目标导向液体治疗对老年单肺通气患者局部脑氧饱和度及血流动力学的影响

目的观察目标导向液体治疗(goal-directed fluid therapy,GDFT)对老年单肺通气患者局部脑氧饱和度(rSO_2)及血流动力学的影响。方法选择择期全麻下行中段食管癌根治术患者58例,男44例,女14例,年龄65~79岁,ASAⅡ或Ⅲ级,采用随机数字表法分为两组:传统液体治疗组(C组)和GDFT组(G组),每组29例。所有患者均通过桡动脉连接FloTrac/Vigileo监测系统连续监测MAP、心输出量(CO)、心脏指数(CI)和每搏量变异度(SVV)。C组根据MAP、CVP及尿量行传统液体疗法;G组于SVV指导下行GDFT,维持CI 2.5~4.0L·min~(-1)·m~(-2)。所有患者于术中持续监测rSO_2,计算术中rSO_2平均值(rSO_2)、术中rSO_2最小值(rSO_2min)以及rSO_2较基础值下降的最大百分比(rSO_(2%max));记录入室建立监测后(T_1)、单肺通气前(T_2)、单肺通气30 min(T_3)、单肺通气1h(T_4)及术毕(T_5)时的MAP、HR、CVP、CI及SVV;记录术中晶体液和胶体液用量、总输液量、出血量、尿量以及血管活性药物的使用情况。结果与C组比较,T_3、T_4时G组MAP明显升高(P0.05);T_3~T_5时G组CVP明显下降、CI明显升高(P0.05);T_2~T_5时G组SVV明显下降(P0.05)。G组rSO_(2%max)明显低于C组(P0.05),两组rSO_2和rSO_(2min)差异无统计学意义。与C组比较,G组术中晶体液用量[(668±187)ml vs(1 052±221)ml]、总输液量[(1 212±318)ml vs(1 519±329)ml]、尿量[(211±47)ml vs(278±54)ml]及血管活性药物使用[4例(14%)vs 14例(48%)]明显减少(P0.05),胶体液用量明显增加[(544±103)ml vs(467±94)ml,P0.05]。结论基于SVV的GDFT可稳定老年患者单肺通气时的血流动力学,维持脑氧供需稳定。     

多模式监测对缺血型烟雾病血管重建术患者术后恢复的影响

目的评价应用包含脑氧饱和度(rSO_2)和每搏量变异率(SVV)的多模式监测对缺血型烟雾病血管重建术患者术后恢复的影响。方法择期首次行缺血型烟雾病血管重建术患者66例,男34例,女32例,年龄18～60岁,ASAⅡ或Ⅲ级,数字减影血管造影(DSA)烟雾病分期(Suzuki分期)≥3期。采用随机数字表法分为两组:多模式监测组(Mon组)和对照组(Con组),每组33例。Mon组进行rSO_2监测,维持rSO_2在55%以上且降低幅度不超过基础值20%,根据SVV指导输液,维持SVV13%。Con组未进行rSO_2监测,采用常规补液原则,维持CVP 10～12 mmHg。记录两组患者手术时间、术中胶体量、晶体量、总液体量、尿量和出血量。分别于麻醉诱导前(T_0)、血管阻断前(T_1)、血管阻断后10 min(T_2)、血管吻合-开放后10 min(T_3)时检测乳酸(Lac)和Hb。术前1 d和术后5 d采用40项恢复质量评分量表(QoR-40量表)评估患者身体舒适度、情绪状态、自理能力、心理支持和疼痛评分。记录患者术后谵妄、恶心呕吐和脑血管意外的发生情况。结果 Mon组术中胶体量和总液体量明显高于Con组(P0.05)。与T_0时比较,T_2和T_3时两组Lac明显升高(P0.05)。T_2和T_3时Mon组Lac明显低于Con组(P0.05)。术后5 d Mon组QoR-40量表评分中身体舒适度评分、情绪状态评分、心理支持评分和总评分明显高于Con组(P0.05),Mon组术后谵妄和恶心呕吐的发生率明显低于Con组(P0.05)。结论在缺血型烟雾病血管重建术中应用包含rSO_2和SVV的多模式监测,可以指导围手术期氧合及液体管理,有利于维持脑氧平衡及有效脑灌注,提高患者术后恢复质量,降低术后并发症。     

目标导向液体治疗对脊柱手术老年患者预后的影响

目的观察以脉压变异率(PPV)为目标的液体导向治疗(goal-directed fluid therapy,GDFT)对脊柱手术的老年患者预后的影响。方法选择择期行全身麻醉下脊柱手术的老年患者520例,男250例,女270例,年龄65~93岁,BMI18.5~34.0kg/m2,ASAⅡ或Ⅲ级。采用随机数字法分为两组:目标导向液体治疗组(G组)和常规输液组(C组),每组260例。G组以PPV为目标,根据GDFT方案对患者进行容量管理,C组麻醉科医师根据经验进行液体管理。记录术前1d(T0)、麻醉诱导前(T1)、手术开始即刻(T2)、手术结束即刻(T3)的HR、MAP、脉压变异率(PPV)。记录手术时间、术中晶体液的输入量、胶体液输入量、输液总量、自体血回输量、出血量、尿量、麻黄碱使用例数和去甲肾上腺素使用例数。记录术后住院时间,恶心呕吐、头晕、伤口感染、肺部感染和发热等术后并发症情况。结果T3时G组PPV明显低于C组(P0.05)。两组不同时点HR和MAP差异无统计学意义。G组晶体液输入量明显少于C组(P0.05),术中去甲肾上腺素使用率明显低于C组(P0.05)。两组胶体液输入量、输液总量、自体血回输量、出血量、尿量和麻黄碱使用率差异无统计学意义。G组术后住院时间明显短于C组(P0.05)。G组发热病例明显少于C组(P0.05)。结论以PPV为目标导向的液体治疗可以减少脊柱手术老年患者术中晶体液的输入量,血流动力学稳定性好,减少术后并发症的发生,缩短术后住院时间。     

目标导向液体治疗下晶体液与胶体液输注对肝切除术患者组织灌注和术后恢复的影响

目的比较目标导向液体治疗下晶体液与胶体液在择期肝切除术中的应用价值。方法选择择期全麻下行肝切除术患者70例,男42例,女28例,年龄18~65岁,ASAⅡ或Ⅲ级,随机分为三组:常规液体治疗组(C组,n=24)、目标导向胶体液组(G1组,n=23)和目标导向晶体液组(G2组,n=23)。C组主要根据MAP进行术中液体管理,G1、G2组桡动脉连接Flotrac/Vigileo系统监测每搏量变异度(SVV)和心脏指数(CI),术中以MAP、SVV和CI为指导行目标导向液体治疗。当SVV13%,G1组给予250ml胶体液快速填充,G2组则给予相同容量晶体液快速填充;当CI2.5L·min~(-1)·m~(-2)则给予多巴酚丁胺2.0~10.0μg·kg~(-1)·min~(-1)持续泵注直至CI≥2.5L·min~(-1)·m~(-2)。检测麻醉诱导前5min(T_1)、肝脏切除前5min(T_2)、肝脏切除后5 min(T_3)和手术结束时(T_4)的中心静脉氧饱和度(ScvO2)、乳酸(Lac)和血糖(Glu)浓度。记录手术时间、液体出入量及术中血管活性药物使用情况。记录排气时间、下床时间和术后住院时间,记录术前、术后肝肾功能指标及术后并发症发生情况。结果与C组比较,G1组晶体液、胶体液和总液体用量明显减少(P0.05),排气时间、下床时间、术后住院日明显缩短(P0.05),T_3、T_4时ScvO_2明显升高,Glu浓度明显降低,T_2~T_4时Lac浓度明显降低(P0.05),术后第3、5天ALT和AST浓度明显降低(P0.05)。与G1组比较,G2组晶体液用量明显增加,恶心呕吐发生率明显升高(P0.05)。两组排气时间、下床时间、术后住院时间、肝肾功能差异无统计学意义。结论肝切除术中运用目标导向液体治疗策略可能有助于改善微循环和组织氧合、保护肝功能、促进胃肠功能恢复、缩短术后住院时间。与晶体液比较,采用胶体液填充可以降低术后恶心呕吐发生率,而在组织灌注和术后恢复等方面未见明显差异。     

右美托咪定对腹腔镜前列腺癌根治术老年患者局部脑氧饱和度和术后认知功能的影响

目的观察右美托咪定对腹腔镜前列腺癌根治术老年患者对局部脑氧饱和度(rSO_2)和术后认知功能的影响。方法选择择期行腹腔镜前列腺癌根治手术的老年患者60例,年龄65~80岁,ASA分级Ⅰ~Ⅲ级,随机均分为两组:右美托咪定组(D组)在全麻诱导插管后泵注右美托咪定0.5μg/kg,10min泵注完毕,然后以0.5μg·kg~(-1)·h~(-1)的速度持续泵注至手术结束前30min,对照组(C组)泵入等量的生理盐水。术中使用FORE-SIGHT_脑氧饱和度监测仪监测rSO_2。记录入室时(T_0)、诱导插管后(T_1)、气腹后60min(T_2)和苏醒后(T_3)的rSO_2、MAP、PaCO_2和PaO_2。记录丙泊酚和瑞芬太尼的使用情况、术后躁动和恶心呕吐的发生情况。于术前1d、术后1d和3d使用蒙特利尔认知功能评分量表(MoCA)进行评分,记录患者术后认知功能障碍(POCD)发生情况。结果T_2时两组rSO_2、PaCO_2明显高于T_1时(P0.05)。D组患者丙泊酚和瑞芬太尼用量明显少于C组(P0.05)。D组MoCA评分明显高于C组(P0.05);D组2例(6.7%)患者发生POCD,明显低于C组的9例(30%)(P0.05)。结论右美托咪定用于老年患者腹腔镜前列腺癌根治手术对rSO_2未见明显影响,但可以减少POCD的发生。     

目标导向液体治疗对妇科腹腔镜手术术中血流动力学及脑氧饱和度的影响

目的观察目标导向液体治疗(GDFT)对妇科腹腔镜手术术中患者血流动力学及脑氧饱和度(rSO2)的影响。方法选择择期全麻下行腹腔镜妇科肿瘤根治手术患者42例,年龄45~65岁,ASAⅠ或Ⅱ级,采用随机数字表法分为两组:传统液体治疗组(C组)和GDFT组(G组),每组21例。通过LiDCOrapid监测系统监测MAP、心输出量(CO)、心脏指数(CI)、每搏量变异度(SVV)。C组采用传统液体疗法;G组采用SVV指导下的GDFT,维持CI≥2.5 L·min^-1·m^-2。记录麻醉诱导前(T0)、麻醉诱导后(T1)、Trendelenburg体位后30 min(T2)、Trendelenburg体位后1 h(T3)及术毕(T4)时的HR、MAP、CO、CI、SVV、rSO2;记录术中总输液量、晶体液用量、胶体液用量、尿量、血管活性药物使用情况;检测患者术后2 h凝血功能及术后3个月肝肾功能。结果与C组比较,T3时G组HR明显加快(P<0.05),CI明显升高(P<0.05),T2、T3时G组CO明显升高(P<0.05),T1-T3时G组SVV明显降低(P<0.05);G组术中晶体用量[(1 519±472)ml vs(2 112±433)ml]和总输液量[(2 526±587)ml vs (2 745±582)ml]明显减少(P<0.05),胶体用量[(1 007±196)ml vs (633±189)ml]明显增加(P<0.05)。两组患者围术期rSO2、术中尿量、血管活性药物使用、术后2 h凝血功能、术后3个月肝肾功能差异无统计学意义。结论在SVV指导下的GDFT可减少术中总输液量,同时可稳定Trendelenburg体位下行腹腔镜妇科手术患者的血流动力学,且不影响rSO2。     

术中GDFT对老年高血压患者胃癌根治术的影响

探讨术中应用目标导向液体治疗(GDFT)对老年胃癌合并高血压患者行胃癌根治术的影响。选取本院收治的93例拟行根治性术的老年胃癌合并高血压患者,采用随机数字表法分为常规组(46例)和GDFT组(47例)。常规组在术中予以常规液体治疗;GDFT组采用GDFT,使患者在FloTrac/Vig血流动力学、并发症及免疫水平。GDFT组T3、T4、T5的MAP高于常规组(P0.05);T2、T3的CVP低于常规组(P0.05),T4、T5的CVP高于常规组(P0.05)。GDFT组输入液体总量低于常规组(P0.05),羟乙基淀粉用量高于常规组(P0.05)。两组术前CD3+、CD4+、CD8+、CD4+/CD8+比较差异均无统计学意义(P0.05);术后24 h GDFT组CD3+、CD4+、CD4+/CD8+高于常规组(P0.05)。GDFT组术后肺部感染、恶心呕吐率、低血压发生率低于常规组(P0.05)。老年高血压胃癌根治术患者术中行GDFT有利于维持血流动力学的稳定,减少术后并发症,维持免疫水平。     

每搏量变异度指导的目标导向液体治疗对胃肠肿瘤患者术中、术后胃肠功能的影响

目的探讨基于每搏量变异度(SVV)指导的目标导向液体治疗(goal-directed fluid therapy,GDFT)对胃肠肿瘤手术患者术中、术后胃肠功能的影响。方法选取2016年1月至2017年2月择期行胃肠道肿瘤根治术患者60例,男31例,女29例,年龄60~85岁,ASAⅡ或Ⅲ级,采用随机数字表法将患者分为以中心静脉血氧饱和度(ScvO_2)指导的液体治疗组(C组,n=30)和以SVV指导的目标导向液体治疗组(G组,n=30)。记录麻醉诱导前(T_0)、肿瘤摘除即刻(T_1)、术毕(T_2)和术后6h(T_3)时动、静脉血pH、BE、HCO_3~-、Lac。抽取T_0、T_3时静脉血测定脂多糖(LPS)、降钙素原(PCT)的浓度。记录术中所输注的晶体液量、胶体液量、总液量、出血量、腹腔冲洗液量、多巴胺使用率等。记录患者术后PACU时间、术后排气、进食及住院时间。结果 T_2、T_3时G组动脉血BE明显高于C组,T_2时动脉血Lac、T_3时动/静脉血Lac明显低于C组(P0.05);T_3时G组LPS、PCT明显低于C组(P0.05);G组胶体液输注量明显多于,晶体液输注量和总液量明显少于C组(P0.05);G组术后PACU时间、排气时间、进食时间、术后住院时间明显短于C组(P0.05)。结论对于行胃肠肿瘤手术患者,采用以SVV指导的目标导向液体治疗更有利于维持患者的酸碱平衡,降低感染的发生率,促进术后胃肠功能的恢复,减少住院时间。     

目标导向液体治疗中晶体液和胶体液对血管内皮多糖包被的影响

目的探讨在相同目标导向液体治疗(GDFT)策略下,晶体液和胶体液对血管内皮多糖包被的影响。方法选取拟于我院行择期腹膜后肿瘤切除手术的患者80例,男,50例,女,30例,ASAⅠ或Ⅱ级,依据随机数字表法分为晶体液组和胶体液组,每组40例。两组患者均以1.5ml·kg~(-1)·h~(-1)连续输注复方乳酸钠以维持基础补液量,连接FloTrac/Vigileo系统监测每搏量变异度(SVV)和心脏指数(CI),并将SVV≤12%、CI≥2.5L·min~(-1)·m~(-2)和MAP≥60mmHg作为目标进行GDFT,晶体液组液体冲击采用复方乳酸钠,胶体液组液体冲击采用羟乙基淀粉130/0.4氯化钠注射液。记录入室、手术开始1、4h、术后24、72h的血清多糖包被降解产物蛋白聚糖~(-1)(SCD~(-1))、透明质酸(HA)和硫酸乙酰肝素(HS)的浓度;记录术中输液总量和术后恶心呕吐(PONV)、切口感染、肺部并发症和急性肾损伤(AKI)等发生情况。结果与入室比较,两组血清多糖包被降解产物在手术开始1、4h、术后24、72h均呈不同程度增加,手术开始4h升至最高,且于术后逐渐回落,但术后72h仍高于入室;术后24、72h,胶体液组血清多糖包被降解产物明显高于晶体液组(P0.05)。胶体液组术中输液总量明显少于晶体液组(P0.05)。两组患者PONV、切口感染、肺部并发症和AKI发生率差异无统计学意义。结论在相同液体管理策略下,胶体液虽然可以在一定程度上减少液体输注量,但也会对血管内皮多糖包被产生更加持久和严重的破坏。     

每搏量变异率指导的目标导向液体治疗在髋关节置换术中的应用

目的探索目标导向液体治疗(GDFT)在全髋关节置换术中的作用。方法选择2016年10月至2017年6月在上海交通大学附属第九人民医院行全髋关节置换术的患者60例,分为GDFT组和对照组,每组30例。GDFT组以每搏量变异率(SVV)为指导,根据GDFT方案进行术中补液。对照组按常规补液方案进行术中补液。观察两组患者术中液体出入量、血流动力学变化及动脉血乳酸值。结果 GDFT组术中总输液量少于对照组(P0.05),胶体液用量多于对照组(P0.05);尿量少于对照组(P0.05);麻黄碱用药量低于对照组(P0.05)。两组患者术中血流动力学均维持平稳。手术结束时GDFT组血乳酸值低于对照组(P0.05)。结论在全髋关节置换术中,以SVV指导的GDFT可以优化容量管理,维持患者术中循环功能稳定。     

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.     

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.     

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.