严重膝关节皮肤软组织缺损的治疗及体会

目的探讨多种原因导致严重膝关节皮肤软组织缺损的系统治疗方法。方法选择2013年1月至2015年9月广州医科大学附属第一医院整形外科收治的27例严重膝关节皮肤软组织缺损患者,均伴有不同程度的髌骨、胫腓骨或关节囊外露,膝关节皮肤软组织缺损面积为(7×6)cm2至(16×15)cm2。感染性创面采用一期行清创+负压封闭引流技术(VSD)治疗,二期行轴型或游离组织瓣封闭创面;非感染性创面一期术行轴型或游离组织瓣封闭创面;均结合术后早期功能锻炼的系统治疗。其中,12例采用腓肠肌内侧头肌皮瓣,10例采用股前外侧逆行岛状皮瓣,5例采用游离背阔肌肌皮瓣。术后随访1~2年,并采用美国膝关节协会评分(KSS评分)对患者膝关节进行功能评价。采用SPSS 17.0统计软件进行分析,并采用配对样本t检验比较术前及术后KSS膝关节评分。结果皮瓣或肌皮瓣移植的27例患者完全成活,其中25例一期愈合,其余2例出现局部坏死,经后期植皮后创面愈合。术后随访膝关节外形可,活动功能良好,膝评分术前(30±16)分,术后(91±9)分,组间差异有统计学意义(t=18.523,P0.01);功能评分术前(34±18)分,术后(86±12)分,组间差异有统计学意义(t=13.952,P0.01)。结论该系统治疗用于伴有不同程度的髌骨、胫腓骨或关节囊外露的严重膝部皮肤软组织缺损病例可获得良好的治疗效果;腓肠肌内侧头肌皮瓣、股前外侧逆行岛状皮瓣、游离背阔肌肌皮瓣,可作为轴型或游离组织瓣的首选。     

全膝关节置换术后皮肤坏死的处理

目的探讨应用真空负压引流术（VSD）、内侧腓肠肌皮瓣转移术治疗全膝关节置换（TKA）术后皮肤坏死,挽救TKA的疗效。方法2007年至2009年本组共有4例患者采用内侧腓肠肌皮瓣转移术治疗TKA术后伤口皮肤坏死,平均随访19个月（12—32个月）,采用KSS膝关节评分系统进行功能评价,在最后随访时对患者的感染消除情况进行临床评价,测量患者活动度。结果根据KSS膝关节评分系统,4例患者结果优良。所有患者均有良好的股四头肌力量。患者不需要助步器行走,所有皮瓣一期愈合,无感染复发。结论内侧腓肠肌皮瓣能提供良好的覆盖,允许早期活动和快速康复,可以降低TKA术失败后关节僵硬的发生率。     

内侧腓肠肌肌(皮)瓣在小腿近端恶性肿瘤手术中的应用

目的探讨采用内侧腓肠肌肌(皮)瓣修复小腿近端恶性肿瘤切除后缺损的方法及临床疗效。方法自2015年10月至2019年1月,对6例小腿近端恶性肿瘤切除后的胫前软组织缺损患者分别采用内侧腓肠肌肌(皮)瓣转移修复、内侧腓肠肌肌瓣转移联合人工网状补片重建伸膝功能,并于术后3个月对切口的愈合情况、肢体功能以及肿瘤控制情况进行评价。结果本组共6例患者,术后获随访11~34个月,平均(13.3±3.2)个月。5例切口一期愈合(占83.3%);1例皮瓣边缘发生部分坏死,经换药后愈合。1例于术后12个月因肿瘤肺转移而死亡;1例于术后3个月时肿瘤局部复发接受了二次手术治疗;其余4例肿瘤无复发,效果较满意。患者术后3个月MSTS评分为17~29分,平均(26.2±4.8)分;评定下肢功能的优良率为83.3%(5/6)。结论采用内侧腓肠肌肌(皮)瓣转移修复小腿近端恶性肿瘤切除后的软组织缺损,以及联合人工网状补片行伸膝功能重建,其方法简单易行,可获得较满意的临床效果。     

髌骨钻孔减压改善全膝关节置换术后膝前疼痛

目的探讨通过髌骨钻孔减压术改善全膝关节置换术(TKA)后膝前痛的临床疗效。方法将符合标准的113例行TKA的骨关节炎患者按数字法随机分为两组:54例为减压组,TKA术中联合髌骨钻孔减压术;59例为非减压组,仅施行TKA不联合髌骨钻孔减压术。术后观察两组患者切口愈合情况、相关并发症、KSS评分及膝前痛发生率。结果两组患者切口均一期愈合,无严重并发症发生,113例均获满12个月的完整随访。KSS评分:减压组术后明显高于非减压组;术后膝前痛的发生率明显低于非减压组,差异均有统计学意义(P0.05)。结论 TKA术中联合髌骨减压术可以在一定程度上改善膝关节KSS评分及降低术后膝前疼痛的发生率。     

缝合锚钉内固定治疗急性髌骨脱位后髌骨内缘撕脱骨折伴内侧髌股韧带断裂

目的评价缝合锚钉内固定治疗急性髌骨脱位后髌骨内缘撕脱骨折伴内侧髌股韧带（MPFL）断裂的临床疗效。方法自2006-07—2012-01采用缝合锚钉内固定治疗急性髌骨脱位后髌骨内缘撕脱骨折伴MPFL断裂21例,术后12个月采用膝关节功能Lysholm评分标准评价膝关节功能。结果术后切口均一期愈合,无感染。本组均获得随访13~24个月,平均14.6个月。末次随访时髌股关节对合良好,解剖关系正常。术后12个月膝关节功能Lysholm评分78~100分,平均93.7分;疗效等级评价：优13例,良7例,可1例,优良率95.2%。结论缝合锚钉内固定治疗急性髌骨脱位后髌骨内缘撕脱骨折伴MPFL断裂临床疗效满意,手术操作简单、损伤小。     

固定平台型与活动平台型膝关节假体人工全膝关节置换术后膝前痛的比较研究

目的比较采用固定平台型与活动平台型膝关节假体行人工全膝关节置换术(total knee arthroplasty,TKA)后发生膝前痛的差异。方法 2008年1月-10月收治72例骨性关节炎患者,其中37例采用固定平台型膝关节假体置换(固定平台组),35例采用活动平台型膝关节假体置换(活动平台组)。固定平台组:男8例,女29例;年龄57～76岁,平均69.6岁。左膝20例,右膝17例。体重55～92 kg,平均66.7 kg。体重指数(body mass index,BMI)为17.6～37.3,平均26.2。病程3～22年。根据膝关节学会评分系统(KSS)标准评定膝评分(29.4±15.3)分,功能评分(33.4±16.8)分。髌骨评分(7.2±2.5)分,疼痛评分(2.5±2.2)分。Insall-Salvat(iI-S)指数为1.6±0.3。活动平台组:男9例,女26例;年龄58～73岁,平均68.2岁。左膝30例,右膝5例。体重50～86 kg,平均67.9 kg。BMI为18.4～34.4,平均25.6。病程6～18年。KSS膝评分(30.9±14.7)分,功能评分(31.4±14.4)分。髌骨评分(6.8±3.1)分,疼痛评分(2.0±2.3)分。I-S指数为1.6±0.2。两组患者一般资料比较,差异均无统计学意义(P>0.05),具有可比性。结果两组患者术后切口均Ⅰ期愈合,无下肢深静脉血栓形成及肺栓塞发生。患者术后均获随访,随访时间为12～16个月。术后活动平台组发生膝关节感染1例,膝关节脱位1例,膝关节弹响3例;固定平台组发生膝关节弹响1例。两组末次随访时KSS膝评分及功能评分、疼痛评分及髌骨评分比较,差异均无统计学意义(P>0.05);两组以上指标分别与术前比较,差异均有统计学意义(P<0.05)。末次随访时两组适合角、外侧髌骨角、髌骨倾斜角、髌骨外移距离、髌骨移位距离及I-S指数比较,差异均无统计学意义(P>0.05)。术后1～5个月固定平台组7例(18.9%)、活动平台组5例(14.3%)出现膝前痛。两组膝前痛发生率比较,差异无统计学意义(χ2=0.227,P=0.634)。术后出现膝前痛患者KSS膝评分、功能评分、髌骨评分及I-S指数与未出现膝前痛患者比较,差异均有统计学意义(P<0.05);其余各指标差异均无统计学意义(P>0.05)。结论采用固定平台型与活动平台型膝关节假体行TKA术后膝前痛发生率及术后近期疗效无明显差异。     

保留髌骨型全膝关节置换术的中期疗效

目的评价膝关节退变性骨关节炎行保留髌骨型全膝关节置换术(total knee arthroplasty,TKA)后膝前痛发生率、临床功能及髌骨软骨退变等级对临床疗效的影响。方法回顾分析2006年2月至2009年2月采用保留髌骨型TKA治疗151例(151膝)膝关节退变性骨关节炎患者的临床资料。其中男59例,女92例;平均年龄72.3岁(56~82岁)。髌骨软骨退变等级采用Outerbridge分级标准、术后膝前痛采用VAS评分、临床功能采用美国膝关节学会评分(the knee society scale,KSS)和髌骨评分(Patellar scores,PS)。结果平均随访时间(6.4±1.8)年。所有患者切口达Ⅰ期愈合。髌骨软骨退变等级:Ⅰ级18例,Ⅱ级36例,Ⅲ级62例,Ⅳ级35例。末次随访时,6例(4.0%)患者有膝前疼痛,其中轻度疼痛4例,中度2例,无重度疼痛。患者平均KSS评分由术前(82.6±9.3)分提高到术后(169.8±13.2)分;患者平均PS由术前(10.5±3.3)分提高到术后(27.8±4.5)分。不同髌骨软骨退变不影响术后膝前痛发生率(χ2=0.42,P=0.94)、KSS评分(膝评分:F=1.83,P=20.14;功能评分:F=0.56,P=20.64)和PS评分(F=0.78,P=20.51)。结论膝关节退变性骨关节炎行保留髌骨型TKA术可取得满意的临床疗效,髌骨软骨退变等级不影响临床疗效。     

腓肠肌远端岛状肌瓣修复膝和小腿上2/3软组织缺损

目的 探讨应用腓肠肌远端岛状肌瓣修复膝关节周围和小腿上2/3软组织缺损的临床效果.方法 2003年5月至2009年5月,应用腓肠肌远端岛状肌瓣修复18例膝关节周围和小腿上2/3软组织缺损,其中腓肠肌内侧头远端岛状肌瓣12例,腓肠肌外侧头6例.肌瓣表面以中厚网状皮片修复,供区直接缝合.结果 18例患者的肌瓣和其上所植皮片均成活,仅有2例术后创缘表浅感染,但经换药后逐渐愈合.术后随访8个月至4.8年,平均3.5年,供区愈合良好,仅有一纵行手术切口痕迹.患肢膝关节屈、伸与小腿内、外旋,以及足的跖屈与站立时上提足跟的肌力强度与功能,与健肢相比无明显差异,未见明显的功能障碍.受区肌瓣质地、厚薄及颜色均较好.结论 腓肠肌远端岛状肌瓣血供丰富,血管解剖恒定,血管蒂长,肌瓣较薄,适宜修复膝关节周围和小腿上2/3软组织缺损.     

全膝置换术经小切口股内侧肌入路与标准髌旁入路临床疗效比较的META分析

目的：系统评价经小切口股内侧肌入路行全膝关节置换术的疗效及安全行。方法使用计算机检索Cochrane图书馆、PubMed和CBM等数据库,并行手工检索,全面搜索关于经小切口股内侧肌入路及髌骨旁入路行全膝关节置换术的临床对比研究。由两名评价员独立筛选及纳入研究、提取数据资料及行方法学质量评估,采用Cochrane协作网提供的RevMan5．2软件进行Meta分析。结果共纳入符合本研究的试验文献11篇,其中小切口股内侧肌入路组395例,传统髌骨旁入路组372例。两组在术后并发症发生率、出血量、术后6周及3个月KSS临床与功能评分、手术时间、假体力线等方面未发现统计学差异。术后膝关节屈曲活动度、切口长度等方面,小切口股内侧肌入路组表现优于传统髌骨旁入路组。结论现有证据表明,小切口股内侧肌入路同髌骨旁入路对比,在并发症发生率、手术时间、假体力线、术后KSS评分、出血量以及术后关节屈曲活动度方面效果相似。但小切口股内侧肌入路行全膝关节置换切口更小,且能获得更快的膝关节功能恢复速度。受纳入研究质量的限制,上述结果还有待开展更多高质量的临床试验来进一步证实。     

改良张力带钢丝联合可吸收带线锚钉内固定治疗髌骨下极撕脱骨折疗效观察

目的观察改良张力带钢丝联合可吸收带线锚钉内固定治疗髌骨下极撕脱骨折的临床疗效。方法回顾性分析自2016-06—2019-08诊治的34例髌骨下极撕脱骨折,采用环形+8字形钢丝张力带联合可吸收带线锚钉内固定。术后6个月采用膝关节活动度、Bostman评分评定患肢功能恢复情况。结果 34例均获得随访,随访时间平均13.2(6～24)个月。切口均一期愈合,术后6周随访时骨折均达到临床愈合。术后即刻Insall-Salvati指数为0.97±0.09,术后6周InsallSalvati指数为0.97±0.06,无明显差异。术后6个月膝关节活动度为(130.2±4.3)°。术后6个月膝关节功能Bostman评分为(28.8±1.1)分,其中优29例,良5例。结论改良张力带钢丝联合可吸收带线锚钉内固定治疗髌骨下极撕脱骨折能够获得满意疗效,手术操作简便,骨折端固定牢靠,并发症发生率低,患者可以早期功能锻炼,膝关节功能恢复良好。     

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.