单开门椎间孔扩大术治疗脊髓神经根颈椎病

[目的]探讨颈椎后路单开门联合椎间孔扩大术治疗脊髓神经根颈椎病的临床疗效。[方法]回顾性分析2015年1月～2018年12月手术治疗脊髓神经根颈椎病患者68例。其中颈后路单开门(单开门组)治疗32例,颈后路单开门联合椎间孔扩大术(联合组)治疗36例。比较两组围手术期、随访与影像资料。[结果]两组患者均顺利完成手术。单开门组术后C5神经根麻痹1例,联合组术后无C5神经根麻痹者。单开门组手术时间显著短于联合组(P0.05),但两组术中失血量的差异无统计学意义(P0.05)。随时间推移,两组患者的JOA评分均显著增加,而NDI评分均显著减少(P0.05)。术前两组间JOA和NDI评分的差异均无统计学意义(P0.05),术后3个月及末次随访,联合组的JOA和NDI评分显著优于单开门组(P0.05)。影像方面:相应时间点,两组间SVA C_2～C_7、C_2～C_7Cobb角,以及C_4～_7节段各椎板的开门角度比较差异无统计学意义(P0.05)。[结论]颈椎后路单开门联合椎间孔扩大术治疗脊髓神经根颈椎病,可有效去除颈髓和神经根的压迫因素,缓解临床症状,而不影响颈椎稳定。     

颈椎间盘切除及椎间孔减压术治疗神经根型颈椎病

目的 探讨颈椎间盘切除及椎间孔减压治疗神经根型颈椎病的方法与效果.方法 自2007年2月～2010年4月对21例神经根型颈椎病行颈椎间盘切除及椎间孔减压、椎间cage植骨、钛板内固定术.按照VAS、NDI评分及融合节段的影像学资料分别对患者治疗前后疼痛的程度、日常生活的影响及颈椎曲度的改变进行疗效评判.结果 17例获得随访,平均19个月.术中均未出现椎动脉损伤、神经根损伤及硬膜破裂的情况.所有患者随访期间均达到骨性融合,钢板无松动.术后1周、终末随访时,VAS、NDI和融合节段曲度较术前均有明显改善(P＜0.05).终末随访与术后1周比较,VAS和融合节段曲度比较,差异无统计学意义(P＞0.05),而NDI比较差异有统计学意义(P＜0.05).结论 颈椎间盘切除及椎间孔减压术治疗神经根型颈椎病疗效可靠,减压彻底,术中应避免损伤推动脉.     

显微镜辅助椎板椎间孔切开术治疗神经根型颈椎病

[目的]探讨显微镜辅助微创椎板椎间孔切开术治疗神经根型颈椎病的疗效。[方法]回顾性分析2016年11月～2019年3月本院手术治疗的单节段神经根型颈椎病患者58例。其中30例采用显微镜辅助椎板椎间孔切开术(MAPLF组),28例采用颈前路经椎间隙减压植骨融合内固定术(ACDF组),比较两组围手术期、随访和影像资料。[结果]两组患者均顺利完成手术,除ACDF组1例患者出现短暂一侧肢体麻木,所有患者均无严重并发症。两组患者在手术时间及出血量的差异无统计学意义(P0.05),MAPLF组在手术切口长度、术后住院天数方面显著优于ACDF组(P0.05)。在13～48个月的随访过程中,两组患者疼痛缓解,功能改善。末次随访时两组患者的VAS和NDI评分均较术前显著减少(P0.05);末次随访时MAPLF组的VAS和NDI评分均小于ACDF组,尽管差异无统计学意义(P0.05)。末次随访时,依据改良Odom's评价标准,临床结果优良率MAPLF组为86.67%(26/30),ACDF组为85.71%(24/28),差异无统计学意义(P0.05)。影像方面,MAPLF组术后椎间孔处压迫得到了充分解除,颈神经根减压彻底。术后动力位X线片显示MAPLF组手术节段无失稳征象。[结论]采用显微镜辅助椎板椎间孔切开术治疗神经根型颈椎病与传统的ACDF相比,具有微创、保留节段活动功能,且不影响原有节段稳定性的优点。     

前路减压椎间植骨融合内固定术治疗神经根型颈椎病保留钩椎关节的可行性分析

目的研究前路减压椎间植骨融合术(Anterior cervical decompression and fusion,ACDF)治疗神经根型颈椎病术中保留钩椎关节的可行性。方法纳入2014年4月~2016年4月行ACDF治疗的72例神经根型颈椎病患者,将术中保留钩椎关节的32例患者设为观察组,切除钩椎关节的40例设为对照组。随访2年,比较两组患者临床疗效及,植骨融合情况。结果两组术后3个月、6个月、2年的NDI指数、VAS评分均显著低于治疗前,JOA评分显著高于治疗前,差异有统计学意义(P0.05),但组间差异无统计学意义(P0.05);观察组手术优良率为87.50%,对照组为90.00%,组间差异无统计学意义(P0.05);两组吞咽不适、切口感染、慢性疼痛等并发症发生率差异无统计学意义(P0.05);观察组的植骨融合效果略优于对照组,但差异无统计学意义(P0.05)。结论 ACDF手术能显著改善神经根型颈椎病疼痛症状及颈椎功能,保留钩椎关节能获得与切除钩椎关节相同的近期疗效,且手术安全有效。     

颈前路椎间盘切除椎间植骨融合术中保留与切除钩椎关节的疗效比较

目的比较颈前路椎间盘切除椎间植骨融合ACDF术中保留与切除钩椎关节减压治疗神经根型颈椎病的临床疗效。方法回顾性分析自2012-09—2018-03采取ACDF治疗的43例神经根型颈椎病,26例在术中采取保留钩椎关节椎间撑开减压治疗(保留钩椎组),17例在术中采取部分切除钩椎关节减压治疗(切除钩椎组)。比较2组手术时间、术中出血量,末次随访时JOA评分、NDI评分和JOA评分改善率。结果 43例均获得随访,随访时间平均40.6个月。保留钩椎组手术时间较切除钩椎组短,差异有统计学意义(t=-2.799,P=0.008)。2组术中出血量、末次随访时JOA评分、NDI评分、JOA评分改善率比较差异无统计学意义(P0.05)。结论 ACDF术中保留椎钩关节和切除椎钩关节可以取得同样的临床疗效,而伴有关节增生致神经根管狭窄的神经根型颈椎病患者应切除椎钩关节。     

颈前路经椎间盘显微手术减压治疗神经根型颈椎病

目的探讨颈前路经椎间盘显微手术潜行减压治疗神经根型颈椎病的临床疗效。方法2010年3月至2016年3月,采用颈前路经椎间盘显微手术椎间孔潜行减压治疗的神经根型颈椎病106例,其中男66例,女40例,年龄32~69岁,平均58.32岁。术后定期随访,应用上肢疼痛的视觉模拟评分(VAS评分)与颈椎功能障碍指数评分(NDI评分)对其临床疗效进行评价。计量资料均数的比较采用t检验。结果全部病例无神经根损伤、脊髓损伤、脑脊液漏、伤口感染、椎动脉损伤及食管损伤等并发症发生。106例患者术前上肢疼痛VAS评分为(8.2±0.4)分,术后即刻为(1.5±0.1)分;术前NDI评分为(27.5±1.4)分,术后即刻为(5.4±0.6)分。100例患者获得12~36个月随访,末次随访上肢疼痛VAS评分为(1.2±0.2)分,与术前比较差异有统计学意义(P<0.05);末次随访NDI评分为(3.8±0.5)分,与术前比较差异也有统计学意义(P<0.05)。结论颈前路经椎间盘显微手术椎间孔潜行减压治疗神经根型颈椎病能取得安全满意的疗效,临床效果良好。     

影响神经根型颈椎病人工颈椎间盘置换术疗效的相关因素分析

目的:探讨影响神经根型颈椎病(cervical spondylotic radiculopathy,CSR)人工颈椎间盘置换术(cervical total disc replacement,CTDR)疗效的因素。方法:回顾性研究2012年5月~2014年5月长征医院骨科收治的接受CTDR的CSR患者45例,随访6个月~2年(1.4±0.5年)。满足以下条件为显效组:(1)末次随访颈部伤残指数(neck disability index,NDI)评分改善(术前NDI评分-末次随访NDI评分)15分;(2)术后末次随访手术节段未出现神经根受损;(3)未出现手术失败及二次手术;(4)随访复查颈椎正侧位、动力位及左右侧屈X线片未见人工椎间盘移位、活动受限及假体相关问题。不满足以上任意一条者为无显效组。比较两组间背景资料及主观变量,分析其手术效果的影响因素,背景资料包括性别、年龄、病程、吸烟史、肌电图确诊神经根受损、受压神经根所支配的肌肉肌力、手术节段数量、术前颈椎活动度(ROM)、手术时间及术中出血量,主观变量包括疼痛视觉模拟评分(visual analogue score,VAS)及NDI。结果:显效组34例,无显效组11例。两组间年龄、病程、吸烟史、肌电图确诊神经根受损例数、术前肌力、术前VAS及NDI评分差异均有统计学意义(P0.05),两组间性别比、术前颈椎ROM、手术节段数量、手术时间、术中出血量比较均无统计学差异(P0.05)。结论:患者年龄、病程、吸烟史、肌电图确诊神经根受损、术前肌力、术前VAS及NDI评分可能与CSR患者CTDR的疗效有关。     

保留与切除钩椎关节在颈前路手术的临床效果比较

[目的]探讨颈前路减压植骨融合术(ACDF)中保留与切除钩椎关节减压治疗神经根型颈椎病患者的临床效果。[方法]回顾性分析2010年08月~2015年12月接受1个或者2个节段的颈前路减压椎间植骨融合内固定术的86例神经根型颈椎病患者,根据是否对钩椎关节椎间孔进行部分切除,29例患者列入钩椎保留组,57例患者列入钩椎减压组。采用日本骨科协会评分(JOA)评估治疗分数、颈椎功能障碍指数(NDI)评分、颈部及上肢疼痛视觉模拟评分(VAS)对治疗效果进行评价并比较。[结果]86例患者均顺利完成手术,术中未出现椎动脉损伤、神经根损伤及硬膜破裂情况。所有患者随访15~85个月,平均(20.2±3.6)个月。所有患者随访期间均达到骨性融合,钢板无松动。两组术后的JOA、VAS、NDI评分均较术前明显改善(P0.05),两组间比较差异无统计学意义(P0.05)。钩椎保留组优27.59%,良55.17%,一般13.79%,差3.45%;钩椎减压组优28.07%,良54.39%,一般14.04%,差3.51%.[结论]神经根型颈椎病患者在颈前路手术中,保留钩椎关节椎间撑开减压可获得与切除钩椎关节减压同样良好的临床效果。因此,神经根型颈椎病患者实施颈前路减压融合术(ACDF)不应常规切除钩椎关节。     

微创前路经上位椎体椎间孔减压术治疗神经根型颈椎病

【摘要】 目的：探讨微创前路经上位椎体椎间孔减压术治疗神经根型颈椎病的有效性。方法：2008年7月~2010年7月12例单侧神经根型颈椎病患者在延边大学医院接受微创前路经上位椎体椎间孔减压术。其中男7例,女5例,年龄为35~68岁,平均49岁。椎间孔狭窄部位：C5/6 4例,C6/7 5例,C7/T1 3例。软性髓核突出3例,钩椎关节骨质增生7例,突出的髓核钙化2例。均行前路手术,术中采用脊柱手术专用显微镜,在病变上位椎体确定钻孔起始部位,利用高速钻石气钻磨出一约6mm直径的通路达到病变区域,减压椎间孔。观察术前及末次随访时上肢放射性疼痛的VAS评分、颈椎功能障碍指数（NDI）及病变水平椎间盘高度。结果：手术时间为56~110min,平均86±6min;术中失血量为40~120ml,平均92±8ml。无椎动脉损伤、贺纳氏综合征、喉返神经损伤等并发症。术后随访时间为12~23个月,平均15.8±1.3个月。术前上肢疼痛VAS评分为8.5±0.5分（7~10分）,末次随访时为1.4±0.2分（0~3分）,两者比较有显著性差异（P<0.05）;术前NDI为26.4±1.3分（22~31分）,末次随访时为4.2±0.6分（3~8分）,两者比较有显著性差异（P<0.05）,改善率为84.1%;术前病变水平椎间盘高度为5.4±0.7mm（4.2~6.1mm）,末次随访时为4.9±0.7mm（3.6~5.8mm）,两者比较无显著性差异（P>0.05）。术后满意度为100%。结论：微创前路经上位椎体椎间孔减压术可减少对椎间盘的损伤,是治疗单侧神经根型颈椎病的有效手术方法。     

颈后路椎板减压联合椎间孔切开术治疗混合型颈椎病的疗效观察

目的探讨颈后路椎板切除减压侧块螺钉内固定联合椎间孔切开术治疗脊髓合并神经根受压的混合型颈椎病疗效。方法 2010年1月-2012年1月,采用颈后路椎板切除减压侧块螺钉内固定联合椎间孔切开术治疗58例混合型颈椎病患者。男31例,女27例;年龄41~72岁,平均52.7岁。病程3~15年,平均5.4年。术前日本骨科协会(JOA)评分为(7.8±1.3)分,疼痛视觉模拟评分(VAS)为(6.8±1.7)分。椎间盘突出伴黄韧带肥厚37例,椎体后缘骨赘形成11例(骨赘椎管占有率为51.7%±18.1%),颈椎不稳合并椎间盘突出10例。颈椎曲度为(—5.5±12.5)°。螺钉固定节段:C3~7 29例,C4~7 19例,C3~6 10例;共切开椎间孔135个,平均每例2.33个。结果手术时间167~260 min,平均204 min;术中出血量为210~378 m L,平均273 m L。术中无椎动脉、神经根损伤发生。术后1例发生皮下血肿,8例轴性疼痛;均无颈神经根麻痹症状发生。患者均获随访,随访时间2.1~4.3年,平均3.4年。术后2年,JOA评分为(14.1±1.7)分,显著高于术前,比较差异有统计学意义(t=—27.672,P=0.000);JOA评分改善率为68.5%±21.9%。VAS评分为(2.1±1.1)分,较术前显著降低,比较差异有统计学意义(t=15.168,P=0.000)。影像学复查示,1例邻近节段发生退变,但未出现临床症状;随访期间无螺钉松动、无假关节形成。术后5 d及2年颈椎曲度分别为(13.6±5.1)、(13.2±4.8)°,与术前比较差异均有统计学意义(P0.05)。术后2年11例骨赘椎管占有率为36.5%±10.4%,与术前比较差异有统计学意义(t=6.921,P=0.000);随访期间骨赘残余压迫逐渐吸收。结论对脊髓合并神经根受压的混合型颈椎病,采用颈后路椎板切除减压侧块螺钉内固定联合椎间孔切开术治疗可获得满意疗效。术中扩大椎板切除(椎板切除和椎间孔切开)能充分缓解脊髓及神经根受压症状,侧块螺钉内固定在纠正颈椎曲度的同时,可进一步降低脊髓及神经根张力。     

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.