基于CT和MRI三维重建前交叉韧带股骨止点的解剖学研究

[目的]通过CT及MRI扫描重建正常人群膝关节ACL股骨止点,为解剖重建ACL准确定位股骨止点提供临床解剖学数据。[方法]对46名志愿者双侧共92个膝关节进行CT及MRI扫描,测量ACL股骨附着点的面积、形态以及与周围结构的关系。并进行性别间比较。[结果]男性ACL股骨止点面积(103.6±13.0)mm2显著大于女性(86.5±11.6)mm2(t=6.637,P=0.000);后距(4.1±1.7)mm长于女性(2.9±1.2)mm(t=3.992,P=0.000);远距(5.4±1.3)mm长于女性(4.0±1.3)mm(t=5.338,P=0.000);内距(2.3±1.3)mm与女性(2.3±1.3)mm比较差异无统计学意义(t=-0.330,P=0.742)。男性ACL长轴角(13.3±5.8)°与女性(10.9±6.3)°比较差异无统计学意义(t=1.867,P=0.065)。[结论]ACL股骨止点有多种形态,股骨止点面积有性别差异,重建ACL应结合股骨止点的形态、位置、大小、性别等特点进行个体化重建。     

国人锁骨中远端三维解剖研究及其内固定置入后的影响

[目的]测量部分国人正常锁骨中远端的三维解剖数据,并观察锁骨骨折置入内固定后的影响.[方法]正常成人单侧锁骨骨折患者165例,选取骨折对侧肢体正常锁骨进行三维CT扫描,扫描层厚1 mm,以1 mm层厚、0.5 mm层间隔进行三维重建,重建后的图像用Mimics与Imageware软件进行处理,进行三维测量,随后待患侧锁骨骨折采用前置解剖型重建钢板内固定后以同样方法三维重建,数据测量,并与健侧数据比对.[结果]国人成人锁骨长平均为(14.49±3.8)cm(11.8～17.7 cm).锁骨的弯曲也不相同,或前曲明显,一般男性锁骨前曲明显度较女性大1倍,长度较女性大.锁骨皮质在中1/3最厚,锁骨中段额状面直径平均为(18.6±0.6)mm,冠状面直径平均为(18.2±0.5)mm,矢状面直径平均为(17.6±0.4)mm.锁骨远端额状面直径平均为(20.8±1.8)mm,冠状面直径平均为(22.4±0.7)mm,矢状面直径平均为(24.3±0.9)mm.中段模拟抗扭转负荷平均为(287.65±28.5)N,模拟抗疲劳负荷为(862.68±35.8)N.中远交界处模拟抗扭转负荷平均为(167.92±22.7)N,模拟抗疲劳负荷为(420.35±26.3)N;远端模拟抗扭转负荷平均为(354.72±30.5)N,模拟抗疲劳负荷为(586.90±48.3)N.分别取样锁骨中段、中远交界处、远端骨折植入内固定后模拟抗扭转、抗负荷数据与正常数据对照,统计学分析无显著差异.[结论]国人正常锁骨骨折采用前置解剖可塑性钢板固定可以恢复锁骨正常解剖力学要求.     

钩钢板治疗肩锁关节脱位术后肩峰下撞击综合征与第二肩关节间隙的关系

目的 探讨锁骨钩钢板治疗肩锁关节脱位(TossyⅢ型)术后发生肩峰下撞击综合征(subacromial impingement syndrome,SIS)与第二肩关节间隙的关系.方法 2005年7月至2008年10月,肩锁关节脱位(TossyⅢ)患者63例,男48例,女15例;年龄21～53岁,平均33.6岁;受伤至手术时间3～7 d,平均4d.所有患者均行切开复位锁骨钩钢板内固定.采用改良野田氏位摄片,并在X线片上测量第二肩关节间隙,即肩峰-肱骨头间距(acromio-humeral interval,AHI)和钢板-肱骨头间距(plate-humeral interval,PHI).术后根据Karlsson疗效标准评价肩关节功能.结果 术后根据有无典型肩痛分为两组,其中有SIS患者14例,无SIS患者49例.所有患者均获得随访,随访时间6～15个月,平均12.2个月.SIS组AHI为5.2～11.4mm,平均(8.5±2.1)mm;无SIS组AHI为6.4～13.7 mm,平均(9.7±2.6)mm,两组比较差异有统计学意义(t=4.89,P＜0.05).SIS组AHI与SIS有相关性(F=7.14,P＜0.05).SIS组PHI为2.7～10.2mm,平均(6.1±2.8)mm;无SIS组PHI为3.1～10.8mm,平均(6.8±2.4)mm,两组比较差异无统计学意义(t=1.34,P=0.243).术后3个月,SIS组患者拆除钢板后Karlsson疗效评价:优11例,良3例,优良率为100%.结论 锁骨钩钢板术后出现SIS与第二肩关节间隙有相关性,第二肩关节间隙较小的患者术后可能出现SIS.     

锁骨解剖钢板与锁骨钩钢板治疗锁骨远端骨折疗效分析

目的比较锁骨解剖钢板与锁骨钩钢板(Clavicular hook plate)治疗锁骨远端骨折(Distal clavicle fracture, DCF)的早期临床疗效。方法 2015年8月～2019年1月我院骨科收治的锁骨远端闭合骨折病人114例,按照手术固定方式不同,将其分为锁骨解剖钢板组(52例,对照组)与锁骨钩钢板组(62例,实验组);比较两组病人术中手术时间、出血量、住院时间、围术期及术后1年随访VAS评分,末次随访并发症发生率如退钉、感染、疼痛、钢板断裂、创伤性关节炎、肩峰撞击征,术后1年Constant肩关节评分。结果两组病人均获得随访,其中对照组随访时间为12～18个月,平均(14.5±2.4)个月,实验组随访时间为14～20个月,平均(16.5±3.8)个月;两组围术期VAS评分比较,差异无统计学意义(P0.05);对照组并发症发病总例数为2例,低于实验组的4例,两组比较差异有统计学意义(P0.05);实验组肩关节活动评分为(85.7±12.6),对照组为(80.1±10.2),两组比较差异有统计学意义(P0.05)。结论锁骨解剖钢板与锁骨钩钢板均可使锁骨远端骨折获得较好的愈合率,二者围术期指标比较无差异,但锁骨钩钢板对于恢复肩关节活动度较锁骨解剖钢板有优势。     

钩钢板术后肩峰下撞击的影响因素分析

目的分析锁骨钩钢板治疗肩锁关节脱位术后并发肩峰下撞击综合征的影响因素与产生原因。方法回顾性研究了南京中医药大学附属医院2014年6月至2016年10月使用钩钢板治疗的肩锁关节脱位RockwoodⅢ型患者共36例,筛选术后并发肩峰下撞击综合征的18例为实验组,无症状的18例为对照组,摄肩关节Grashey位片,通过肩关节Constant评分比较两组肩关节活动情况,并测量肩峰指数及对肩峰进行分型。结果术后6个月两组肩关节Constant评分对照组(90.17±1.73)分,明显优于实验组(57.02±1.49)分,差异具有统计学意义。实验组的肩峰指数为(0.79±0.07),对照组为(0.56±0.09),P0.05,说明钩钢板治疗肩锁关节脱位术后肩峰下撞击征的发生率与肩峰指数有一定的正相关性。两组的肩峰分型比较差异无统计学意义(P0.05),但实验组中肩峰Ⅲ型占较大比例(66.7%)。结论肩峰指数及肩峰形态对于钩钢板治疗肩锁关节脱位术后肩峰下撞击综合征的发生有一定的影响。     

尺骨鹰嘴影像学参数测量及临床意义

目的通过测量尺骨鹰嘴的影像学数据,为尺骨鹰嘴骨折张力带手术克氏针置入方向、角度及宽度提供理论参考。方法回顾性收集2020年9月至2020年12月我院60例成人正常肘关节正侧位X线片,其中男30例,女30例;男性平均年龄(37.63±13.75)岁,女性平均年龄(39.70±14.60)岁。分别测量并记录肘关节正位尺骨近端内翻角、鹰嘴最狭窄处宽度,肘关节侧位鹰嘴尖端过鹰嘴窝切线与尺骨轴线的夹角。结果尺骨近端内翻角男性平均为(10.71±2.77)°,女性平均(9.97±2.89)°,两组比较差异无统计学意义(P=0.70);男性鹰嘴最狭窄处宽度(1.90±0.96)mm,女性(1.61±0.12)mm,两组比较差异有统计学意义(P=0.00);鹰嘴尖端过鹰嘴窝切线与尺骨轴线的夹角男性平均(25.42±2.31)°,女性平均(23.12±2.64)°,两组比较差异无统计学意义(P=0.10)。结论通过测量的尺骨鹰嘴影像学参数,为鹰嘴骨折张力带手术时克氏针进针方向、角度及宽度提供参考,提高手术准确度。     

锁骨外侧锁定钢板与锁骨钩钢板内固定治疗NeerⅡB型锁骨远端骨折的疗效比较

目的通过影像学结果和临床疗效分析,比较锁骨外侧锁定钢板与锁骨钩钢板内固定治疗Neer ⅡB型锁骨远端骨折的效果。方法回顾性分析自2014-07—2016-06诊治的72例Neer ⅡB型锁骨远端骨折,33例行锁骨外侧锁定钢板内固定(锁定钢板组),39例行锁骨钩钢板内固定(锁骨钩钢板组)。结果锁定钢板组随访时间为(18.9±4.4)个月,锁骨钩钢板组随访时间为(18.9±4.4)个月。锁定钢板组与锁骨钩钢板组骨折愈合时间、术后双侧喙锁间分离比值、末次随访时肩关节功能Constant-Murley评分、肩关节Oxford评分差异无统计学意义(P0.05)。锁定钢板组并发症发生率明显低于锁骨钩钢板组,差异有统计学意义(P 0.05)。结论锁骨钩钢板与锁骨外侧锁定钢板内固定治疗Neer ⅡB型锁骨远端骨折均能取得满意的影像学结果和临床疗效,均可以恢复锁骨的垂直稳定性。值得注意的是,锁骨钩钢板内固定术后喙锁间距离恢复程度并没有明显优于锁定钢板组,而且术后肩峰撞击、肩峰下骨吸收发生率更高。     

与国人舟骨形态学相关的舟骨螺钉内固定应用

目的 探讨与国人舟骨形态学相关的舟骨螺钉内固定应用.方法 测量27例成人舟骨标本的舟骨长轴长度(沿舟骨长轴线从近极到远极关节面的距离)、舟骨腰部宽度、远极宽度和近极宽度(垂直于舟骨长轴的方向,分别测量舟骨腰部最窄部位的宽度、距离远极关节面2 mm处的远极宽度和距离近极顶端2 mm处的近极宽度),男17例,女10例.比较男性和女性标本的测量数据,并分别同国内可供选择的舟骨内固定螺钉的各项指标进行比较分析.结果 舟骨长轴长度:男性标本(29.3±1.3)mm,女性标本(25.4±1.1)mm,两者比较差异有统计学意义.舟骨腰部宽度、近极宽度和远极宽度男性标本分别为(10.3±0.8)mm、(4.5±0.6)mm和(6.0±0.5)mm,女性标本分别为(9.0±0.8)mm、(4.0±0.4)mm和(5.6±0.4)mm,男性标本的测量值均显著大于女性标本.所有舟骨标本的平均近极宽度均小于远极宽度.国内部分可供选择的舟骨螺钉产品(3.0空心螺钉垫圈系统和部分Acutrak标准型螺钉)的尾端直径大于舟骨近极平均宽度.结论 根据舟骨形态学相关测量结果,治疗舟骨骨折螺钉的适宜平均长度男、女性分别为25 mm和21 mm.因国人舟骨近极宽度相对较窄小,选择背侧入路从近极置入螺钉时,应选择尾端直径适宜的螺钉产品,以减少并发症的发生率.     

双源CT三维重建前交叉韧带胫骨止点印迹的临床研究

目的通过双源CT(dual-source computed tomography,DSCT)三维重建前交叉韧带(anterior cruciate ligament,ACL)胫骨止点印迹,测量印迹相关参数,为临床解剖重建提供依据。方法对55名志愿者双侧共110个膝关节进行DSCT扫描,其中男32例,女23例,年龄20～50岁。64排工作站(GE,Volume Share2-AW4.4版本软件)三维重建膝关节胫骨平台,再现胫骨平台ACL印迹,测量印迹面积,长短轴,印迹中心点在胫骨平台相对位置等。结果男性ACL胫骨印迹面积(200.99±30.42)mm2显著大于女性(170.30±26.94)mm2(t=5.471,P=0.000)。男性ACL胫骨印迹短轴(9.25±1.56)mm显著长于女性(8.30±1.46)mm(t=3.235,P=0.002)。男性ACL胫骨印迹长轴(14.00±1.76)mm与女性(13.63±1.65)mm无统计学差异(t=1.116,P=0.267)。男性ACL胫骨矢状面位置(48.35±6.13)%与女性(47.53±4.34)%比较无统计学差异(t=0.778,P=0.439)。男性ACL胫骨冠状面位置(49.70±2.37)%与女性(49.00±2.68)%比较无统计学差异(t=1.446,P=0.151)。结论双源CT三维重建可再现ACL胫骨止点自然印迹,其形态、位置存在个体化差异,要实现ACL解剖重建必须采用个体化重建技术。     

小切口重建钢板治疗锁骨中段骨折的比较研究

目的比较小切口与传统切口重建钢板治疗锁骨中段骨折的临床效果。方法 2007年3月～2009年5月,采用小切口(0.5～3.5cm)重建钢板治疗15例锁骨中段骨折,与前期2005年8月～2007年3月采用传统切口重建钢板治疗的20例进行比较。手术由同一术者完成,记录每个病例的手术切口长度、手术时间、出血量、术后24h疼痛评分、骨折愈合时间、术后3个月功能、并发症及病人对切口的满意率,并进行统计分析。结果所有病例均获随访6～18个月,平均13个月。小切口手术在切口长度[(3.5±0.5)cmvs(7.3±1.1)cm,t=-12.540,P=0.000],出血量[(55.0±10.2)mlvs(95.0±15.7)ml,t=-8.578,P=0.000],术后24h疼痛评分[(29.0±9.3)分vs(46.0±9.4)分,t=-5.318,P=0.000],骨折愈合时间[(9.1±1.1)周vs(10.8±1.3)周,t=-4.007,P=0.000]及病人对切口的满意率[80%(12/15)vs25%(5/20),χ2=10.380,P=0.001]方面均明显优于传统切口手术,而手术时间、并发症和术后3个月肩关节功能差异无显著性(P0.05)。结论小切口重建钢板治疗锁骨骨折能减小创伤、减少出血、加快骨折愈合,且外形美观,是一种治疗锁骨中段骨折较好的方法,但此种术式对医师的技术要求较高。     

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.