经皮穴位电刺激对无痛胃肠镜检查后恶心呕吐的影响

目的 观察经皮穴位电刺激(TEAS)双侧足三里穴（ST36）、脾俞穴（BL20）及大陵穴（PC7）对预防无痛胃肠镜检查后恶心呕吐的影响。
方法 选择行无痛胃肠镜检查患者159例,男72例,女87例,年龄25～64岁,BMI 18~28 kg/m²,ASA Ⅰ或Ⅱ级。采用随机数字表法将患者分为两组：TEAS组（T组,n=80）和对照组（C组,n=79）。麻醉诱导前T组给予TEAS双侧ST36、BL20及PC7 20 min;C组仅在相应穴位予电极片贴敷不行电刺激。两组麻醉诱导均采用丙泊酚1.5 mg/kg复合舒芬太尼0.1 μg/kg,并根据检查中患者情况追加丙泊酚0.5 mg/kg。记录患者苏醒后30 min头晕、恶心呕吐发生情况。记录检查中最低HR、SBP、DBP和苏醒后30 min的SBP、DBP。记录患者、麻醉科医师满意情况及患者留观时间。
结果 与C组比较,T组检查后恶心呕吐发生率明显降低（P＜0.05）,检查中最低SBP明显升高（P＜0.05）,患者和麻醉科医师满意度明显升高（P＜0.05）,留观时间明显缩短（P＜0.05）。
结论 经皮穴位电刺激双侧足三里穴、脾俞穴及大陵穴可有效预防无痛胃肠镜患者检查后恶心呕吐的发生。     

小剂量艾司氯胺酮预防无痛人工流产患者丙泊酚注射痛的效果

目的 探讨小剂量艾司氯胺酮预防无痛人工流产患者丙泊酚注射痛（PIP）的效果。
方法 选择行无痛人流患者198例,年龄18～50岁,BMI 19～26 kg/m²,ASA Ⅰ或Ⅱ级。采用随机数字表法将患者分为三组：生理盐水组（C组）、利多卡因组（L组）和艾司氯胺酮组（E组）,每组66例。C组静脉注射等体积生理盐水5 ml,L组静脉注射利多卡因0.5 mg/kg,E组静脉注射艾司氯胺酮0.15 mg/kg。每组静脉注射相应药物60 s后,以0.2 ml/s的速度静脉注射丙泊酚2 mg/kg。采用Ambesh四分法评价PIP发生情况。记录麻醉前、手术开始前和手术结束时的HR、SBP、DBP。记录术中丙泊酚总用量、麻醉时间、手术时间、苏醒时间。记录去氧肾上腺素和阿托品使用情况。记录术中低血压、低氧血症、心动过缓、谵妄、恶心呕吐、体动等不良反应发生情况。
结果 与C组比较,L组和E组中重度疼痛和PIP发生率明显降低（P＜0.05）。与L组比较,E组轻度疼痛和PIP发生率明显降低（P＜0.05）。与E组比较,手术开始前C组和L组SBP和DBP明显降低,术中丙泊酚总用量明显增多,麻醉时间和苏醒时间明显延长,低氧血症及需托下颌的发生率均明显升高（P＜0.05）。三组患者术中低血压、心动过缓、恶心呕吐、谵妄等不良反应发生率差异无统计学意义。
结论 小剂量艾司氯胺酮（0.15 mg/kg）可有效抑制无痛人工流产术中丙泊酚注射痛,维持血流动力学稳定并降低不良反应发生率,可安全用于无痛人工流产术。     

口服不同剂量咪达唑仑对腹腔镜腹股沟斜疝疝囊高位结扎术患儿术前焦虑的影响

目的： 观察口服不同剂量咪达唑仑用于缓解腹腔镜腹股沟斜疝疝囊高位结扎术患儿术前焦虑的效果。
方法： 选择择期在全麻下行腹腔镜腹股沟斜疝疝囊高位结扎术的患儿120例,男93例,女27例,年龄2～6岁,身高78～120 cm,体重11～25 kg,ASA Ⅰ或Ⅱ级。采用随机数字表法将患儿分为三组：麻醉前30 min口服咪达唑仑0.25 mg/kg组(M1组)、0.5 mg/kg(M2组)和0.75 mg/kg(M3组),每组40例。记录服药前、与父母分离时、麻醉诱导即刻简化版改良耶鲁术前焦虑量表(mYPAS-SF)评分和麻醉诱导期合作度量表(ICC)评分。记录苏醒时间、拔管时间、PACU停留时间、术后30 min 儿童麻醉苏醒期躁动量表(PAED)评分和改良面部表情疼痛量表(FLACC)评分。
结果： 与服药前比较,M2组和M3组在与父母分离时、麻醉诱导即刻mYPAS-SF评分明显降低(P<0.05)。与M1组比较,M2组和M3组与父母分离时、麻醉诱导即刻mYPAS-SF明显降低(P<0.05),麻醉诱导即刻ICC评分明显降低(P<0.05),苏醒时间、拔管时间和PACU停留时间明显延长(P<0.05),术后30 min PAED评分明显降低(P<0.05)。与M2组比较,M3组苏醒时间和拔管时间明显延长(P<0.05)。
结论： 麻醉前30 min口服咪达唑仑0.5 mg/kg或0.75 mg/kg均可有效缓解患儿术前焦虑,提高麻醉诱导合作度,降低术后躁动的发生,口服咪达唑仑0.75 mg/kg的患儿苏醒时间和拔管时间延长,因此,口服咪达唑仑0.5 mg/kg为患儿术前抗焦虑方案比较合适的剂量。     

前锯肌平面阻滞对心肺转流下胸腔镜心脏手术患者应激反应和术后镇痛的影响

目的 探讨前锯肌平面阻滞（SAPB）对心肺转流（CPB）下胸腔镜心脏手术患者应激反应和术后镇痛的影响。
方法 选择2018年1月至2019年3月行CPB下胸腔镜心脏手术患者40例,男25例,女15例,年龄18～64岁,BMI 18～28 kg/m²,ASA Ⅲ级。采用随机数字表法分为两组：SAPB组(S组)和对照组(C组),每组20例。S组于麻醉诱导前行超声引导下SAPB,在前锯肌表面缓慢注射0.5%罗哌卡因20 ml,30 min后测定阻滞效果,满意后实施全凭静脉麻醉。C组不做处理。两组采用相同的全凭静脉麻醉方法,术毕均行静脉自控镇痛。分别于麻醉诱导前（T1）、CPB前（T2）、CPB结束时（T3）、手术结束时（T4）、手术结束后24 h（T5）抽取静脉血,测血浆皮质醇（Cor）、肾上腺素（E）、血糖（Glu）、白细胞介素-6（IL-6）、白细胞介素-10（IL-10）的浓度。记录术中及术后24 h舒芬太尼的用量、苏醒时间、气管拔管时间、心胸外科重症监护室（ICU）停留时间、术后24 h的VAS疼痛评分以及术后并发症发生情况。
结果 与T1时比较,T2—T5时两组血清Cor、E、Glu、IL-6浓度明显升高,血清IL-10浓度明显降低（P＜0.05）。与C组比较,T2—T5时S组Cor、E、Glu、IL-6浓度明显降低,IL-10浓度明显升高,术中及术后24 h舒芬太尼用量明显减少,术后24 h静息和活动时VAS疼痛评分明显降低,苏醒时间、气管拔管时间、心胸外科ICU停留时间明显缩短（P＜0.05）。两组术后恶心呕吐、肺部感染、低氧血症、肾功能失代偿等并发症发生率差异无统计学意义。
结论 对心肺转流下胸腔镜心脏手术患者实行超声引导前锯肌平面阻滞联合全凭静脉麻醉,可明显降低应激反应,术后镇痛效果更好。     

经皮穴位电刺激联合帕洛诺司琼对腹腔镜非胃肠手术患者术后早期恢复质量的影响

目的 探讨经皮穴位电刺激（TEAS）联合帕洛诺司琼对腹腔镜非胃肠手术患者术后恶心呕吐和早期恢复质量的影响。

方法 选择择期全麻下行腹腔镜非胃肠手术患者648例,男28例,女620例,年龄18～50岁,BMI 15～40 kg/m²,ASA Ⅰ—Ⅲ级。采用随机数字表法将患者分为两组：TEAS组（T组,n=330）和对照组（C组,n=318）。两组患者均在麻醉诱导时预防性使用地塞米松和帕洛诺司琼,T组于麻醉苏醒后和术后第1天上午TEAS双侧内关穴和足三里穴,持续30 min;C组穴位选择同T组,患者连接电针刺激仪,但不给予通电刺激。记录术后24 h内恶心呕吐发生情况、40项恢复质量评分（QoR-40）、止吐补救和术后并发症发生情况。

结果 与C组比较,T组术后24 h内恶心、持续恶心、呕吐和呕吐累积发生率、恶心和呕吐最高VAS评分、止吐补救率和术后并发症发生率均明显降低（P＜0.05）,QoR-40总评分、身体舒适、情绪状态、心理支持、身体独立和疼痛评分均明显升高（P＜0.05）。

结论 术后TEAS双侧内关穴和足三里穴联合帕洛诺司琼可降低腹腔镜非胃肠手术患者PONV和术后并发症发生率,提高术后早期恢复质量。     

揿针联合托烷司琼对腹腔镜全子宫切除术后恶心呕吐及炎性因子的影响

目的 观察揿针联合托烷司琼对腹腔镜全子宫切除术后恶心呕吐（PONV）及炎性因子的影响。

方法 选择择期全麻下行腹腔镜全子宫切除手术患者90例,年龄25～60岁,BMI 18～28 kg/m²,ASA Ⅰ或Ⅱ级。采用随机数字表法将患者随机分为三组：托烷司琼组（A组）、揿针组（B组）和揿针组联合托烷司琼（C组）,每组30例。A组麻醉前30 min静脉推注托烷司琼5 mg;B组麻醉前30 min应用揿针刺激患者中脘、双侧内关、足三里穴,留针48 h;C组麻醉前30 min静脉推注托烷司琼5 mg,并应用揿针刺激患者中脘、双侧内关、足三里穴,留针48 h。记录术后6、12、24 h恶心呕吐严重程度评分、术后首次肛门排气和排便时间。分别在术前30 min和术后24 h抽取静脉血检测TNF-α和IL-6的浓度。

结果 与C组比较,术后6、12、24 h A组和B组恶心呕吐严重程度评分明显升高,术后24 h TNF-α和IL-6浓度明显升高（P＜0.05）。与A组比较,B组和C组术后首次肛门排气、排便时间明显缩短（P＜0.05）。

结论 揿针联合托烷司琼能够有效预防PONV的发生,改善胃肠功能,缓解免疫抑制,减轻术后炎症反应。     

超声引导下高位髂筋膜阻滞在经导管主动脉瓣置换术中的应用

目的 探索超声引导下高位髂筋膜阻滞用于经导管主动脉置换术的效果。
方法 收集2016年12月至2020年12月监测麻醉下行经导管主动脉置换术患者资料126例,男85例,女41例,年龄65～90岁,BMI 22～25 kg/m²,ASA Ⅲ或Ⅳ,术前诊断为主动脉瓣重度狭窄,NYHA Ⅲ或Ⅳ级且首次经历心脏手术。按照术中是否进行高位髂筋膜阻滞分为两组：对照组（C组,n=56）和联合组（T组,n=70）。C组仅采用监测麻醉,T组采用监测麻醉联合高位髂筋膜阻滞。采用卡钳法进行倾向值匹配。收集并记录性别、年龄、BMI、ASA分级、主动脉瓣口面积、主动脉瓣平均跨瓣压、合并症（冠心病、高血压、糖尿病）。记录手术时间、术中丙泊酚和舒芬太尼用量、术后补救镇痛情况、苏醒时间、ICU停留时间、术后住院时间、术后30 d死亡例数。记录术中呼吸抑制、术后恶心呕吐、谵妄/脑卒中的发生情况。
结果 44对患者资料匹配成功。匹配后,与C组比较,T组术中丙泊酚和舒芬太尼用量明显减少（P<0.05）,术后补救镇痛率明显降低（P<0.05）,术后苏醒时间、ICU停留时间和术后住院时间明显缩短（P<0.05）,术中呼吸抑制发生率和术后恶心呕吐发生率明显降低（P<0.05）。两组其余指标差异均无统计学意义。
结论 超声引导下高位髂筋膜阻滞用于经导管主动脉置换术可减少术中麻醉药物用量,缩短苏醒时间和ICU停留时间,减少术后补救镇痛和不良反应的发生,有助于早期康复。     

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。     

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。     

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。     

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 comparison of the inhibitory effects of four volatile anaesthetics on the metabolism of chlorzoxazone, a substrate for CYP2E1, in rabbits

Background: Halothane inhibits in vitro and in vivo activity of cytochrome P-450 (CYP) 2E1. There are several fluorinated volatile anaesthetics besides halothane, and most of them are defluorinated by CYP2E1. It is unclear whether other fluorinated anaesthetics inhibit the in vivo activity of CYP2E1.
Methods: We compared the inhibitory effects of therapeutic concentrations of four inhalational anaesthetics, halothane, enflurane, isoflurane, and sevoflurane, on chlorzoxazone metabolism in rabbits receiving artificial ventilation.
Results: All four inhalational anaesthetics decreased arterial blood pressure and increased plasma chlorzoxazone concentration. However, no significant differences in the plasma chlorzoxazone concentration were found between the four anaesthetics. The estimated chlorzoxazone clearance increased after beginning inhalation with all four agents, but no significant difference in clearance was noted between agents.
Conclusions: At therapeutic concentrations, the in vivo inhibitory effect on chlorzoxazone metabolism was similar for all four inhalational anaesthetics examined, even though their chemical characteristics and extent of hepatic metabolism differ considerably.     

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.     

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.     

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.     

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.