及Cobb角变化等并进行多因素Logistic回归分析;记录再次手术前、后第1天及末次随访VAS评分。结果 16个椎体发生在PVP术后相邻椎体(84.2%),其中9个椎体术后2个月内发生;骨水泥向椎间盘渗漏在A、B组间有显著性差异(P<0.05);椎体强化术在再骨折术前、后VAS评分有显著性差异(P<0.05)。结论骨质疏松性椎体再骨折发生具有一定危险因素,椎体强化术可以取得满意的治疗效果,同时应该加强骨质疏松药物治疗。     

网袋椎体成形术与常规PVP手术治疗骨质疏松性椎体压缩骨折的疗效对比

目的探讨常规PVP手术与网袋椎体成形术治疗骨质疏松性椎体压缩骨折的疗效差异。方法回顾性分析2014-03-2016-03手术治疗的91例OVCF患者,其中常规PVP手术53例,作为A组;网袋椎体成形术38例,作为B组。对两组患者手术前后的VAS评分、骨水泥渗漏情况、伤椎高度和后凸畸形矫正情况进行对比。结果两组术后共发生骨水泥渗漏18例,其中A组15例(28.3%),B组仅3例(7.9%),A组显著高于B组(P0.05)。两组患者术后3 d和术后12个月的VAS评分均较术前显著下降(P0.05),但组间差异无统计学意义(P0.05)。术后3 d与12个月时,B组的伤椎前缘相对高度与后凸Cobb角改善效果显著优于A组,差异有统计学意义(P0.05)。结论与常规PVP手术相比,网袋椎体成形术治疗OVCF可达到相近的止痛效果,但对伤椎高度和后凸畸形的矫正能力更佳,且有效降低了骨水泥渗漏率。     

经皮椎体成形术后手术椎体再发骨折的相关因素分析

目的分析经皮椎体成形术(percutaneous vertebroplasty,PVP)治疗骨质疏松性椎体压缩骨折(osteoporotic vertebral compression fracture,OVCF)患者的临床资料,探讨PVP术后手术椎体再发骨折的相关因素。方法回顾性分析2007年2月至2011年11月因单节段骨质疏松性椎体压缩骨折而行椎体成形术的患者的临床资料,共156例,其中男62例,女94例;年龄56~77岁,平均70.1岁。随访时间12~26个月,平均17.3个月。根据症状、体格检查及影像学资料判断手术椎体是否再发骨折。分析性别、年龄、身高、体重、骨质疏松程度、骨水泥注射量、单侧或双侧注入、骨水泥是否同时接触上下终板、骨水泥是否偏一侧分布、骨水泥椎间盘渗漏以及术前椎体裂隙样变等因素对手术椎体是否出现再发骨折的影响。结果 10例患者发生了手术椎体的再发骨折,4例的新发骨折出现在PVP术后3个月内。术前椎体存在裂隙样变的患者发生手术椎体再骨折的概率明显增高(B=-2.864,OR=0.004,95%CI=0.002-0.05,P=0.000)。骨水泥是否同时接触上下终板、骨水泥是否偏一侧分布、骨水泥有无椎间盘渗漏未增加手术椎体再骨折的风险,差异无统计学意义(P0.05)。结论术前合并裂隙样变的骨折椎体是PVP后手术椎体再发骨折的高风险因素。     

骨水泥弥散对经皮椎体成形术治疗骨质疏松性椎体压缩骨折疗效的影响

目的 探讨单侧穿刺经皮椎体成形术(PVP)中骨水泥弥散对治疗骨质疏松性椎体压缩骨折(OVCF)疗效的影响.方法 将173例采用单侧穿刺PVP治疗的OVCF患者根据骨水泥弥散情况分为A组(骨水泥弥散好,47例)和B组(骨水泥弥散差,126例).记录手术前后疼痛VAS评分、Cobb角及骨水泥渗漏率、邻近椎体骨折发生率和强化...     

高黏度骨水泥在重度骨质疏松性椎体压缩骨折的临床应用

目的 探讨Confidence高黏度骨水泥PVP技术在重度骨质疏松性椎体压缩骨折(osteoporotic vertebral compressive fracture,OVCF)的临床应用价值。方法 2012-10-2014-10共纳入了80例重度OVCF患者,采用随机数字表法,将其分为A组与B组各50例,A组患者采用Confidence高黏度骨水泥PVP技术治疗,B组采用传统PMMA骨水泥行PKP技术治疗。结果 两组治疗后3 d、3个月和1年,VAS评分和ODI指数均有显著改善(P0.05);组间相比,治疗后各时间点的两项指标变化较为相近(P0.05)。A组骨水泥渗漏发生率为28.6%,B组为23.2%,差异无统计学意义(P0.05)。结论 针对重度OVCF患者,Confidence高黏度骨水泥PVP技术可取得常规PKP技术相当的疗效,其骨水泥渗漏率低,疗效可靠,且明显减轻了患者的医疗负担,值得在临床推广应用。     

高粘度骨水泥经皮椎体成形术治疗骨质疏松性椎体压缩骨折的疗效分析

目的 :比较高粘度骨水泥经皮椎体成形术(PVP)与低粘度骨水泥经皮椎体后凸成形术(PKP)治疗骨质疏松性椎体压缩骨折(OVCF)的临床疗效及影像学特征,评价高粘度骨水泥PVP治疗OVCFs的临床价值。方法:2015年6月~2016年12月我院收治单节段骨质疏松性椎体压缩骨折患者115例,其中65例行高粘度骨水泥PVP(A组),50例行低粘度骨水泥PKP(B组),两组患者年龄、性别、体重指数(BMI)、骨密度(BMD)均无统计学差异。统计两组患者的手术时间、术中透视次数、骨水泥用量、骨水泥渗漏、骨水泥弥散分布情况、伤椎椎体前缘高度和椎体后凸角(Cobb角)、术前和术后VAS评分及ODI等资料,应用SPSS 20.0进行统计学分析。结果:两组患者术后VAS评分、ODI、伤椎椎体前缘高度及Cobb角均较术前显著性改善(P0.01);两组间骨水泥渗漏率无显著性差异;A组手术时间、术中透视次数均显著性少于B组(P0.05)。A组骨水泥单侧弥散分布、双侧不对称分布、双侧对称分布分别为6例(9.2%)、12例(18.5%)、47例(72.3%),未弥散至终板、单侧终板弥散、双侧终板弥散分别为3例(4.6%)、16例(24.6%)、46例(70.8%);B组骨水泥单侧弥散分布、双侧不对称分布、双侧对称分布分别为33例(66.0%)、7例(14.0%)、10例(20.0%),未弥散至终板、单侧终板弥散、双侧终板弥散分别为17例(34.0%)、22例(44.0%)、11例(22.0%),两组间比较有显著性差异(P0.01)。结论:高粘度骨水泥PVP治疗OVCF可获得良好的短期临床疗效,骨水泥可对称地弥散至椎体前柱两侧以及椎体上下终板,使伤椎均衡强化,有利于减少手术椎体再骨折风险,骨水泥渗漏风险与低粘度骨水泥PKP相当。     

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.