腰椎管狭窄行腰椎减压术后腰痛改善的预测因素

目的探讨腰椎管狭窄患者行未融合腰椎减压术术后早期(2周)下腰痛(low back pain, LBP)的改善情况,并进一步探讨腰椎减压术后腰痛改善的术前预测因素。方法 2006年1月-2016年12月,选取诊断为腰椎管狭窄(lumbar spinal stenosis, LSS)126例行单纯椎板切除或椎板开窗术,术前及术后2周、3个月、6个月采用疼痛视觉模拟评分(visual analogue scale, VAS)评估LBP的严重程度,采用单因素Logistic回归分析术后6个月残存LBP的危险因素,进一步采用多因素分析对年龄、性别和术前LBP进行校正。结果术前及术后2周、3个月、6个月平均VAS评分分别为(4.3±3.2)、(1.3±1.6)、(1.4±1.9)及(2.1±2.4),术后2周LBP显著改善(P0.001),2周～3个月相对较稳定,3～6个月显著加剧(P0.001)。术后6个月LBP患者VAS评分1比例降为60 (47.6%),对其残存LBP采用Logistic回归分析进行预测,得出术前LBP高VAS评分(P0.001),手术方式(P=0.04)、减压节段(P=0.007)、退行性脊柱侧凸(P=0.006)及Cobb角(P=0.002)。多因素分析,在校正年龄、性别、术前VAS评分后,退行性脊柱侧凸(P=0.008)及Cobb角过大(P=0.003)是残存LBP的独立风险因素。结论 LSS患者行腰椎减压术后2周LBP显著改善。退行性脊柱侧凸和术前压迫严重对于腰椎减压术后是否发生残存LBP是有价值的预测因素。     

陈旧性骨质疏松椎体压缩骨折继发胸腰椎后凸畸形的手术治疗

[目的]观察后路截骨矫形手术治疗陈旧性骨质疏松椎体压缩骨折(osteoporotic vertebral compression fracture,OVCF)继发胸腰椎后凸畸形的临床疗效。[方法]2004年5月~2014年7月,采用后路截骨矫形手术治疗18例陈旧性骨质疏松椎体压缩骨折继发胸腰椎后凸畸形患者。男2例、女16例,年龄54~73岁,平均65.8岁。15例采用后路经后凸顶点(椎弓根或椎间隙)截骨(PSO)闭合矫形或前方撑开后方闭合矫形术。3例采用后凸节段切除截骨(VCR)双轴旋转矫形和前柱重建术。观察手术前后的脊柱矢状位平衡(C7铅垂线与S1后上缘的水平距离,SVA)、后凸角、腰椎前凸角(LL)的变化。通过术前及末次随访JOA29评分、VAS和Oswestry功能障碍评分(ODI)的比较评估患者生活质量。应用改良Frankel分级系统评估手术前后神经功能变化。[结果]手术前后凸角度平均(45.9°±13.2°),腰椎前凸角平均(35.9°±20.8°),脊柱SVA平均(38.4±51.1)mm。随访时间平均51个月,末次随访后凸角度平均(10.7°±6.7°),平均改善率76.7%,腰椎前凸角平均(27.7°±12.5°)。末次随访脊柱SVA平均(14.6±49.5)mm,平均改善率为63.2%。术前4例神经损害患者改良Frankel分级为3例D2、1例D3,术后提高至3例D3、1例E。术前腰痛VAS评分平均为6.8、JOA29评分平均为14.6、ODI评分平均为58.8%,术后腰痛VAS评分平均为2.3分、JOA29评分平均为20.2分、ODI评分平均为31.1%,相比术前明显改善,差异具有统计学意义(P0.05)。[结论]后路截骨矫形手术可有效治疗陈旧性OVCF继发胸腰椎后凸畸形,恢复脊柱序列,获得较好的临床效果。     

退变性腰椎侧凸合并多节段腰椎管狭窄的手术治疗

[目的]探讨多节段开窗椎管潜行扩大减压、椎体间及后外侧植骨融合内固定治疗退变性腰椎侧凸合并多节段腰椎管狭窄的临床疗效。[方法]回顾分析2003年4月~2013年6月收治的35例退变性腰椎侧凸合并多节段腰椎管狭窄患者施行多节段开窗椎管潜行扩大减压、椎体间及后外侧植骨融合内固定术,必要时辅助对侧椎板间小开窗减压。术前腰椎Cobb角24.2°±9.6°,腰椎侧凸角21.2°±8.8°,VAS评分(8.4±1.9)分,JOA评分(11.3±4.2)分。评价术前、末次随访时腰椎Cobb角及腰椎前凸角的矫正及维持情况,根据术前、末次随访时VAS评分、JOA评分评价临床疗效。[结果]本组患者未出现死亡、瘫痪、中枢神经系统感染等严重并发症,肺部感染、泌尿系统感染、术口愈合不良、术后神经症状等经积极处理后均得到治愈。35例患者均获得随访,术后随访12~60个月,平均19个月。末次随访时腰椎Cobb角减小至9.2°±4.5°,腰椎前凸角增加至33.8°±8.6°,矫正率分别为61.9%、37.2%,较术前相比差异均有统计学意义(P<0.05);末次随访时VAS、JOA评分分别为(2.8±1.5)分、(27.8±4.5)分,改善率分别为66.6%、93%,差异有统计学意义(P<0.05)。[结论]多节段开窗椎管潜行扩大减压、椎体间及后外侧植骨融合内固定术,必要时辅助对侧椎板间小开窗减压治疗退变性腰椎侧凸合并多节段腰椎管狭窄安全,脊柱畸形的矫正和维持以及临床症状的改善令人满意。     

退变性腰椎侧凸患者腰椎前凸矫正程度与疗效的关系

目的:评价退变性腰椎侧凸(degenerative lumbar scoliosis,DLS)患者行长节段固定矫形术的疗效,探讨合适的腰椎前凸矫正程度。方法:回顾性分析55例行长节段矫形固定术(至少4个椎体)的DLS患者的临床和影像学资料,随访时间至少2年。采用腰痛和下肢痛VAS评分、ODI评价患者的健康相关生活质量。在全脊柱正侧位X线片上测量脊柱骨盆矢状位参数。根据末次随访时骨盆入射角(pelvic incidence,PI)与腰椎前凸角(lumbar lordosis,LL)之差(PI-LL)是否在±9°范围内分为PI-LL在±9°范围内(PI-LL+组)和不在±9°范围内组(PI-LL-组),使用独立样本t检验比较两组影像参数和生活质量;用散点图和拟合曲线探索合适的LL范围,用独立样本t检验比较该范围内(A组)、外(B组)患者的评分差异;并分组比较不同矢状位平衡(SVA)范围的ODI差异。结果 :55例DLS患者年龄为40~75岁(63.2±6.9岁),术前Cobb角为10.2°~52.3°(25.1°±11.5°),PI为23.4°~72.7°(47.5°±11.2°)。术前LL为-19.7°~50.1°(27.6°±15.2°),末次随访时为6.6°~64°(34.5°±11.9°),差异有显著性(P0.01);术前和末次随访时SVA无显著性差异(46.1±47.7mm vs 49.6±36.9mm,P0.05)。末次随访时PI-LL+患者15例,PI-LL-患者40例,PI-LL+患者末次随访时腰痛VAS评分较PI-LL-患者高(4.6±2.5 vs.2.9±2.1,P=0.015),下肢痛VAS评分和ODI无显著性差异(P0.05)。散点图及拟合曲线显示腰痛VAS评分和ODI在PI-LL为15°~28°时较低,在15°~28°的19例患者与不在15°~28°的36例患者比较,术后腰痛VAS评分更低(P0.05),下肢痛VAS评分和ODI无显著性差异(P0.05)。29例SVA50mm患者的ODI与17例50≤SVA80mm患者无显著性差异(P0.05),9例SVA≥80mm患者的ODI高于50≤SVA80mm的患者(P0.01)。结论:L=PI±9°可能并不适合作为国人DLS患者的矫形目标,按照PI-LL=15°~28°的对应关系矫正腰椎前凸可获得较好的疗效;对于老年DLS患者而言,SVA=80mm作为矢状位失衡的评价标准可能更加准确。     

计算机导航辅助下与传统全膝关节置换术后下肢力线和假体位置的比较

目的 比较计算机导航辅助下和传统方法进行全膝关节置换(TKA)术后膝关节下肢力线和假体位置. 方法 对2007年5月至2009年12月收治的60例膝骨关节炎患者进行前瞻性研究,随机分为计算机导航组(导航组)和传统方法组(传统组),每组 30例.导航组:男11例,女19例;平均年龄(69.2±8.3)岁,术前患者下肢力线平均偏差9.4°±5.3°;膝关节骨关节炎分级:Ⅲ级12例,Ⅳ级18例.传统组:男17例,女13例;平均年龄(71.9±8.1)岁;术前患者下肢力线平均偏差8.9°±4.8°.膝关节骨关节炎分级:Ⅲ级17例,Ⅳ级13例.均采用同种产品的TKA,所有手术均由同一组医生完成.比较两组患者膝外翻角、冠面和矢状面的假体组件角度和手术时间. 结果 导航组髋-膝-踝角平均偏差角度(0.7°±0.2°)小于常规组(1.2°±0.3°),差异有统计学意义(t=3.972,P=0.000).导航组额面股骨部分角平均偏差角度(1.5°±0.4°)小于传统组(2.1°±0.5°),差异有统计学意义(t=2.433,P=0.017).导航组额而胫骨部分角(1.4°±0.5°)平均偏差角度小于传统组(1.5°±0.6°)差异无统计学意义(t=0.326、P=0.116).导航组侧面股骨部分角(7.3°±0.4°)和侧面胫骨部分角(2.5°±0.2°)平均偏差角度均小于传统组(9.5°±0.4°、4.5°±0.6°),差异均有统计学意义(P＜0.05).导航组平均手术时间比传统组延长15～28min,差异有统计学意义(t=2.553,P=0.008).结论 计算机导航辅助下TKA与传统方法相比,下肢力线和假体组件的位置更准确.     

伴与不伴弥漫性特发性骨质增生症的腰椎管狭窄症患者脊柱骨盆参数的比较

目的 :探讨弥漫性特发性骨质增生症(diffuse idiopathic skeletal hyperostosis,DISH)对腰椎管狭窄症(lumbar spinal stenosis,LSS)患者脊柱骨盆矢状面参数的影响。方法 :回顾性分析2014年1月~2017年6月于南京鼓楼医院行腰椎后路全椎板切除减压椎间融合手术的伴DISH的LSS患者40例,其中男23例,女17例,年龄51~75岁(65.1±7.3岁)。同时选取年龄及性别匹配且接受相同术式的不伴DISH的LSS患者40例作为对照组,其中男23例,女17例,年龄51~75岁(64.7±7.1岁)。两组患者性别、年龄、责任节段分布均无统计学差异(P0.05)。分别测量两组患者术前胸椎后凸角(thoracic kyphosis,TK)、腰椎前凸角(lumbar lordosis,LL)、矢状面平衡(sagittal vertical axis,SVA)、骨盆入射角(pelvic incidence,PI)、骨盆倾斜角(pelvic tilt,PT)、骶骨倾斜角(sacral slope,SS)、腰骶角(lumbar-sacral angle,LSA)、腰5入射角(L5 incidence,L5I)等脊柱骨盆参数,并用术前VAS评分和ODI评分评估入选对象的生活质量。采用独立样本t检验比较两组患者脊柱骨盆参数的差异及生活质量的差异。结果:伴DISH的LSS患者的术前SVA显著低于不伴DISH的LSS患者(20.0±38.7mm vs.40.0±46.3mm,P=0.039),而TK(27.2°±10.7°vs 25.5°±16.0°)、LL(48.1°±13.7°vs 47.1°±13.5°)、PI(51.4°±14.1°vs 52.5°±13.9°)、PT(18.0°±8.0°vs 19.0°±7.6°)、SS(33.6°±9.5°vs 34.4°±7.8°)、LSA(17.0°±12.0°vs 18.4°±6.7°)及L5I(22.4°±9.8°vs 24.7°±11.9°)两组均无统计学差异(P0.05)。伴DISH患者术前腰痛和下肢痛VAS评分及ODI评分(分别为5.6±1.0,6.5±1.3,36.9±4.9)均高于不伴DISH组患者(分别为5.4±1.2,6.2±1.7,36.8±5.0),但差异均无统计学意义(P0.05)。结论:与不伴DISH的LSS患者相比,伴DISH的LSS患者SVA显著降低,TK、LL、PI、PT、SS、LSA及L5I等其他脊柱骨盆矢状面参数无显著差异。     

短节段固定融合术治疗退变性腰椎侧凸合并腰椎管狭窄疗效观察

目的探讨短节段固定融合术治疗退变性腰椎侧凸(DLS)合并腰椎管狭窄的手术策略、影像学及临床疗效。方法选择性减压、短节段固定融合术治疗68例DLS合并腰椎管狭窄患者,比较患者术前及末次随访时的Cobb角、腰椎前凸角、冠状面躯干偏移及矢状面躯干偏移。以Oswestry功能障碍指数(ODI)评估患者功能改善情况。结果患者均获得随访,时间36~60个月。Cobb角术前12°~28°(15.9°±4.6°),末次随访3.6°~9.8°(5.2°±3.1°);腰椎前凸角术前1.2°~3.3°(1.9°±2.9°),末次随访-28.1°~4.6°(-23.6°±3.7°);冠状面躯干偏移术前8.2~13.7(10.8±5.2)mm,末次随访2.8~5.6(4.3±1.8)mm;矢状面躯干偏移术前10.2~15.6(12.6±3.7)mm,末次随访3.1~6(4.6±2.2)mm;ODI评分术前25.2~29.8(27.6±2.1)分,末次随访2.1~4.2(3.6±1.3)分。以上各项指标末次随访与术前比较差异均有统计学意义(P0.05)。术后早期并发症发生率为7.3%。末次随访时未发现钉棒松动或断裂等情况。结论对于冠状面Cobb角30°且躯干失平衡较小的DLS合并腰椎管狭窄患者,行选择性减压、短节段固定融合可获得良好的中期临床疗效。     

腰椎融合联合邻近节段K-Rod动态固定治疗腰椎退行性疾病

[目的]观察单节段腰椎后路椎间融合联合邻近节段K-Rod动态固定术治疗腰椎退行性疾病的临床疗效。[方法]回顾性分析2010年6月~2012年9月手术治疗的50例腰椎退行性疾病患者的临床资料,根据手术方式不同分为2组:单节段腰椎后路融合联合邻近节段K-Rod动态固定术组(A组)和单节段腰椎后路融合术组(B组),其中A组男14例,女11例;平均年龄(41.2±5.6)岁;B组男12例,女13例;平均年龄(47.4±5.2)岁。评估两组患者的神经改善情况、腰椎总活动度、近端邻近节段活动度及椎间隙高度情况。[结果]随访时间12~25个月,平均16.7个月。无不可逆性神经症状加重、内置物失败等并发症,临床疗效满意。在末次随访时,两组患者术后VAS及ODI评分均获得显著改善(P<0.05);A组动态固定节段的活动度术前(8.50±0.76)°,末次随访(3.45±0.49)°,存在统计学差异(P<0.05);A组动态固定节段的近端临近节段的活动度术前(7.62±0.50)°,末次随访(7.87±0.62)°,无统计学差异;B组近端临近节段活动度术前(8.20±1.13)°,末次随访(8.90±1.03)°,存在统计学差异(P<0.05);在末次随访时,两组腰椎总活动度及椎间隙高度均无统计学差异(p>0.05)。[结论]腰椎后路融合联合邻近节段K-Rod动态固定术治疗腰椎退行性疾病早期疗效明确,能够维持一定的脊柱生物学功能,并能避免相邻节段退变的进展,但远期疗效有待进一步观察。     

颈椎单开门微型钛板固定与缝线悬吊固定治疗颈椎病

[目的]探讨颈椎单开门椎管扩大成形术(expansive open-door laminoplasty,ELAP)中微型钛板固定技术与传统缝线悬吊固定技术治疗脊髓型颈椎病的临床疗效。[方法]以2008年6月～2010年6月本院微型钛板固定ELAP术治疗的23例脊髓型颈椎病患者为A组,选择同期采用传统缝线悬吊门轴ELAP术治疗的23例患者为B组。比较两组间的手术时间、术中出血量,随访时JOA评分改善率、颈椎曲度变化值、轴性症状及椎板掀开角度。[结果]两组随访时间[A组为(13.5±3.5)个月、B组为(14.1±3.2)个月]、手术时间[A组(121±35)min、B组(112±30)min]、术中出血量[A组(330±115)ml、B组(328±123)ml]和JOA评分改善率[A组(58.3±9.7)、B组(56.7±8.9)]差异无统计学意义(P>0.05);A组颈椎曲度术前(17.2°±4.2°)与术后(17.9°±5.2°)差异无统计学意义(P>0.05),B组颈椎曲度术前(18.2°±4.7°)与术后(16.3°±4.5°)差异有统计学意义(P<0.05),颈椎曲度变化率两组差别有统计学意义(A组0...     

保留棘突韧带复合体腰椎管扩大术的早期疗效

[目的]探讨保留棘突韧带复合体腰椎管扩大减压术与传统椎板减压植骨融合内固定术治疗腰椎管狭窄症的早期疗效。[方法] 2014年12月～2017年12月1～2节段腰椎管狭窄症患者60例,分为两组,每组30例,椎管扩大组采用保留棘突韧带复合体腰椎管扩大减压术,减压融合组采用传统的椎板减压植骨融合内固定术。记录围手术期资料,采用视觉疼痛指数(VAS)腰痛/腿痛评分、Oswestry功能障碍指数(ODI)、连续行走距离、手术满意度等评价疗效。[结果]两组患者均顺利手术,无严重并发症。两组随访6～12月,平均(8.53±2.53)月。椎管扩大组手术时间、手术出血量、术后引流量显著优于减压融合组。随时间延长,两组患者的腰痛VAS、下肢痛VAS和ODI评分均显著减少,而两组患者的连续行走距离均显著增加,不同时间点间差异有统计学意义。术前、术后1周时两组间上述指标差异均无统计学意义,但末次随访时,椎管扩大组在腰痛VAS、ODI评分和连续行走距离方面显著优于减压融合组。末次随访时,患者自我非常满意度椎管扩大组优于减压融合组(86.67%vs 60.00%)。减压融合组平均椎间融合时间为(7.26±1.32)个月,未出现内固定相关并发症;末次随访时,椎管扩大组椎管矢状径及椎管横径较术前明显增大,且差异有统计学意义。两组均未见明显相邻节段退变或病椎间隙变窄。[结论]对于1～2节段无腰椎失稳的腰椎管狭窄症,保留棘突韧带复合体腰椎管扩大减压术比传统椎板减压植骨融合内固定术创伤更小,术后恢复更快,且在术后早期缓解腰痛方面更有优势。     

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.     

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.     

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.     

Synergistic interaction between the effects of propofol and midazolam with fentanyl on phrenic nerve activity in rabbits

Background: It has been shown that the depressive effects of both propofol and midazolam on consciousness are synergistic with opioids, but the nature of their interactions on other physiological systems, e. g. respiration, has not been fully investigated. The present study examined the effect of propofol and midazolam alone and in combination with fentanyl on phrenic nerve activity (PNA) and whether such interactions are additive or synergistic. Methods: PNA was recorded in 27 anaesthetised and artificially ventilated rabbits. In three groups, propofol, fentanyl and midazolam were administered intravenously in incremental doses to construct dose-response curves for the depressant effects of each one on PNA. In another two groups, the effect of pretreatment with either fentanyl 1 μg · kg^?1 i. v. or midazolam 0.05 mg · kg^?1 i. v. on the effects of propofol and fentanyl respectively on PNA were studied. Results: Propofol and fentanyl caused a dose-dependent depression of PNA with complete abolition at the highest total doses of 16 mg · kg^?1 i. v. and 32 μg · kg^?1 i. v., respectively. In contrast, midazolam in incremental doses to a total of 0.8 mg · kg^?1 reduced mean PNA by 63%, but approximately 12% of PNA remained at a total dose as high as 6.4 mg · kg^?1. The mean ED₅₀s, calculated from dose-response curves, were 5.4 mg · kg^?1, 3.9 μg · kg^?1 and 0.4 mg · kg^?1 for propofol, fentanyl and midazolam, respectively. Initial doses of either fentanyl 1 μg · kg^?1 i. v. or midazolam 0.05 mg · kg^?1 i. v. acted synergistically with subsequent doses of either propofol or fentanyl to abolish PNA at total doses of 8 mg · kg^?1 and 8 μg · kg^?1, respectively. Conclusion: Fentanyl has a synergistic interaction with both propofol and midazolam on PNA and hence potentially on respiration.     

Intrathecal administration of sameridine to patients subjected to arthroscopic knee joint surgery

Background: Sameridine, a new substance with both local anesthetic and opioid effects, was administered intrathecally for the first time to humans, i. e. in patients subjected to arthroscopic knee joint surgery.
Method: A dose-escalating (10, 15, 20 and 25 mg), open study was performed in 33 patients. Only two patients were included in the 25 mg group.
Results: Sameridine provided good quality of surgical anesthesia in all patients except those receiving 10 mg. The maximum level of sensory block, Th5–Th7, was reached within 30 min with a median duration of 3.6–3.9 h. The motor block was more profound with increasing dose, but never lasted longer than the sensory block. The influence on heart rate and blood pressure was minor and atropine and ephedrine were needed in four patients. No clinically significant ECG-changes were detected and no arrhythmias were recorded. Oxygen saturation and respiratory rate did not decrease in a clinically significant way and were not affected by concomitant morphine given i. v. postoperatively. There were few side-effects, the most frequent being mild pruritus (10/33).
Conclusion: Sameridine provided clinically adequate anesthesia for the patients receiving the doses of 15, 20 and 25 mg. Further studies are needed to evaluate the substance and it is of great interest to clinically investigate the opioid component with respect to postoperative analgesia.     

Reduction of Plasma Fibrinogen, Immunoglobulin G, and Immunoglobulin M Concentrations by Immunoadsorption Therapy with Tryptophan and Phenylalanine Adsorbents

Abstract Immunoadsorption (1A) therapy with tryptophan (TR-350) or phenylalanine (PH-350) adsorbents has been used to reduce the concentration of serum antibodies in human lymphocyte antigen (HLA)-immunized patients. Other forms of plasma purification have been reported to reduce the level of fibrinogen, which affects the blood properties. In this study we investigated the effects of IA therapy using both adsorbents on plasma fibrinogen and immunoglobulins G and M in 13 patients (8 patients were treated with TR-350, and 5 patients were treated with PH-350). During each session 1 plasma volume (2.8 ± 0.4 L of plasma) was processed through the immunocolumn and then returned to the patient together with the blood cells. Compared with the pretreatment values, the plasma fibrinogen, IgG, and IgM concentrations were significantly reduced after IA therapy (p < 0.01 for TR-350; p < 0.04 for PH-350). There was a positive correlation between the degree of reduction of plasma proteins and the number of IA treatments given. A nonpara-metric test (Wilcoxon's signed-rank test or the Mann-Whitney test) was used for statistical analysis. We conclude from our study that IA therapy effectively lowers the plasma levels of fibrinogen, IgG, and IgM and thus can be considered a valuable alternative to other blood purification methods.