PMMA增强的多孔中空椎弓根螺钉治疗腰椎退变性疾病的疗效和安全性

【摘要】 目的：通过与传统骨水泥（PMMA）增强椎弓根螺钉固定方法的对比,分析使用PMMA增强的多孔中空椎弓根螺钉治疗退变性腰椎疾病的临床疗效及安全性。方法：2010年3月～2011年6月间在我科接受腰椎手术治疗的骨质疏松患者45例,其中24例患者采用传统的骨水泥增强椎弓根螺钉固定（对照组）,平均年龄71.2岁（59～86岁）,平均骨密度为0.60±0.16g/cm2;21例采用骨水泥增强的多孔中空椎弓根螺钉（TangoRS系统）固定（观察组）,平均年龄72.0岁（58～87岁）,平均骨密度0.57±0.24g/cm2。应用术前及术后ODI及JOA评分对比评价两组患者的临床效果;应用术后CT及X线评价椎体的融合融合情况及螺钉位置;通过统计术后并发症评价安全性。结果：两组患者均顺利完成手术,对照组患者平均手术时间158±43min,术中出血量233±23ml,平均住院时间12.3±4.6天;观察组患者平均手术时间146±34min,术中出血量225±36ml,平均住院时间13.2±6.5d;两组患者平均手术时间、术中出血量及平均住院时间比较,差异无统计学意义（P＞0.05）。对照组患者平均随访20.5个月,有3例患者PMMA渗漏至椎管内,1例PMMA由于椎体前壁破裂而穿出椎体前壁,未出现相应的神经并发症。有2例患者出现螺钉松动且未形成融合。观察组平均随访18.4个月,有1例患者PMMA渗漏至椎体前侧方,1例患者PMMA渗漏至椎管内,均未出现相应的神经并发症。对照组患者JOA评分术前为10.21±2.27分、术后为21.32±2.80分,ODI评分术前为47.34±6.30分、术后为18.47±4.89分;观察组患者JOA评分术前为10.12±2.64分、术后为21.83±2.43分,ODI评分术前为48.07±5.06分、术后为17.67±3.64,两组患者术前、术后JOA及ODI评分,组间对比无显著差异（P＞0.05）,组内术后术前对比有显著差异（P＜0.05）,两种方法均取得良好的效果。结论：采用PMMA增强的多孔中空椎弓根螺钉固定治疗骨质疏松退变性腰椎疾病与传统的骨水泥加强方式同样有较好的临床效果,安全性好,且采用注射的方式操作更为简单方便。     

椎弓根螺钉短节段固定联合椎体成形术治疗单节段胸腰段骨质疏松性椎体爆裂骨折

【摘要】 目的：探讨椎弓根螺钉短节段固定联合椎体成形术治疗单节段胸腰段骨质疏松性椎体爆裂骨折的临床疗效。方法：回顾性分析我院2008年1月～2012年3月收治的86例单节段胸腰段爆裂椎体骨折患者的临床资料,对其中32例合并骨质疏松症的患者进行随访分析。男14例,女18例;年龄56～78岁,平均64.5岁;跌倒伤14例,车祸伤9例,高处坠落伤5例,重物砸伤4例;骨折节段：T11 3例;T12 10例;L1 15例;L2 4例。手术时均在骨折上下椎置入椎弓根螺钉,安装连接棒,通过体位结合撑开实现骨折椎体复位,然后在伤椎注入骨水泥。应用VAS及SF-36量表评估患者疼痛及生活质量改变情况,通过X线片测量计算伤椎椎体前缘高度恢复、受伤节段后凸矫正及丢失情况,随访观察治疗效果。结果：所有患者均顺利完成手术,术中无明显并发症。随访12～36个月,平均16.5个月。术后VAS评分（2.43±1.81分）及末次随访时VAS评分（2.17±1.81分）与术前（7.67±2.25分）比较差异有统计学意义（P<0.05）;末次随访SF-36评分（123.5±22.3分）与术前（95.7±17.5分）比较差异有统计学意义（P<0.05）。术前Cobb角为22.3°±3.6°,术后Cobb角矫正至5.2°±1.2°,末次随访时为6.0°±2.3°,丢失0.8°±1.5°;术前椎体高度（56.4±5.8）%,术后椎体高度恢复至（95.3±2.9）%,末次随访时为（91.4±3.7）%,丢失（4.0±2.5）%。3例出现椎旁静脉骨水泥栓塞,无明显症状,无内固定断裂。结论：后路短节段椎弓根螺钉固定联合椎体成形术能够有效恢复并维持伤椎高度,减少后凸畸形矫正丢失及内固定失败的发生,具有良好的疗效。     

骨水泥螺钉与可膨胀椎弓根螺钉治疗严重骨质疏松腰椎病手术的比较

[目的]对比可灌注椎弓根骨水泥螺钉与可膨胀椎弓根螺钉应用于严重骨质疏松老年患者腰椎退变疾病手术的临床效果。[方法]选择本院2012～2015老年腰椎退变疾病合并严重骨质疏松患者30例;完善术前X线片、CT及MRI检查后,15例行经皮可灌注骨水泥螺钉固定+Mis-TILF减压手术技术,另15例行可膨胀螺钉固定+Mis-TILF减压手术技术。分别记录术前、术后VAS评分、JOA评分以及椎弓根钉松动率并进行统计分析。[结果]所有患者均顺利手术,术中均未出现神经损伤、骨水泥渗漏。所有患者随访1年以上。VAS评分随术后时间延长而逐渐减小、JOA评分随术后时间延长而逐渐增加,不同时间点间的差异均有统计学意义(P0.05)。随访中均未见螺钉断钉、断棒现象。可灌注椎弓根骨水泥螺钉组所有患者椎弓根螺钉未见松动现象,可膨胀椎弓根螺钉组有2例患者椎弓根钉出现不同程度松动,占可膨胀螺钉组13.3%,两组椎弓根钉松动率差异有统计学意义。[结论]微创下中空可灌注骨水泥螺钉应用于老年严重骨质疏松患者,在术后恢复过程中效果更可靠,固定更牢固,不易松动,可为老年微创手术患者提供稳定有效的脊柱内固定。     

急性症状性骨质疏松性胸腰椎骨折分型Ⅳ型患者短节段和长节段固定的临床疗效比较

【摘要】 目的：比较急性症状性骨质疏松性胸腰椎骨折（acute symptomatic osteoporotic thoracolumbar fracture,ASOTLF）分型Ⅳ型短节段和长节段固定的临床疗效。方法：回顾性分析2016年1月～2019年12月在我院收治的骨质疏松性胸腰椎骨折患者临床资料,参照ASOTLF分型符合Ⅳ型的为35例。将其按照固定节段的长短进行分组,A组为短节段组（以伤椎为中心,固定节段包含伤椎及上下各1个正常椎节）;B组为长节段固定组（以伤椎为中心,固定节段包含伤椎及上下各2个正常椎节）;手术方式为：A组患者伤椎进行骨水泥强化并进行螺钉固定,伤椎上下椎体进行椎弓根螺钉固定并进行钉道强化;B组患者伤椎进行骨水泥强化及螺钉固定,同时进行伤椎上下各两组椎弓根螺钉固定并进行钉道强化;两组手术都进行后方固定节段范围内小关节突关节植骨融合;其中A组18例,男6例,女12例,年龄72．1±3．5岁,腰椎骨密度T值－3．2±0．2,随访时间12．0±3．3个月;B组17例,男 7 例,女10例,年龄72．4±3．5岁,腰椎骨密度T值－3．1±0．4,随访时间15．3±2．8个月。比较两组患者的性别、年龄、随访时间、手术时间、术中出血量、骨水泥渗漏、邻椎骨折率,以及手术前后的疼痛视觉模拟评分（visual analogue scale,VAS）、Oswestry功能障碍指数（Oswestry disability index,ODI）、后凸角变化,记录并发症。结果：术前两组患者年龄、性别、骨密度T值、疼痛VAS评分、ODI、后凸角比较差异无统计学意义（P＞0.05）,手术时间（63．7±10．6min vs 93．5±12．1min）及术中出血量（205．3±28．4ml vs 326．0±37．9ml）A组少于B组,术后7d及末次随访时两组患者的疼痛VAS评分、ODI、后凸角较术前均有显著改善（P＜0.05）,组间比较差异无统计学意义（P＞0.05）。两组骨水泥渗漏（4/18 vs 3/17）及其他椎体骨折发生（2/18 vs 1/17）情况无统计学差异（P＞0.05）。结论：急性症状性骨质疏松性胸腰椎骨折分型Ⅳ型选择后路短节段或长节段固定,都能达到较满意的伤椎复位、临床疗效和畸形矫正,短节段固定在手术时间及术中出血上更具优势。     

双椎体截骨术矫正强直性脊柱炎重度胸腰椎后凸畸形

【摘要】 目的：观察双椎体经椎弓根楔形截骨矫正强直性脊柱炎重度胸腰椎后凸畸形的治疗效果。方法：2009年5月～2010年12月我院采用双椎体经椎弓根楔形截骨、椎弓根螺钉内固定术治疗强直性脊柱炎重度胸腰椎后凸畸形患者18例,均为男性,年龄19～47岁,平均34.8岁。术前全脊柱最大后凸Cobb角70°~108°（82.6°±17.5°）,顶椎均位于胸腰段;胸椎后凸角46°~67°（55.2°±15.3°）,胸腰段后凸角25°~43°（32.4°±12.6°）,腰椎前凸角-37°~-11°（-19.5°±10.3°）;站立位颌眉角43°～130°（67.2°±21.9°）;侧位X线片上C7铅垂线距S1后上角的距离为11～35cm（18.3±14.8cm）。采用Bridwell-Dewald脊柱疾患疼痛及功能评定标准进行手术前后疗效评价。结果：手术时间为5.3±1.0h（3.7～6.9h）,术中出血量1887.5±850.9ml（600～3000ml）。术中硬膜破裂4例,术后伤口表浅感染1例,一侧下肢神经症状1例,经治疗后均恢复良好。随访24～48个月,平均33.5个月。术后1周时测量,全脊柱最大后凸Cobb角矫正到21.3°±4.2°,颌眉角改善到9.3°±12.8°,C7铅垂线距S1后上角的距离改善到3.0±4.7cm;术后1周全脊柱最大后凸Cobb角、胸椎后凸角、胸腰段后凸角、腰椎前凸角、颌眉角和C7铅垂线距S1后上角距离均较术前明显改善（P<0.05）。末次随访时,上述指标与术后1周比较差异无统计学意义（P>0.05）;X线片显示所有患者内固定位置良好。患者能平视行走,末次随访时疼痛、工作限制情况及社交限制情况较术前明显改善（P<0.05）。结论：对强直性脊柱炎严重胸腰椎后凸畸形患者,应用双椎体经椎弓根楔形截骨术治疗是一种安全、有效的方法,可较好地恢复脊柱矢状位生理曲度。     

不对称经椎弓根截骨矫治成人先天性脊柱侧后凸畸形

【摘要】 目的：分析应用不对称经椎弓根截骨技术矫治成人先天性脊柱侧后凸畸形的临床疗效。方法：2009年9月~2013年10月采用不对称经椎弓根截骨矫治成人先天性脊柱侧后凸畸形患者16例,男9例,女7例。年龄18～42岁,平均23.6岁。均有腰背痛,无神经受压症状。16例患者脊柱侧凸Cobb角43°~97°,后凸Cobb角15°~70°。侧凸畸形和后凸畸形顶椎均位于同一节段,其中顶椎位于胸椎10例、腰椎6例。于术前、术后及末次随访时在X线片上测量脊柱冠状面主弯Cobb角、矢状面后凸角、冠状面平衡及矢状面平衡,比较术前、术后及末次随访时影像学参数评估手术矫形效果。于术前、末次随访时填写SRS-22问卷量表,评估患者术后的生活质量变化。结果：手术融合节段5~12个,平均7.23个节段。手术时间3~7h,平均4.26h。术中出血量700～2500ml,平均1265ml。1例L1部位截骨患者术后出现双下肢痛觉过敏,急诊手术探查发现截骨部位硬脊膜皱褶,脊髓受压,对截骨部位椎板切开减压,术后症状明显好转,术后3个月随访神经症状消失。2例患者术后出现一侧胸腔积血,紧急行胸腔闭式引流术,1周后拔除引流管。15例患者获得6～48个月（平均13.4个月）随访。获得随访的15例患者冠状位主弯Cobb角术前为58.67°±20.36°（43°～97°）,术后为20.32°±8.76°（8°～37°）,末次随访时为21.76°±8.34°（10°～41°）,术后与术前比较差异有统计学意义（P<0.01）,矫正率为50.76%~82.36%,平均为65.36%,末次随访时与术后比较丢失率为2.45%。术前矢状位后凸角度为45.62°±16.26°（15°～70°）,术后为16.35°±16.87°（-20°～40°）,末次随访时为18.27°±13.92°（-15°～40°）,术后与术前比较差异有统计学意义（P<0.01）,矫正率为50.97%~79.32%,平均为64.16%,末次随访时与术后比较丢失率为4.2%。15例患者中,6例术前存在冠状面失平衡,术后均恢复平衡;4例术前存在矢状面失平衡,术后3例恢复平衡,1例仍为失平衡。SRS-22问卷量表总得分由术前66.47±12.35分（49～79分）提高至末次随访时的84.13±6.42分（76～92分）（P<0.01）。15例患者均获得骨性融合,无假关节形成或内固定断裂。结论：应用不对称经椎弓根截骨技术矫治先天性脊柱侧后凸畸形,可获得较好的矫形效果,显著改善患者躯体外观及躯体平衡,同时明显改善患者的生活质量。     

颈椎椎板成形椎管扩大术结合椎弓根螺钉矫形内固定融合术治疗多节段压迫性颈脊髓病合并退变性颈椎后凸的中长期疗效

【摘要】 目的：观察颈后路椎板成形椎管扩大术结合椎弓根螺钉矫形内固定融合术治疗多节段压迫性颈脊髓病合并退变性颈椎后凸患者的中长期疗效。方法：回顾性分析2008年3月~2019年9月，采用颈后路单开门椎板成形椎管扩大术结合椎弓根螺钉矫形内固定融合术治疗的18例多节段脊髓受压的慢性颈脊髓病合并退变性颈椎后凸患者，其中男11例，女7例，年龄52.3±8.1岁；颈椎后纵韧带骨化症（ossification of posterior longitudinal ligament，OPLL）合并慢性颈脊髓病5例，脊髓型颈椎病13例。减压节段：17例为C3~C7，1例为C3~T1，术中固定融合3.8±1.0个椎体。12例患者出院时（术后2周左右）复查颈椎MRI，11例患者获得随访，随访时间2.1~13.5年（10.5±2.8年）。在术前、出院时颈椎侧位X线片上测量后凸节段Cobb角，在颈椎MRI上测量脊髓前缘角及改良K线，末次随访时在X线片上评估手术固定节段骨性融合及后凸矫形角度丢失情况。术前及末次随访时进行JOA评分及颈痛VAS评分。结果：18例患者术前后凸节段的局部Cobb角为6.6°±6.5°后凸，术后2周为3.8°±8.0°前凸，有显著性差异（P<0.01）； 术前C2~C7颈椎Cobb角为1.3°±9.4°前凸，术后2周为5.8°±7.0°前凸，无显著性差异（P＞0.05）。12例患者颈椎MRI上测量脊髓前缘角术前为11.1°±4.2°后凸，术后2周为1.3°±5.2°后凸，有显著性差异（P<0.01）；C2~C7节段脊髓前缘角术前为6.5°±4.4°后凸，术后2周为1.1°±6.3°前凸，有显著性差异（P<0.01）。7例（39%）患者术后出现C5神经根麻痹，均在术后1~4个月内完全恢复。术后末次随访11例患者颈椎侧位X线片显示手术固定节段均获骨性融合，后凸矫形角度无丢失；颈椎MRI显示脊髓无受压，正中矢状位片显示脊髓前缘角无丢失。11例患者JOA评分术前8.0±2.8分，末次随访时15.6±0.9分，有显著性差异（P<0.01），JOA评分改善率（83±14）%；颈痛VAS评分术前为2.2±3.0分，末次随访时为1.1±1.2分，术前与末次随访时相比无显著性差异（P>0.05）。结论：对于合并有退变性颈椎后凸的多节段受压的慢性压迫性颈脊髓病，采用椎板成形椎管扩大术结合椎弓根螺钉矫形内固定融合术可以获得长期稳定、良好的脊髓功能改善的效果。     

椎弓根螺钉治疗胸腰椎爆裂性骨折

目的探讨椎弓根螺钉在胸腰椎爆裂性骨折治疗中的疗效。方法回顾性分析2002年以来应用椎弓根螺钉的治疗45例胸腰椎骨折患者资料。全部患者采用后路椎管减压,椎体植骨加椎弓根螺钉内固定治疗。结果全部病例得到随访,平均20个月(6～60个月),其中18例脊髓不全损伤患者Frankel分级提高l～3级(平均2级)。A级10例有2例恢复到B级,1例恢复到C级,其余患者部分术后感觉平面下降或下肢感觉部分恢复,运动功能无明显改善。术后遗留轻度腰背痛3例,1例螺钉松动,无一例发生感染。随访病例均行X线片检查,后凸角由术前平均25°(11°～35°)矫正到术后10°(0°～15°),椎体前缘高度矢状径指数术前30°(15°～55°),恢复到术后85°(72°～100°)。结论后路椎管减压,椎体植骨加椎弓根螺钉内固定治疗胸腰椎爆裂性骨折是一种较理想的手术方法。此方法操作简单、安全,在解除神经及硬膜囊压迫的同时扩大了椎管,杜绝了继发性椎管狭窄,增加了脊柱稳定性,值得推广。     

后路截骨矫形手术治疗老年骨质疏松性陈旧胸腰椎骨折伴后凸畸形

【摘要】 目的：评价采用后路截骨矫形手术治疗老年骨质疏松性陈旧胸腰椎骨折伴后凸畸形患者的临床效果。方法：2005年6月～2011年2月采用后路经椎弓根椎体截骨矫形术或经关节突“V”型截骨矫形术的方法治疗22例老年骨质疏松性陈旧胸腰椎骨折伴后凸畸形的患者,男7例,女15例,平均年龄66.5岁。共30个椎体骨折,两个椎体骨折8例,单个椎体骨折14例。患者均有不同程度的腰痛,VAS评分6～9分,平均8.3分,脊髓功能Frankel分级C级1例,D级6例,E级15例。胸腰椎后凸Cobb角为38°～54°,平均47.4°。采用X线片观察Cobb角改善情况,应用VAS评分评价患者疼痛情况,应用Frankel分级评价患者脊髓功能情况。结果：9例患者接受经椎弓根椎体截骨矫形术治疗,13例患者接受经关节突“V”型截骨矫形术治疗。手术时间190～260min,平均221min;术中出血量650～1400ml,平均876ml。术后5d时Cobb角3°～14°,平均9.1°,较术前明显改善（P<0.05）,改善率79.5%,术后VAS评分1～5分,平均4.2分,较术前明显改善（P<0.05）,脊髓功能Frankel分级2例由E级变为D级,经营养神经治疗后恢复为E级,其余未有加重情况。术后随访3～62个月,平均20.2个月。末次随访时Cobb角5°～22°,平均12.5°,VAS评分0～6分,平均4.1分,脊髓功能Frankel分级1例C级患者改善为D级,2例D级患者改善为E级,无加重病例。影像学显示植骨融合,未见内固定断裂、松动现象。1例患者术后8个月出现固定节段上位椎体骨折,1例患者术后5个月出现固定节段上位第二个椎体骨折,均予对症、抗骨质疏松治疗后胸背痛症状缓解。结论：采用后路截骨矫形手术治疗老年骨质疏松性陈旧胸腰椎骨折伴后凸畸形可以取得良好的临床效果。     

PVP治疗中上段胸椎骨质疏松性重度椎体压缩骨折的临床效果

【摘要】 目的：探讨经皮椎体成形术（percutaneous vertebroplasty,PVP）治疗中上段胸椎（T6以上胸椎）骨质疏松性重度椎体压缩骨折（severe vertebral compression fractures,SVCF）的临床效果。方法：回顾性分析2011年1月~2012年12月我院采用PVP治疗的12例中上段胸椎骨质疏松性SVCF患者,男4例,女8例;年龄61~83岁,平均74.5岁。骨折节段：T2 1例,T3 3例,T5 3例,T6 5例。受累节段椎体前缘平均压缩为68%（65%~72%）。腰椎骨密度T值为-3.8~-5.2,平均-4.2。术前胸背痛VAS评分为6.75±1.14分,ODI为（68.58±5.70）%,受累节段椎体前缘高度为0.96±0.09cm,受累节段椎体后凸角为18.90°±1.03°。均行PVP,其中10例采用椎弓根入路,2例采用椎弓根外侧入路,所有患者均采取双侧穿刺置管。结果：所有患者均顺利完成手术,10例经椎弓根入路的手术时间为27～51min,平均41min;2例经椎弓根外侧入路的平均手术时间为62min。术中出血量为5～16ml,平均10ml。骨水泥注入量为1.7~2.8ml,平均为2.2ml。1例术前CT显示上终板裂口的患者术后发现椎间隙骨水泥渗漏,但无不适症状,未行特殊处理。术后2d,胸背痛VAS评分为3.17±1.03分,ODI为（33.00±17.54）%,均较术前明显改善（P＜0.05）;受累节段椎体前缘高度为0.98±0.11cm,受累节段椎体后凸角为19.10°±0.99°,与术前比较无明显改善（P＞0.05）。随访6个月～1年,手术椎体未再发生骨折及塌陷,未发现相邻节段骨折。末次随访时,胸背痛VAS评分为3.75±0.85分,ODI为（32.33±17.11）%,受累节段椎体前缘高度为0.97±0.12cm,受累节段椎体后凸角为19.08°±1.00°,与术后2d比较均无统计学差异（P＞0.05）。结论：PVP治疗中上段胸椎骨质疏松性SVCF可以有效缓解胸背痛,但受累节段椎体前缘高度及后凸角恢复不显著。     

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.     

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.     

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.     

Systemic analgesia adapted to the children's condition

A concept of balanced analgesia using nonsteroidal anti-inflammatory drugs (NSAIDs), paracetamol (acetaminophen), opioids, and corticosteroids can also be used in patients with pre-existing illnesses. NSAIDs are the most effective treatment for acute pain of moderate intensity in children; however, these drugs should be avoided in patients at increased risk for serious side effects, e.g. patients with renal impairment, bleeding tendency, or extreme prematurity. NSAIDs can be given with minimal risks to the younger child with mild to moderate asthma, and, in these patients, the use of steroids can be encouraged; in addition to their antiemetic and analgesic action, a beneficial effect on asthma symptoms can be expected. In the non-intubated child with cerebral trauma, exaggerated sedation caused by opioids and increased bleeding tendency caused by NSAIDs must be avoided. In neonates and small infants, the oral administration of sucrose or glucose is helpful to minimize pain reaction during short uncomfortable interventions.     

Dilemma of Membrane Biocompatibility and Reuse

Abstract: Numerous articles have been published on the multiple use of dialyzers and on the effect of different reprocessing chemicals and techniques on the dialyzer biocompatibility and performance. The results often appear contradictory, especially those comparing standard biocompatibility parameters. Despite this confusion, a discerning review of the published works allows certain limited conclusions to be drawn. Reprocessing of used hemodialyzers changes the biocompatibility profile of a dialyzer as defined by the parameters complement activation. leukopenia, and cytokine release. The effect of reprocessing depends on the chemicals and reprocessing technique applied and also on the type of membrane polymer being subjected to the reprocessing procedure. Reports of pyrogenic reactions indicate that the flux of the membrane also influences how suitable it is for safe reuse. An increased risk of allergic and pyrogenic reactions appears to be associated with dialyzer reuse. Furthermore, there has been a lack of investigations into the immunologic effect of the layer of adsorbed and chemically altered proteins that remains on the inner surface of reprocessed dialyzers. We conclude that the clinical benefit of dialyzer reuse cannot be generally accepted from a biocompatibility point of view.