儿童发育不良性重度腰椎滑脱手术复位后脊柱-骨盆矢状位序列改变

目的 :评估手术复位对儿童L5发育不良性重度滑脱患者脊柱-骨盆矢状位序列的影响。方法:回顾性分析13例行手术复位治疗的儿童L5发育不良性重度滑脱患者,其中男2例,女11例。均行减压复位内固定融合术。手术时年龄11.5±2.4岁(7~15岁)。采用配对样本t检验比较术前、末次随访时的滑脱程度(slip degree)、腰椎前凸角(lumbar lordosis,LL)、Boxall滑脱角(Boxall′s slip angle,BSA)、SDSG发育不良性腰骶角(Spinal Deformity Study Group dysplastic lumbosacral angle,SDSG-dys LSA)、骨盆投射角(pelvic incidence,PI)、骨盆倾斜角(pelvic tilt,PT)、骶骨倾斜角(sacral slope,SS)的差异,评估手术复位后脊柱-骨盆矢状位序列的变化。结果:随访20.6±21.9个月(3~64个月),滑脱程度由术前的(76.01±15.65)%改善至末次随访时的(17.57±16.64)%(P0.01),滑脱复位程度为(58.44±16.31)%,其中4例Ⅲ度滑脱患者完全复位。11例患者行S1上终板拱顶样部分切除,平均切除程度为(30.16±14.54)%。术前、末次随访时的LL分别为74.75°±18.11°、57.77°±14.83°,BSA分别为48.98°±16.01°、19.56°±18.70°,SDSG-dys LSA分别为19.78°±20.19°、-1.72°±19.04°,SS分别为28.68°±23.21°、41.13°±15.67°,末次随访时均较术前有显著性改变(P0.05);PI分别为65.64°±19.88°、73.20°±18.85°,PT分别为36.88°±11.68°、32.03°±11.76°,末次随访时较术前无显著性改变(P0.05)。C7铅垂线距骶骨后上角距离(sagittal vertical axis,SVA)较术前减小。末次随访时10例后倾型骨盆患者中2例(20%)转变为平衡型骨盆。结论:手术复位可改善儿童L5发育不良性重度滑脱患者脊柱-骨盆矢状位序列,矫正腰骶部后凸畸形,改善骶骨-骨盆矢状位序列。     

改良Halo-骨盆架分期牵引治疗重度僵硬性脊柱侧凸的疗效分析

目的：探讨改良Halo-骨盆架分期牵引联合手术治疗重度僵硬性脊柱侧凸的临床疗效。方法：自2004年1月至2010年5月治疗50例重度僵硬性脊柱侧凸患者,男23例,女27例;年龄4～16岁,平均10.8岁;先天性脊柱侧凸24例（分节不良11例,形成障碍7例,混合型6例）,特发性脊柱侧凸26例。采用改良Halo-骨盆架分期牵引联合手术治疗：Ⅰ期术前牵引,Ⅱ期松解牵引,Ⅲ期牵引矫形内固定。对治疗前后患者身高、侧凸Cobb角、后凸Cobb角及矫正率进行观察。结果：患者身高由治疗前平均（152.1±11.1）cm矫正至（158.5±10.5）cm,侧凸Cobb角由平均（91.8±14.5）°矫正至（30.8±7.9）°,后凸Cobb角由平均（69.5±14.0）°矫正至（31.6±10.1）°。Ⅰ期术前牵引后侧凸、后凸Cobb角平均矫正率分别为（30.4±6.6）%、（22.3±5.2）%;Ⅱ期松解牵引后侧凸、后凸Cobb角平均矫正率分别为（26.7±5.1）%、（21.2±6.0）%;Ⅲ期牵引矫形内固定后侧凸、后凸Cobb角平均矫正率分别为（33.7±7.2）%、（27.1±5.3）%（矫正率参照的基准Cobb角是上一期治疗的Cobb角）;分期牵引联合手术治疗的侧凸、后凸Cobb角平均矫正率分别为（66.5±7.2）%、（55.1±6.4）%。各期治疗前后患者身高、侧凸Cobb角、后凸Cobb角及矫正率差异均有统计学意义（P〈0.05）。结论：采用改良Halo-骨盆架分期牵引联合手术治疗重度僵硬性脊柱侧凸,可获得良好的畸形矫正和躯干平衡,并能减少术中、术后并发症,具有临床可操作性。     

青少年L5滑脱患者脊柱-骨盆矢状面形态的特征及临床意义

目的:研究青少年L5滑脱患者的脊柱-骨盆矢状面形态,分析不同类型滑脱的矢状面参数特征及临床意义。方法:回顾性分析2010年1月～2019年12月在我院就诊的资料完整的青少年L5滑脱患者36例,男、女各18例,平均年龄14.1±2.5岁(10～18岁);按照Wiltse滑脱分型分为峡部裂组28例和发育不良组8例;按照Meyerding分度标准分为轻度滑脱组32例(Ⅰ度29例、Ⅱ度3例)和重度滑脱组4例(Ⅲ度2例、Ⅳ度2例)。在站立位全长脊柱侧位片上测量脊柱-骨盆矢状面参数。其中滑移参数包括:滑脱率(slip rate,SR)、滑脱角(slip angle,SA);骨盆矢状面参数包括:骨盆入射角(pelvic incidence,PI)、骨盆倾斜角(pelvic tilt,PT)、腰骶角(lumbosacral angle,LSA)、骶骨平台角(sacral table angle,STA);脊柱矢状面参数包括:胸椎后凸角(thoracic kyphosis,TK)、腰椎前凸角(lumbar lordosis,LL)和矢状垂直偏距(sagittal vertical axis,SVA)。对比研究峡部裂组和发育不良组以及轻度和重度滑脱患者的脊柱-骨盆矢状面参数特点和相关临床意义。结果:峡部裂组SR=(13.7±8.1)%,PT=15.7°±8.3°,LSA=105.9°±11.8°,STA=102.8°±6.5°;发育不良组SR=(42.4±27.8)%,PT=34.2°±9.6°,LSA=78.7°±11.2°,STA=76.4°±9.5°;两组相比具有显著的统计学差异(P0.05)。轻度滑脱组SR=(14.4±7.8)%,PT=18.1°±10.4°,LSA=102.1°±15.5°,STA=99.9°±10.8°;重度滑脱组SR=(65.0±19.6)%,PT=33.9°±11.1°,LSA=77.4°±6.7°,STA=77.7°±8.8°,两组相比具有显著的统计学差异(P0.05)。峡部裂组SA=2.6°±13.1°,PI=54.6°±9.0°,TK=23.5°±15.5°,LL=-53.0°±18.3°;发育不良组SA=11.2°±10.5°,PI=60.8°±14.5°,TK=21.5°±14.3°,LL=-45.3°±15.9°;两组相比无统计学差异(P0.05)。轻度滑脱组SA=3.3°±12.6°,PI=55.3°±10.4°,TK=24.0°±13.1°,LL=-52.7°±17.4°;重度滑脱组SA=14.5°±12.8°,PI=61.0°±12.2°,TK=14.8°±3.7°,LL=-40.0°±20.0°,两组相比无统计学差异(P0.05)。结论:青少年L5滑脱中,发育不良性多为重度滑脱,而峡部裂性多为轻度滑脱。发育不良性重度滑脱容易出现矢状面失衡和滑脱进展,其脊柱-骨盆矢状面呈现躯干前倾,骶骨垂直和骨盆后倾的形态。     

儿童SDSG 5/6型发育不良性腰椎滑脱患者手术治疗后骨盆平衡情况变化

目的 :探讨在儿童重度发育不良性腰椎滑脱伴不平衡型骨盆[即脊柱畸形研究学组(Spinal Deformity Study Group,SDSG)分型5和6型]患者中手术复位及重建腰骶前凸对骨盆平衡的影响。方法 :回顾性分析2015年2月～2019年2月手术治疗的23例儿童重度发育不良性腰椎滑脱患者,男2例,女21例,年龄9.6±2.4岁。均为L5滑脱,术前均伴有骨盆后倾。SDSG分型5型21例,6型2例。均行减压复位腰骶后凸矫正内固定融合术。测量术前及术后1年随访时脊柱骨盆矢状面相关参数,包括骨盆入射角(pelvic incidence,PI)、骨盆倾斜角(pelvic tilt,PT)、骶骨倾斜角(sacral slope,SS)、L5倾斜角(L5 slope,L5S)、腰椎前凸角(lumbar lordosis,LL)、滑脱程度(slip percentage,SP)、SDSG发育不良腰骶角(SDSG dysplastic lumbosacral angle,SDSG-dys LSA)、Boxall′s滑脱角(Boxall′s slip angle,BSA)、Dubousset′s腰骶角(Dub-LSA)、腰骶后凸角(kyphotic Cobb angle,k-Cobb)。根据术后1年时骨盆旋转情况分为术后平衡型骨盆组和不平衡型骨盆组,对比两组患者后凸改善、滑脱复位率及近端固定椎的差异。结果:随访26±11个月(13～48个月),术后1年时PI无显著性改变(P0.05),SS及Dub-LSA较术前均有显著性增加(P0.05);PT、L5S、LL、SP、SDSG dys-LSA及BSA较术前均有显著性减少(P0.05);k-Cobb由术前11.6°±12.8°改善至-11.5°±16.3°(P0.05);滑脱复位率为(85.5±16.4)%。术后1年时23例患者中有5例(22%)骨盆改善为平衡型,骨盆平衡组患者滑脱复位率显著性高于不平衡组(90.9%vs. 76.2%,P0.05),两组腰骶后凸改善及近端固定椎位置无显著性差异(P0.05)。结论 :手术治疗儿童SDSG5/6型发育不良性腰骶滑脱可有效改善脊柱-骨盆矢状位序列,部分患者可从不平衡型骨盆改善为平衡型骨盆,且骨盆平衡的改善与滑脱复位相关。     

后路单侧经椎弓根半椎体截骨治疗青少年先天性脊柱侧凸

目的评估后路经椎弓根截骨矫形部分半椎体保留治疗先天性半椎体所致脊柱侧凸畸形的临床疗效。方法共18例先天性半椎体合并脊柱侧凸患者纳入随访研究,平均年龄16.17岁（14～21岁）,术前测量半椎体所致脊柱畸形的节段性主弯Cobb角45.39°±6.81°,头侧代偿弯Cobb角27.5°±2.71°,尾侧代偿弯Cobb角为26.44°±6.85°,顶椎偏距为4.28±0.58cm,节段性后/前凸角度为14.11°±18.07°。所有病例均采用后路一期经半椎体椎弓根截骨,双侧固定矫正侧凸畸形。随访时间为14.17±6.56个月。综合评估影像学、临床疗效以及并发症的情况。结果手术时间为2.82±0.74h,术中失血量317.22±65.15ml。术后节段性主弯Cobb角为11.33°±4.68°,矫正34.06°±7.88°,末次随访14.61°±4.96°;头侧代偿弯Cobb角为8.72°±1.44°,矫正18.78°±3.17°,末次随访18.78°±3.17°;尾侧代偿弯Cobb角为7.98°±1.82°,矫正18.47°±5.83°,末次随访18.47°±5.83°;节段性后/前凸角为-1.94°±12.35°,矫正14.94°±10.18°,末次随访-1.5°±12.67°。顶椎偏距的矫正为2.31±0.52cm,末次随访2.1±0.24cm。术中没有血管、神经损伤、骨折等重大并发症发生,术后没有发生冠状面和矢状面的失代偿。结论后路半椎体经椎弓根截骨矫形能有效矫正轻、中度先天性半椎体所致脊柱侧凸畸形,缩短手术时间,创伤小,减少术中失血量,矫形效果满意,所选病例骨骼发育相对成熟者,避免矫形丢失。     

骨盆腰椎匹配值与成人退变性脊柱侧凸畸形术后疗效的相关性研究

目的 :探讨成人退变性脊柱侧凸畸形患者骨盆腰椎匹配值(PI-LL)与术后临床疗效的关系。方法:选取2011年1月~2012年12月间因退变性脊柱侧凸于我院行长节段减压融合手术的患者共42例,随访时间3年以上。术前及末次随访时行站立位脊柱全长正侧位X线片检查,记录患者视觉模拟评分(visual analogue scale,VAS)和Oswestry功能障碍评分(Oswestry disability index,ODI)。影像学上测量侧凸Cobb角、骨盆投射角(pelvic incidence,PI)、骶骨倾斜角(sacral slope,SS)、骨盆倾斜角(pelvic tilt,PT)、腰椎前凸(lumbar lordosis,LL)、胸椎后凸(thoracic kyphosis,TK)、骨盆腰椎前凸角(pelvic radius-T12,PR-T12)、T1骨盆角(T1 pelvic angle,TPA)和矢状垂直轴(sagittal vertical axis,SVA)。统计患者术前术后影像学参数和功能评分的改善情况,分析这些参数与PI-LL值的相关性及不同PI-LL值对患者生活质量(ODI)的影响。结果:患者平均年龄68.8岁。术前冠状位侧凸Cobb角为19.5°±5.4°,末次随访时改善为6.1°±3.5°,差异显著(P0.01)。腰椎前凸由术前平均20.7°增加至34.3°,末次随访时平均PI-LL为9.0°,SVA由术前平均7.6cm减少至5.7cm,差异显著(P0.01)。术前矢状位平衡组患者10例,末次随访时PI-LL为1.0°±5.9°。矢状位失衡组患者32例,末次随访时PI-LL为11.8°±9.0°。两组术前的VAS和ODI评分无显著差异,术后均得到明显改善;两组术后VAS和ODI评分差异无统计学意义(P=0.074/0.053)。术后PI-LL与术后PR-T12、TPA、SVA、VAS及ODI显著相关。末次随访时PI-LL≤10°与10°PI-LL≤15°两组之间ODI评分无显著差异(P=0.205),但均与PI-LL15°组间差异显著(P=0.010/0.048)。结论 :成人退变性脊柱侧凸畸形患者手术治疗时应注意对矢状位的充分评估。对于高龄患者,术后PI-LL≤15°提示骨盆腰椎匹配良好,有助于维持脊柱-骨盆矢状位平衡,显著提高患者的临床疗效和生活质量。     

青少年脊柱侧凸合并腰椎滑脱的术式选择

目的 :探讨青少年脊柱侧凸合并腰椎滑脱患者手术治疗方式的选择,观察脊柱侧凸及滑脱程度的转归。方法:对2002年5月~2011年1月收治的有完整影像学资料的9例青少年脊柱侧凸合并腰椎滑脱的患者进行回顾性分析。年龄10~18岁,平均14.4±2.7岁。功能性脊柱侧凸3例,特发性脊柱侧凸6例;发育性腰椎滑脱3例,峡部裂性腰椎滑脱6例。滑脱节段均为L5/S1,Ⅰ度滑脱4例,Ⅱ度滑脱2例,Ⅲ度滑脱2例,Ⅳ度滑脱1例。3例(1、3、4号)功能性侧凸患儿均行腰椎滑脱后路复位内固定植骨融合术。1例(2号)特发性脊柱胸腰双弯患儿侧凸Cobb角未达到手术干预标准,行单一腰椎滑脱后路复位内固定植骨融合术;2例(5、6号)无滑脱症状的特发性脊柱侧凸患儿行脊柱侧凸后路矫形内固定植骨融合术;3例(7~9号)伴腰椎滑脱症状者同时行后路滑脱复位与脊柱侧凸矫形联合手术。测量患者术前、术后、末次随访时的Cobb角及滑脱相关参数。结果:仅行单一腰椎滑脱后路复位内固定植骨融合术的4例患儿末次随访时的侧凸主弯Cobb角改善率分别为58.1%、11.5%、57.9%、36.7%,滑脱百分比改善率分别为61.3%、76.9%、59.7%、27.3%;2例仅行脊柱侧凸后路矫形内固定植骨融合术患儿的侧凸主弯Cobb角改善率分别为81.8%及68.6%,滑脱百分比改善率分别为71.8%及25.0%;3例同时行腰椎滑脱后路复位和脊柱侧凸矫形内固定植骨融合术患儿末次随访时Cobb角改善率分别为86.2%、75.6%、72.9%,滑脱百分比改善率分别为31.8%、50.0%、67.7%。7例患儿术前有不同程度的腰痛症状,1~4号患儿ODI评分为26.0(21.0~31.0)分,7~9号为23.0(15.0~29.0)分,末次随访时分别为7.0(5.0~10.0)分和6.0(5.0~8.0)分。9例患儿在术后及随访过程中均未出现并发症。结论:对青少年脊柱侧凸合并腰椎滑脱患儿应根据侧凸类型及腰椎滑脱程度选择手术方式,侧凸Cobb角大于40°伴腰椎滑脱所致腰痛症状时,应同时行脊柱侧凸矫形术和腰椎滑脱复位术;若仅满足腰椎滑脱复位内固定或者仅满足脊柱侧凸矫形的手术干预要求,可考虑行单一后路行腰椎滑脱复位内固定术或单一后路脊柱侧凸矫形手术。     

先天性脊柱侧后凸畸形的手术治疗

目的 探讨半椎体切除后采用平移技术及悬梁臂技术治疗先天性脊柱侧后凸的有效性.方法 回顾性分析2005年1月~2010年1月于本院行手术治疗的先天性脊柱侧后凸患儿24例,男11例,女13例;年龄为6~14岁,平均10.3岁.均于全麻下接受半椎体切除联合内固定矫正脊柱侧后凸畸形,记录患者的手术时间、出血量,术后侧凸角和后凸角的矫正率及末次随访时丢失率.结果 所有患者均获随访,平均随访14个月,手术时间 （148±25） min,手术出血量 （760±85） mL.11例患者置入4对椎弓根螺钉,8例患者置入5对椎弓根螺钉,5例患者置入6对椎弓根螺钉,平均置入4.75对.侧凸Cobb角术前为52.7°±6.2°,术后为9.4°±2.3°,矫正率为82.2%,末次随访时为10.2°±1.2°,矫正丢失率为8.5%.后凸Cobb角术前为30.2°±5.3°,术后为7.2°±1.4°,矫正率为76.2%,末次随访时为7.7°±1.0°,矫正丢失率为6.9%.随访期间未发生内固定物相关并发症,无曲轴现象出现.结论 半椎体切除联合内固定矫形是治疗先天性脊柱侧凸的理想方法,应用平移及悬梁臂技术可显著矫正脊柱侧后凸畸形.     

胸腔镜与开胸前方松解在脊柱侧凸后路矫形中的作用

目的比较胸腔镜与开胸前方松解对脊柱侧凸后路矫形的作用,评估胸腔镜脊柱侧凸前方松解手术的临床效果。方法2001年11月～2002年9月共施行14例胸腔镜脊柱侧凸前方松解手术和22例开胸前方松解手术,所有病例均为特发性脊柱侧凸。胸腔镜组男1例,女13例;平均年龄15.9岁;其中KingⅡ型9例,KingⅢ型5例;Cobb角88°±10.4°,柔软度(Bending片侧凸矫正率)25.5%±6.1%;松解节段5.8±0.9个。开胸组男5例,女17例;平均年龄15.5岁;其中KingⅡ型13例,KingⅢ型9例;Cobb角90°±15.2°,柔软度24.8%±7.8%;松解节段6.0±1.1个。两组患者均于前方松解后2周行后路TSRH矫形手术。对两组的术后侧凸矫正率以及半年后的矫正丢失率进行比较。结果胸腔镜组术后Cobb角39.6°±10.8°,侧凸矫正率54.7%±10.3%,半年后矫正丢失率2.9%±1.1%;开胸组术后Cobb角41.9°±13.2°,侧凸矫正率53.2%±12.5%,半年后矫正丢失率3.2%±1.3%。两组比较差异均无显著性(P >0.05)。结论胸腔镜脊柱侧凸前方松解手术能达到开胸前方松解手术的临床效果。     

应用Isola内固定系统矫治重度脊柱侧凸

目的:探讨Isola脊柱内固定系统矫治重度脊柱侧凸的方法并评价其疗效。方法:1998年6月至2003年1月应用Isola脊柱内固定系统治疗重度脊柱侧凸32例,其中特发性脊柱侧凸25例,神经纤维瘤病性脊柱侧凸3例,神经肌肉性脊柱侧凸4例。冠状面主弯Cobb角92.1°±11.4°(75°～116°)。根据不同的侧凸类型、侧凸角度、柔韧性等采用一期前后路联合矫形、分期前后路联合矫形或单纯后路矫形手术,术中运用悬臂技术产生的平移力进行矫形,同时应用椎板下钛缆固定。比较术前、术后冠状面和矢状面的畸形程度,并通过躯干侧移(LT)值分析躯干平衡的重建。结果:随访6~48个月,平均18个月,全组患者术后冠状面矫形效果明显,Cobb角术后与术前相比有显著性差异(P<0.01),主弯平均Cobb角矫正率为53.8%,末次随访冠状面Cobb角平均丢失3.3°±3.8°。矢状面上81.3%的患者恢复了胸椎生理性后凸(30°~50°),84.4%的患者恢复了腰前凸(40°~60°)。术后LT值矫正率为67.1%,与冠状面Cobb角的矫正率呈正相关。结论:应用Isola内固定系统矫治重度脊柱侧凸,利用悬臂技术产生的平移力尤其与椎板下钛缆矫形固定相结合,可获得冠状面上较高的矫正率,同时可获得矢状面的矫正并达到躯干平衡。     

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 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.     

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.     

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.     

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.     

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.     

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.     

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.     

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.