0.75%罗比卡因蛛网膜下隙阻滞用于老年患者下腹部及下肢手术的麻醉效果及影响

目的 探讨0．75％罗比卡因蛛网膜下隙阻滞用于老年患者的麻醉效果。方法 50例65岁以上择期行下腹部及下肢手术患者随机分成0．75％罗比卡因2ml(Ⅰ)组(n=25)和0．5％布比卡因2ml(Ⅱ)组(n=25)。观察比较两组腰麻阻滞效果。结果 Ⅰ组麻醉起效时间、镇痛向头和向尾延伸时间、运动阻滞起效时间、达最大运动阻滞时间均大于Ⅱ组，而镇痛总时间、运动阻滞持续时间均小于Ⅱ组。Ⅰ组痛觉减退平面低于Ⅱ组。痛觉消失平面：Ⅱ组较Ⅰ组高1．2个节段。Ⅱ组SBP在给药后12．5～30min比麻醉前或Ⅰ组的同时总值下降明显。结论 0．75％罗比卡因溶液2ml可用于老年患者蛛网膜下隙阻滞，其对血压的影响较等容量的0．5％布比卡因小，其镇痛总时间、运动阻滞持续时间较等容量的0．5％布比卡因短。     

小剂量轻比重罗比卡因连续腰麻在高龄髋关节置换术中的应用

目的研究轻比重小剂量罗比卡因连续腰麻用于高龄患者的安全性和有效性。方法择期髋关节置换手术患者60例,年龄78~93岁,ASAⅡ~Ⅳ级,随机分为两组。用Spinocath导管针于L3~4间隙穿刺蛛网膜下隙并置管。两组分别以0.1ml/s蛛网膜下隙注入0.3%罗比卡因或0.3%左旋布比卡因轻比重溶液1.0~1.2ml,术中酌情追加0.6~0.8ml维持麻醉。比较两组痛觉、运动阻滞及恢复的异同,并观察用药后的不良反应。结果两组患者均可达到完善的镇痛效果,但罗比卡因的镇痛起效时间、运动阻滞起效时间、最大阻滞时间、最大运动阻滞时间均比左旋布比卡因显著延长(P<0.05或P<0.01);麻醉持续时间、痛觉恢复时间、运动恢复时间比左旋布比卡因显著缩短(P<0.05或P<0.01);罗比卡因最大Bromage评分明显优于左旋布比卡因(P<0.01)。结论轻比重小剂量罗比卡因连续腰麻用于高龄患者髋关节置换手术是安全的,并能达到完善的镇痛效果,不良反应少。     

轻比重罗哌卡因腰麻用于老年病人人工关节置换术的量-效关系

目的 探讨轻比重罗哌卡因腰麻用于老年病人人工关节置换术的量-效关系.方法 选择70～98岁的人工关节置换术病人75例,随机均分为三组.用Spinocath 24G导管针于L3～4椎间隙穿刺,蛛网膜下腔置管2.0～2.5 cm.Ⅰ、Ⅱ、Ⅲ组依次应用0.3%、0.4%、0.5%罗哌卡因轻比重(1.001～1.002,20℃)腰麻液1.0～1.2ml.观察镇痛起效时间、运动阻滞起效时间、最高痛觉阻滞平面、麻醉持续时间、最大运动阻滞程度、痛觉及运动恢复时间、阻滞完全病人比例及用药后的不良反应.结果 三组镇痛起效时间、最高痛觉阻滞平面、完全阻滞病人比例(Ⅰ组2例痛觉阻滞不全)差异无统计学意义;运动阻滞起效时间Ⅲ组比Ⅰ组短(P<0.01),麻醉持续时间、最大Bromage评分、痛觉和运动恢复时间Ⅲ组>Ⅱ组>Ⅰ组(P<0.05或P<0.01).三组均出现单侧下肢阻滞.结论 0.4%罗哌卡因轻比重液4.0～4.8 mg腰麻用于老年病人人工关节置换术,可达到完善的镇痛效果,且较安全.     

连续腰麻与腰硬联合麻醉用于老年人下肢手术的比较

目的比较连续腰麻(CSA)、腰-硬联合麻醉(CSEA)用于高龄患者下肢手术的临床效应。方法择期下肢骨科手术患者60例,70~98岁,ASAⅡ~Ⅳ级,分为CSA组(Ⅰ组)和CSEA(Ⅱ组)两组,每组30例。两组以0.1ml/s速率蛛网膜下隙注入0.4%罗比卡因1.0~1.2ml,60min后Ⅰ组蛛网膜下隙、Ⅱ组硬膜外腔分别追加0.6~0.8ml或5~6ml维持麻醉。比较两组患者痛觉、运动阻滞的异同及不良反应。结果两组蛛网膜下隙用药后镇痛效果满意,阻滞平面均未超过T10。Ⅱ组硬膜外腔用药后8例(26.6%)患者出现痛觉阻滞不全、9例(30%)阻滞平面超过T10、6例(20%)血压下降≥30%,显著多于Ⅰ组(P<0.01);Ⅰ组罗比卡因和麻黄碱的用量显著小于Ⅱ组(P<0.01)。Ⅱ组1例患者硬膜外导管误入蛛网膜下隙,2例无脑脊液回流。结论CSA、CSEA均可用于高龄患者下肢手术;但CSA术中镇痛效果确切,用药量小,对血液动力学影响轻微。     

蛛网膜下隙注射吗啡术后镇痛

目的　探讨蛛网膜下隙注射吗啡术后镇痛的临床效果及不良反应。方法　ASAⅠ～Ⅱ级 6 0例择期妇科手术病人 ,随机分为两组 ,每组 30例 ,均采用腰麻 硬膜外联合阻滞。腰麻用药为0 5 %重比重布比卡因 10mg ,然后硬膜外腔置管。研究组于腰麻药中加入吗啡 0 2 5mg ,对照组则于硬膜外腔注射吗啡 2mg。术后行视觉模拟评分 (VAS)、Ramsay镇静评分、BCS(Bruggrmanncomfortscale)舒适评分并观察不良反应发生情况。结果　蛛网膜下隙吗啡组术后完全无痛时间和持续镇痛时间明显长于硬膜外吗啡组 ,VAS评分明显低于硬膜外吗啡组 (P <0 0 5或P <0 0 1)。Ramsay评分和BCS评分明显高于硬膜外吗啡组 (P <0 0 5或P <0 0 1)。蛛网膜下隙吗啡组术后不良反应发生率明显增加 (P <0 0 5 )。结论　蛛网膜下隙注射吗啡镇痛效果确切、持续时间长 ,但不良反应发生率较高于硬膜外吗啡镇痛     

0.15%罗比卡因轻比重腰-硬联合麻醉用于侧卧位下肢骨科手术的可行性

目的观察0·15%罗比卡因轻比重腰-硬联合麻醉(CSEA)用于侧卧位下肢骨科手术的麻醉效果及其安全性。方法侧卧位下肢骨科手术患者60例,随机分为两组。CSEA组(Ⅰ组,n=30),硬膜外麻醉(EA)组(Ⅱ组,n=30)。Ⅰ组先行硬膜外穿刺,继以针内针实施腰麻,脑脊液流出,将腰麻针斜面向患侧,以0·2~0·3ml/s的速度注入0·15%罗比卡因7~8ml(用灭菌注射用水配制)后置入硬膜外导管。根据阻滞平面情况调节手术台角度,阻滞平面上界控制在T9~T12。Ⅱ组实施硬膜外穿刺置管,给予2%利多卡因5ml为试验量以确定导管在硬膜外腔,追加0·75%罗比卡因12ml。结果Ⅰ组感觉阻滞起效时间显著高于Ⅱ组(P<0·01)。骨性操作期间视觉模拟评分(VAS)比较,Ⅰ组低于Ⅱ组(P<0·05)。两组改良Bromage评分差异无显著意义。而Ⅰ组组内患侧与健侧VAS及改良Bromage评分差异有显著意义(P<0·05)。Ⅱ组低血压发生率为20%,高于Ⅰ组(P<0·05)。结论0·15%罗比卡因轻比重CSEA用于侧卧位下肢骨科手术,镇痛效果优于硬膜外麻醉,安全可行。     

不同浓度的罗比卡因用于可行走式分娩镇痛

目的　比较不同浓度的罗比卡因用于分娩镇痛的效果。方法　 90例初产妇随机分成三组行分娩镇痛 ,Ⅰ组为 0 0 75 %罗比卡因加 1μg/ml芬太尼 ,Ⅱ组为 0 1%罗比卡因加 1μg/ml芬太尼 ,Ⅲ组为 0 12 5 %罗比卡因加 1μg/ml芬太尼。观察指标有首剂量、起效时间、PCA次数、VAS评分、运动神经阻滞评分、第一、二产程时间、分娩方式等指标 ,全程监测孕妇血压、心率、宫缩以及胎儿胎心。结果　Ⅱ组和Ⅰ组相比较 ,下肢运动神经阻滞程度无显著差异 ,但孕妇镇痛良好率明显高于Ⅰ组 (P <0 0 1) ,满意率也明显高于Ⅰ组 (P <0 0 5 ) ,产程时间和分娩方式没有显著差异 ;Ⅱ组和Ⅲ组比较 ,镇痛效果、产程时间、分娩方式均无显著差异 ;但Ⅲ组发生轻度运动神经阻滞的比例明显高于Ⅱ组 (P <0 0 5 )。结论　 0 1%罗比卡因加 1μg/ml芬太尼不仅具有良好的镇痛效果 ,而且对运动神经影响轻微 ,是可行走式分娩镇痛较为理想的用药方案。     

0.2%罗比卡因用于腰麻-硬膜外联合麻醉的临床应用

腰麻 硬膜外联合麻醉 (ＣＳＥＡ)中腰麻用药以 0 5 %布比卡因和 0 5 %罗比卡因重比重溶液为多[1～ 3 ] ,但下肢手术多采用侧卧位 ,重比重溶液有诸多不便 ,为此 ,作者选用 0 2 %罗比卡因用于ＣＳＥＡ下肢手术并与 0 5 %布比卡因进行比较 ,现报告如下。资料与方法本组 80例 ,ＡＳＡⅠ～Ⅱ级 ,男 44例 ,女 36例 ,年龄 15～73(4 3 7± 10 2 )岁 ,体重 41～ 83(5 2 3± 5 6 )ｋｇ。病种与手术 :髋关节置换 10例 ,股骨颈骨折固定术 18例 ,股骨干骨折内固定 37例 ,其他下肢手术 15例 ,随机分为两组 ,0 2 %罗比卡因组 40例 (Ｒ组 ) ,0 5 %…     

轻比重罗哌卡因连续腰麻在老年前列腺电切及股骨头置换术中的应用

目的探讨轻比重罗哌卡因连续腰麻用于老年病人前列腺气化电切和人工关节置换术的药量与疗效的关系。方法选择60~98岁前列腺气化电切和人工关节置换术病人150例,随机均分为三组,采用24G导管针于L3~4椎间隙穿刺蛛网膜下腔置管2.5~3 cm。三组依次应用0.3%、0.4%、0.5%罗哌卡因(1.001~1.002)轻比重腰麻液1.2~1.5 ml,观察疼痛起效时间,运动阻滞起效时间,痛觉阻滞平面,麻醉持续时间,运动阻滞程度,痛觉及运动恢复时间、阻滞完全病人比例及用药后的不良反应。结果三组镇痛起效时间,痛觉阻滞平面,完全阻滞病人比例差异无统计学意义。运动阻滞起效时间,Ⅲ组比Ⅰ组短(P<0.01),麻醉持续时间改良Bromage评分、痛觉和运动恢复时间Ⅲ组>Ⅱ组>Ⅰ组(P<0.05,P<0.01)。结论0.45罗哌卡因4.8~6 mg腰麻用于老年前列腺气化电切和股骨头置换可达到完善的镇痛效果,对呼吸、循环干扰不,较为安全。     

剖宫产术患者重比重罗哌卡因混合小剂量舒芬太尼腰麻的效果

目的探讨重比重罗哌卡因混合小剂量舒芬太尼用于剖宫产术患者腰麻的效果。方法择期行剖宫产术的单胎和妊娠足月初产妇40例,年龄22～34岁,体重60～73 kg,ASAⅠ级。随机分为2组（n=20）,罗哌卡因组（R组）蛛网膜下腔注射1%罗哌卡因1.5 ml（15 nag）＋生理盐水0.7ml＋ 50%葡萄糖0.3 ml;罗哌卡因＋舒芬太尼组（R＋S组）蛛网膜下腔注射1%罗哌卡因1.5 ml（15 mg）＋舒芬太尼5μg（0.1 ml）＋生理盐水0.6 ml＋50%葡萄糖0.3ml。蛛网膜下腔穿刺成功后,将混合药液注入蛛网膜下腔,速率0.1 ml/s。记录感觉阻滞、运动阻滞情况,术中疼痛程度、腹肌松弛程度和牵拉反应程度,术中低血压、心动过缓、恶心、呕吐及瘙痒等不良反应的发生和处理情况,新生儿体重及出生后1 min和5 min Apgar评分。结果R＋S组蛛网膜下腔注药后感觉阻滞平面达到T10、T6和最高阻滞平面的时间短于R组,且最高阻滞平面升高（P〈0.05或0.01）;蛛网膜下腔注药后2组下肢运动阻滞起效时间和达最大运动阻滞时间差异无统计学意义,2组最大运动阻滞评分均为3分（P〉0.05）。R＋S组感觉阻滞恢复至L3、首次感觉疼痛和开始PCA镇痛的时间比R组长（P〈0.05或0.01）,下肢运动阻滞完全恢复时间组间比较差异无统计学意义（P〉0.05）。R＋S组牵拉反应程度低于R组（P〈0.01）。2组不良反应发生率、麻黄碱和阿托品使用率及新生儿体重、出生后1min和5 min Apgar评分差异无统计学意义（P〉0.05）。结论剖宫产术患者重比重罗哌卡因混合舒芬太尼5μg腰麻感觉阻滞起效时间缩短,阻滞平面上移,持续镇痛作用时间延长。     

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.