青少年特发性脊柱侧凸主胸弯融合后未融合上胸弯的变化及其与肩部平衡的关系

【摘要】 目的：探讨青少年特发性脊柱侧凸（AIS）患者主胸弯融合后未融合上胸弯的变化及其与肩部平衡的关系。方法：回顾性分析2008年1月~2010年12月在我院接受手术治疗的AIS患者,选取年龄10～18岁,Lenke分型为Lenke 1、2、3、4型,右胸弯且Cobb角＜80°,采用后路椎弓根螺钉系统固定矫形,固定融合上端椎在T4或T4以下,随访时间2年以上的患者,排除翻修手术和截骨手术患者。术前根据Lenke分型判断上胸弯是否为结构性,分成结构性上胸弯组和非结构性上胸弯组,统计比较两组术前、术后3个月和末次随访时外观肩部平衡以及影像学各项参数的变化。结果：共有62例患者纳入本研究,平均年龄14.4岁,随访时间24~62个月,平均36.4个月,其中结构性上胸弯组17例,非结构性上胸弯组45例。两组患者术后上胸弯均能自发性矫正,末次随访时,上胸弯Cobb角平均由27.9°减小至19.4°,T1倾斜角由-0.21°增加至4.7°,第一肋倾斜角（FRT）由0.4°增加至3.7°,锁骨角（CA）由-1.5°增加至0.8°,双肩高度差（CSH）由-13.0mm增加至5.2mm,改变均有统计学意义（P=0.000）。Pearson相关性分析显示,T1倾斜角的改变（术后T1倾斜角-术前T1倾斜角）与CSH变化（术后CSH-术前CSH）有较强相关性（r=0.624,P=0.000）,术后主胸弯的矫正率和FRT与CSH变化为中等程度相关（r=0.437,0.345,P=0.007,0.006）,术前主胸弯Cobb角与CSH变化为弱相关（r=0.262,P=0.040）。上胸弯Cobb角及柔韧性、主胸弯柔韧性、T1倾斜角等参数与CSH变化无统计学相关性。结论：AIS患者结构性与非结构性上胸弯在主胸弯矫正以后均有自发性矫正现象,但T1倾斜角、第一肋倾斜角和双肩高度差均会增加。右胸弯患者左肩被抬高的程度与T1倾斜角增加的程度、主胸弯的矫正率及术后第一肋倾斜角相关。     

含有上胸弯的青少年特发性脊柱侧凸患者的矫形效果分析

目的分析含有上胸弯的特发性脊柱侧凸患者的矫形效果。方法含有上胸弯的特发性脊柱侧凸患者26例,其中双胸弯（PUMCⅡa）13例,三弯13例（PUMCⅢa11例,Ⅲb2例）,分为手术融合范围含上胸弯组（A组,18例）,未含上胸弯组（B组,8例）。根据其临床及影像学资料,对侧凸及双肩平衡的矫形效果进行回顾性分析。结果上胸弯与主胸弯冠状面Cobb角术前A组为45．3°和61．2°,B组为35．6°和58．9°,术后A组为24．2°和20．1°、B组为26．4°和20．3°,A组上胸弯与主胸弯冠状面矫形率为48．2％和68．7％,B组上胸弯自动矫形率与主胸弯冠状面矫形率为24．5％和66．3％,上胸弯矫形率A组明显优于B组,主胸弯矫形率二组问比较差异无统计学意义（P〉0．05）。术后放射学检查双肩高度差〉10mm（双肩不平衡）的发生比例,A组与B组差异有统计学意义（P〈0．05）。术前左肩高或双肩等高的患者术后双肩失平衡的发生率明显高于术前右肩高的患者（P〈0．05）。结论对于含有上胸弯、术前左肩高或双肩等高的特发性脊柱侧凸患者,手术矫形时应考虑融合上胸弯,以获得更好的上胸弯冠状面矫形率,同时避免或减少术后双肩失平衡的发生。     

Lenke 1型青少年特发性脊柱侧凸患者不同上端融合椎对术后双肩平衡的影响

【摘要】 目的：探讨不同上端融合椎对术前双肩水平的Lenke 1型青少年特发性脊柱侧凸（adolescent idiopath?鄄ic scoliosis,AIS）患者术后双肩平衡的影响。方法：选取2006年6月~2009年6月在我院行后路主胸弯融合术并有2年以上完整影像学随访资料的32例Lenke 1型AIS患者。所有患者术前均表现为双肩水平,其中男6例,女26例,手术时年龄13~19岁,平均14.9岁,上胸弯Cobb角平均为23.7°±8.0°（10°~36°）,主胸弯Cobb角平均47.5°±6.9°（40°~62°）。按照上端融合椎不同将AIS患者分为两组：A组,上端融合椎为T3,19例;B组,上端融合椎为T4,13例。A组患者的手术时年龄、Risser征、上胸弯及主胸弯柔韧度与B组比较均无统计学差异（P>0.05）。采用方差分析比较两组患者术前、术后1年和末次随访时的上胸弯及主胸弯Cobb角、顶椎及躯干偏移距离、影像学肩关节高度差（radiographic shoulder height, RSH）、喙突高度差（CPH）和锁骨角（CA）。结果：A组随访时间2~4.5年,平均3.6±1.3年;B组随访时间2~4.8年,平均3.1±2.1年,两组比较无统计学差异（P>0.05）。术前、术后1年和末次随访时,A组患者的上胸弯Cobb角、主胸弯Cobb角、顶椎及躯干偏移距离、RSH、CPH及CA与B组比较均无统计学差异（P>0.05）。A、B两组患者术后1年和末次随访时的上胸弯Cobb角、主胸弯Cobb角、顶椎及躯干偏移距离、RSH、CPH、CA分别与术前比较均有显著性改善（P<0.05）;末次随访时,两组患者的上胸弯Cobb角及RSH、CPH、CA较术后1年均显著减小（P<0.05）,均获得较满意的双肩平衡。结论：对于术前双肩水平的Lenke 1型AIS患者,上端融合椎为T3或T4对重建术后双肩平衡的疗效无明显差别;对此类患者上端融合至T4即可获得良好的矫形效果和满意的双肩平衡。     

电视辅助胸腔镜下脊柱侧凸矫形融合术

目的:探讨电视辅助胸腔镜下脊柱侧凸矫形融合术的操作技术和初期临床结果。方法:回顾性分析我院2003年3月至2004年1月完成的10例胸腔镜下Eclipse矫形融合术病例,特发性脊柱侧凸9例,先天性脊柱侧凸1例,年龄11￣17岁,平均13.3岁。对手术前后及随访时冠状面和矢状面Cobb角进行测量,并对手术时间、术中出血量、围手术期并发症及初步矫形效果进行分析。结果:手术时间平均6.5h,固定融合节段5￣7个(平均6.3个)椎体,每一节段手术时间0.75￣1.70h(平均1.1h),手术总失血量200～600ml(平均360ml)。手术前后主胸弯冠状面Cobb角分别为44.0°和16.4°,手术矫形率63.2%;手术前后腰弯冠状面Cobb角分别为29.0°和12.9°,自动矫形率54.4%。随访6￣24个月,平均14.7月,随访时胸、腰弯冠状面Cobb角分别为20.1°和19.6°,分别丢失3.7°和6.7°。手术前后主胸弯的顶椎偏距分别为28.6mm和9.6mm,腰弯的顶椎偏距分别为14.1mm和8.6mm。手术前后矢状面上胸后凸的Cobb角分别为12.3°和23.9°。结论:电视辅助胸腔镜下脊柱侧凸矫形融合术具有创伤小,出血少和小切口美容效果,对轻中度侧凸可获得良好矫形效果,但矫形容易丢失。     

青少年特发性脊柱侧凸术后肩部外观可塑性与融合策略

【摘要】 目的：本研究旨在探讨青少年特发性脊柱侧凸（adolescent idiopathic scoliosis,AIS）术后肩部外观可塑性,分析基于该现象的胸弯融合上端椎选择策略。方法：对56例Lenke Ⅰ型AIS患者进行回顾性研究,术后随访2～5年。术前Cobb角主胸弯57.65°±12.28°、上胸弯20.34°±9.52°。根据术前肩部平衡、上胸弯柔韧度情况,主胸弯融合上端椎选择方案为：术前右肩抬高非僵硬性上胸弯（柔韧度＞30%）患者10例,选择端椎下位椎（端椎－1）;僵硬性上胸弯（柔韧度≤30%）患者7例,选择端椎。术前双肩平衡非僵硬性上胸弯患者,7例选择端椎上位椎（端椎＋1）,7例选择T3;僵硬性上胸弯患者,5例选择T4,6例选择T3。术前左肩抬高非僵硬性上胸弯患者4例,选择端椎上位椎（端椎＋1）;僵硬性上胸弯患者,1例选择T4,9例选择T3。配对t检验比较术后即刻、末次随访外观肩高（CSD）,评估术后肩部外观可塑性。并对术后肩部平衡进行主观评价,其中患者和家属一方或双方认为肩部外观未恢复平衡,为主观评价不满意。通过分析外观CSD变化,影像学冠状面平衡及T2～T5后凸角,患者及家属主观评价,总结基于肩部外观可塑性的上端椎选择策略。结果：末次随访Cobb角主胸弯19.16°±10.34°、上胸弯11.83°±8.65°,冠状面平衡0.67±0.56cm,T2～T5后凸角17.23°±7.28°。1例患者2年内随访主观评价左肩抬高,其余患者无并发症发生。术前、术后即刻、末次随访时,CSD值：1.04±0.24cm、0.92±0.22cm、0.63±0.16cm;CSD≥1cm患者例数：31例、23例、5例。术后即刻与末次随访CSD存在显著差异（t=7.98,P＜0.001）,最大肩部外观可塑值ΔCSD为1.69cm。随访中肩部恢复平衡的上端椎选择方案：术前右肩抬高非僵硬性上胸弯患者选择端椎－1,右肩抬高僵硬性上胸弯患者选择端椎,双肩平衡非僵硬性上胸弯患者选择端椎＋1或T3,双肩平衡僵硬性上胸弯患者选择T3后,患者末次随访CSD均＜1cm,主观评价满意;术前左肩抬高非僵硬性上胸弯患者选择端椎＋1后1例末次随访CSD为1.06cm,左肩抬高僵硬性上胸弯患者选择T3后1例末次随访CSD为1.02cm,主观评价满意。随访中肩部未恢复平衡的上端椎选择方案：术前双肩平衡僵硬性上胸弯患者选择T4后,2例CSD分别为1.45cm、1.54cm,其中1例随访2年内主观评价左肩抬高;术前左肩高僵硬性上胸弯患者选择T4,1例CSD较大为1.52cm。结论：AIS患者术后肩部外观存在可塑性,基于该特性Lenke Ⅰ型AIS患者胸弯融合上端椎策略为：术前右肩抬高非僵硬性上胸弯患者选择端椎－1,僵硬性上胸弯患者选择端椎;双肩平衡非僵硬性上胸弯患者选择端椎＋1,僵硬性上胸弯患者选择T3;左肩抬高非僵硬性上胸弯患者选择端椎＋1,僵硬性上胸弯患者选择T3。     

不同Risser征的胸弯青少年特发性脊柱侧凸前路矫形术后矢状面重建

 目的 探讨不同Risser征的胸弯青少年特发性脊柱侧凸(adolescent idiopathic scoliosis, AIS）行前路矫形术后胸椎及远端腰椎矢状面的重建模式。
方法 分析2002年6月至2006年11月行胸弯前路矫形内固定术且有2年完整随访资料的L enke 1型AIS患者43例,男3例,女40例;年龄11~18岁,平均（14.1±1.7）岁;胸弯Cobb角39°~ 65°,平均46.0°±7.5°。按照患者Risser征评分分为：A组（Risser 0）、B组（Risser 1～3）和C组（Risser 4～5）。分别测量这三组患者术前及术后历次随访时的胸弯Cobb角、腰弯Cobb角、胸椎后凸角、腰椎前凸角、内固定远端交界性后凸角、胸腰椎交界性后凸及骶骨后上缘与C 7铅垂线的距离。
结果 三组患者均获得随访,随访时间24~60个月,平均27.4个月。末次随访时,A组胸腰椎交界性后凸角为6.6°,较术前的- 1.7°增大8.3°;B组为0.6°,较术前的- 7.3°增大7.9°;C组术后历次随访与术前均无显著性差异。三组患者胸椎后凸角分别为21.2°、18.4°和14.7°,胸椎后凸角历次随访时的变化无统计学差异。三组患者的内固定远端交界性后凸角均表现为前凸丢失,后凸增大。
结论 低Risser征的Lenke 1型AIS患者行前路矫形内固定术后胸椎后凸角及胸腰椎交界性后凸增加,可能与胸椎后份生长后矢状面重建引起的胸腰椎交界区失代偿有关。     

凹侧撑开预矫形技术治疗重度僵硬性脊柱侧凸的早期研究

目的 研究凹侧撑开预矫形技术治疗重度僵硬性特发性脊柱侧凸的早期疗效和安全性。方法 回顾性分析2020年1月至2022年12月山西医科大学第二医院收治并进行手术治疗的重度僵硬性脊柱侧凸的8例病人的临床资料。手术均采用凹侧撑开预矫形后双侧依次上棒二次矫形的手术方法。分别测量术前、术后及末次随访时的影像学参数包括主弯Cobb角、次弯Cobb角、胸椎后凸角（TK）、腰椎前凸角（LL）、主弯顶椎偏距（AVT）、躯干偏移（TS）。结果 病人随访（9.0±6.3）个月（1~16个月）。术前主弯Cobb角：97.4°±10.0°,次弯Cobb角：55.6°±8.4°,TK：50.4°±20.3°,LL：62.7°±6.3°,AVT：（7.64±1.55） cm,TS：（2.00±1.93） cm;术后即刻主弯Cobb角：25.8°±8.1°,次弯Cobb角：21.0°±12.0°,TK：24.9°±9.6°,LL：31.6°±11.9°,AVT：（2.34±1.45） cm,TS：（1.26±0.63） cm;末次随访主弯Cobb角：21.2°±9.1°,次弯Cobb角：22.4°±16.1°,TK：32.8°±12.0°,LL：37.6°±14.0°,AVT：（2.41±0.81） cm,TS：（1.6±1.4） cm。除TS外,上述其他指标术后即刻、末次随访时的数值与术前比较,差异有统计学意义（P＜0.05）,但术后即刻与末次随访时的数值比较,差异无统计学意义（P＞0.05）。1例术后7个月出现迟发性感染,遂进行手术清创以及内固定取出术后再愈合。结论 采用凹侧撑开预矫形治疗重度脊柱侧凸能够获得满意的矫形效果,且出血少,术中及术后神经系统并发症发生率低,是一种安全有效且实用的治疗方法。     

重度僵硬型脊柱侧凸的一期后路Ponte截骨置钉二期后路矫形术

 目的 探讨一期后路Ponte截骨置钉二期后路矫形在治疗重度僵硬型脊柱侧凸中的疗效及安全性。方法 回顾性分析2010年6月至2012年12月接受一期后路Ponte截骨二期后路矫形治疗的Cobb角大于100°的僵硬型脊柱侧凸患者24例,男9例,女15例;年龄14~30岁,平均（21.4±4.1）岁。术前冠状面主弯Cobb角106°~156°,平均125.8°;后凸角59°~141°,平均100.1°。一期后路Ponte截骨松解、置钉,术后Halo-股骨髁上牵引,再行二期后路置棒矫形融合术。比较术前站立位、后路松解牵引后仰卧位、术后及末次随访的冠状面主弯Cobb角。结果 术前仰卧Bending位主弯侧凸柔韧性为14.8%±7.5%;后路松解牵引后主弯侧凸柔韧性为29.1%±9.9%;较术前平均提高14.3%,差异有统计学意义。后路矫形术后主弯Cobb角平均74.4°±14.5°,矫正率平均41.0%±8.1%;与术前仰卧Bending位和松解牵引后比较矫正率分别提高了26.2%和11.9%,差异有统计学意义。术后随访15~36个月,平均（24.0±5.9）个月。末次随访时主弯Cobb角平均丢失1.4°。术后后凸角平均53.0°±13.7°,较术前（100.1°±23.7°）明显改善,矫正率平均46.1%±11.9%,末次随访时无矫正丢失。牵引中1例发生左侧股骨髁上钉道感染,2例发生左下肢静脉血栓。结论 后路Ponte截骨松解+Halo-股骨髁上牵引能够使重度僵硬型脊柱侧凸患者获得满意的矫正率,但应注意下肢静脉血栓形成的风险。     

小切口微创与开放前路矫形内固定术治疗特发性胸腰椎脊柱侧凸的临床疗效比较

目的比较传统开放与保护膈肌的小切口微创前路矫形内固定术治疗胸腰椎脊柱侧凸的临床疗效和并发症。方法系统性回顾分析72例特发性胸腰椎脊柱侧凸患者的临床资料。其中A组34例,行保护膈肌的小切口微创前路矫形内固定术,男3例,女31例,平均年龄16岁(12~25岁),术前Cobb角平均58°(42°~76°),内固定节段T11~L318例,T11~L410例,T11~L26例;B组38例,行传统开放胸腰段前路矫形内固定术,男4例,女34例,平均年龄17岁(13~26岁),术前冠状面Cobb角平均54°(40°~74°),内固定节段T10~L37例,T11~L320例,T11~L411例。结果A组随访12~24个月(平均18个月),术后Cobb角平均12°,纠正率为81%,4例胸腰段后凸畸形术后矢状面恢复形态良好。最终随访冠状面Cobb角平均14°,丢失率4%。出现手术侧下肢皮温升高3例,术后渗出性胸膜炎2例,胸腔积液2例(其中1例行穿刺引流)。B组随访6~22个月(平均13个月)。术后冠状面侧凸术后平均15°,矫正率73%,最终随访Cobb角平均18°,丢失率5%。5例出现手术侧下肢皮温升高,胸腔积液2例。结论保护膈肌的小切口微创胸腰椎脊柱侧凸前路矫形是可行的,在减少手术创伤的同时能够达到与传统入路相似的临床疗效,并发症的发生率无明显增加,具有较大的临床实用价值。     

新型滑槽钉生长棒内固定系统治疗儿童脊柱侧凸的初步报告

 目的 评价新型滑槽钉生长棒内固定系统在儿童脊柱侧凸治疗中的初步临床疗效。 方法 自2009年1月至2011年7月,使用滑槽钉生长棒内固定系统治疗脊柱侧凸患儿10例,男3例,女7例;年龄4～12岁,平均7.8岁。Risser征均为0级。均为特发性脊柱侧凸。单胸弯3例,单胸腰弯或腰弯6例,双胸弯1例。入院时冠状位Cobb角38°~85°,平均66.8°;矢状位Cobb角38°~66°,平均45.5°;坐高36~64 cm,平均48.6 cm。疗效评价指标包括冠状位、矢状位Cobb角及其矫正率、坐高、躯干偏移、双肩高度差、植骨融合情况、矫正丢失率和并发症,重点在身高和发育情况。结果 术后即刻冠状位Cobb角17°~39°,平均28°,矫正率为48%～65%,平均为52%。术后矢状位Cobb角25°~39°,平均31°,坐高46~70 cm,平均56.8 cm。全部病例随访12～44个月,平均26.5个月。随访期间矫正角度丢失率＜ 5%,坐高平均增加2 cm ,3例出现矫形棒尾端皮肤感染,均予以局部换药后痊愈,1例术后出现肩部失平衡,余未出现断钉、断棒等内固定相关并发症。结论 新型滑槽钉生长棒内固定系统治疗儿童脊柱侧凸的初步临床疗效证实该系统的有效性和安全性。     

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.     

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.     

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.