不同剂量环泊酚用于无痛胃镜检查的效果

目的 比较不同剂量环泊酚应用于无痛胃镜检查的效果。
方法 选择择期行无痛胃镜检查患者160例,男78例,女82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：环泊酚0.4 mg/kg组（C1组,n=40）、环泊酚0.5 mg/kg组（C2组,n=40）、环泊酚0.6 mg/kg组（C3组,n=40）和丙泊酚2 mg/kg组（P组,n=39）。C1组、C2组和C3组分别静脉注射环泊酚0.4、0.5、0.6 mg/kg,P组则静脉注射丙泊酚2 mg/kg。若检查过程中发生呛咳或体动,C1组、C2组和C3组追加环泊酚0.1 mg/kg,P组追加丙泊酚0.5 mg/kg。10 min内追加次数≤1次,则为镇静成功。记录镇静成功例数、环泊酚或丙泊酚追加例数、胃镜检查时间、苏醒时间和离院时间。记录麻醉前即刻（T₀）、进镜前即刻（T₁）、内镜到达十二指肠降部时（T₂）、内镜退出咽腔时（T₃）的HR、SBP、DBP、SpO₂。记录检查过程中呛咳、体动、注射痛和低氧血症（SpO₂＜90%）等不良反应的发生情况。
结果 与C1组比较,C2组、C3组和P组镇静成功率明显升高（P＜0.05）。与C2组比较,C1组环泊酚追加比例明显升高,C3组环泊酚追加比例明显降低（P＜0.05）。与T₀比较,T₁、T₂时四组HR明显减慢,SBP和DBP明显降低,C3组SpO₂明显降低（P＜0.05）。与C3组比较,T₁、T₂时C1组、C2组和P组SpO₂明显升高（P＜0.05）。与C1组比较,C2组、C3组和P组的呛咳、体动发生率明显降低,P组注射痛发生率明显升高（P＜0.05）。与C3组比较,C1组和C2组的低氧血症发生率明显降低（P＜0.05）。
结论 静脉注射环泊酚0.5 mg/kg镇静成功率高,呼吸抑制及注射痛发生率低,可安全有效地应用于胃镜检查。     

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。     

环泊酚和丙泊酚在老年患者纤维结肠镜治疗中镇静效果比较

目的 比较环泊酚和丙泊酚在老年患者纤维结肠镜治疗中的镇静效果。

方法 选择行纤维结肠镜治疗的老年患者330例,男179例,女151例,年龄65～84岁,BMI 18～29 kg/m²,ASA Ⅰ或Ⅱ级。随机分为两组：环泊酚组（C组,n=160）和丙泊酚组（P组,n=162）。C组麻醉诱导给予环泊酚0.4 mg/kg,麻醉维持泵注环泊酚1～1.5 mg·kg^-1·h^-1,P组麻醉诱导给予丙泊酚2 mg/kg,麻醉维持泵注丙泊酚4～6 mg·kg^-1·h^-1。记录镇静成功率、诱导时间、完全清醒时间,麻醉诱导前（T0）、进镜时（T1）、进镜后10 min（T2）、完全清醒时（T3）时SBP、DBP、BIS,术中心动过缓、低血压、低氧血症、注射痛、体动,气道干预、术中追加镇静和术后恶心呕吐发生情况。

结果 与P组比较,C组T2时SBP、DBP明显升高（P<0.05）,T2和T3时BIS明显降低（P<0.05）,术中低氧血症和注射痛发生率明显降低（P<0.05）。两组镇静成功率、诱导时间、完全清醒时间,术中心动过缓、低血压、体动发生率,气道干预、术中追加镇静和术后恶心呕吐发生率差异无统计学意义。

结论 与丙泊酚比较,环泊酚在老年患者纤维结肠镜治疗中有同样的镇静效果,且有着更低的低氧血症和注射痛发生率,值得临床推广。     

环泊酚与丙泊酚用于腹腔镜胆囊切除术全麻诱导与维持的比较

目的 比较环泊酚和丙泊酚用于腹腔镜胆囊切除术患者全麻诱导与维持的效果。



方法 选择择期行腹腔镜胆囊切除术患者80例,男32例,女48例,年龄18～64岁,BMI 18～30 kg/m²,ASAⅠ或Ⅱ级。采用随机数字表法将患者分为两组：环泊酚组和丙泊酚组,每组40例。环泊酚组、丙泊酚组分别静脉给予环泊酚0.4 mg/kg、丙泊酚2 mg/kg,两组均依次给予舒芬太尼0.5 μg/kg及罗库溴铵0.6 mg/kg行全麻诱导。环泊酚组静脉泵注环泊酚0.8～2.4 mg·kg^-1·h^-1,丙泊酚组泵注丙泊酚4～12 mg·kg^-1·h^-1,同时均泵注瑞芬太尼8～15 μg·kg^-1·h^-1维持麻醉,维持NI值36～64。记录手术时间、诱导时间、苏醒时间、PACU恢复时间,记录诱导前及诱导后1、3 min的HR和MAP。记录注射痛、诱导期呼吸暂停的发生情况。

结果 与丙泊酚组比较,环泊酚组诱导时间明显延长（P＜0.05）,环泊酚组诱导后1、3 min HR明显增快,MAP明显升高（P＜0.05）,注射痛发生率明显降低（P＜0.05）,诱导期呼吸暂停发生率明显降低（P＜0.05）。两组手术时间、苏醒时间、PACU恢复时间差异无统计学意义。

结论 环泊酚与丙泊酚均能有效应用于腹腔镜胆囊切除术患者全麻的诱导与维持,与丙泊酚比较,环泊酚诱导时间延长,但呼吸抑制和注射痛发生率更低。     

复合羟考酮时环泊酚用于无痛人工流产术的半数有效剂量

目的 探讨复合羟考酮时环泊酚用于无痛人工流产术的半数有效剂量（ED₅₀）。
方法 选择择期行无痛人工流产术患者23例，年龄22～40岁，BMI 20～30 kg/m²，ASA Ⅰ或Ⅱ级。麻醉诱导前静脉推注羟考酮0.08 mg/kg，环泊酚剂量采用序贯法。第1例患者环泊酚剂量为0.6 mg/kg，阳性反应定义为术中发生体动反应，若出现阳性反应则升高一个剂量等级，相邻剂量相差为0.05 mg/kg，若出现阴性反应则降低一个剂量等级，直至出现第7个拐点终止研究。计算复合羟考酮时环泊酚用于无痛人工流产术的ED₅₀和95%有效剂量（ED₉₅）及其95%可信区间（CI）。根据术中是否发生体动将患者分为两组：阳性组和阴性组。记录睫毛反射消失时间、手术时间、苏醒时间。记录术中恶心、呕吐、注射痛、呼吸抑制、过敏的发生情况。
结果 复合羟考酮时环泊酚用于无痛人工流产术的ED₅₀为0.469 mg/kg（95%CI 0.453～0.486 mg/kg），ED₉₅为0.542 mg/kg（95%CI 0.519～0.583 mg/kg）。与阴性组比较，阳性组苏醒时间明显延长（P<0.05）。两组无一例出现恶心、呕吐、注射痛、呼吸抑制、过敏等不良反应。
结论 复合羟考酮时环泊酚用于无痛人工流产术的ED₅₀为0.469 mg/kg（95%CI 0.453～0.486 mg/kg），ED₉₅为0.542 mg/kg（95%CI 0.519～0.583 mg/kg）。     

小剂量艾司氯胺酮对环泊酚用于无痛胃肠镜检查麻醉诱导半数有效剂量的影响

目的： 探讨小剂量艾司氯胺酮对环泊酚用于无痛胃肠镜检查麻醉诱导半数有效剂量（ED₅₀）的影响。
方法： 选择择期行无痛胃肠镜检查患者59例,男26例,女33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两组：艾司氯胺酮联合环泊酚组（EC组,n=29）和环泊酚组（C组,n=30）。EC组给予环泊酚前2 min静注艾司氯胺酮0.3 mg/kg,C组于相同时点静注等量生理盐水。麻醉诱导环泊酚初始剂量为0.4 mg/kg,剂量调整梯度为0.04 mg/kg,检查时若出现阳性反应则下一例患者环泊酚诱导剂量增加0.04 mg/kg,阴性反应则下一例患者环泊酚诱导剂量减少0.04 mg/kg。阳性反应为麻醉诱导后2 min患者BIS无法降至60或置入胃镜时出现呛咳或体动反应2级及以上。记录环泊酚总用量、苏醒时间、出室时间、术中及术后不良反应发生情况。采用Probit概率回归分析法计算ED₅₀、95%有效剂量(ED₉₅)和95%可信区间（CI）。
结果： 与C组比较,EC组检查过程中环泊酚总用量、低血压发生率及血管活性药物使用率均明显降低（P<0.05）。EC组使用环泊酚行无痛胃肠镜检查的麻醉诱导ED₅₀为0.21 mg/kg（95%CI 0.12～0.25 mg/kg）,ED₉₅为0.32 mg/kg（95%CI 0.26～0.39 mg/kg）,C组使用环泊酚行无痛胃肠镜检查的麻醉诱导ED₅₀为0.37 mg/kg（95%CI 0.32～0.40 mg/kg）,ED₉₅为0.48 mg/kg（95%CI 0.43～0.54 mg/kg）。与C组比较,EC组使用环泊酚行无痛胃肠镜检查的麻醉诱导ED₅₀、ED₉₅明显降低（P<0.05）。两组其他不良反应发生率差异无统计学意义。
结论： 联合艾司氯胺酮0.3 mg/kg可降低环泊酚用于无痛胃肠镜检查麻醉诱导时的ED₅₀并减少检查过程中环泊酚总用量,术中循环稳定,可安全用于无痛胃肠镜检查。     

瑞马唑仑复合舒芬太尼在无痛超声胃镜检查中的安全性

目的 瑞马唑仑复合舒芬太尼在无痛超声内镜检查中的安全性。

方法 选择2022年4—6月行无痛超声胃镜检查的患者76例，男28例，女48例，年龄18～64岁，BMI 18～30 kg/m²，ASA Ⅰ—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38例。静脉推注舒芬太尼0.1 μg/kg，4 min后R组静脉推注瑞马唑仑0.2 mg/kg，P组静脉推注丙泊酚1.5 mg/kg，待患者改良警觉/镇静（MOAA/S）评分≤3分时进行超声胃镜操作。记录检查期间、恢复期间低血压、呼吸抑制发生情况。记录镇静时间、苏醒时间、离室时间、镇静成功例数，下镜成功例数及注射痛等不良事件发生情况。记录患者、麻醉科医师、内镜医师满意度评分。

结果 与P组比较，R组检查期间、恢复期间低血压发生率和呼吸抑制发生率、注射痛发生率均明显降低（P<0.05）。两组镇静时间、苏醒时间、离室时间、镇静成功率、下镜成功率、患者、麻醉科医师、内镜医师满意度评分差异均无统计学意义。

结论 瑞马唑仑复合舒芬太尼在无痛超声胃镜检查围术期安全性更高，血流动力学更稳定，不良反应少，镇静效果与丙泊酚类似。     

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。     

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。     

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.     

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.     

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.     

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.     

Immunomodulation in Transplantation with Photopheresis

Abstract: Photopheresis is a technique in which peripheral blood mononuclear cells, in the presence of a photoacti-vatable compound, are exposed extracorporeally to ultraviolet A light and reinfused, inducing a host autoregula-tory immune response. Experimental work and ongoing clinical studies are helping to define the role of this novel, safe, and non-toxic immunomodulating technology in the field of transplantation.