尼卡地平对冠状动脉旁路移植术患者脑血流和功能的影响

目的 探讨冠状动脉旁路移植术（CABG）患者在心肺转流（CPB）期间输注小剂量尼卡地平对脑血流和功能的影响。

方法 选择CPB下CABG患者64例,男41例,女23例,年龄60～79岁,BMI 18～29 kg/m²,ASA Ⅱ或Ⅲ级,NYHA分级Ⅱ或Ⅲ级,左室射血分数≥50%。采用随机双盲数字表法将患者分为两组：尼卡地平组（N组）和生理盐水组（C组）,每组32例。N组在CPB开始后输注尼卡地平0.2～0.5 μg·kg^-1·min^-1,于CPB停机后停止输注。C组于相同时点输注同等容量生理盐水。记录麻醉诱导前（T₀）、外科切皮时（T₁）、CPB 30 min（T₂）、60 min（T₃）、停CPB 30 min（T₄）、60 min（T₅）的动脉血气、心输出量（CO）、颈内动脉血流量（Q-ICA）、颈内动脉直径（D-ICA）和局部脑氧饱和度（rScO₂）。记录术中去氧肾上腺素用量、术后拔管时间、ICU停留时间和术后住院时间。

结果 与C组比较,T₂—T₅时N组Q-ICA和D-ICA明显增加,rScO₂明显升高（P＜0.05）。两组T₀—T₅时动脉血气指标、T₀、T₁时Q-ICA、D-ICA和rScO₂、术中去氧肾上腺素用量、术后拔管时间、ICU停留时间和术后住院时间差异均无统计学意义。

结论 在CABG患者CPB期间输注小剂量尼卡地平可以增加颈内动脉血流量,升高rScO₂,减轻围术期神经功能损伤。     

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。     

瑞马唑仑和丙泊酚用于肝硬化患者内镜下静脉曲张套扎术的比较

目的 探讨瑞马唑仑和丙泊酚对肝硬化患者内镜下静脉曲张套扎术血流动力学和不良反应的影响。
方法 纳入拟行内镜下静脉曲张套扎术的肝硬化患者96例,男43例,女53例,年龄18～70岁,BMI 18.5～27.9 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（R组）和丙泊酚组（P组）,每组48例。R组静脉注射瑞马唑仑0.2 mg/kg行麻醉诱导,静脉泵注瑞马唑仑1～2 mg·kg^-1·h^-1行麻醉维持;P组静脉注射丙泊酚2 mg/kg行麻醉诱导,静脉泵注丙泊酚4～10 mg·kg^-1·h^-1行麻醉维持。记录麻醉诱导前（T₀）、麻醉诱导后（T₁）、气管插管后（T₂）、手术开始后5 min（T₃）、拔管后（T₄）的HR和MAP。记录患者意识消失时间、拔管时间、意识恢复时间、PACU停留时间。记录术前、术后1 d谷氨酸-丙酮酸转氨酶（ALT）、天门冬氨酸氨基转移酶（AST）。记录术中低血压、术后低氧血症、头晕、恶心呕吐、苏醒延迟、苏醒期躁动的发生情况。
结果 与P组比较,R组T₁—T₃时HR、MAP明显升高（P＜0.05）,意识消失时间明显延长（P＜0.05）,拔管时间、意识恢复时间和PACU停留时间明显缩短（P＜0.05）,术中低血压、术后低氧血症发生率明显降低（P＜0.05）。两组T₀、T₄时HR、MAP差异无统计学意义。两组术后1 d ALT、AST和头晕、恶心呕吐、苏醒延迟、苏醒期躁动发生率差异均无统计学意义。
结论 与丙泊酚比较,瑞马唑仑对行内镜下静脉曲张套扎术肝硬化患者的血流动力学影响较小,可明显降低低血压发生率,安全性较高。     

不同剂量瑞马唑仑用于宫腔镜手术的安全性和有效性

目的 比较三种剂量瑞马唑仑和丙泊酚用于宫腔镜手术的安全性和有效性。
方法 选择择期全麻下行宫腔镜手术患者180例,年龄18~60岁,ASA Ⅰ—Ⅲ级。采用随机数字表法将其分为四组：C组、R1组、R2组和R3组,每组45例。所有患者静脉注射舒芬太尼5 μg后,C组静脉注射丙泊酚1～2 mg/kg进行麻醉诱导,待改良警觉/镇静评分（MOAA/S）为0分后予以5 mg·kg^-1·h^-1静脉泵注维持;R1组、R2组和R3组均静脉泵注瑞马唑仑6 mg·kg^-1·h^-1进行麻醉诱导,MOAA/S为0分后,R1组、R2组和R3组分别调整剂量为0.5、1.0和1.5 mg·kg^-1·h^-1术中维持。记录镇静起效时间、术中补救镇痛例数以及苏醒时间。记录入室平静时（T₀）、麻醉诱导后MOAA/S为0分时（T₁）、术中SBP最低时（T₂）、麻醉苏醒（T₃）后HR、SBP和DBP。记录术中知晓、体动、多巴胺使用例数、呼吸抑制、肌震颤、头痛、注射痛、瘙痒、恶心、呕吐、咳嗽、出汗、寒战和苏醒后眩晕等不良事件的发生情况。
结果 R1组、R2组和R3组镇静起效时间明显长于C组（P＜0.05）,R2组、R3组术中补救镇痛率明显低于R1组（P＜0.05）,R2组和R3组苏醒时间明显长于C组和R1组（P＜0.05）。T₁时R1组、R3组HR明显快于C组（P＜0.05）。T₁、T₂时R1组、R2组和R3组SBP和DBP均明显高于C组（P＜0.05）。R1组术中体动发生率明显高于R2组、R3组（P＜0.05）,R1组、R2组和R3组术中多巴胺使用率和注射痛发生率明显低于C组（P＜0.05）。
结论 以瑞马唑仑6 mg·kg^-1·h^-1静脉诱导、1.0 mg·kg^-1·h^-1麻醉维持应用于宫腔镜手术时相对于应用丙泊酚对循环系统影响更小,注射痛发生率更低,可安全、有效地应用于此类手术患者。     

右美托咪定减轻肺叶切除术患者单肺通气相关肺损伤

目的 评价右美托咪定对胸腔镜肺叶切除术中单肺通气相关肺损伤时转化生长因子（TGF）-β/果蝇MAD类似基因(Smad)信号通路的影响。
方法 选取2018年6月至2019年6月择期全麻下拟行胸腔镜下肺叶切除术患者886例,男444例,女442例,年龄40~65岁,BMI 20～24 kg/m²,ASA Ⅰ或Ⅱ级。采用随机数字表法分为两组：右美托咪定组(D组)和对照组(C组)。每组443例。D组于麻醉诱导前10 min以1.0 μg/kg静脉输注右美托咪定负荷剂量,随后以0.3 μg·kg^-1·h^-1速率输注至术毕前30 min,C组静脉输注等容量的生理盐水。于单肺通气即刻（T₀）、单肺通气15 min（T₁）、30 min（T₂）、60 min(T₃)、双肺通气后1 h（T₄）时采集动脉和静脉血2 ml,行血气分析并计算氧合指数（OI）和肺内分流率(Qs/Qt)。HE染色观察肺组织,计算肺湿干重(W/D)比值和肺病理学损伤评分。采用Western blot 法检测肺组织TGF-β1、Smad2、Smad3、IL-6和TNF-α。记录术后48 h内肺炎、肺不张和呼吸衰竭的发生情况,记录术后住院时间。
结果 与C组比较,D组T₁—T₄ 时OI明显升高,Qs/Qt明显降低(P<0.05),W/D比值明显降低,肺病理学损伤评分明显降低(P<0.05),肺组织TGF-β1、Smad2、Smad3、IL-6和TNF-α明显降低(P<0.05),术后肺炎、肺不张并发症的发生率明显降低(P<0.05),术后住院时间明显缩短(P<0.05)。
结论 右美托咪定可降低胸腔镜肺叶切除术患者肺组织TGF-β1、Smad2、Smad3、IL-6和TNF-α,从而减轻急性肺损伤。     

超声引导下腹股沟韧带上髂筋膜阻滞对膝关节镜下交叉韧带重建术患者止血带相关反应的影响

目的 探讨超声引导下腹股沟韧带上髂筋膜阻滞对全麻下行膝关节镜下交叉韧带重建术（ACLR）患者术中止血带相关反应以及缺血-再灌注损伤的影响。

方法 选择行膝关节镜下交叉韧带重建术患者86例，男58例，女28例，年龄18～64岁，BMI 17～28 kg/m²，ASA Ⅰ或Ⅱ级。采用随机数字表法将患者分为两组：超声引导下腹股沟韧带上髂筋膜阻滞联合全麻组（B组）和单纯全麻组（C组），每组43例。B组于超声引导下行腹股沟韧带上髂筋膜阻滞联合全麻，C组仅行全麻，术毕均行静脉自控镇痛。记录麻醉诱导时（T₀）、止血带充气即刻（T₁）、止血带充气后60 min（T₂）、止血带充气后90 min（T₃）、放松止血带即刻（T₄）、放松止血带后10 min（T₅）的HR和MAP，于T₁、T₅时抽取静脉血测定血清丙二醛（MDA）和乳酸（Lac）浓度。记录入PACU即刻（T₆）、术后6 h（T₇）、12 h（T₈）、24 h（T₉）静息和活动时VAS疼痛评分。记录术中丙泊酚和瑞芬太尼总用量、术后镇痛泵总按压次数、镇痛泵有效按压次数和氟比洛氛酯补救镇痛例数。记录术后神经损伤、寒颤、术后恶心呕吐等不良反应的发生情况。

结果 与T₁时比较，T₅时两组血清MDA和Lac浓度明显升高（P<0.05）。与C组比较，T₂—T₅时B组HR明显减慢，MAP明显降低（P<0.05），T₅时B组MDA和Lac浓度明显降低（P<0.05），T₆、T₇时B组静息和活动时VAS疼痛评分明显降低（P<0.05），B组术中丙泊酚和瑞芬太尼总用总量明显减少（P<0.05），B组术后镇痛泵总按压次数、有效按压次数明显减少、氟比洛氛酯补救镇痛率明显降低（P<0.05）。T₈、T₉时两组静息和活动时VAS疼痛评分、术后神经损伤、寒颤、术后恶心呕吐等不良反应发生率差异无统计学意义。

结论 腹股沟韧带上髂筋膜阻滞可减轻止血带相关反应，减轻肢体缺血-再灌注后脂质过氧化反应，减少MDA及Lac等生成，从而减轻缺血-再灌注损伤。     

丙泊酚与七氟醚对妇科腹腔镜患者视神经鞘直径的影响

目的 应用超声测量视神经鞘直径（ONSD）方法评价丙泊酚与七氟醚对妇科腹腔镜患者颅内压的影响。
方法 选择择期行妇科腹腔镜手术患者40例,年龄20～60岁,BMI 18～27 kg/m²,ASAⅠ或Ⅱ级。采用随机数字表法分为丙泊酚组（P组）和七氟醚组（S组）,每组20例。麻醉维持：P组静脉泵注丙泊酚4～12 mg·kg^-1·h^-1,S组吸入1%～2%七氟醚。使用容量控制模式,V_T6～8 ml/kg,FiO₂ 50%,I∶E 1∶2,RR 12～20次/分。记录麻醉诱导后5 min（T₀）、气腹开始后头低脚高位5 min（T₁）、气腹开始后头低脚高位30 min（T₂）、气腹开始后头低脚高位60 min（T₃）时的HR、MAP、气道峰压（Peak）、气道平台压（Plat）、P_ET CO₂ 和ONSD。
结果 与T₀时比较,T₁—T₃时P组MAP明显降低,T₂—T₃时S组MAP明显降低（P＜0.05）,T₁—T₃时两组Peak、Plat明显升高（P＜0.05）,T₁—T₃时两组ONSD明显升高（P＜0.05）。T₁时P组MAP明显低于S组（P＜0.05）。T₃时P组ONSD明显低于S组（P＜0.05）。
结论 在妇科腹腔镜手术中,与单纯使用七氟醚比较,应用丙泊酚维持可一定程度减轻颅内压的升高。     

环泊酚或丙泊酚复合瑞芬太尼用于无痛纤维支气管镜检查的比较

目的 探讨环泊酚或丙泊酚复合瑞芬太尼用于无痛纤维支气管镜检查的麻醉效果及对梦境状态的影响。
方法 选择择期行全麻下无痛纤维支气管镜检查的患者60例，男27例，女33例，年龄18～75岁，BMI 20～30 kg/m²，ASA Ⅰ或Ⅱ级。将患者随机分为两组：丙泊酚组（P组）和环泊酚组（C组），每组30例。麻醉诱导：P组静注丙泊酚2.5 mg/kg和瑞芬太尼1 μg/kg；C组静注环泊酚0.4 mg/kg和瑞芬太尼1 μg/kg。麻醉维持：P组泵注丙泊酚4～6 mg·kg^-1·h^-1；C组泵注环泊酚0.8～1.2 mg·kg^-1·h^-1。记录低血压的发生情况、麻黄碱用量，麻醉诱导前5 min（T₀）、插入喉罩即刻（T₁）、纤维支气管镜进至隆突时（T₂）、镜检完毕（T₃）及拔除喉罩时（T₄）的HR、MAP和SpO₂。记录呛咳评分、利多卡因用量、手术时间、苏醒时间、定向力恢复时间、梦境的发生情况和状态、静脉注射痛、心动过缓、呼吸暂停、呛咳及恶心呕吐等相关不良事件的发生情况。
结果 与T₀时比较，T₁时两组MAP均明显降低（P<0.05）。与P组比较，C组低血压的发生率明显降低（P<0.05），麻黄碱用量明显减少(P<0.05)，T₁和T₃时MAP明显升高(P<0.05)，梦境的情绪评分明显升高(P<0.05)，静脉注射痛及呼吸暂停相关不良事件的发生率明显降低(P<0.05)。两组呛咳评分、利多卡因用量、手术时间、苏醒时间、定向力恢复时间、梦境发生率、心动过缓、呛咳及恶心呕吐相关不良事件的发生率差异无统计学意义。
结论 与丙泊酚比较，环泊酚复合瑞芬太尼在无痛纤维支气管镜检查中对循环呼吸影响小，不良事件发生率更低，同时可产生更优情绪的梦境状态。     

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。     

低每搏量变异度指导的液体治疗对老年患者肺叶切除术后恢复质量的影响

目的 探究低每搏量变异度（SVV）指导的液体治疗对老年患者肺叶切除术后恢复的影响。

方法 选择2022年2月至2023年1月择期胸腔镜下肺叶切除术的老年患者100例,男50例,女50例,年龄65～75岁,BMI 18～24 kg/m²,ASA Ⅱ或Ⅲ级。采用随机数表法将患者分为两组：低SVV阈值目标导向液体治疗（GDFT）组（G组）和对照组（C组）,每组50例。G组8%＜SVV≤10%,C组10%＜SVV≤13%。记录麻醉时间、手术时间、单肺通气（OLV）时间,记录入手术室即刻（T₀）、插管即刻（T₁）、OLV开始即刻（T₂）、手术开始即刻（T₃）、OLV结束即刻（T₄）和术毕（T₅）时的HR和MAP。记录术中液体出入量以及各种血管活性药使用情况。记录术前24 h和术后24、48 h血浆胃动素（MTL）、胃泌素（GAS）、肠型脂肪酸结合蛋白（IFABP）浓度。记录术后2、6、12、24、48 h静息时VAS疼痛评分以及术后48 h内PCIA有效按压次数、PCIA总按压次数以及补救镇痛例数。记录术后首次肛门排气时间、首次排便时间、首次下床活动时间、术后住院时间、胃肠道并发症（恶心呕吐、腹胀）发生情况。

结果 与C组比较,G组T₁—T₅时MAP、术后24、48 h血浆MTL和GAS浓度均明显升高（P<0.05）,术后24、48 h血浆IFABP浓度、术中胶体输注量和总液输注量均明显降低（P<0.05）,术后首次肛门排气时间、首次排便时间、首次下床活动时间和术后住院时间均明显缩短（P<0.05）。两组尿量、出血量、术后2、6、12、24、48 h静息时VAS疼痛评分、术后48 h内PCIA有效按压次数、PCIA总按压次数、补救镇痛率差异均无统计学意义。

结论 低SVV阈值（8%＜SVV≤10%）GDFT能很好地促进胃液分泌和肠黏膜屏障功能恢复,对老年患者肺叶切除术后胃肠功能的恢复有积极作用。     

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.     

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.