门静脉高压症术后门静脉血栓形成的危险因素分析

目的:分析肝硬化门静脉高压症术后出现门静脉血栓的危险因素。方法 :回顾性分析2008年1月至2010年7月,因肝硬化门静脉高压导致脾功能亢进和消化道出血在我院行手术治疗的92例病人的临床资料。分为血栓组和非血栓组,对可能导致门静脉血栓形成的各种因素进行多因素分析。结果:92例病人中有40例(43.47%)出现门静脉血栓形成。病人的性别、年龄、病因、肝功能Child-Pugh分级、血清总胆红素、白蛋白、凝血酶原时间、门静脉流速及流量、手术方式、手术前后门静脉压力、手术前后血小板数量及术前D-二聚体均不是门静脉血栓形成的危险因素。门静脉直径和脾静脉直径是血栓形成的独立危险因素(P11.65 mm或脾静脉直径>9.5 mm时,术后容易形成门静脉血栓。结论:肝硬化门静脉高压症行手术治疗的病人,术前门静脉直径及脾静脉直径是术后门静脉血栓形成的独立危险因素。     

肝炎肝硬化脾切除术后门静脉系统血栓形成的相关因素分析和预防

目的分析肝炎肝硬化门静脉高压症脾切除术后门静脉系统形成血栓的相关因素,寻找预防门静脉高压症脾切除术后门静脉系统形成血栓的方法。方法回顾性分析我院1999年3月至2005年6月收治的肝炎肝硬化门静脉高压症行单纯脾切除、脾切除加EVL或脾切除加贲门周围血管断流术的病人132人,用Logistic回归分析分析术前肝功能Child-Pugh分级、门静脉和脾静脉直径、脾脏的大小以及术后血小板的数量与门静脉系统血栓形成的关系;将其中符合要求的112人分为三组,A组56人:术后未用抗凝、祛凝药;B组33人:术后在血小板＞300×109／L时用抗凝、祛凝药; C组23人:术后早期应用抗凝、祛凝药。比较三组门静脉系统血栓的发生率。结果Logistic单因素分析提示门静脉系统的血栓形成与门静脉直径、脾脏的大小、脾脏的厚度、血清总胆红素以及术后血小板的数量有关;多因素回归分析发现门静脉系统的血栓形成与门静脉和脾静脉直径、脾脏的大小和是否行抗凝祛凝治疗有关;A组、B组和C组门静脉系统发生血栓的人数分别为19人、9人和1人,发生率分别为33．9％、27．3％和4．3％,门静脉血栓发生率的比较A组和B组的差异无显著性(x2= 0.427,P=0.514),A组和C组的差异有显著性(x2=7.545.082,P=0.006),B组和C组的差异有显著性(x2=4．856,P=0.028)。结论肝炎肝硬化门静脉高压症脾切除术后门静脉系统血栓的形成与门静脉和脾静脉直径、脾脏的大小和是否行抗凝祛凝治疗有关;早期、全身应用抗凝、祛凝药能有效的预防肝炎肝硬化门静脉高压症脾切除术后门静脉系统血栓的形成。     

腹腔镜脾脏切除术后门静脉系统血栓形成的危险因素及抗凝治疗：系统综述与Meta分析

目的:对门静脉系统血栓形成(PSVT)的危险因素进行Meta分析,探讨腹腔镜脾切除术(LS)后预防PSVT的方法。方法:由两名研究人员独立检索自建库以来至2020年11月的PubMed、Web of Science、Medline、Scopus、中国期刊全文数据库,检索LS术后PSVT危险因素或药物预防的相关研究,采用Stata 12.0、Review Manager 5.3进行数据分析。结果:共纳入前瞻性研究3项,随机对照试验2项,回顾性队列研究13项,总体质量较高。门静脉直径[WMD=-1.86,95%CI(-2.26,-1.46),I~2=13.0%,P0.001]、脾脏重量[WMD=-409.78,95%CI(-517.96,-301.6),I~2=32.9%,P0.001]是PSVT的危险因素。在抗凝治疗预防PSVT时,新疗法组PSVT发生率低于常规治疗组,差异有统计学意义[RR=0.76,95%CI(0.61,0.94),I~2=0,P=0.012]。结论:术前门静脉直径与脾脏重量是LS术后发生PSVT的良好预测指标。LS术后尽早应用抗凝药物对预防PSVT的发生是有效的。     

Efficacy of angiotensin Ⅱ receptor blockers in the treatment of portal hypertension in patients with cirrhosis: A meta-analysis

目的 评价血管紧张素Ⅱ受体阻滞剂(ARB)治疗肝硬化门静脉高压症(PHT)的疗效.方法 检索PubMed、EMBASE、Web of Science、The Cochrane Central Register of Controlled Trials、中国期刊全文数据库、中国科技期刊数据库(维普)、万方数字化期刊全文数据库等关于血管紧张素Ⅱ受体阻滞剂降低肝硬化门静脉压力的随机对照试验,使用RevMan 5.0版软件对人选试验进行Meta分析.结果 共9个随机对照试验包含327例病人符合人选标准,其中5个为ARB与安慰剂或空白对照对比的对照试验,另4个为ARB与普萘洛尔对比的对照试验.Meta分析结果显示:①ARB降低肝静脉压力梯度的幅度明显大于安慰剂或空白对照(WMD=1.88 mm Hg,95％CI:0.99～2.77mm Hg,P＜0.0001),而与普萘洛尔相比无统计学差异(WMD=0.92 mm Hg,95％CI:-0.41～2.26 mm Hg,P=0.17).②ARB降低平均动脉压幅度明显大于安慰剂或空白对照(WMD=8.94mm Hg,95％CI:7.24～10.63 mm Hg,P＜0.000 01),而与普萘洛尔相比差异无统计学意义(WMD=0.41 mm Hg,95％CI:-4.46～5.28 mm Hg,P=0.87);ARB与空自对照相似,对心率无明显影响(P＞0.05),但普萘洛尔与ARB相比则可显著降低病人心率(WMD=-21.25,95％CI:- 25.83～(- 16.68),P＜0.000 01).③ARB对病人血清胆红素及肌酐的影响与安慰剂或空白对照相比差异无统计学意义(P＞0.05); ARB组其他不良反应发生率(P=0.03)高于安慰剂,而与普萘洛尔组相比差异无统计学意义(P=0.72).结论 ARB可有效降低肝硬化PHT病人的门静脉压力,其疗效及对血压的影响与普萘洛尔相似,对心率及肝肾功能无明显影响,不良反应相对较少,可能成为肝硬化PTH治疗的一种新选择.     

肝炎肝硬化病人脾切除术后门静脉血栓形成的相关因素分析

目的 分析肝炎肝硬化门静脉高压症病人脾切除术后门静脉系统血栓形成的相关因素.方法 我院2000年8月至2007年6月共为226例肝炎肝硬化门静脉高压症病人施行了脾切除或脾切除加断流术.本文对其中154例进行回顾性分析.根据是否形成血栓将病例分为门静脉系统血栓形成和无血栓形成两组.用Logistic回归分析术前术后门静脉压力下降水平、术前凝血酶原比值(PTR)、术前纤维蛋白原水平(FIB)、术前及术后1、7、14 d血小板水平、术前门静脉直径、术前胆红素水平、术中出血量各指标与门静脉系统血栓形成的关系.结果 在154例病人中,门静脉系统血栓形成31例,123例无血栓形成.Logistic单因素分析和多因素回归分析均显示门静脉系统血栓形成与门静脉压力下降水平有关;术前凝血酶原比值(PTR)、术前纤维蛋白原水平(FIB)、术前及术后1、7、14 d血小板水平、术前门静脉直径、术前胆红素、术中出血量水平与门静脉血栓形成无关.结论 术前、术后门静脉压力下降水平可能是影响门脉高压脾切除术后门脉系统血栓形成的重要因素,术后门静脉压力下降越多,门静脉系统血栓形成几率越高.     

超声刀在甲状腺切除术中应用效果的Meta分析

目的:综合评价超声刀在开放性甲状腺切除术中的应用价值.方法:检索国内数据库上所有关于超声刀在开放性甲状腺切除术中使用的随机对照试验(RCT).按照纳入排除标准筛选和提取数据,并采用RevMan5.2软件进行统计学分析.结果:最终纳入13个随机对照试验,共1 527例患者.Meta分析结果显示,与传统手术方法比较,超声刀能缩短甲状腺全切除术和甲状腺腺叶切除术的手术时间(WMD=-22.73,95％ CI=-29.15-16.32,P＜0.00001；WMD=-16.21,95％CI=-19.74-12.69,P＜0.00001)；可以减少甲状腺全切术时术中出血量和术后引流量(WMD=-31.00,95％CI=-38.85-23.15,P＜0.00001；WMD=-12.56,95％CI=-21.36-3.76,P=0.005),以及术后暂时性低钙血症发生率(OR=0.59,95％CI=0.42-0.83,P=0.003).喉返神经麻痹发生率方面,超声刀和传统手术无统计学差异(OR=1.38,95％CI=0.70-2.74,P=0.35).结论:超声刀能缩短甲状腺切除术中的手术时间、术中出血量、术后引流量以及术后低钙血症的发生率.     

术前门静脉血流速度在门静脉高压症断流术后血栓形成中的预测价值

目的 评价术前门静脉血流速度对乙型肝炎肝硬化门静脉高压症断流术后门静脉血栓形成(PVT)中的预测价值.方法 对2007年1月至2008年7月在四川大学华西医院同一外科小组行脾切除和断流术的连续45例乙型肝炎后肝硬化门静脉高压症患者,运用彩色多普勒超声测量术前1 d门静脉直径、流速以及术后7 d有无门静脉系统血栓形成.同时计算患者术前Child-Pugh评分.术后测量去脾脏血液后的脾脏重量,检测术前1 d、术后7 d凝血酶原时间(PT)和血小板计数(PLT).并将患者分为血栓组与非血栓组、高速组与低速组,分别对上述指标进行统计学对比分析.结果 术后发生门静脉系统血栓13例(28.9%),血栓组(n=13)术前门静脉流速为(19.5±5.3)cm/s,其中12例低于25 cm/s[平均(18.4±3.8)cm/s],1例为32.3 cm/s;非血栓组(n=32)术前门静脉流速为(29.6±8.0)cm/s,两组差异有统计学意义(P<0.01).低速组(n=17)和高速组(n=28)血栓发生率分别为70.6%和3.6%,差异有统计学意义(P<0.01).分别比较两种分组的患者术前Child-Pugh评分、脾脏重量、手术前后PT和PLT,差异均无统计学意义(P>0.05).25 cm/s作为指标预测术后血栓形成的敏感性为92.3%,特异性为70.6%.结论 术前门静脉直径增加及血流速度降低是导致术后门静脉系统发生血栓的主要危险因素,尤其当门静脉流速降低(<25 cm/s)时,断流术后血栓发生率将显著增高.门静脉直径与血流速度存在负相关系,可根据门静脉流速预测门静脉高压症断流术后的血栓的形成.     

门静脉高压症术后门静脉血栓形成相关因素分析

目的探讨门静脉高压症术后门静血栓形成（Portal Vein Thrombosis,PVT）相关因素。方法回顾性分析我院2001年04月至2008年12月采用脾肾分流术加贲门周围血管离断联合手术和贲门周围血管离断术治疗129例肝硬化门静脉高压症患者的临床资料,对患者年龄、性别、门静脉直径、门脉脉直径、门静脉血流流速的变化、门静脉压力变化、血小板数值等相关指标监测分析,评估门静脉高压症患者术后门静者术后门静脉血栓形成相关因素。结果门静脉高压症患者术后门静脉血栓形率为15．50％（20／129）,其中断流手术后门静脉系统血栓形成率为18．18％（16／88）,联合手术后血栓形成率为9．76％（4／41）。血栓组患者门静脉主干直径、脾静脉直径较非血栓组患者增宽,有显著性差异。术后血全组PV、SV的流速下降显著（P〈0．05）。血栓组患者术前、术后门静脉压力均较无血栓组患者低,有统计不差异（P〈0．05）年龄,性别,肝功能child—pugh分级,凝血酶原时间,术后血小板增高等因素不是脾切除术后门静脉血栓形成的危检因素。结论门脉高压脾切除术后门静脉主干直径、脾静直径增宽,门静系统血液流速减缓,门静脉压力降低有显著性差异,是门脉高压脾切除术后门静脉血栓形成的危除因素。进一步的大样本的随机对照临床研究对解决这个问题是必要的和重要的。     

乙肝肝硬化门静脉高压症脾切除术后腹腔积液预测模型

目的 探讨乙肝肝硬化门静脉高压症患者行脾切除术后腹腔积液危险因素，并建立预测脾切除术后腹腔积液的预测模型。方法 回顾性收集2017年1月至2023年2月南方医科大学南方医院肝胆外科收治的行脾切除术的乙肝肝硬化门静脉高压症患者的临床资料。根据术后是否存在腹腔积液，将患者分为腹腔积液组(n=32)和无腹腔积液组(n=89)。采用SPSS 25.0软件进行术后腹腔积液的危险因素分析。基于多因素分析结果，采用R语言建立和评估术后腹腔积液列线图预测模型。结果 单因素分析显示两组患者年龄、身体质量指数(BMI)、术前脾静脉直径、术前门静脉直径、术前腹腔积液、行贲周血管离断术、术中失血量、术后第1天、第5天白蛋白差异存在统计学意义(P<0.05)。多因素分析结果显示患者术前门静脉直径(OR=229.127,95%CI 9.348-5 615.995)、术前存在腹腔积液(OR=3.331,95%CI 1.128-9.842)、行贲周血管离断术(OR=6.745,95%CI 1.334-34.093)是脾切除术后腹腔积液的独立危险因素。纳入独立危险因素变量构建乙肝肝硬化门静脉高压症脾切除术后腹腔积...     

门静脉高压症外科手术后门静脉系统血栓形成的原因及防治

目的　探讨门静脉高压症外科手术后门静脉系统血栓形成的原因及处理。方法　回顾性分析我院 1992～ 2 0 0 1年施行肝炎后肝硬化门静脉高压症手术伴脾切除术 32 9例患者的临床资料 ,对其中 4 3例 (13 1% )术后出现门静脉系统血栓患者的临床资料进行统计和分析。结果　 4 3例门静脉系统血栓患者中 ,1例发生感染性门静脉炎死亡 ,其余均康复出院。单纯行脾切除或脾切除加断流术患者 138例 ,血栓形成 2 6例 (18 8% ) ;行脾切除加分流术患者 191例 ,血栓形成 17例 (8 9% ) ,差异有显著意义 (χ2 =8 4 4 ,P <0 0 1)。结论　门静脉高压症外科手术后门静脉系统血栓形成的主要原因是脾切除术后血小板升高 ,且与选择不同术式导致术后门静脉系统血流动力学改变有关。手术操作规范化、术后动态监测血小板总数、常规彩超检查及早期行抗凝祛聚疗法是防治门静脉高压症术后门静脉系统血栓形成的有效方法。     

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.