中老年人群脊柱-骨盆矢状位参数及其序列拟合关系

目的 :测量我国中老年人群的脊柱-骨盆矢状位参数并分析其相关性,建立腰椎前凸角与相关脊柱-骨盆矢状位参数的拟合关系。方法:采用影像学测量方法,对106例中老年志愿者进行研究,其中男48例,女58例;年龄62.4±5.2岁(55~76岁)。所有志愿者行全脊柱正、侧位X线摄片,利用院内影像归档与通信系统(picture archiving and communication system,PACS)测量骨盆入射角(pelvic incidence,PI)、骨盆倾斜角(pelvic tilt,PT)、骶骨倾斜角(sacral slope,SS)、腰椎前凸角(lumber lordosis,LL)、上腰弯前凸角(upper arc of total lumbar lordosis,UALL)、下腰弯前凸角(lower arc of total lumbar lordosis,LALL)、胸椎后凸角(thoracic kyphosis,TK)、矢状位平衡(sagittal vertical axis,SVA)等参数,按照脊柱矢状面解剖定义和形态特点分析脊柱-骨盆矢状位形态参数及其相关性,并与青年人群相关参数进行比较,利用线性回归分析建立中老年人群LL与PI、TK的拟合关系。结果 :我国中老年人群的PI为46.5°±7.6°,PT为13.1°±6.6°,SS为32.3°±9.5°,LL为49.2°±9.1°,UALL为15.9°±5.9°,LALL为32.3°±9.5°,TK为34.0°±10.7°,SVA为-5.0±30mm;LL与SS、TK、PI、PT、SVA呈显著性相关(P0.05),PT与TK、SS呈显著性相关(P0.05),UALL与TK、SVA相关,LALL与PI相关。中老年人群与青年人群比较PI、SS、LL、LALL无显著性差异(P0.05),PT、TK、SVA、UALL有显著性差异(P0.01)。中老年人群LL预测值=0.6PI+0.4TK+10°,R2=0.375。结论:中老年人群中LL与其他相关脊柱-骨盆各参数之间存在显著相关性,我国中老年人群LL的理想预测值为LL=0.6PI+0.4TK+10°;TK、UALL、PT、SVA与青年人群有显著性差异。     

退变性腰椎侧凸脊柱-骨盆参数测量及临床意义

目的测量退变性腰椎侧凸(degenerative lumbar scoliosis,DLS)患者骨盆-脊柱参数并分析其临床意义。方法选取2006年3月—2014年3月在本院脊柱外科就诊的DLS且有完整影像学资料的患者30例(DLS组)及影像学资料完整的无DLS者30例(对照组),测量2组的骨盆入射角(pelvic incidence,PI)、骨盆倾斜角(pelvic tilt,PT)、骶骨倾斜角(sacrum slope,SS)、腰椎前凸角(lumbar lordosis,LL)、胸椎后凸角(thoracic kyphosis,TK)、矢状位平衡(sagittal vertical axis,SVA)。结果 DLS组的LL值明显小于对照组,差异有统计学意义(P0.05);PT、SVA值明显大于对照组,差异有统计学意义(P0.05)。2组的SS、PI及TK值差异无统计学意义(P0.05)。2组的SS与LL、PT与SVA均有相关性。对照组骨盆参数之间(PI、SS及PT)均有相关性,但DLS组骨盆参数之间均无相关性。对照组中LL与SVA显著相关,但DLS组中LL与SVA无相关性。结论骨盆形态的变化与脊柱的矢状位序列密切相关,DLS患者表现为更小的LL以及更大的SVA。     

退变性腰椎侧凸矫形术后腰椎前凸角变化对临床疗效的影响

目的 :评估退变性腰椎侧凸(degenerative lumbar scoliosis,DLS)患者行长节段固定矫形术后腰椎前凸角与脊柱-骨盆矢状位参数匹配与否对临床疗效的影响。方法:对我院2015年6月~2016年6月行腰椎长节段矫形固定术(至少4个椎体)的DLS患者,参照理想腰椎前凸角(lumbar lordosis,LL)=0.6PI+0.4TK+10°,根据出院时LL分为两组,A组(匹配组,术后LL在理想LL±10°范围内)和B组(非匹配组,术后LL在理想LL±10°范围外),利用院内影像归档与通信系统(picture archiving and communication system,PACS)在全脊柱正侧位X线片上测量侧凸Cobb角、冠状位平衡(coronal vertical axis,CVA)、骨盆入射角(pelvic incidence,PI)、骨盆倾斜角(pelvic tilt,PT)、骶骨倾斜角(sacral slope,SS)、腰椎前凸角(lumber lordosis,LL)、胸椎后凸角(thoracic kyphosis,TK)、矢状位平衡(sagittal vertical axis,SVA)等,采用视觉模拟评分(visual analogue scale,VAS)、Oswestry功能障碍指数(Oswestry disability index,ODI)评价患者术后生活质量,随访至少12个月。使用独立样本t检验比较两组影像参数和生活质量评分。结果:共纳入患者100例(A组53例,B组47例),其中男性43例,女性57例,平均侧凸Cobb角为17.5°±7.8°。两组患者随访时间、手术节段、术前侧凸Cobb角、术前的CVA、LL、SS、SVA均无明显差异性(P0.05);术后两组患者的LL、SS、SVA、PT具有明显差异性(P0.01),A组患者LL(42.2°±10.2°)较术前(31.6°±15.5°)明显改善,TK、SS增大,PT减小,术后SVA(17.9±28.5mm)较术前(46.0±37.9mm)明显改善。B组患者术后相关矢状位参数较术前均无明显变化。两组患者术后VAS评分、ODI评分较术前均有明显改善,经3~6个月的短期随访两组患者术后症状评分无明显差异性;经12个月以上随访,A组患者较B组患者腰腿痛VAS评分明显改善(P0.05),ODI评分无明显差异(P=0.08)。结论:退变性腰椎侧凸患者根据公式0.6PI+0.4TK+10°重建腰椎前凸,可以获得满意的脊柱-骨盆矢状位平衡,有助于提高DLS患者术后生活质量。     

胸腰椎骨质疏松性椎体压缩骨折患者脊柱-骨盆矢状位参数的研究

目的 :分析胸腰椎骨质疏松性椎体压缩骨折(OVCFs)患者脊柱-骨盆矢状位影像学特点,为临床该病的治疗提供理论依据。方法:分析116例胸腰椎OVCFs患者资料(胸腰椎OVCFs组),选取102例骨质疏松症非骨折患者作为单纯骨质疏松对照组(单纯OP组),46例骨量正常健康体检者作为骨量正常对照组(骨量正常组)。统计胸腰椎OVCFs组骨折椎体分布情况。在脊柱全长侧位X线片上测量各组矢状位参数:胸椎后凸角(TK)、胸腰后凸角(TLK)、腰椎前凸角(LL)、矢状位平衡(SVA)、T1骨盆角(TPA)、骨盆入射角(PI)、骨盆倾斜角(PT)、骶骨倾斜角(SS),并行Oswestry功能障碍指数(Oswestry disability index,ODI)评分问卷调查,分析3组间参数差异及各组内参数间的相关性。以脊柱矢状位平衡判定标准作为分组依据,将3组再分为失衡亚组、平衡亚组,分别统计3组失衡亚组人数所占比例。分析胸腰椎OVCFs组的失衡亚组与平衡亚组矢状位参数、ODI评分、骨折椎体分布差异和两亚组内参数间的相关性。结果:(1)3组间TK、PI差异无统计学意义(P0.05);胸腰椎OVCFs组TLK、SVA、TPA、PT、ODI均大于单纯OP组,单纯OP组均大于骨量正常组(P0.05);胸腰椎OVCFs组LL、SS均小于单纯OP组,单纯OP组均小于骨量正常组(P0.05)。骨量正常组TPA与SVA、PI、PT、SS相关,LL与TK、PI、SS相关,PI与PT、SS相关(P0.05);单纯OP组TPA与SVA、LL、PI、PT、SS相关,TK与SVA、TPA、TLK相关,LL与TK、TLK、PI、SS相关,PI与PT、SS相关(P0.05);胸腰椎OVCFs组TPA与SVA、LL、PI、PT、SS相关,TK与SVA、TLK相关,PT与PI、SS相关(P0.05)。(2)单纯OP组、胸腰椎OVCFs组失衡亚组人数所占比例分别为29.41%、44.83%,骨量正常组未发现脊柱矢状位失平衡者。(3)胸腰椎OVCFs组的平衡亚组、失衡亚组多节段椎体骨折人数所占比例分别为37.5%、67.31%,骨折椎体分布无统计学差异(P0.05);平衡亚组TK、TLK、SVA、TPA、PT、ODI均小于失衡亚组,LL、SS均大于失衡亚组(P0.05),两组间PI差异无统计学意义(P0.05);平衡亚组SVA与TPA、TK、TLK、LL、PI、PT相关,TPA与TK、TLK、LL、PI、PT、SS相关,TK与TLK、LL、PT、SS相关,TLK与LL、PI、PT相关,LL与PT、SS相关,PT与PI、SS相关(P0.05);失衡亚组TPA与SVA、LL、PI、PT、SS相关,PT与PI、SS相关(P0.05)。结论 :胸腰椎OVCFs患者胸椎后凸、腰椎前凸及骨盆参数间相关性丧失,易发生矢状位失平衡,应积极手术治疗,根据矢状位平衡状况采用不同的手术方法。     

退变性脊柱侧凸患者脊柱-骨盆矢状位特点及各参数间的相关性分析

【摘要】 目的：分析退变性脊柱侧凸患者脊柱-骨盆矢状位平衡情况及各矢状位参数之间的相关性。方法：选取86例退变性脊柱侧凸患者,以侧凸角度的均数作为分组依据,分为轻度侧凸组（Cobb角＜34°）和重度侧凸组（Cobb角≥34°）,选取40例同年龄段健康体检者作为对照组,三组年龄及性别组成相匹配。测量并比较三组的脊柱矢状位参数：胸椎后凸角（TK）、腰椎前凸角（LL）、C7铅垂线与骶骨后上角的水平距离（SVA）,骨盆矢状位参数：骨盆指数（PI）、骶骨倾斜角（SS）、骨盆倾斜角（PT）。采用Pearson相关性检验判断脊柱-骨盆矢状位参数间的相关性。结果：对照组与轻度侧凸组、重度侧凸组之间PI无统计学差异（F=0.915,Ｐ=0.403）。三组之间TK、LL、SVA、PT及SS存在着统计学差异,多重比较检验结果显示：（1）重度侧凸组LL小于轻度侧凸组和对照组,轻度侧凸组小于对照组（Ｐ<0.05）;（2）重度侧凸组和轻度侧凸组TK小于对照组（Ｐ<0.05）,重度侧凸组和轻度侧凸组之间无差异（Ｐ>0.05）;（3）重度侧凸组和轻度侧凸组SVA大于对照组（Ｐ<0.05）,重度侧凸组和轻度侧凸组之间无差异（Ｐ>0.05）;（4）重度侧凸组PT大于轻度侧凸组和对照组,轻度侧凸组大于对照组（Ｐ<0.05）;（5）重度侧凸组SS小于轻度侧凸组和对照组,轻度侧凸组小于对照组（Ｐ<0.05）。相关性分析显示：对照组PI与PT、SS、TK及LL相关,SS与LL相关,TK与LL相关（Ｐ<0.05）;轻度侧凸组PI与PT、SS及LL相关,SS与LL相关,LL与SVA、Cobb角负相关（Ｐ<0.05）;重度侧凸组PI与PT、SS及LL相关,SS与LL相关,SS与Cobb角负相关,LL与SVA、Cobb角负相关（Ｐ<0.05）。结论：退变性脊柱侧凸引起的脊柱-骨盆矢状位参数变化主要为胸椎后凸、腰椎前凸、骶骨倾斜角的减小和SVA、骨盆倾斜角的增大,骨盆指数并无显著性变化。     

正常国人脊柱-骨盆矢状位序列拟合关系研究

目的:建立国人腰椎前凸角(lumbar lordosis,LL)与骨盆矢状位序列间的拟合关系。方法:采用影像学分析,对171例正常青年志愿者进行影像学研究,男94例,女77例,年龄23.0±1.8岁(18~28岁)。均行全脊柱正侧位X线片检查,利用院内影像归档与通信系统测量脊柱与骨盆矢状位参数,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)、LL、胸椎后凸角(thoracic kyphosis,TK)、颈椎前凸角(cervical lordosis,CL)、矢状位平衡(sagittal vertical axis,SVA)。利用Pearson检验进行LL与其他各参数间相关性分析,利用线性回归分析建立LL与其他各参数间线性拟合关系。根据既往研究LL=PI+9,以PI测量值为基础,运用配对样本t检验进行LL预测值与实际测量值间对比。结果:PI为44.6°±9.5°,LL为48.4°±10.8°,SS为34.4°±8.0°,TK为24.2°±9.6°,CL为7.9°±9.6°,SVA为-20.5±30.1mm;LL与PI、SS、TK、CL、SVA呈显著相关(P0.05)。运用多元线性回归分析,LL=2.958+0.760 SS+0.323 TK+0.198 PI+0.122 CL-0.118 SVA;运用简单线性回归分析,LL=0.623 PI+20.611。根据既往文献报道LL=PI+9,以此计算出的LL预测值53.7°±9.5°与实际测量值差异显著(t=7.025,P10-6)。结论:以PI为自变量的简单线性回归LL=0.623 PI+20.611能准确估计个体的LL,在西方人群中得到的LL=PI+9结果并不适用于国人LL的估计。     

中老年人从站立位到坐位的脊柱矢状位序列变化

目的:探究中老年人脊柱矢状位序列从站立位到坐位的变化,比较中老年人与青年人在体位改变时矢状位序列的变化差异。方法:回顾性分析在北京大学第三医院行健康检查的53例中老年人资料[男性17人,女性36人,年龄60.7±9.3(45～81)岁]和145例青年人资料[男性51人,女性94人,年龄23.1±2.3(19～29)岁]。所有人均有站立位和坐位时的全脊柱X线检查结果,通过院内影像归档与通信(PACS)系统,测量骨盆入射角(PI)、骨盆倾斜角(PT)、骶骨倾斜角(SS)、腰椎前凸角(LL)、胸椎后凸角(TK)、脊柱骶骨角(SSA)、腰椎倾斜角(LT)、脊柱矢状轴(SVA)、T1骨盆角(TPA)等参数。采用配对样本t检验比较中老年组站立位-坐位时矢状位序列的不同,通过独立样本t检验比较中老年组与青年组从站立位到坐位时矢状位序列变化。结果:中老年组站立位SVA为3.9±27.7mm,TPA为8.5°±6.9°,PT为12.7°±7.2°,SSA为124.3°±9.0°,LL为47.2°±12.1°,LT为-6.0°±6.9°,TK为33.2°±8.7°,SS为32.8°±8.2°,坐位时SVA为25.9±26.0mm,TPA为18.1°±8.5°,PT为21.1°±9.5°,SSA为113.6°±10.3°,LL为33.8°±12.9°,LT为-4.4°±5.7°,TK为28.5°±9.7°,SS为25.1°±9.2°,除LT外均存在统计学差异(P0.05)。站立位到坐位时,其SVA增加22.0±32.6mm,TPA增加9.6°±6.2°,PT增加8.4°±7.3°,LT增加1.5°±6.2°,LL减小13.4°±8.8°,TK减小4.6°±5.0°,SS减少7.6°±7.2°,SSA减小10.7°±8.1°,变化程度均小于青年组(P0.05)。结论:中老年人从站立位到坐位脊柱-骨盆矢状位形态表现为骨盆后倾,脊柱生理曲度变浅,矢状轴前移,脊柱-骨盆矢状位序列受体位影响变化程度明显小于青年人。     

退变性腰椎侧凸患者矢状面平衡的特点及对腰椎侧凸的影响

目的 :分析退变性腰椎侧凸矢状面平衡参数的特点及其对腰椎侧凸的影响,探讨矢状面平衡参数改变在退变性腰椎侧凸进展中的作用。方法:回顾分析2012年3月～2017年3月经我院诊治的退变性腰椎侧凸患者(病例组)90例,男37例,女53例,年龄51～77岁(57.1±5.8岁)。选取同时期、同年龄段及同性别比的无腰椎侧凸的55例腰椎退行性疾病患者作为照组(对照组),男31例,女24例,年龄50～76岁(56.8±6.1岁)。所有患者均行脊柱全长X线检查,同时填写Oswestry功能障碍指数(Oswestry disability index,ODI)、视觉模拟评分(visual analogue scale/score,VAS)及脊柱侧凸研究学会22项(scoliosis research society-22,SRS-22)量表。测量矢状面平衡相关参数:(1)脊柱参数,脊柱矢状轴(sagittal vertical axias,SVA)、胸椎后凸角(thoracic kypho-sis,TK)、腰椎前凸角(lumbar lordosis,LL)、骶骨倾斜角(sacrum slop,SS);(2)骨盆参数,骨盆入射角(prlbrv in-cidence,PI)、骨盆倾斜角(pelvic tilt,PT);(3)脊柱-骨盆参数,T1骨盆角(T1 pelvic angle,TPA)、L1骨盆角(L1pelvic angle,LPA)。比较两组患者各矢状面平衡参数是否具有统计学差异,分析各矢状面平衡参数与生活质量及腰椎侧凸Cobb角的相关性。结果:两组患者的SVA、TK、PI、PT及TPA差异无统计学意义(P0.05);SS、LL及LPA差异有统计学意义(P0.05)。两组患者ODI、VAS及SRS-22差异有统计学意义(P0.05)。病例组资料相关性分析显示,ODI、VAS及SRS-2与矢状面平衡参数SS、LL及LPA有显著相关性(-1r1,P0.05),与SVA、TK、PI、PT及TPA无显著相关性(P0.05);侧凸Cobb角与LL呈负相关(-1r0,P0.05);与SS及LPA均呈正相关(0r1,P0.05)。进一步回归分析显示,侧凸Cobb角与SS、LL及LPA存在直线回归关系(F=417.331,P0.01),其回归方程为Cobb角=19.526-8.223×LL+3.727×SS+1.618×LPA。结论:退变性腰椎侧凸患者矢状面平衡参数以LL和SS改变为主,表现为LL减小及SS增大并随侧凸的加重而进展,降低了患者的生活质量。     

退变性胸腰椎后凸与陈旧性胸腰椎骨折后凸矢状面代偿模式的比较

目的 :比较退变性胸腰椎后凸(DTK)与陈旧性胸腰椎骨折后凸(PTK)患者矢状面代偿模式的差异。方法:回顾性分析2010年6月~2015年2月在我科门诊或在院接受诊疗的32例DTK患者和28例PTK患者的一般资料,并纳入30例健康成人作为对照组。90例研究对象中男性42例,女性48例,平均年龄47.2岁(30~70岁),DTK组、PTK组和对照组年龄分别为56.0±7.3岁、39.0±8.5岁和45.5±5.5岁。所有研究对象均拍摄立位全脊柱正、侧位X线片。分别测量三组研究对象脊柱矢状位后凸角(KA)、胸椎后凸角(TK)、腰椎前凸角(LL)、骨盆入射角(PI)、骨盆倾斜角(PT)、骶骨倾斜角(SS)及矢状位平衡(SVA),比较三组之间以上脊柱骨盆参数的差异。结果:(1)DTK组和对照组的TK明显大于PTK组(分别为26.5°±5.8°、26.0°±6.3°和23.3°±7.8°,P0.05),而DTK组与对照组比较无显著性差异(P0.05);(2)DTK组的LL、SS(分别为23.1°±12.4°、20.4°±7.7°)均明显小于PTK组(分别为43.4°±7.8°、30.4°±6.6°)和对照组(分别为42.1°±8.5°、31.1°±5.5°)(P0.001),而PTK组的LL、SS与对照组比较无显著性差异(P0.05);DTK组的SVA、PT(分别为62.7±17.5mm、26.1°±11.9°)均明显大于PTK组(分别为16.7±7.1mm、16.7°±8.6°)和对照组(分别为15.8±7.4mm、15.4°±6.6°)(P0.001),而PTK组与对照组的SVA、PT比较无显著性差异(P0.05);(3)DTK组与PTK组的KA(分别为46.7°±12.8°、46.0°±13.8°)无显著性差异(P0.05);DTK组、PTK组和对照组的PI(分别为45.5°±9.7°、46.1°±8.8°、45.1°±8.8°)无显著性差异(P0.05)。结论:退变性胸腰椎后凸患者表现为腰椎前凸减小,骨盆后旋转,并最终出现躯干前倾的矢状面失代偿;陈旧性胸腰椎骨折后凸患者仅表现为TK减小、以骨折椎体为中心的局部后凸,而未发生整体脊柱骨盆参数的代偿。     

青少年特发性脊柱侧凸Lenke1 B、C型患者的胸椎后凸状态对腰骶椎矢状面形态的影响

[目的]探讨青少年特发性脊柱侧凸(adolescent idiopathic scoliosis,AIS)Lenke1B、C患者的胸椎矢状面形态(thoracic kyphsis,TK)对腰骶椎矢状面形态的影响及意义。[方法]86例Lenke1B、C患者(男37例、女49例;平均年龄14.2岁)被纳入本研究,所有患者均摄站立位全脊柱正侧位X线片。根据胸椎后凸(TK)分为两组:A型TK<10°和B型10°≤TK≤40°。统计、测量以下影像学参数:腰椎前凸(LL)、上腰椎前凸、下腰椎前凸、主胸弯Cobb角、矢状面平衡(SVA)、骨盆投射角(PI)、骶骨倾斜角(SS)和骨盆倾斜角(PT)。[结果]A型的LL和上腰椎前凸小于B型的LL和上腰椎前凸(P<0.01)。相关性结果显示TK与LL(r=0.68,P=0.02)、上腰椎前凸(r=0.89,P=0.003)存在线性相关。此外,PT、SS及PI之间也存在线性相关。[结论]AIS Lenke1B、C患者的胸椎矢状面形态对腰椎前凸有明显影响,并通过上腰椎对整个腰椎形态产生影响。因此,对此类型患者在进行选择性胸椎融合时必须考虑这种相互影响,避免术后发生远端失代偿。     

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.     

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.     

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.     

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.