全脊椎截骨治疗静止型胸腰椎结核伴后凸畸形

目的:评估一期后路全脊椎截骨手术治疗静止型胸腰椎结核伴后凸畸形的疗效。方法:自1998年到2004年诊治静止型胸腰椎结核伴严重后凸畸形患者72例,均行一期后路全脊椎截骨矫形术,术前术后分别测量脊柱后凸Cobb角、侧位片上C7-S1水平距离及神经功能Frankel分级。结果:随访1～7年,平均27.8个月,后凸Cobb角术前平均为56.7°,术后平均为11.2°,平均矫正45.5°,矫正率80.2%;C7-S1水平距离术前平均为13.7mm,术后平均为3.8mm,矫正率72.3%;术前有神经功能障碍者19例,FrankelC级8例,D级11例,术后Frankel分级D级2例,神经功能改善率89.5%(17/19);术中并发症发生率为6.9%,术后并发症发生率为5.6%,永久性神经组织损害者1例,随访过程中未发现内固定相关并发症,所有病例均获得良好的骨性融合,矫正无显著丢失。结论:对静止型胸腰椎结核伴严重后凸畸形患者通过一期后路全脊椎截骨手术可获得良好的矫形结果,并发症发生率较低。     

一期前路病灶清除植骨内固定治疗胸腰椎结核

目的:总结一期前路病灶清除、自体骨椎间植骨融合、前路或后路内固定治疗胸腰椎结核的临床效果。方法:2002年2月～2006年2月手术治疗胸、腰椎结核86例,均采用一期前路病灶清除、自体骨椎间植骨,侧前方内固定52例,后路内固定34例。根据术前、术后X线平片分析植骨融合及脊柱后凸畸形矫正效果。结果:随访8个月～4年,平均23个月。除1例术后2周出现切口皮下血肿、4例1年后仍存在髂骨供骨区疼痛外,无其他并发症;无复发。均获骨性愈合,愈合时间3～7个月,平均4.5个月,无内固定松动、脱出及断裂;术前Cobb角平均为33.6°,术后1周及末次随访时Cobb角分别为平均15.6°、18.6°。结论:对胸、腰椎结核患者行一期前路病灶清除、自体骨椎间植骨融合、前路或后路内固定治疗可有效矫正脊柱后凸畸形,重建脊柱稳定性,获得良好的骨性融合,临床效果良好。     

PVCR技术治疗重度胸腰椎角状后凸畸形疗效观察

目的探讨一期后路全脊柱切除联合前方钛网支撑治疗重度胸腰椎角状后凸畸形的策略及安全性。方法 2007-01-2012-10,采用后路全脊椎切除(PVCR)联合前方钛网支撑手术治疗18例胸腰椎角状后凸畸形患者,术前、术后和末次随访时分别测量患者后凸Cobb’s角,并评估神经功能ASIA分级。结果本组患者手术均顺利,手术时间250~460 min,平均318 min;术中出血量1600~2600 ml,平均2120 ml,术后Cobb’s角平均10~21°,平均16.6°,矫正率77.8%,术中及术后无脊髓及神经根损伤、大血管及脏器损伤等并发症发生,平均随访时间16.8月,复查X线,后凸矫形无丢失,内固定及椎间植骨融合钛网无移位。结论一期后路全脊柱切除联合前方钛网支撑治疗重度胸腰椎角状后凸畸形是较可靠的手术技术。     

一期手术内固定治疗胸腰椎脊柱结核

目的总结一期后路病灶清除、椎间植骨及后路手术内固定治疗胸腰段和腰段脊柱结核的临床疗效。探讨一期重建脊柱稳定性的必要性和安全性。方法自1999-2004年6月共收治24例胸腰段脊柱结核患者,采用一期后路病灶清除、椎体间植骨及后路内固定治疗,其中胸腰椎18例,腰椎6例,受累椎体5个椎体1例,3个椎体8例,2个椎体15例。结果经平均26个月随访,所有患者均临床治愈,无伤口感染或窦道形成,植骨完全融合,融合时间平均4.2个月。术前后凸畸形角度43°±10.6°,术后11.5°±8.3°。后凸畸形矫正角度为28.6°±9.3°。后期矫正度丢失为2.2°±3.3°。结论一期后路手术GSS固定治疗胸腰段脊柱结核能有效清除病灶,矫正后凸畸形,早期重建脊柱稳定性及促进椎体间植骨的融合,是一种安全有效的治疗方法。     

前路一期病变椎体切除并重建治疗胸腰椎结核并后凸畸形

目的:观察前路一期病变椎体切除、人工椎体或钛网融合器植骨替代、椎体钉板或钉棒系统内固定治疗连续两个及以上节段胸腰椎结核并后凸畸形的疗效。方法:34例病变累及连续两个及两个以上椎节的胸腰椎结核患者,术前后凸Cobb角27.8°￣65.4°(38.6°±10.3°),一期行前路病变椎体切除,椎间撬拔撑开复位,人工椎体或钛网融合器植骨替代,辅以椎体钉板或钉棒系统短节段邻近椎节内固定,重建脊柱稳定性,术后均给予短疗程化疗。观察术后局部疼痛缓解、脊髓神经功能恢复、后凸畸形矫正及脊柱稳定性情况。结果:患者术后局部疼痛缓解,术前伴有脊髓神经损伤的12例患者术后神经功能均有不同程度恢复。影像学检查示脊柱内固定物位置良好,椎体序列恢复良好,椎间高度恢复。后凸Cobb角矫正至2.1°￣14.2°(7.5°±8.3°),平均矫正31.2°±8.5°。随访18￣54个月,平均35个月。末次随访时后凸矫正度丢失4.3°±3.8°,均无结核复发。结论:连续两个及两个以上节段的胸腰椎结核采用前路一期行病变椎体切除有利于病灶彻底清除,减少复发;也有利于椎管彻底减压。前路椎体替代、植骨内固定重建脊柱稳定性可更好地纠正和预防脊柱后凸畸形。     

后路全脊椎切除折顶椎管三维同心闭合矫形治疗重度脊柱角状后凸畸形

目的:评价后路全脊椎切除折顶矫形治疗重度脊柱角状后凸畸形的安全性和临床初步效果.方法:2004年6月至2008年5月,收治重度脊柱角状后凸畸形患者11例.男4例,女8例,年龄16-42岁,平均27.9岁:其中先天性椎体形成不良6例,胸腰椎结核3例,陈旧性脊柱骨折2例,神经纤维瘤病1例.术前矢状面角状后凸Cobb角82°～150°,平均107.0°;10例合并侧凸畸形,冠状面侧凸Cobb角11°～128°,平均52.7°;6例先天性椎体发育不良中有1例合并神经损害,3例结核中有1例合并神经损害,根据Frankel分级均为D级.均采用顶椎全脊椎切除折顶椎管三维同心闭合矫形术治疗,随访观察治疗效果.结果:手术时间为7.9～14.7h.平均11.1h.术中出血2400～5100ml,平均3866ml.脊髓短缩1.6～2.7cm,平均2.1cm.融合同定节段为8～14节椎体,平均12.5节.矢状面Cobb角由术前平均107.0°矫正至26.1°矫正率75.6%.冠状面Cobb角由术前平均52.7°矫正至12.3°,矫正率76.7%.躯干矢状偏移距离平均矫正率76.4%.术前2例神经损害者,术后Frankl分级恢复到E级,随访9～61个月,平均25.9个月.所有患者获得良好的骨质愈合,无脊髓损伤,也无矫正度的丢失.结论:全脊椎切除折顶复位术矫正重度脊柱角状后凸畸形疗效满意,椎管三维同心闭合技术保证了截骨面椎管在矢状面、冠状面及水平面的安全闭合.     

经后路全脊柱截骨治疗胸腰椎骨折晚期后凸畸形

[目的]评价经后路全脊柱截骨治疗胸腰椎骨折晚期后凸畸形的效果及探讨其手术指征。[方法]28例胸腰椎骨折晚期后凸畸形患者,22例腰背部疼痛剧烈,平卧困难、后凸畸形进行性加重,6例伴有不同程度神经损害症状(Frankel分级:C级2例,D级4例);术前后凸Cobb′s角32°~60°,平均47.5°。均采用经后路全脊柱截骨术式纠正后凸畸形、植骨内固定稳定脊柱,重建脊柱矢状面平衡。[结果]术后Cobb′s角平均6.8,°胸腰椎后凸畸形纠正率85.7%,重建脊柱矢状面平衡,神经损害症状恢复(Frankel分级C、D级5例神经功能恢复正常,1例C级恢复至D级),外观满意;无神经并发症。术后平均随访18个月,平均矫正丢失度数为2.8°。[结论]对于胸腰椎骨折晚期后凸畸形僵硬、度数<50°的中老年患者经后路全脊柱截骨术式是理想选择。     

后路全脊椎切除牵引后伸交叉棒加压矫治重度高位胸椎角状后凸

目的:评价后路全脊椎切除牵引后伸交叉棒加压矫形治疗重度高位胸椎角状后凸畸形的安全性和临床初步效果。方法:2005年3月~2008年11月采用后路全脊椎切除牵引后伸交叉棒加压矫形治疗重度高位胸椎角状后凸畸形患者10例,男5例,女5例,年龄4~44岁,平均17.7岁;其中先天性椎体形成不良7例,陈旧性胸腰椎结核1例,神经纤维瘤病1例,陈旧性T3骨折1例。角状后凸节段:T3、T4和T5各3例,T6 1例。术前矢状面角状后凸Cobb角73°～155°,平均98.9°;腰前凸角24°～81°,平均48.2°;矢状位偏移距离-5.0～5.5cm。7例合并侧凸畸形,冠状面侧凸Cobb角11°～110°,平均56.0°;冠状位偏移距离0.2～6.5cm,平均3.24cm。2例先天性椎体形成不良和1例结核患者合并神经损害,Frankel分级C级2例,D级1例。结果:均顺利完成手术,手术时间为7.9～14.7h,平均10.6h;术中出血1400～5600ml,平均3750ml。切除椎体1～2个,平均1.5个。脊髓短缩1.6～2.6cm,平均2.1cm。融合固定5～12个椎体,平均8.7个。术后矢状面后凸Cobb角矫正至平均19.0°,矫正率80.3%;腰前凸角矫正至平均34.3°,矫正率33.5%;冠状面Cobb角矫正至平均12.0°,矫正率79.9%;躯干矢状位偏移距离矫正至-0.5~0.5cm,矫正率90.4%;冠状位偏移距离矫正至平均0.51cm,矫正率89.5%。术前2例Frankel C级和1例D级神经损害者,术后恢复到E级。随访25～69个月,平均38.2个月,所有患者获得良好的骨性愈合,无脊髓损伤和矫正度的显著丢失。结论:后路全脊椎切除牵引后伸交叉棒加压矫治重度高位胸椎角状后凸畸形可提供安全有效的矫正力并能获得满意的疗效。     

一期后路全脊椎切除术治疗重度僵硬性胸腰椎畸形的并发症分析

目的 分析一期后路全脊椎切除、椎弓根螺钉固定矫治重度胸腰椎畸形的并发症.方法 2000年2月至2009年2月通过一期后路全脊椎切除治疗重度胸腰椎畸形患者54例,男性23例,女性31例;年龄16～58岁,平均28.3岁.侧凸畸形9例,冠状面主弯Cobb角平均91.7°;侧后凸畸形22例,冠状面主弯Cobb角平均101.5°,后凸角平均69.4°;角状后凸畸形21例,后凸角平均72.2°;圆弧状后凸2例,后凸角平均93.6°.采用主弯区顶椎全脊椎切除、全节段椎弓根螺钉内固定和360°植骨融合术.对临床结果进行评估,统计并分析并发症发生情况.结果 平均切除椎体1.4个,手术时间平均470 min,术中出血量平均4180 ml.随访时间12～66个月,平均26个月.末次随访侧凸畸形平均矫正61.4°(67%);侧后凸畸形中侧凸平均矫正59.7°(56%),后凸平均矫正42.3°(59%);角状后凸平均矫正48.5°(71%);圆弧状后凸平均矫正62.7°(67%).共有17例患者出现21例次并发症(38.9%),其中早期神经系统并发症5例次(9.3%),包括1例完全性脊髓损伤.非神经系统并发症早期11例次(20.4%),后期5例次(9.3%).结论 一期后路全脊椎切除治疗胸腰椎脊柱畸形可以取得较为满意的畸形矫正结果,但其潜在的严重并发症不可忽视.     

一期后路病灶清除、楔形截骨矫形治疗胸腰椎结核并后凸或侧后凸畸形

目的探讨一期后路病灶清除、楔形截骨矫形及内固定治疗胸、腰椎结核并后凸或侧后凸畸形的可行性、应用指征及临床意义。方法对16例胸、腰椎结核并后凸或侧后凸畸形的患者采取一期后路病灶清除、楔形截骨矫形及内固定术。男性12例,女性4例,年龄17~53岁,平均37 1岁。术前后凸角为54°~138°,平均78 3°; 2例合并侧凸,角度分别为31°和24°; 1例伴随侧方移位。7例合并脊髓损害, 2例为C级, 5例为D级, 2例表现为马尾及神经根损害。结果手术时间为215~325min,平均265min,术中出血450~2200ml,平均1100ml。术后结果满意, 14例为优, 2例为良,无严重并发症发生,脊髓神经功能损害均获显著改善。术后后凸角度为0°~67°,平均28 5°,矫正率63 6%,侧凸和侧方移位基本矫正。随访14 ~52个月,平均26 3个月。无内固定松动、断裂及明显矫正度丢失,融合良好。结论对胸、腰椎结核并后凸或侧后凸畸形的患者采取一期后路病灶清除、楔形截骨矫形及内固定术是一较为有效、可行的方法。与联合前、后路手术比较,该技术减少了创伤且有更好的畸形矫正效果。     

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.