不同剂量右美托咪定对妇科腹腔镜手术围术期炎症因子的影响

目的探讨不同剂量右美托咪定对妇科腹腔镜手术围术期炎症因子的影响。方法选择2012年1月至2013年12月择期妇科腹腔镜手术患者90例,按照随机数字表法将其分为高剂量右美托咪定组(D1组)、低剂量右美托咪定组(D2组)和对照组(C组),每组30例。D1组和D2组分别于麻醉诱导后持续静脉输注右美托咪定0.5和0.2μg·kg-1·h-1,C组则以等容量生理盐水代替。记录麻醉诱导前10 min(T1)、气管插管后1 min(T2)、气腹后1 min(T3)、术毕(T4)的MAP和HR,并检测血清TNF-α、IL-6、IL-10水平。结果与T1时比较,T2~T4时D2组和C组MAP明显升高,D1组HR明显减慢,T2、T3时C组HR明显增快(P0.05)。与C组比较,T2~T4时D1组和D2组MAP明显降低,HR明显减慢(P0.05)。与T1时比较,T2~T4时三组TNF-α、IL-6和IL-10水平明显升高(P0.05)。与C组比较,T2~T4时D1组和D2组TNF-α和IL-6水平明显降低,但D1组IL-10水平明显升高,T2、T3时D2组IL-10水平明显降低(P0.05)。结论持续输注右美托咪定可减轻妇科腹腔镜手术围术期炎症反应,且0.5μg·kg-1·h-1较0.2μg·kg-1·h-1更为明显。     

右美托咪定对瑞芬太尼复合丙泊酚靶控输注全麻的影响

目的观察预先给予右美托咪定对瑞芬太尼复合丙泊酚靶控输注(TCI)全麻的影响。方法择期全麻行妇科腹腔镜手术患者40例,随机均分为右美托咪定组(D组)和对照组(C组),D组诱导前15min静脉泵注右美托咪定0.8μg/kg,C组则给予等量生理盐水。观察注药前(T1)、麻醉诱导前(T2)、插管前即刻(T3)、插管后即刻(T4)、插管后3min(T5)、拔管后即刻(T6)、拔管后3min(T7)的BIS、MAP、HR、肾上腺素(E)、去甲肾上腺素(NE)浓度变化;记录丙泊酚和瑞芬太尼的用量、麻醉恢复情况,随访术后延迟性呼吸抑制、术中知晓情况。结果 T2时D组BIS明显低于T1时和C组(P<0.01);与D组比较,T2、T4、T6时C组MAP明显升高,HR明显增快(P<0.05或P<0.01);T4、T6时C组的E、NE浓度明显高于T3时和D组(P<0.01),而D组则无明显变化;D组丙泊酚和瑞芬太尼的用量明显少于C组(P<0.05);D组拔管期间体动、呛咳的发生率明显低于C组(P<0.01),两组呼吸恢复时间、睁眼时间、拔管时间组间差异无统计学意义。结论瑞芬太尼复合丙泊酚靶控输注全麻预先静注右美托咪定0.8μg/kg可产生明显的镇静效应,有效抑制患者的应激反应,减少麻醉药的用量,且不延长麻醉恢复时间。     

不同剂量右美托咪定对丙泊酚诱导效应室靶浓度的影响

目的观察不同剂量右美托咪定在全麻患者气管插管时有效性和安全性及对丙泊酚效应室靶浓度(Ce)的影响。方法 60例全麻下行择期上腹部手术患者,随机均分为四组:D1、D2、D3、C组,分别在麻醉诱导前10min静脉泵注右美托咪定0.25μg/kg(D1组)、0.5μg/kg(D2组)和1.0μg/kg(D3组)及10ml生理盐水(C组)。麻醉诱导采用靶控输注丙泊酚,以BIS为靶控目标。丙泊酚初始Ce设为1.5μg/ml,递增梯度为0.5μg/ml,同时泵注瑞芬太尼0.2μg·kg-1·min-1。BIS≤60时推注罗库溴铵0.9mg/kg,BIS≤50并维持5s行气管插管。于输注右美托咪定前(T0)、诱导前(T1)、气管插管前(T2)、气管插管后1min(T3)、3min(T4)、5min(T5)、10min(T6)时记录SBP、DBP、HR、BIS、丙泊酚Ce。结果与T0时比较,T1时D2、D3组HR减慢、D3组SBP、DBP升高(P<0.05);与T1时比较,T2时D1组和C组SBP、DBP下降,HR减慢(P<0.05);与T2时比较,T3～T5时D1组和C组SBP、DBP升高,HR增快,T3时C组BIS升高(P<0.05)。T2～T6时丙泊酚CeD1、D2、D3组明显低于C组(P<0.05)。不同剂量右美托咪定各时点对丙泊酚Ce存在明显负相关关系。结论麻醉诱导前静脉输注不同剂量右美托咪定对丙泊酚诱导效应室浓度存在负相关关系。麻醉诱导前静脉输注右美托咪定0.5μg/kg心血管反应平稳并能显著减少诱导时所需丙泊酚Ce。     

右美托咪定对全麻子宫切除术中血流动力学及应激反应的影响

目的探讨右美托咪定对全麻子宫切除术中血流动力学及应激反应的影响。方法择期行子宫切除术的患者40例,年龄42~58岁,随机均分为右美托咪定组(D组)和对照组(C组)。D组右美托咪定0.2mg用生理盐水稀释至50ml(4μg/ml),麻醉诱导前10min开始以10ml/h持续泵注到子宫标本切下为止,C组给予等容量生理盐水。采用咪达唑仑、舒芬太尼、顺式阿曲库铵、丙泊酚行麻醉诱导,气管插管控制呼吸。麻醉维持:静脉输注丙泊酚、瑞芬太尼,间断静注顺式阿曲库铵。记录给右美托咪定前(T0)、打开腹膜子宫操作开始时(T1)、子宫操作开始10min(T2)、20min(T3)、30min(T4)、子宫切下时(T5)和后腹膜缝合完毕时(T6)的SBP、DBP、HR和血浆肾上腺素、去甲肾上腺素和皮质醇浓度。结果 C组T1~T5时的SBP、DBP明显高于,HR明显快于T0时(P0.05),且SBP、DBP明显高于、HR明显快于D组(P0.05)。C组T1~T5时的肾上腺素、去甲肾上腺素和皮质醇浓度明显高于T0时(P0.05),且明显高于D组(P0.05)。结论右美托咪定用于全麻子宫切除术中,血流动力学稳定,可降低应激反应。     

右美托咪定联合插管型喉罩在困难气道插管中的应用

目的 评价右美托咪定诱导联合插管型喉罩或纤维支气管镜(FOB)在清醒保留呼吸情况下气管插管的效果.方法 择期手术全麻患者96例,ASAⅡ或Ⅲ级,术前气道评估Mallampati分级≥Ⅲ级,Cormack-Lehane分级≥Ⅲ级.随机均分为四组:A组静注右美托咪定1μg/kg(10min)+芬太尼2 μg/kg联合插管型喉罩插管;B组静注咪达唑仑0.03 mg/kg+芬太尼2μg/kg联合插管型喉罩插管;C组静注右美托咪定1 μg/kg(10min)+芬太尼2μg/kg经鼻FOB插管;D组静注咪达唑仑0.03mg/kg+芬太尼2μg/kg经鼻FOB插管.记录麻醉前(T0)、静脉推注右美托咪定或咪达唑仑完毕即刻(T1)、静脉推注芬太尼后(T2)、置入插管型喉罩或FOB到达会厌即刻(T3)、插入气管导管时(T4)、插入气管导管后1 min(T5)、插入气管导管后给予肌松药后3min(T6)时MAP、HR、SpO2、BIS,并记录插管成功率、心动过速、高血压、有无躁动、呛咳等插管反应,记录插管前心动过缓使用阿托品和插管后的心动过速使用艾司洛尔情况,术后随访患者对插管过程是否耐受.结果 与T0时比较,T2、T3时A、C组HR明显减慢,T3～T5时B、D组HR明显增快,T3～T5时B、D组和T4、T5时C组MAP明显升高(P＜0.05).诱导插管前阿托品使用率A、C组明显高于B、D组;插管后艾司洛尔使用率A、C组明显低于B、D组(P＜0.05);术后躁动发生率A、B、C组均明显低于D组(P＜0.05);对麻醉中插管的耐受、下次是否愿意使用同样的麻醉方法A组均明显高于B、C、D组(P＜0.05).结论 右美托咪定联合插管型喉罩在困难气道保留呼吸插管安全有效,而且可以减少心动过速、高血压及心肌缺血发生率,增强对气管插管的耐受.     

右美托咪定在老年患者髋关节置换术中的应用

目的观察右美托咪定在老年患者髋关节置换术中的应用。方法选择65～82岁实施全麻的髋关节置换术患者40例,ASAⅠ或Ⅱ级,随机均分为右美托咪定组(D组)和对照组(C组)。D组患者诱导前10min泵注0.5μg/kg右美托咪定,C组患者给予相同剂量生理盐水,两组均常规诱导插管。术中D组持续静脉泵注右美托咪定0.4μg·kg-1·h-1。记录诱导前10min(T0)、诱导后5min(T1)、10min(T2)、插管即刻(T3)、插管后1min(T4)、3min(T5),手术30min(T6)、1h(T7)、2h(T8)的HR、MAP和SpO2,并记录两组维持相同麻醉深度的丙泊酚用量。结果 C组患者T1、T2时HR快于、MAP高于T0时(P<0.05或P<0.01),D组T1～T8时HR慢于、MAP低于C组(P<0.05);T3时两组HR均快于T0时,MAP高于T0时(P<0.05),但T3～T5时D组明显慢于和低于C组(P<0.05);T6～T8时D组HR慢于C组、MAP低于C组(P<0.05)。手术过程中,在维持相同的麻醉深度下,D组患者丙泊酚用量明显少于C组(P<0.05)。结论右美托咪定可减轻老年患者全麻气管插管时的心血管反应,减少术中丙泊酚用量。     

辅用右美托咪定全麻诱导对麻黄碱升压效应的影响

目的观察辅用右美托咪定全麻诱导对麻黄碱升压效应的影响。方法择期行腹腔镜胆囊切除术患者44例,年龄18~65岁,随机分为生理盐水组(N组)和右美托咪定组(D组)。D组麻醉诱导前泵注右美托咪定0.8μg/kg,15min后改为0.4μg·kg-1·h-1维持,同时开始麻醉诱导和气管插管,插管后5min给予麻黄碱0.1 mg/kg。N组诱导前以同样方式泵注生理盐水,余同D组。记录泵注右美托咪定或生理盐水前(T0)、麻醉诱导前(T1)、插管即刻(T2)、插管后2min(T3)、给麻黄碱即刻(T4)及之后2min(T5)、5min(T6)、10min(T7)、15min(T8)的SBP、DBP和HR。结果与T0时比较,T2时N组SBP、DBP明显升高,HR明显增快(P0.05或P0.01),其余时点SBP、DBP均明显降低(P0.05或P0.01),T4、T7和T8时HR明显减慢(P0.05或P0.01);D组在T1~T8时的SBP、T1~T4和T8时的DBP明显降低,T1和T3~T4时的HR均明显减慢(P0.05或P0.01)。与T2时比较,T3、T4时N组SBP、DBP明显降低,HR明显减慢(P0.01);D组仅T4时SBP明显降低(P0.01)。与T4时比较,T5、T6时N组SBP明显升高(P0.05或P0.01);T5~T7时D组SBP、DBP明显升高,HR明显增快(P0.01)。与N组比较,T1~T3时D组HR明显减慢(P0.05或P0.01),T2时D组SBP、DBP明显降低(P0.01),T5~T8时SBP和DBP明显升高(P0.05或P0.01)。结论全麻麻醉诱导时辅用右美托咪定不仅可减轻气管插管反应,而且可增强麻黄碱的升压反应。     

不同剂量右美托咪定对丙泊酚复合瑞芬太尼用于整形外科手术患者麻醉效果的影响

目的 评价不同剂量右美托咪定对丙泊酚复合瑞芬太尼用于整形外科手术患者麻醉效果的影响.方法 择期行大面积皮肤瘢痕切除和进行皮瓣转移的手术患者60例,性别不限,年龄18～64岁,体重45 ～ 75 kg,ASA分级Ⅰ或Ⅱ级,采用随机数字表法,将患者分为3组(n=20):对照组(C组)、低剂量负荷量右美托咪定组(D1组)和高剂量负荷量右美托咪定组(D2组),D1组和D2组分别于麻醉诱导前10 min静脉输注右美托咪定0.6、1.0μg/kg负荷量,随后以0.4 μg· kg-1·h-1速率静脉输注至手术结束前30 min.麻醉诱导:靶控输注丙泊酚(血浆靶浓度4.0μg/ml)和瑞芬太尼(效应室靶浓度2.0 ng/ml),患者意识消失后静脉注射罗库溴铵0.6 mg/kg,气管插管后,机械通气,麻醉维持:靶控输注丙泊酚(血浆靶浓度2.0 ～ 3.5 μg/ml)和瑞芬太尼(效应室靶浓度1.5 ～ 2.5 ng/ml),维持Narcotrend指数为D级.分别于麻醉前、右美托咪定输注10 min、气管插管前即刻、气管插管后1 min、气管插管后5 min、停止输注右美托咪定、拔除气管导管前即刻、拔除气管导管后1 min、拔除气管导管后5min时记录Narcotrend指数、收缩压(SP)、舒张压(DP)和HR.记录麻醉诱导时间、丙泊酚和瑞芬太尼的用量,记录自主呼吸、定向力恢复和拔除气管导管的时间.拔除气管导管后10 min时行镇静-躁动评分,记录术中窦性心动过缓和麻醉恢复期不良事件的发生情况.结果 与C组比较,D1组和D2组丙泊酚、瑞芬太尼的总用量和拔除气管导管后10 min时镇静-躁动评分、麻醉恢复期恶心、呛咳和躁动的发生率降低,右美托咪定输注10 min时Narcotrend指数和HR降低,D2组麻醉诱导时间缩短(P＜0.05或0.01),D2组术中窦性心动过缓发生率高于C组和D1组(P＜0.05),3组间自主呼吸恢复时间、定向力恢复时间和拔除气管导管时间差异无统计学意义(P＞0.05).D1组和D2组气管插管前后和拔除气管导管前后SP、DP和HR差异无统计学意义(P＞0.05).结论 对于整形外科手术患者,麻醉诱导前静脉输注右美托咪定负荷量0.6 μg/kg,随后以0.4 μg·kg-1 ·h-1速率输注可缩短麻醉诱导时间,减少丙泊酚和瑞芬太尼用量,有效地抑制气管插管和拔除气管导管时的应激反应,降低了不良反应的发生.     

右美托咪定用于运动诱发电位监测神经外科手术患者的安全性和可行性

目的观察右美托咪定用于运动诱发电位(MEP)监测神经外科手术患者的安全性和可行性。方法选择择期全麻下需做MEP监测颅脑肿瘤切除术患者30例,男15例,女15例,年龄20~60岁,体重40~80kg,ASAⅠ或Ⅱ级,随机分为两组:右美托咪定组(D组)和对照组(C组),每组15例。D组在麻醉诱导前经静脉10 min输注右美托咪定0.5μg/kg,随后以右美托咪定0.5μg·kg-1·h-1输注至术毕,C组采取同样方法给予等容量生理盐水。于入室时(T0),切皮时(T1),停肌松药时(T2),停肌松药后50min(T3)观察HR、MAP和BIS值;记录诱发MEP的电流强度,监测等待时间(停肌松药后至首次诱发MEP时间),T3时大鱼际肌MEP(直接电刺激运动皮质诱发的大鱼际肌MEP)的波幅及潜伏期;同时记录术中丙泊酚和瑞芬太尼的用量,不良反应发生情况。结果与T0时比较,T1、T3时C组HR明显增快(P0.05),T2、T3时D组HR明显减慢(P0.05),T1~T3时C组MAP明显升高(P0.05),T1~T3时两组BIS值明显降低(P0.05);T1~T3时D组HR明显慢于C组、MAP明显低于C组(P0.05)。D组丙泊酚用量和首次诱发MEP的电流强度明显低于C组(P0.05),T3时大鱼际肌MEP波幅明显高于C组(P0.05)。D组高血压和心动过速发生率明显低于C组、心动过缓发生率明显高于C组(P0.05)。结论右美托咪定用于MEP监测神经外科手术患者,可满足手术需求、维持围术期血流动力学稳定,降低部分不良反应发生率,改善MEP监测质量,是一种安全、可行的麻醉方法。     

右美托咪定用于腹腔镜胆囊切除术中的临床观察

目的 探讨右美托咪定用于腹腔镜胆囊切除术中的安全性和有效性.方法 ASA Ⅰ或Ⅱ级择期行腹腔镜胆囊切除术的患者32例,随机均分为右美托咪定组(D组)和生理盐水对照组(C组).D组和C组于气管插管后手术开始前10 min分别静脉泵注右美托咪定0.6μg/kg和生理盐水(泵注时间为10 min).两组均以吸入异氟醚维持麻醉.观察记录患者入室及切皮和拔管时的血压、心率以及术中维持麻醉时异氟醚的肺泡气浓度和拔除气管导管的时间.结果 与入室时比较,切皮时和拔管时C组血压明显升高和心率明显增快(P＜0.05),D组血压,心率无明显变化.D组术后烦躁的发生率显著低于C组(P＜0.05).结论 右美托咪定可使腹腔镜胆囊切除术患者的血流动力学更稳定,术后苏醒迅速而完全.     

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.     

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.     

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.     

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.