二氮嗪对幼龄大鼠深低温脑缺血再灌注后氧自由基及细胞凋亡的影响

目的 探讨二氮嗪对幼龄大鼠深低温脑缺血再灌注后氧自由基和细胞凋亡的影响及相关的脑保护作用机制.方法 将54只3周龄健康sD大鼠随机分为假手术组、模型组和二氮嗪组,每组18只,建立深低温脑缺血再灌注模型.于术后24 h处死大鼠,检测脑组织超氧化物歧化酶(SOD)、丙二醛的含量,Western Blot法检测脑组织细胞质细胞色素C含量,免疫组化法检测脑组织细胞质Caspase-3含量.结果 模型组脑组织中SOD含量为(198±41)U/mg,低于假手术组的(321±36)U/rag(P<0.01);丙二醛含量为(212±21)nmol/mg,高于假手术组的(100±23)nmol/mg(P<0.01);细胞色素C蛋白表达(0.72±0.09)和Caspase-3蛋白表达(83±10)均高于假手术组(0.17±0.02和115±9)(P<0.01).二氮嗪组脑组织SOD含量为(264±34)U/rag,高于模型组(P<0.05);而丙二醛含量(174±19)nmol/mg、细胞色素C蛋白表达(0.41±0.05)和Caspase-3蛋白表达(99±11)均低于模型组(P<0.05).结论 二氮嗪对幼龄大鼠深低温脑缺血再灌注损伤具有脑保护作用,其机制与抑制氧自由基产生和细胞凋亡有关.     

七氟烷后处理减轻大鼠局灶性脑缺血-再灌注损伤与黄嘌呤氧化酶

目的：探讨七氟烷后处理减轻大鼠局灶性脑缺血-再灌注（I／R）损伤中黄嘌呤氧化酶（xanthine oxidase,XO）含量变化的意义。方法：40只SD大鼠,随机入假手术（Sham）组、缺血-再灌注（I／R）组、七氟烷后处理（PostS）组．IR＋别嘌醇（Adenock A,I／R＋A）组。各10只。大脑中动脉线栓（MCAO）法建立大鼠局灶性脑缺血损伤模型。观察缺血前、再灌注后各组血清XO．超氧化物岐化酶（SOD）活性．丙二醛（MDA）含量及脑组织Na^＋-K^＋-ATP酶（Na^＋-K^＋-ATPase）活性变化。实验结束后,处死大鼠。取脑组织经HE．TTC染色,观察各组脑组织梗死体积。结果：再灌注24h末,Sham组血清XO活性,MDA含量低于其它三组（p〈0．05）。SOD及脑组织Na^＋-K^＋-ATPase活性高于其它三组（p〈0．05）：I／R组与Posts组、I／R＋A组比较．XO活性升高（p〈0．05）,MDA含量增加（p〈0．05）,SOD、Na＋^-K^＋-ATPase活性降低（p〈0．05）;S组SOD、XO以及Na^＋-K^＋-ATPase活性均高于IR＋A组（p〈0．05）．MDA含量低于IR＋A组（p〈0．05）。结论：下调XO活性。可能是七氟烷后处理有效减轻大鼠脑缺血-再灌注损伤重要途径之一。     

异氟醚、七氟醚和地氟醚预处理对脑缺血再灌注损伤大鼠海马CBS/H2S、iNOS/NO和HO-1/CO的影响

目的 研究异氟醚、七氟醚和地氟醚预处理对脑缺血再灌注损伤大鼠海马CBS／H，S、iNOS／NO和HO-1／CO的影响，探讨吸入麻醉药脑保护作用的机制。方法30只Wistar大鼠随机分为5组（n=6）：对照组（C组）、脑缺血再灌注组（I／R组）、异氟醚组（I组）、七氟醚组（S组）和地氟醚组（D组）。采用四动脉阻断法建立大鼠全脑缺血再灌注模型。Ⅰ组、S组和D组夹闭两侧颈总动脉前分别吸入氧气＋0．65MAC的异氟醚、七氟醚和地氟醚30min，C组和I／R组吸入氧气。缺血20min，再灌注12h后处死大鼠，取海马，测定大鼠海马组织中HS、NO、CO、cAMP和cGMP含量和CBS，iNOS和HO活性以及CBS—mRNA、iNOS，mRNA和HO—1-mRNA的表达水平；电镜下观察海马线粒体的变化。结果与C组相比，I／R组海马组织CO、H2S、NO、cAMP、cGMP含量和HO、CBS、iNOS活性升高，CBS—mRNA、iNOS-mRNA和HO-1-mRNA表达升高，海马神经细胞线粒体变性率升高（P〈0．01）；与I／R组相比，Ⅰ组、D组和S组CO含量和HO活性升高，H2S、NO、cAMP含量和CBS、iNOS活性降低，CBS—mRNA和iNOS-mRNA表达降低而HO-1-mRNA表达升高，线粒体变性率降低（P〈0．05或0．01）。结论 异氟醚、七氟醚和地氟醚预处理可通过抑制CBS／142S、iNOS／NO，激活HO-1／CO，减轻了大鼠脑缺血再灌注损伤。     

丙泊酚对大鼠脑缺血-再灌注损伤后海马线粒体ATP含量和ATP酶活性的影响

目的观察丙泊酚对大鼠脑缺血-再灌注损伤后海马线粒体三磷酸腺苷（ATP）含量、ATP酶活性、脂质过氧化和超微结构的影响.方法采用大鼠全脑缺血-再灌注损伤模型.40只Wistar大鼠随机分为假手术组（A组）、缺血-再灌注对照组（B组）和缺血-再灌注丙泊酚预处理组,后者按丙泊酚用量又分为50 mg/kg（C1组）、100 mg/kg（C2组）和150 mg/kg（C3组）三个亚组.观察全脑缺血10 min再灌注60 min时海马线粒体的超微结构、ATP和丙二醛（MDA）的含量及Na^＋-K^＋-ATP酶、Ca^2＋-ATP酶、超氧化物歧化酶（SOD）和谷光甘肽（GSH）活性的变化.结果与B组比较,丙泊酚各处理组海马线粒体的ATP含量、Na^＋-K^＋-ATP酶、Ca^2＋-ATP酶、SOD和GSH的活性均有不同程度的增高（P〈0.05或0.01）,MDA含量有不同程度的降低（P〈0.05或0.01）,线粒体超微结构的损伤程度亦明显减轻.结论丙泊酚对脑缺血-再灌注损伤的保护效应可能与其抑制线粒体脂质过氧化反应,减轻线粒体的损伤,促进线粒体ATP含量和ATP酶活性的恢复有关.     

缺血-再灌注损伤对扩张皮瓣转移术后的影响

目的：探讨缺血-再灌注损伤对扩张皮瓣转移术后的影响。方法：以实验兔每侧腹壁浅动脉为中线,于两侧腹部植入50ml软组织扩张器各一只,术后定期注水扩张至80ml为止。分别于扩张皮瓣转移前、转移后1h、24h、72h检测腹壁浅动脉血流速度,切取皮瓣远端组织在200倍光镜下进行白细胞计数,检测皮瓣组织中丙二醛（MDA）、髓过氧化物酶（MPO）含量。结果：扩张皮瓣转移前腹壁浅动脉的血流速度为（13.2±0.78）cm/s,光镜下白细胞计数为（8.33±2.61）个,皮瓣组织内MDA含量为（1.72±0.57）nmol/mgprot,MPO含量为（126.50±20.70）U/g。皮瓣转移术后1h血流速度为（6.22±0.93）cm/s,白细胞计数为（19.08±4.94）个,MDA含量为（4.05±0.67）nmol/mgprot,MPO含量为（349.42±27.27）U/g。皮瓣转移术后24h血流速度为（8.37±0.56）cm/s,白细胞计数为（60.17±6.24）个,MDA含量为（6.68±0.73）nmol/mgprot,MPO含量为（558.08±26.99）U/g。皮瓣转移术后72h血流速度为（17.36±1.06）cm/s,白细胞计数为（34.00±3.79）个,MDA含量为（2.51±0.41）nmol/mgprot,MPO含量为（215.92±25.97）U/g。结论：在扩张皮瓣转移术后发生缺血-再灌注的过程中,皮瓣组织发生再灌注损伤。     

去铁酮对糖尿病大鼠肾小管间质的抗氧化作用

目的：研究去铁酮对糖尿病大鼠肾小管间质损伤的干预作用。方法：48只wistar雄性大鼠按随机数字表法分为4组。正常组（10只）普通饲料喂养6周后,腹腔注射柠檬酸缓冲液（40mg／kg）,余38只大鼠高糖高脂饲料喂养6周后,腹腔注射链脲佐菌素（STZ）（40mg／kg）建立糖尿病模型。药物干预组分别给予50mg／kg,100mg／kg去铁酮溶液每日1次灌胃,共8用。糖尿病对照组造模后无药物干预。药物干预8周后测定24h尿总蛋白;取血测定血清铁和铁蛋白;取肾脏做病理检查,并测定肾脏组织丙二醛（MDA）、总超氧化物歧化酶（TSOD）含量。对TGF—β1、NF—κB进行免疫组化分析。结果：（1）50mg去铁酮干预组和100mg去铁酮干预组MDA分别为（32．44±10．83）nmol／mgprot和（62．48,4±18．46）nmol／mgprot、均低于糖尿痛组含量（81．7±23．54）nmol／mgprot;TSOD含量50mg和100mg去铁酮干预组分别为（146．724±14．61）nmol／mgprot和（253．5±85．39）nmol／mgprot,均高于糖尿病组（114．67±16．48）nmol／mgplot,差异均有统计学意义（P＜0。0001）。（2）尿总蛋白两两比较50mg干预组和100mg干预组的水平无差别,其余组间比较差异均有统计学意义（P＜0．0001）。（3）HE染色糖尿病组和去铁酮干预组肾小管间质存在病理损害,电镜结果显示药物干预组病理改变较糖尿痛对照组明显减轻。（4）四组免疫组化TGF—B水平不相同（P＜0．0001）。对TSOD和TGF—B,应用spearman相关分析提示有显著的负相关关系（r=-0．76166,P＜0．0001）。结论：去铁酮通过干预氧化应激反应来减少TGF—B1、NF—KB的表达以减轻糖尿病大鼠肾小管损伤。     

线粒体钙单向转运体对大鼠脑缺血/再灌注损伤中线粒体能量代谢的影响

目的 探讨线粒体钙单向转运体(mitochondrial calcium uniporter,MCU)活动在大鼠脑缺血/再灌注损伤(ischemia/reperfusion injury,I/RI)中对能量代谢的影响. 方法 52只雄性Wistar大鼠按照完全随机法分为对照组(sham)、脑缺血/再灌注(ischemia/reperfusion,I/R)组、脑缺血/再灌注复合钌红(ischemia/reperfusion +ruthenium red,I/R+RR)组、脑缺血/再灌注复合精胺(ischemia/reperfusion+ spermine,I/R+Sper)组,线栓法建立大鼠大脑中动脉闭塞模型,缺血2h,再灌注24 h后检测脑梗死面积百分比,线粒体呼吸链酶复合体Ⅰ～Ⅳ活性、线粒体膜电位(mitochondrial membrane potential,△Ψm)、组织中三磷酸腺苷(adenosine triphosphate,ATP)含量和活性氧(reactive oxygen species,ROS)的含量. 结果 I/R组、I/R+RR组及I/R+Sper组的粒体呼吸链酶复合体Ⅰ～Ⅳ的活性(17.67±0.21)、(6.17±0.42)、(22.29± 1.40)、(31.73±0.84) nmol·mina·mg-1,△Ψm和组织中ATP的含量(5.2±60.19)nmol/mg protein均低于sham组(P＜0.01),而这3组的脑梗死面积百分比(35.43±0.74)％和ROS含量(1 455.21±39.52) U/mg protein高于对照组(P＜0.01).钌红能够改善上述指标:与I/R组比较,I/R+RR组中的钌红能够明显提高线粒体呼吸链酶复合体的活性(22.1±70.55)、(7.50±0.15)、(36.92±2,13)、(49.32 ± 1.33) nmol· min-1· mg-1,△ Ψm和组织中ATP的含量(7.85 ±0.17) nmol/mg protein(P＜0.01),明显缩小梗死面积(26.00 ±1.71)％,降低ROS的含量(1 262.53±29.92) U/mg protein (P＜0.01);而I/R+Sper组中的能量代谢指标则均较脑I/R组差. 结论 抑制MCU的活动可以明显改善I/RI中线粒体的能量代谢.     

胱硫醚β-合酶/硫化氢和血红素氧合酶-1/一氧化碳体系在大鼠脑缺血再灌注损伤中的作用

目的 研究胱硫醚β-合酶（CBS）／硫化氢（H2S）体系和血红素氧合酶-1（HO-1）／一氧化碳（CO）体系在大鼠脑缺血再灌注损伤中的作用。方法 30只Wistar大鼠随机分为5组（n=6）：对照组（C组）、脑缺血再灌注组（I／R组）、脑缺血再灌注＋锌原卟啉（HO-1抑制剂）组（I／R＋Z组）、脑缺血再灌注＋羟氨（CBS抑制剂）组（I／R＋H组）、脑缺血再灌注＋锌原卟啉＋羟氨组（I／R＋Z＋H组）。采用四血管阻断法建立全脑缺血再灌注损伤模型，I／R＋Z组、I／R＋H组和I／R＋Z＋H组夹闭两侧颈总动脉前30min分别腹腔注射锌原卟啉45／zmol／kg、羟氨5mmol／L、羟氨5mmol／L＋锌原卟啉45／maol／kg1ml，C、I／R组给予等量生理盐水。再灌注6h时处死大鼠，取海马，测定海马组织H2S、CO、还原型谷胱甘肽（GSH）、丙二醛（MDA）、超氧化物歧化酶（SOD）水平及CBSmRNA和HO-1mRNA的表达；电镜下观察海马线粒体变性情况。结果 与C组比较，I／R组海马组织CO、H2S、CBSmRNA和HO-1mRNA、MDA水平及线粒体变性率均升高，海马组织SOD、GSH水平降低（P〈0．01）；与I／R组比较，I／R＋Z组海马组织CO、HO-1mRNA水平降低，海马组织H2S、CBSmRNA、GSH、MDA水平升高，I／R＋H组海马组织CO、HO-1mRNA、MDA水平升高，H2S、CBSmRNA、GSH水平降低；I／R＋Z＋H组海马组织CO、RS、HO-1mRNA和CBSmRNA、SOD、GSH水平降低，线粒体变性率升高（P〈0．05）。结论 CBS／H1S体系和HO-1／CO体系可拮抗大鼠脑缺血再灌注损伤，其作用可相互代偿。     

全反式维甲酸在肠道缺血再灌注中的抗氧化作用

目的 探讨全反式维甲酸（ATRA）在肠道缺血再灌注中的抗氧化作用。方法根据随机数字表法将32只雄性SD大鼠分为假手术组、阻断组、DMSO组和ATRA组,每组8只。采用血管钳钳夹肠系膜上动脉60min后,使血液复流120rain的方法制备大鼠肠道缺血再灌注损伤模型。假手术组仅分离肠系膜上动脉不钳夹。ATRA组大鼠术前5d以15μg／gATRA每日灌胃1次,开腹前6h再予ATRA处理1次;DMSO组则在相同时间点给予等量的DMSO液灌胃处理;应用高效液相色谱法检测大鼠术前5h的血浆ATRA浓度。HE染色观察回肠黏膜病理形态学改变,对肠黏膜组织行Chiu氏评分;比色法测定血清二胺氧化酶（DAO）水平、回肠组织丙二醛（MDA）含量以及超氧化物歧化酶（SOD）活性;Westernblot检测回肠组织中锰超氧化物歧化酶（MnSOD）的蛋白表达量。组问比较采用单因素方差分析,两两比较采用LSD—t检验。结果ATRA组大鼠血浆ATRA浓度为（827±276）μg/L,高于假手术组、阻断组和DMSO组的（48±12）μg/L、（55±15）μg／L和（63±20）μg／L（t=11．242,11．138,11．013,P〈0．05）。假手术组大鼠回肠黏膜形态正常;阻断组和DMSO组大鼠回肠黏膜结构破坏严重;ATRA组大鼠回肠黏膜损伤程度明显减轻。阻断组、DMSO组和ATRA组大鼠回肠黏膜Chiu氏评分分别为（3．83±0．77）分、（3．92±0．87）分和（2．42±0．75）分,显著高于假手术组的（O．37±0．28）分（t=9．803,10．040,5．793,P〈0．05）,而ATRA组评分明显低于阻断组和DMSO组（t=4．009,4．247,P〈0．05）。阻断组、DMSO组和ATRA组大鼠血清DAO水平分别为（26．3±4．4）U／L、（25．1±4．3）U／L、（20．8±3．8）U／L,均显著高于假手术组的（14．2±1．9）U／L（t=6．493,5．835,3．534,P〈0．05）;但与阻断组及DMSO组比较,ATRA组血清DAO水平明显降低（t=2．959,2．301,P〈0．05）。阻断组、DMSO组和ATRA组大鼠回肠组织中MDA含量分别为（16．9±4．0）μmol／g、（16．0±3．5）μmol／g、（11．3±3．1）μmol／g,明显高于假手术组的（5．4±1．0）μmol／g（t=7．397,6．821,3．821,P〈0．05）;ATRA组显著低于阻断组和DMSO组（t=3．575,3．000,P〈0．05）。阻断组、DMSO组和ATRA组大鼠回肠组织的SOD活性分别为（108±22）U／mg、（98±19）U／rag和（181±38）U／mg,明显低于假手术组的（243±37）U／mg（t=8．939,9．647,4．106,P〈0．05）;ATRA组明显高于阻断组及DMSO组（t=4．833,5．541,P〈0．05）。阻断组和DMSO组大鼠回肠组织中MnSOD的蛋白相对表达量分别为0．36±0．08、0．28±0．07,显著低于假手术组的0．93±0．13（t=8．972,10．101,P〈0．05）;ATRA组为0．80±0．19,明显高于阻断组和DMSO组（t=6．948,8．077,P〈0．05）,但与假手术组比较,差异无统计学意义（t=2．024,P〉0．05）。结论ATRA预处理可以促进氧自由基清除剂MnSOD的表达,增加组织的抗氧化能力,对大鼠肠道缺血再灌注损伤具有保护作用。     

乳化异氟烷对兔心肌缺血再灌注损伤的保护作用

背景比较乳化异氟烷和吸入异氟烷的心肌保护效应。方法给32只兔进行临时结扎左冠状动脉前降支30分钟以造成心肌缺血,然后再灌注3小时。在结扎左前降支前,随机将兔分为4组（每组8只）：c组,无缺血前预处理措施;IS组：吸入呼气末浓度为1．1％异氟烷;EI组：持续泵注8％乳化异氟烷以达到呼气末浓度为0．64％;IN组：持续泵注30％脂肪乳。在缺血前30分钟进行预处理,异氟烷组随后还有15分钟的洗脱时间。再灌注3小时后取标本测定心肌梗死面积、乳酸脱氢酶和肌酸激酶活性及线粒体超微结构。结果IS组和EI组在再灌注3小时后心肌梗死面积明显低于C组和Ⅲ组（20％±8％,18％±8％,39％±6％和34％±9％,P〈0．01）。IS组和EI组的心肌梗死面积无差异,C组和IN组的心肌梗死面积亦无差异。心肌再灌注3小时后IS组和EI组血浆乳酸脱氢酶（456±58U／L,451±54U／L）和肌酸激酶活性（1725±230U／L,1686±444U／L）明显低于C组（676±82U／L,2373±529U／L;P〈0．01）。IS组和EI组心肌线粒体超微结构改变比对照组减轻。结论静脉注射乳化异氟烷对兔心肌缺血再灌注有保护作用,其效应与吸入异氟烷相似。     

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.     

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.     

The analgesic effect of racemic ketamine in patients with chronic ischemic pain due to lower extremity arteriosclerosis obliterans

Background : Ketamine in sub-dissociative doses has been shown to have analgesic and phantom-Limb pain, where conventional treatment has often failed. Chronic ischemic pain due to lower extremity arteriosclerosis obliterans often responds poorly to analgesics, and the pain-generating mechanisms are not well understood.
Methods : Eight patients with rest pain in the lower extremity due to arteriosclerosis obliterans were given sub-dissociative doses of 0.15, 0.30, or 0.45 mg/kg racemic ketamine and morphine 10 mg as a 5-min infusion on four separate days in a cross-over, double-blind, randomised protocol. Plasma levels of (S)- and (R)-ketamine and their nor-metabolites were analysed with an enantioselective high-performance liquid chromatography (HPLC) method. Pain levels were evaluated with a visual analogue scale (VAS).
Results : Individual pain levels were highly variable during and after all the infusions but the pooled pain levels showed a dose-dependent analgesic effect of ketamine with a transient but complete pain relief in all patients at the highest dose (0.45 mg/ kg). Side-effects, mainly disturbed cognition and perception, were pronounced and dose-dependent. Morphine 10 mg had an analgesic peak at 20 min and 5/8 patients had complete pain relief. The remaining 3 patients also had high baseline pain scores, indicating a higher analgesic potency for the 0.30 and 0.45 mg/ kg ketamine doses than for morphine 10 mg.
Conclusion : We have demonstrated a potent dose-dependent analgesic effect of racemic ketamine in clinical ischemic pain. Due to a narrow therapeutic window, this analgesic effect is probably best utilised in combination with other analgesics.     

Intravenous endotoxin does not increase tissue extravasation of albumin in rats

Background : It is unclear whether activation of the inducible nitric oxide synthase (iNOS) increases or decreases the extravasation of plasma.
Methods : Chloralose anaesthetised male Wistar rats received E. coli lipopolysacharide (LPS), 3 mg kg^-1 i.v., or the corresponding volume of saline, 3 or 5 h before the end of the experiment. Mean arterial pressure (MAP) and heart rate (HR) were recorded. Tissue clearance of radio-labelled albumin, during the last 2 h of each experiment, was determined by a double-isotope method. In separate animals, the serum concentration of nitrite and nitrate was determined, 5 h after LPS or the solvent.
Main Results : LPS initially decreased MAP and lastingly increased HR. In the 3-h LPS animals (n=8), tissue plasma clearance was lower in the heart and calf muscle and increased only in diaphragm, compared to corresponding control animals (n=8). In the 5-h LPS rats, clearance was lowered (n=8) in the entire gastrointestinal tract and in testes, compared to controls (n=8). The serum nitrite/nitrate concentration was higher in animals given LPS (n=6) than in controls (n=6).
Conclusion : After LPS, tissue clearance of albumin was not increased in any major tissue, in spite of increased serum levels of NO end products. Apparently, after activation of iNOS, the augmented release of NO is not necessarily associated with increased albumin extravasation.     

Adrenaline markedly improves thoracic epidural analgesia produced by a low-dose infusion of bupivacaine, fentanyl and adrenaline after major surgery: A randomised, double-blind, cross-over study with and without adrenaline

Background: Basic pharmacological research indicates that there are synergistic antinociceptive effects at the spinal cord level between adrenaline, fentanyl and bupivacaine. Our clinical experience with such a mixture in a thoracic epidural infusion after major surgery confirms this. The objectives of the present study were to evaluate the effects on postoperative pain intensity, pain relief and side effects when removing adrenaline from this triple epidural mixture. Methods: A prospective, randomised, double-blind, cross-over study was carried out in 24 patients after major thoracic or abdominal surgery. Patients with only mild pain when coughing during a titrated thoracic epidural infusion of about 10 ml · h^?1 of bupivacaine 1 mg · ml^?1, fentanyl 2 μg · ml^?1, and adrenaline 2 μg · ml^?1 were included. On the 1^st and 2^nd postoperative days each patient was given a double-blind epidural infusion, at the same rate, with or without adrenaline. The effect was observed for 4 h or until pain when coughing became unacceptable in spite of a rescue analgesic procedure. Rescue analgesia consisted of up to two epidural bolus injections per hour and i.v. morphine if necessary. All patients received rectal paracetamol 1 g, every 8 h. Fentanyl serum concentrations were measured with a radioimmunoassay technique at the start and end of each study period. Main outcome measures were extent of sensory blockade and pain intensity at rest and when coughing, evaluated by a visual analogue scale, a verbal categorical rating scale, the Prince Henry Hospital pain score, and an overall quality of pain relief score. Results: The number of hypaesthetic dermatomal segments decreased (P <0.001) and pain intensity at rest and when coughing increased (P <0.001) when adrenaline was omitted from the triple epidural mixture. This change started within the first hour after removing adrenaline. After 3 h pain intensity when coughing had increased to unacceptable levels in spite of rescue analgesia (epidural bolus injections and i.v. morphine). Within 15–20 min after restarting the triple epidural mixture with adrenaline, pain intensity was again reduced to mild pain when coughing. Serum concentration of fentanyl doubled from 0.22 to 0.45 ng · ml^?1 (P <0.01), and there was more sedation during the period without adrenaline. Conclusions: Adrenaline increases sensory block and improves the pain-relieving effect of a mixture of bupivacaine and fentanyl infused epidurally at a thoracic level after major thoracic or abdominal surgery. Serum fentanyl concentrations doubled and sedation increased when adrenaline was removed from the epidural infusion, indicating more rapid vascular absorption and systemic effects of fentanyl.     

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.     

Utilisation des médicaments prokinétiques en réanimation : indications et limites ?

Enteral feeding is often limited by gastric and intestinal motility disturbances in critically ill patients, particularly in patients with shock. So, promotility agents are frequently used to improve tolerance to enteral nutrition. This review summaries the pathophysiology, presents the available pharmacological strategies, the clinical data, the counter-indications and the principal limits. The clinical data are poor. No study demonstrates a positive effect on clinical outcomes. Metoclopramide and erythromycin seems to be the more effective. Considering the risk of antibiotic resistance, the first line use of erythromycin should be avoided in favor of metoclopramide.     

Anesthésie générale chez l’enfant : quid des pratiques en 2010 ?

Introduction

The practice of pediatric anesthesia requires a regular update of scientific knowledge and technical skills. To provide the most adequate Continuing Medical Education programs, it is necessary to assess the practices of pediatric anesthesiologists. Thus, the objective of this survey was to draw a picture of the current clinical practices of general anesthesia in children, in France.

Material and methods

One thousand one hundred and fifty questionnaires were given to anesthesiologists involved in pediatric cases. These questionnaires collected information on various aspects of clinical practice relative to induction, maintenance, recovery from general anaesthesia and also classical debated points such as children with Upper Respiratory Infection (URI), emergence agitation, epileptoid signs or anaesthetic management of adenoidectomy. Differences in practices between CHG (general hospital), CHU (teaching hospital), LIBERAL (private) and PSPH (semi-private) hospitals were investigated.

Results

There were 1025 questionnaires completed. Fifty-five percent of responders worked in public hospitals (CHG and CHU); 77% had a practice that was 25% or less of pediatric cases. In children from 3 to 10 years: 72% of respondents used always premedication and two thirds performed inhalation induction in more than 50% of cases. For induction, 53% used sevoflurane (SEVO) at 7 or 8%. Respondents from LIBERAL used higher SEVO concentrations. Tracheal intubation was performed with SEVO alone (37%), SEVO and propofol (55%) and SEVO with myorelaxant (8%), 93% of respondents used a bolus of opioid. For maintenance, the majority of respondents used SEVO associated with sufentanil; desflurane and remifentanil were more frequently used in CHU. Two thirds of respondents used N₂O. Depth of anesthesia was commonly assessed by hemodynamic changes (52%), end tidal concentration of halogenated (38%) or automated devices based on EEG (7%). In children with URI, 98% of respondents used SEVO for anesthesia. To control the airway 42% used a tracheal tube, 30% a laryngeal mask and 20% a facial mask. Emergence agitation was an important concern for two thirds of respondents, while epileptoid signs were considered as important by only 20%. Eighty-nine percent of respondents practiced anesthesia for adenoidectomy. Anesthesia was induced by inhalation of SEVO 7–8% (41%), 6% (39%) or 4% (12%), 66% put an intravenous line (less frequently in LIBERAL). 67% of the responders managed adenoidectomy without any device to control the airway (more frequently in LIBERAL), 32% administrated a bolus of opioid (less frequently in LIBERAL).

Discussion

This survey demonstrated that the practices regarding general anesthesia in children are relatively homogenous. Most of the differences appeared between LIBERAL and the others structures; the anaesthetic management for adenoidectomy illustrates these findings.     

Intérêt d’une rééducation précoce pour les patients neurologiques

Rehabilitation improves the functional prognosis of patients after a neurologic lesion, and tendency is to begin rehabilitation as soon as possible. This review focuses on the interest and the feasibility of very early rehabilitation, initiated from critical care units. It is necessary to precisely assess patients’ impairments and disabilities in order to define rehabilitation objectives. Valid and simple tools must support this evaluation. Rehabilitation will be directed to preventing decubitus complications and active rehabilitation. The sooner rehabilitation is started; the better functional prognosis seems to be.