控制性低中心静脉压对腹腔镜肝癌切除术患者中心静脉血氧饱和度和乳酸的影响

目的 探讨腹腔镜肝癌切除术中硝酸甘油控制性低中心静脉压（CLCVP）对患者术中中心静脉血氧饱和度（ScvO₂）和动脉血乳酸（Lac）的影响。
方法 选择择期行腹腔镜肝癌切除术患者50例,男27例,女23例,年龄36～64岁,BMI 18~25 kg/m²,ASA Ⅰ或Ⅱ级,采用随机数字表将患者随机分为两组：CLCVP组（L组）和对照组（C组）,每组25例。L组在切肝前5 min通过静脉泵注硝酸甘油0.2～0.5 μg·kg^-1·min^-1,维持CVP≤5 cmH₂O;C组常规输液并维持CVP 6～12 cmH₂O。记录术中出血量、输液量和苏醒时间,记录切肝前15 min、切肝中10、40 min、切肝后30 min的ScvO₂、Lac、HR和MAP。记录术后不良反应的发生情况。
结果 与C组比较,L组术中出血量和输液量明显降低（P＜0.05）。与切肝前15 min比较,切肝中10、40 min,L组ScvO₂和MAP明显降低（P＜0.05）;切肝中10 min,L组HR明显增快（P＜0.05）。与C组比较,切肝中10、40 min,L组ScvO₂和MAP明显降低（P＜0.05）。两组苏醒时间、术后不良反应发生率差异无统计学意义。
结论 腹腔镜肝切除术中硝酸甘油CLCVP可有效减少术中出血,使ScvO₂下降,对Lac值无明显影响,且不增加不良反应。     

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。     

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。     

肝切除术中肾脏局部氧饱和度与术后急性肾损伤的相关性

目的 应用近红外光谱技术（NIRS）监测肝切除术中肾脏局部氧饱和度（rSKO₂）的变化，评估其与术后急性肾损伤（AKI）的相关性。
方法 选择2020年9月至2021年10月择期在全麻下行开腹肝切除术的患者99例，男77例，女22例，年龄60～80岁，BMI 18～30 kg/m²，ASA Ⅱ或Ⅲ级。根据改善全球肾脏病预后（KDIGO）标准判断术后7 d内是否发生AKI，并将患者分为两组：AKI组和非AKI组。记录基础值（T₀）、麻醉诱导即刻（T₁）、手术开始即刻（T₂）、肝门阻断即刻（T₃）、肝门阻断后5 min（T₄）、10 min（T₅）、肝门开放即刻（T₆）、肝门开放后10 min（T₇）、20 min（T₈）、30 min（T₉）、手术结束时（T₁₀）的rSKO₂。记录肝门阻断时间、液体输注量、出血量等术中情况。采用单因素和多因素Logistic回归分析术中rSKO₂与AKI的相关性。
结果 术后7 d内有16例（16%）患者发生AKI。与AKI组比较，非AKI组T₁、T₃—T₇、T₉、T₁₀时rSKO₂水平明显升高（P＜0.05）。术中rSKO₂绝对值低于70%（OR=3.87，95%CI 1.17~15.37，P＜0.05）或下降幅度大于基础值的20%（OR=4.96，95%CI 1.53~18.66，P＜0.05）与术后AKI发生呈正相关。
结论 术中rSKO₂下降与术后AKI发生呈正相关，NIRS监测rSKO₂可以较好地反映患者术中肾脏氧供需状态。     

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。     

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。     

内镜喉罩对胃内镜黏膜下剥离术气道管理和术后恢复的影响

目的： 评价内镜喉罩用于胃内镜黏膜下剥离术（ESD）患者围术期气道管理和术后恢复的效果。
方法： 选择择期行胃ESD的患者90例,男48例,女42例,年龄18～64岁,BMI 18～25 kg/m²,ASA Ⅰ或Ⅱ级。将患者随机分为两组：内镜喉罩组（E组）和气管插管组（C组）,每组45例。麻醉诱导后E组行内镜喉罩通气,消化内镜从喉罩的内镜通道置入;C组则采取气管内插管通气,消化内镜经口置入。记录插管情况（插管成功时间、插管一次性成功例数）、消化内镜置入情况（消化内镜置入时间和退镜例数）、手术时间、拔管时间以及PACU停留时间。记录入室时（T₀）、置入喉罩或气管插管后即刻（T₁）、消化内镜置入时（T₂）、内镜退出时（T₃）、拔除喉罩或气管导管后即刻（T₄）、离开PACU时（T₅）的HR、MAP。记录T₁—T₃时的平均气道压和气道峰压。记录E组改变体位前后、手术结束时的气道密封压和内窥镜显露分级（EVGS）。记录不良反应发生情况以及麻醉科医师和消化内镜医师的满意度。
结果： 与T₀时比较,T₁、T₄时两组HR和MAP明显升高（P＜0.05）。与C组比较,E组置入喉罩成功时间、拔除喉罩时间及PACU停留时间明显缩短,T₁、T₄时HR和MAP明显降低,围拔管期呛咳以及术后咽痛、声嘶发生率明显降低（P＜0.05）。两组插管或置入喉罩一次性成功率、消化内镜置入时间和退镜率差异无统计学意义。E组内镜喉罩的密封性和对位良好。
结论： 内镜喉罩可缩短胃ESD患者的人工气道建立成功时间,对消化内镜操作不造成干扰,缩短拔管时间和PACU停留时间,加快患者术后恢复。     

术中持续输注胰岛素对心肺转流心脏手术患者心肌血流灌注的影响

目的： 探讨术中持续输注胰岛素对心肺转流（CPB）心脏手术患者心肌血流灌注的影响。
方法： 选择择期行CPB心脏手术患者48例,男21例,女27例,年龄55～80岁,BMI 18～28 kg/m²,ASA Ⅱ—Ⅳ级。将患者随机分为两组：胰岛素组（I组,n=25）和对照组（C组,n=23）。两组采用相同麻醉方案。麻醉诱导后I组静脉输注胰岛素30 mU·kg^-1·h^-1、葡萄糖0.12 g·kg^-1·h^-1、氯化钾0.06 mmol·kg^-1·h^-1混合液,C组予以生理盐水10 ml/h输注,均输注至术毕。术中目标血糖值为6.1～11.1 mmol/L。于麻醉诱导后10 min（T₂）和术毕（T₆）行经食管超声心动图（TEE）检测,记录冠状静脉窦（CS）血流频谱、直径及肺静脉血流频谱,并计算CS净向前血流流速时间积分（VTI）。记录T₂、CPB前2 min（T₃）、CPB结束时（T₅₂）和T6时的股动脉平均动脉压（MAP）、中心静脉压（CVP）、每搏量（SV）、心脏指数（CI）及外周血管阻力指数（SVRI）。记录麻醉诱导前5 min（T₁）、T₃、CPB后30 min（T₄）、T₅、T₆、术后6 h（T₇）、术后12 h（T₈）及术后24 h（T₉）时血糖及乳酸浓度。记录术前1 d、术后1、2 d时超敏C反应蛋白（hs-CRP）、高敏肌钙蛋白I（hs-TnI）和肌酸激酶同工酶（CK-MB）水平。
结果： 与C组比较,I组T₆时CS净前向血流VTI及每分钟CS血流量均明显增加（P<0.05）,肺静脉心房收缩期峰值流速（ARp）明显减小（P<0.05）,T₅、T₆时SV和CI明显增大、SVRI明显降低（P<0.05）,T₇、T₈时乳酸浓度明显降低（P<0.05）,术后1、2 d时hs-CRP和CK-MB水平明显降低（P<0.05）,术后2 d时hs-TnI明显降低（P<0.05）。
结论： CPB心脏手术中持续输注胰岛素,同时维持血糖6.1～11.1 mmol/L,可改善心肌血流灌注,减轻术后炎症反应及心肌损伤。     

允许性高每搏量变异度在老年患者腹腔镜肝切除术中的应用

目的探讨允许性高每搏量变异度（SVV）在老年患者腹腔镜肝切除术中的应用效果。
方法选择2020年8月至2021年8月拟行腹腔镜肝脏切除手术的患者100例,男67例,女33例,年龄65～80岁,BMI 18～25 kg/m²,ASA Ⅱ或Ⅲ级。采用随机数字表法将患者分为两组：以SVV指导补液的研究组（S组）和以CVP指导补液的对照组（C组）,每组50例。S组：第1阶段以允许性高SVV值（13%～20%）行液体治疗,第2阶段以SVV（9%～13%）为目标进行补液;C组：第1阶段以低CVP值（0～5 cmH₂O）行液体治疗,第2阶段以CVP（5～12 cmH₂O）为目标进行补液。记录第1、2阶段持续时间、血管活性药使用情况、术中出血量、输液量、尿量、术毕乳酸浓度。记录入室、切皮、开始切肝、切肝完成、术毕的HR、MAP。持续记录术中脑氧饱和度（rSO₂）,计算术中rSO₂平均值（rSO_2mean)、术中rSO₂最小值（rSO_2min）、rSO₂较基础值下降的最大百分比（rSO_2%max）。记录术前1 d、术后1、2、3 d的肌酐（Cr）、尿素氮（BUN）。
结果S组去氧肾上腺素、硝酸甘油使用率明显低于C组（P<0.05）,S组术中出血量明显少于C组（P<0.05）,术中输液量、尿量明显多于Ｃ组（P<0.05）,术毕时S组血清乳酸浓度明显低于C组（P<0.05）。与C组比较,在开始切肝、切肝完成时S组HR明显减慢(P<0.05),MAP明显升高（P<0.05）。S组rSO_2%max明显低于C组（P<0.05）。术后1、2、3 d S组Cr明显低于C组（P<0.05）。
结论在腹腔镜肝切除术中采用允许性高SVV指导目标导向液体治疗,可减少术中出血,维持血流动力学稳定,保证重要脏器的血液灌注。     

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。     

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.