瑞马唑仑用于经皮穿刺椎体后凸成形术患者围术期镇静的效果

目的 探讨瑞马唑仑应用于经皮穿刺椎体后凸成形术（PKP）患者围术期镇静的效果。
方法 选择行PKP患者80例,男39例,女41例,年龄60～80岁,BMI 18～24 kg/m²,ASA Ⅱ或Ⅲ级。采用随机数字表法将患者分为两组：瑞马唑仑组（RM组）和右美托咪定组（DM组）,每组40例。两组依次缓慢静脉注射氟比洛芬酯1 mg/kg、舒芬太尼0.2 μg/kg后,RM组静脉输注瑞马唑仑0.2 mg/kg,DM组静脉输注右美托咪定0.3 μg/kg,输注时间均为10 min,待两组Ramsay评分为3分时,调整药物的输注速度持续镇静（RM组：0.3～0.5 mg·kg^-1·h^-1;DM组：0.20～0.75 μg·kg^-1·h^-1）,术中镇静深度保持Ramsay评分为3～5分,BIS 60～80。记录镇静用药前（T₀）、局麻开始时（T₁）、骨水泥注入时（T₂）、苏醒时（T₃）及苏醒后30 min（T₄）的Ramsay评分和BIS。记录镇静起效时间、苏醒时间和术中知晓的发生情况。
结果 与T₀时比较,T₁、T₂时RM组Ramsay评分及BIS均明显降低（P<0.05）,T₁、T₄时DM组Ramsay评分及BIS均明显降低（P<0.05）。与DM组比较,T₃、T₄时RM组Ramsay评分明显降低、BIS明显升高（P<0.05）,RM组镇静起效时间和苏醒时间均明显缩短（P<0.05）,RM组术中知晓发生率明显降低（P<0.05）。
结论 瑞马唑仑或右美托咪定用于PKP患者,术中均能获得良好的镇静效果且对患者呼吸及循环功能影响较小。与使用右美托咪定的患者比较,使用瑞马唑仑的患者镇静起效时间和苏醒时间明显缩短、术中知晓发生率明显降低,术后苏醒质量明显提升。     

右美托咪定滴鼻联合髂筋膜间隙阻滞在老年髋部骨折患者围术期的应用效果

目的 探讨右美托咪定滴鼻联合髂筋膜间隙阻滞在老年髋部骨折患者围术期的应用效果。
方法 选择择期行腰-硬联合麻醉下髋部骨折手术的老年患者59例,男14例,女45例,年龄≥65岁,BMI 14.1～30.3 kg/m²,ASA Ⅱ或Ⅲ级。采用随机数字表法将患者分为两组：右美托咪定滴鼻联合髂筋膜间隙阻滞组（D组,n=29）和髂筋膜间隙阻滞组（F组,n=30）。术前1 d晚间D组给予右美托咪定滴鼻后在超声引导下行患侧髂筋膜间隙阻滞,F组仅在超声引导下行患侧髂筋膜间隙阻滞。记录右美托咪定滴鼻前（T₁）、髂筋膜间隙阻滞后1 h（T₂）、过转运床即刻（T₃）、过手术床即刻（T₄）、摆体位时（T₅）的HR、MAP、SpO₂和疼痛数字评价量表（NRS）评分。记录术前1 d、手术当日及术后1、2 d的汉密尔顿焦虑（HAM-A）评分和里兹睡眠问卷（LSEQ）评分。记录术后7 d内谵妄发生情况及术后住院时间。记录低血压、心动过缓以及术后48 h内恶心呕吐、头晕、日间嗜睡等不良反应的发生情况。
结果 与T₁时比较,T₃—T₅时F组HR明显增快,MAP明显升高,D组NRS明显降低（P<0.05）;与F组比较,T₃—T₅时D组HR明显减慢,MAP和NRS明显降低（P<0.05）。与术前1 d比较,手术当日及术后1、2 d D组HAM-A评分明显降低,LSEQ评分明显增高,F组LSEQ评分明显增高（P<0.05）。与F组比较,手术当日及术后1、2 d D组LSEQ评分明显增高,HAM-A评分明显降低（P<0.05）。与F组比较,D组术后住院时间明显缩短,术后7 d谵妄总发生率明显降低,日间嗜睡发生率明显降低（P<0.05）。
结论 老年髋部骨折手术患者术前右美托咪定滴鼻联合髂筋膜间隙阻滞可使术前血流动力学更加稳定,同时减轻术前疼痛,降低焦虑及术后谵妄发生率,提高围术期睡眠质量,缩短术后住院时间。     

预注不同负荷剂量右美托咪定在腹腔镜胆囊切除术中的应用

目的 比较麻醉诱导前预注不同负荷剂量右美托咪定在腹腔镜胆囊切除术中的应用效果。
方法 选择2019年12月至2020年12月择期全麻下行腹腔镜胆囊切除术的患者120例,男52例,女68例,年龄18～64岁,BMI 20～35 kg/m²,ASA Ⅰ或Ⅱ级。采用随机数字表法将患者分为四组：生理盐水组（C组）、右美托咪定0.5 μg/kg组（L组）、右美托咪定0.75 μg/kg组（M组）和右美托咪定1.0 μg/kg组（H组）,每组30例。C组麻醉诱导前10 min恒速静脉泵注生理盐水0.5 ml/kg,L组、M组和H组麻醉诱导前10 min分别恒速静脉泵注右美托咪定0.5、0.75和1.0 μg/kg。所有患者为全凭静脉麻醉,麻醉用药相同。记录输注生理盐水/右美托咪定前即刻（T₁）、麻醉诱导前即刻（T₂）、气管插管后即刻（T₃）、手术切皮即刻（T₄）、气腹开始即刻（T₅）、气腹后10 min（T₆）、缝合完毕即刻（T₇）、气管拔管后即刻（T₈）的HR和MAP。记录术中丙泊酚、瑞芬太尼用量、阿托品使用例数、苏醒时间、拔管时间、术后1、4 h咳嗽时VAS疼痛评分。记录苏醒期躁动、术后心动过缓、术后低血压、术后48 h内恶心呕吐等不良反应发生情况。
结果 与C组比较,L组、M组和H组T₂—T₈时HR明显减慢（P<0.05）,T₃—T₈时MAP明显降低（P<0.05）,术中丙泊酚和瑞芬太尼用量明显减少（P<0.05）,术后1、4 h咳嗽时VAS疼痛评分明显降低（P<0.05）,苏醒期躁动、术后恶心呕吐发生率明显降低（P<0.05）;M组苏醒时间、拔管时间明显缩短（P<0.05）;H组阿托品使用率明显升高（P<0.05）,苏醒时间、拔管时间明显延长（P<0.05）,术后心动过缓和低血压发生率明显升高（P<0.05）。与L组比较,H组T₂—T₆时HR明显减慢（P<0.05）,M组和H组术后1、4 h咳嗽时VAS疼痛评分明显降低（P<0.05）。
结论 腹腔镜胆囊切除术全麻诱导前预注右美托咪定0.75 μg/kg可以有效维持围术期血流动力学稳定,减少麻醉药物用量,缩短苏醒时间,减少术后并发症,有利于患者术后恢复。     

右美托咪定对肺癌根治术患者单肺通气相关肺损伤的影响

目的 评价右美托咪定对肺癌根治术患者单肺通气（OLV）相关肺损伤的影响。
方法 选择择期行肺癌根治手术的患者40例,男30例,女10例,年龄42～70岁,ASA Ⅰ或Ⅱ级,且术中OLV超过2 h。采用随机数字表法将患者分为两组：右美托咪定组（D组）和对照组（C组）,每组20例。麻醉诱导后,D组给予右美托咪定初始剂量0.5 μg/kg,给药时间大于10 min,继之以0.5 μg·kg^-1·h^-1的速度维持至手术结束前30 min,C组给予等容量的生理盐水。分别于给药前即刻、OLV 60、90和120 min、恢复双肺通气30 min时采集桡动脉血,测定血清肿瘤坏死因子-α（TNF-α）、白细胞介素-8 （IL-8）浓度,并进行血气分析,计算氧合指数（OI）和动态肺顺应性（Cdyn）;免疫组织化学法观察OLV前即刻、肺叶离体时肺组织肺水通道蛋白5（AQP5）的染色程度,计算免疫组织化学评分。
结果 与给药前即刻比较,OLV 60、90和120 min、恢复双肺通气30 min时两组血清TNF-α、IL-8浓度明显升高（P<0.05）,OI和Cdyn明显降低（P<0.05）。OLV 60、90和120 min、恢复双肺通气30 min时D组血清TNF-α、IL-8浓度明显低于C组（P<0.05）,OI明显高于C组（P<0.05）。OLV 90、120 min时D组Cdyn明显高于C组（P<0.05）。肺叶离体时D组AQP5蛋白染色程度明显深于C组,AQP5蛋白免疫组织化学评分明显高于C组（P<0.05）。
结论 右美托咪定降低血清TNF-α、IL-8 浓度,促使AQP5 在肺组织中表达的增强,减轻肺癌根治术患者单肺通气期间的肺损伤,改善肺功能。     

艾司氯胺酮与右美托咪定在中老年患者全髋关节置换术中的比较

目的 比较艾司氯胺酮与右美托咪定在中老年患者全髋关节置换术中的应用效果。
方法 选择择期行单侧全髋关节置换术的中老年患者60例,男17例,女43例,年龄60～80岁,BMI 18～28 kg/m²,ASA Ⅱ或Ⅲ级。将患者随机分为两组：右美托咪定组（D组,n=30）和艾司氯胺酮组（S组,n=30）。选择L2-3间隙行腰-硬联合麻醉（CSEA）,维持平面T₆—T₁₀。D组：静脉注射咪达唑仑0.04 mg/kg,5 min后静脉注射右美托咪定0.25 μg/kg,后维持0.2～0.7 μg·kg^-1·h^-1。S组：静脉注射咪达唑仑0.04 mg/kg,5 min后静脉注射艾司氯胺酮0.35 mg/kg,后维持0.3～0.4 mg·kg^-1·h^-1。记录入室时、椎管内麻醉10 min后、静注咪达唑仑后10、30、60 min的HR和MAP。记录术中血管活性药物使用情况。记录静注咪达唑仑30、90 min以及开始缝皮时的Ramsay镇静评分。记录术中及术后不良反应的发生情况。
结果 与D组比较,静注咪达唑仑后30、60 min,S组HR明显增快（P＜0.05）,术中麻黄碱、阿托品、去甲肾上腺素的使用率明显降低（P＜0.05）。两组不同时点Ramsay镇静评分、术中及术后不良反应发生率差异均无统计学意义。
结论 艾司氯胺酮与右美托咪定均可安全有效地应用于中老年患者全髋关节置换术,但艾司氯胺酮术中血流动力学更加稳定,且不增加不良反应的发生。     

不同剂量右美托咪定对全麻患者围术期心肌细胞电生理的影响

目的 探讨不同剂量右美托咪定对全麻患者围术期心肌细胞电生理及心功能的影响。
方法 选择2020年9月至2021年3月行择期全麻手术患者69例,男33例,女36例,年龄18～64岁,BMI 18～30 kg/m²,ASA Ⅰ或Ⅱ级。采用随机数字表法将患者分为四组：右美托咪定负荷剂量1 μg/kg及维持剂量1 μg·kg^-1·h^-1（D₁组）、右美托咪定负荷剂量1 μg/kg及维持剂量0.5 μg·kg^-1·h^-1（D₂组）、右美托咪定负荷剂量0.5 μg/kg及维持剂量0.5 μg·kg^-1·h^-1（D₃组）和生理盐水负荷剂量50 ml/h输注10 min及维持剂量10 ml/h（C组）。于右美托咪定/生理盐水使用前（T₁）、负荷剂量完成时（T₂）、手术结束即刻（T₆）、入PACU后1 h（T₇）、术后24 h（T₈）、术后48 h（T₉）、术后72 h（T₁₀）及术后1个月（T₁₁）时采集12导联心电图,记录QTc间期,计算心脏电生理平衡指数（iCEB）。于T₁、T₂、手术开始时（T₃）、手术开始30 min（T₄）、手术开始1 h（T₅）、T₆、T₇时记录心脏循环效率（CCE）等心功能指标。
结果 与C组比较,T₂时D₁组和D₂组QTc间期明显延长（P<0.05）,T₇、T₈时D₃组QTc间期明显缩短(P<0.05),T₈时D₃组iCEB明显减小（P<0.05）,T₂时D₁组和D₂组、T₃时D₁组CCE明显减小（P<0.05）。与D₁组比较,D₃组T₂、T₆、T₇、T₉、T₁₀时QTc间期明显缩短（P<0.05）,T₈时iCEB明显减小（P<0.05）,T₂—T₄时CCE明显增大（P<0.05）。与D₂组比较,D₃组T₂时QTc间期明显缩短（P<0.05）、T₈时iCEB明显减小（P<0.05）,T₂—T₃时CCE明显增大（P<0.05）。
结论 全身麻醉手术中静脉输注右美托咪定负荷剂量0.5 μg/kg及维持剂量0.5 μg·kg^-1·h^-1可维持患者围术期心肌电生理的稳定,降低心律失常的发生率,且不影响心脏输出效率。     

血管紧张素-（1-7）及其受体激动剂AVE0991治疗大鼠急性肺损伤的效果

目的 探讨血管紧张素-（1-7）［Ang-（1-7）］及其特异性受体激动剂AVE0991用于治疗大鼠急性肺损伤（ALI）的效果。
方法 选择清洁级雄性SD成年大鼠45只，6～8周龄，体重250～300 g。采用随机数字表法将大鼠分为五组：对照组（C组）、ALI组（L组）和Ang-（1-7）组（LA组）、AVE0991组（LAV组）和Ang-（1-7）抑制剂（A-779）（LAN组），每组9只。L组静脉注射脂多糖（LPS） 5 mg/kg，机械通气V_T 15 ml/kg，持续4 h；C组静脉注射与 L组等容量的生理盐水，机械通气V_T 8 ml/kg，持续4 h；LA组、LAV组和LAN组静注LPS 5 mg/kg，机械通气V_T 15 ml/kg，持续2 h后分别静注Ang-（1-7） 50 pmol·kg^-1·min^-1、AVE0991 500 pmol·kg^-1·min^-1和A-779 100 pmol·kg^-1·min^-1，继续机械通气2 h 。记录机械通气前（T₀）、机械通气 2 h（T₁）、药物处理 30 min（T₂）、60 min（T₃）、90 min（T₄）、120 min（T₅）时的肺动脉压（PAP）；T₁和T₅时取肺动脉血行血气分析，记录LA组、LAV组和LAN组的PaCO₂、PaO₂。处死大鼠，对支气管肺泡灌洗液（BALF）采用瑞氏-姬姆萨染色行白细胞分类计数，采用ELISA法检测股静脉血TNF-α浓度，采用肺组织称重法计算肺湿/干重比（W/D），采用HE染色观察肺组织病理改变并评估肺损伤程度。
结果 与T₁时比较，T₂时LA组PAP明显降低（P<0.05），T₂—T₄时LAV组PAP明显降低（P<0.05），T₅时LA组PaO₂明显升高（P<0.05）。与C组比较，L组和LAN组BALF中白细胞计数明显增多（P<0.05），L组、LA组、LAV组和LAN组血清TNF-α浓度和W/D值明显升高（P<0.05）。与L组比较，LA组和LAV组BALF中白细胞计数、血清TNF-α浓度和W/D值明显降低（P<0.05）。与LA组比较，LAN组BALF中白细胞计数、血清TNF-α浓度和W/D值明显升高（P<0.05）。C组肺组织损伤轻微，L组肺组织损伤中度，LA组和LAV组肺组织损伤轻度，LAN组肺组织损伤严重。
结论 Ang-(1-7)及AVE0991可以减轻大鼠大潮气量通气合并LPS所致ALI的炎症反应，改善肺损伤，具有肺保护作用。     

右美托咪定对罗哌卡因前锯肌平面阻滞半数有效浓度的影响

目的 探讨右美托咪定作为佐剂对罗哌卡因前锯肌平面阻滞(SAPB)半数有效浓度(EC₅₀)的影响。
方法 选择择期行胸腔镜下肺叶或肺段切除术患者44例,男26例,女18例,年龄40～64岁,BMI 18.5～24.0 kg/m²,ASA Ⅰ或Ⅱ级。随机分为两组:右美托咪定复合罗哌卡因组(DR组,n=21)和罗哌卡因组(R组,n=23)。两组均在超声引导下行SAPB,DR组注入含右美托咪定1.0 μg/kg的罗哌卡因混合溶液30 ml,R组注入罗哌卡因30 ml。罗哌卡因初始浓度为0.4％,按照序贯法确定下一例罗哌卡因浓度,相邻浓度比值为1.1。若上一例阻滞效果评定为良好,则下一例采用低1个等级的浓度,反之则采用高1个等级的浓度,获得7个上下交叉点后结束试验。采用Probit回归分析计算罗哌卡因的EC₅₀及其95％CI。记录神经阻滞前和神经阻滞后10、20、30 min的MAP、HR、麻醉趋势指数(NI)和Ramsay镇静评分。神经阻滞前以及神经阻滞后30 min,采用视觉模拟焦虑量表评估焦虑程度。记录神经阻滞后30 min内心动过缓、低血压、镇静过度、呼吸抑制、恶心呕吐、局麻药中毒、局部血肿、气胸等不良反应的发生情况。
结果 DR组和R组罗哌卡因EC₅₀分别为0.26％(95%CI 0.23％～0.28％)和0.32％(95%CI 0.30％～0.34％)。与R组比较,神经阻滞后30 min DR组MAP明显降低,HR明显减慢(P<0.05)。与R组比较,神经阻滞后20、30 min DR组NI明显降低,Ramsay镇静评分明显升高(P<0.05)。与R组比较,神经阻滞后30 min DR组视觉模拟焦虑评分明显降低(P<0.05)。两组均未发生严重不良反应。
结论 右美托咪定可降低罗哌卡因前锯肌平面阻滞的EC₅₀,提供有效的镇静和抗焦虑作用,较好地维持血流动力学的稳定。     

不同剂量右美托咪定对胃肠道恶性肿瘤根治术患者围术期电解质及术后康复的影响

目的 观察不同剂量右美托咪定对胃肠道恶性肿瘤根治术患者围术期电解质及术后康复的影响。
方法 选择择期全麻下胃肠道恶性肿瘤根治术患者106例,男40例,女66例,年龄55～75岁,BMI 18.5～25.0 kg/m²,ASA Ⅰ—Ⅲ级。采用随机数字表法将患者分为四组：麻醉诱导前,D1组、D2组和D3组右美托咪定负荷剂量分别为1.0、1.0、0.5 μg/kg（均于10 min内静脉泵注完成）,维持剂量分别为0.25、0.5、0.5 μg·kg^-1·h^-1;C组生理盐水50 ml/h泵注10 min,维持量10 ml/h,四组维持剂量均至术毕前约30 min停止输注。于动脉穿刺完成后5 min（t₀）、手术开始后1 h（t₁）、术毕（t₂）、入PACU后1 h（t₃）、术后48 h（t₄）测定血清K⁺、Na⁺、Ca²⁺浓度,于t₀—t₃时测定血清乳酸浓度。记录丙泊酚及瑞芬太尼用量。记录术后48 h内腹腔引流量、镇痛泵总按压次数、镇痛泵有效按压次数、氟比洛芬酯追加例数。记录住院时间及术后肺部感染等并发症的发生情况。
结果 与T₀时比较,t₄时D1组、D2组和C组血清K⁺浓度明显升高（P<0.05）,t₂—t₄时D3组血清K⁺浓度明显升高（P<0.05）。t4时D2组血清K⁺浓度明显低于C组（P<0.05）;t₂时D3组血清K+浓度明显高于D2组（P<0.05）。与T₀时比较,t₄时D1组、D2组和C组血清Na+浓度明显降低（P<0.05）。t4时D1组和D3组血清Na+浓度明显高于C组（P<0.05）。与t₀时比较,t4时D1组、D2 组和C组血清Ca²⁺浓度明显升高（P<0.05）。t₃、t₄时D3组血清Ca2+浓度明显升高（P<0.05）。t3时D3组血清Ca²⁺浓度明显高于C组（P<0.05）。与t₀时比较,t₁时D2组和D3组血清乳酸浓度明显降低(P<0.05)。与C组比较,D2组丙泊酚用量明显减少（P<0.05）,D1组、D2组和D3组瑞芬太尼用量明显减少（P<0.05）。四组术后48 h内腹腔引流量、镇痛泵总按压次数、镇痛泵有效按压次数、氟比洛芬酯追加率、住院时间和肺部感染率差异无统计学意义。
结论 右美托咪定的使用未降低胃肠道恶性肿瘤根治术患者围术期K+浓度,负荷剂量0.5 μg/kg、维持剂量0.5 μg·kg^-1·h^-1可轻度升高入PACU后1 h血清K+浓度,明显降低血清乳酸浓度,减少瑞芬太尼用量,且对术后康复无不利影响。     

右美托咪定滴鼻联合腹股沟韧带上髂筋膜阻滞对股骨近端骨折病人术前镇静效果的影响

目的 探讨右美托咪定滴鼻联合腹股沟韧带上髂筋膜阻滞（suprainguinal fascia iliaca block, SIFIB）对股骨近端骨折病人术前镇静效果的影响。方法 收集60例拟行股骨近端骨折手术的病人,按随机数字表法分为三组：0.5 μg/kg右美托咪定滴鼻组（D1组）、1 μg/kg右美托咪定滴鼻组（D2组）以及给予生理盐水滴鼻的对照组。三组病人入室后分别滴注对应的滴鼻剂,而后行超声引导下SIFIB（0.375%罗哌卡因30 ml）,神经阻滞20 min后开始摆体位穿刺。记录滴鼻前（T₀）、神经阻滞时（T₁）、神经阻滞后10 min（T₂）、体位摆放成功即刻（T₃）的平均动脉压（MAP）、心率（HR）、血氧饱和度（SpO₂）、疼痛视觉模拟量表（visual analogue scale, VAS）评分、Ramsay镇静评分和焦虑评分。结果 T₂时,D1组、D2组的心率明显较对照组慢,D2组的Ramsay镇静评分明显高于D1组和对照组,焦虑评分明显低于D1组和对照组;T₃时,D1组、D2组的心率明显较对照组慢,D2组的焦虑评分明显低于D1组和对照组。结论 股骨近端骨折手术病人麻醉前给予右美托咪定1 μg/kg滴鼻联合SIFIB可获得良好的术前镇静效果,减少病人的焦虑。     

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.     

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.     

Risiko Schlaganfall — Öffentlichkeitsarbeit und Aufklärung dringend erforderlich

Zusammenfassung Das wesentliche — und zugleich noch wenig ausgeschöpfte — Potenzial der Schlaganfallmedizin liegt in der langfristigen Prophylaxe. Durch Beeinflussung von Lifestylefaktoren wie Ernährungsgewohnheiten, Zigarettenkonsum und körperlichem Training durch entsprechende Aufklärung ließe sich ein erheblicher Teil an zerebralen Ereignissen vermeiden. Ein weiterer in Deutschland noch zu wenig beachteter Faktor ist die konsequente Blutdruckeinstellung. Breitgestreute Aufklärung könnte außerdem potenziellen Patienten helfen, bereits auftretende Warnsymptome wie die transiente ischämische Attacke richtig einzuschätzen, um eine rechtzeitige Behandlung zu ermöglichen.