乌司他丁对心肺转流患者血浆S-100β蛋白、炎性因子及认知功能的影响

目的 观察乌司他丁对心肺转流(CPB)下瓣膜置换术患者血浆S-100β蛋白、炎性细胞因子及认知功能的影响.方法 择期行瓣膜置换术患者40例,随机均分为乌司他丁组(U组)和对照组(C组).U组于切皮前静脉注射乌司他丁10 000 U/kg,并在预充液中加入10 000 U/kg;C组给予等容量生理盐水.于给药前(T1)、CPB结束后即刻(T2)、2 h(T3)、6 h(T4)及24 h(T5)抽取颈内静脉血测定血浆IL-6、TNF-α浓度及S-100β蛋白;于麻醉前1d和术后1、3、7d对患者进行评分并判断是否发生术后认知功能障碍(POCD).结果 与T1时比较,T2～T5时两组血浆S-100β蛋白及IL-6、TNF-α浓度均升高(P＜0.05);与C组比较,U组中的S-100β蛋白及IL-6、TNF-α浓度显著降低(P＜0.01);U组2例、C组7例发生POCD( P＜0.05).结论 乌司他丁可减轻瓣膜置换术患者CPB时炎性介质的释放,降低患者术后POCD的发生率.     

血清S100β及NSE含量与心肺转流心脏瓣膜置换术后早期认知功能障碍的相关性研究

目的探讨血清S100β及神经元特异性烯醇化酶(NSE)的含量变化与心脏瓣膜置换术后早期认知功能障碍(POCD)的相关性。方法择期行心脏瓣膜置换术的患者98例,分别于术前1d、术后1d采用简易智力量表(MMSE)进行神经功能测试,以术后评分下降大于或等于术前评分的一个标准差评定为POCD,根据评分结果,将患者分为POCD组(P组)及非POCD组(NP组)。分别于麻醉诱导前(T0)、手术结束时(T1)、术后24h(T2)、术后48h(T3)抽取动脉血检测S100β和NSE的含量。结果术后1dPOCD的发生率为45例(45.9%)。与T0时比较,T1时两组S100β蛋白明显升高(P0.05);T1、T2时两组NSE含量明显升高,T3时NP组仍明显升高(P0.05);两组组间差异无统计学意义。患者清醒时间延长(OR=1.222,P=0.004)及术后即刻S100β含量升高(OR=1.85,P=0.009)为术后1d发生POCD的危险因素。结论心脏术后存在较高的认知功能障碍发生率,清醒时间延长及术后即刻S100β含量的升高是术后1d发生POCD的危险因素。     

全身麻醉对不同术式老年腹股沟疝患者术后认知的影响

目的研究65岁以上全身麻醉腹股沟疝术后认知与麻醉方式的关系。方法选定马鞍山市中心医院2018年1月至2019年12月住院治疗的60例65岁以上全身麻醉腹股沟疝手术患者,根据手术麻醉方式不同分组,将30例腔镜全身麻醉的患者作为参照组,30例开腹全身麻醉的患者作为试验组,对比2组简易智力状态检查量表(MMSE)评分、蒙特利尔认知评估量表(MoCA)评分、睁眼时间、应答时间、术后认知功能障碍(POCD)发生率。结果术后3 d试验组MMSE评分、MoCA评分均高于参照组,试验组睁眼时间、应答时间均短于参照组,差异均有统计学意义(P<0.05);试验组术后1、3 d POCD发生率(3.33%、3.33%)均低于参照组(23.33%、6.66%),差异有统计学意义(P<0.05);试验组术后7 d POCD发生率(0)低于参照组(3.33%),但差异无统计学意义(P>0.05)。结论65岁以上腹股沟疝患者采取开腹全身麻醉,对术后认知功能影响较小,患者睁眼及应答时间较短,POCD发生率较低,值得借鉴。     

老年全麻患者血清脂联素、基质金属蛋白酶-9水平与术后认知功能障碍的关系

目的 评价老年全身麻醉患者血清脂联素(adiponectin,ADP)及基质金属蛋白酶-9(matrix metalloproteinase-9,MMP-9)水平与术后认知功能障碍(postoperation cognitive dysfunction,POCD)的关系.方法 择期全身麻醉下行全髋关节置换术老年患者98例,年龄65岁～83岁,美国麻醉医师协会(ASA)分级Ⅰ～Ⅱ级,性别不限.所有患者分别于手术前3d及术后1、2、3、7d采用蒙特利尔认知评估表(montreal cognitie assessment,MoCA)评估认知功能,并采集空腹静脉血标本测定血清ADP及MMP-9水平.根据术后3d是否发生POCD分为POCD组和无POCD组.结果 28例患者发生POCD,发生率为28.5％,POCD组患者术后1、2、3d及7d血清MMP-9水平[(537±68)、(481±64)、(432±64)、(393±48) μg/L]较术前[(293±50) μg/L]明显升高(P＜0.05),血清ADP水平[(4.3±1.6)、(4.7±1.2)、(5.1±1.6)、(6.0±1.1) mg/L]较术前[(9.39± 1.36) mg/L]明显下降(P＜0.05).无POCD组术后1、2d血清MMP-9水平较术前明显升高(P＜0.05),血清ADP水平较术前明显下降,术后3d均恢复至术前水平.组间比较,POCD组术后各时间血清MMP-9水平明显高于无POCD组[(439±53)、(387±66)、(301±67)、(296±54)μg/L](P＜0.05);而ADP水平均明显低于无POCD组[(5.7±1.0)、(6.7±1.4)、(9.1±1.0)、(9.4±1.2)mg/L] (P＜0.05).直线相关分析:POCD组患者血清MMP-9水平与MoCA评分呈负相关(r=-0.833,P＜0.01),ADP水平与MoCA评分呈正相关(r=0.513,P＜0.01).结论 老年全麻患者术后血清ADP水平下降与MMP-9水平升高可能参与了POCD发生的病理生理过程.     

体外循环诱发炎性反应与患者术后认知功能障碍的关系

目的 探讨体外循环(CPB)诱发炎性反应与患者术后认知功能障碍(POCD)的关系.方法 择期CPB下心脏瓣膜置换手术的患者25例,随机分为2组:对照组(C组,n=12)和乌司他丁组(U组,n=13).两组麻醉诱导、麻醉维持及体外循环方法相同.U组麻醉诱导后立即静脉注射乌司他丁1.2万U/kg,CPB预充液中加入乌司他丁0.6万U/kg,主动脉开放前5 min体外循环中加入乌司他丁0.6万U/kg,C组给予等容量生理盐水.分别于麻醉诱导后切皮前、CPB结束时、术后24 h时采 集外周静脉血样,测定血浆IL-6浓度及外周血中性粒细胞NF-kB表达水平.分别于术前、术后3、7 d时测试认知功能,记录POCD发生情况.结果 与C组比较,U组血浆IL-6浓度和中性粒细胞NF-kB表达降低(P<0.05或0.01),POCD发生率差异无统计学意义(P>0.05).结论 CPB诱发炎性反应与患者POCD发生无关.     

星状神经节阻滞对CPB心脏瓣膜置换术患者脑损伤的影响

目的 评价星状神经节阻滞(SGB)对CPB心脏瓣膜置换术患者脑损伤的影响.方法 择期CPB心脏瓣膜置换术患者40例,随机分为2组(n=20),SGB组以0.25%罗哌卡因10ml行右侧SGB,C组不行SGB,SGB后10 min进行麻醉诱导.分别于SGB前(基础状态)、CPB 30 min、开放升主动脉后10 min、术后6、24 h时采集左颈内静脉球部血样,测定血浆一氧化氮(N0)、内皮素-1(ET-1)、S-100β蛋白及神经特异性烯醇化酶(NSE)的浓度和一氧化氮合酶(NOS)活性.分别于术前1 d、术后1、7 d时进行简易智能评价量表(MMSE)评分.结果 与C组比较,SGB组术中及术后血浆ET-1、S-100β蛋白及NSE的浓度降低;开放升主动脉后10 min时血浆NO浓度升高,术后血浆NO浓度降低;CPB30 min和开放升主动脉后10 min时NOS活性升高;术后1 d时MMSE评分升高(P＜0.05).与基础值比较,C组术中及术后NO/ET-1比值降低(P＜0.05),SGB组NO/ET-1比值差异无统计学意义(P＜0.05).结论 SGB可调节CBP心脏瓣膜置换术患者脑循环NO和ET-1浓度,维持NO/ET-1相对平衡,有利于脑组织灌注,从而减轻脑损伤.     

老年患者髋关节置换术后早期认知功能障碍的因素分析

目的 分析影响老年患者髋关节置换术后早期认知功能障碍(POCD)的因素.方法 择期髋关节置换术老年患者33例,随机分为2组:静吸复合全麻组(G组,n=15)和脊椎.硬膜外麻醉组(E组,n=18).术中收缩压波动幅度不超过基础值的25%,SpO2≥95%.术后48 h静脉输注0.001%芬太尼2 ml/h镇痛.于麻醉诱导前、术后3 h、6 h、1 d、3 d时记录MMSE评分;采集颈内静脉血样,测定血清S-100β蛋白及神经元特异性烯醇化酶(NSE)浓度.计算麻醉诱导前MMSE评分的标准差,每例患者以麻醉诱导前评分为对照,术后评分与麻醉诱导前比较≥1个标准差时即判断发生POCD.根据术后3 h有无POCD分为POCD组(A组)和无POCD组(B组).结果 E组术后3 h时POCD发生率(22%)低于G组(67%)(P＜0.05).与麻醉诱导前比较,G组和A组术后3、6 h、1 d时、E组和B组术后3、6 h时S-100β蛋白和NSE浓度均升高(P＜0.05或0.01);与术后3 h比较.4组术后其余时点S-100β蛋白浓度均降低,G组和B组术后3 d时NSE浓度降低(P＜0.01);与G组比较,E组术后3 h时NSE浓度降低(P＜0.05);与A组比较,B组术后3 h时S-100β蛋白浓度降低,术后6 h时NSE浓度降低(P＜0.05或0.01).结论 髋关节置换术老年患者行全身麻醉较行脊椎.硬膜外麻醉术后早期POCD发生率高,且与S-100β蛋白和NSE浓度的升高有关.     

老年患者术后认知功能障碍的危险因素

目的 筛选老年患者发生术后认知功能障碍(POCD)的危险因素.方法 择期手术患者240例,ASA Ⅰ或Ⅱ级,年龄65～86岁,根据麻醉方法不同分为3组(n=80):全身麻醉组(G组)、硬膜外阻滞组(E组)和局部麻醉组(L组).分别于术前1 d、术后1、3、5 d记录MMSE评分,计算术前MMSE评分的标准差,每例患者术后MMSE评分与术前MMSE评分比较≥1个标准差时即发生POCD.将不同年龄、性别、文化程度、麻醉方法、手术时间和术前MMSE评分的老年患者POCD发生率进行比较,若差异有统计学意义,该因素进入非条件logistic回归模型,筛选老年患者发生POCD的危险因素.结果 性别、文化程度、麻醉类型、手术时间≥90 min及术前MMSE评分＜23分不是老年患者POCD发生的危险因素;年龄≥75岁与老年患者POCD的发生有关(P＜0.05).结论 年龄≥75岁是老年患者发生POCD的危险因素.     

胸横肌平面阻滞对老年患者心肺转流下心脏瓣膜置换术后早期康复的影响

目的 探讨胸横肌平面（TTP）阻滞对老年患者心肺转流（CPB）下心脏瓣膜置换手术后早期康复的影响。
方法 选择择期行CPB下瓣膜置换术的老年患者58例，男39例，女19例，年龄≥65岁，BMI 18～25 kg/m²，ASA Ⅱ或Ⅲ级，NYHA Ⅱ或Ⅲ级。采用随机数字表法将患者分为两组：胸横肌平面阻滞组（T组）和对照组（C组），每组29例。T组在麻醉诱导前使用超声定位于双侧4—5肋间隙，在肋间内肌和胸横肌注入0.25%罗哌卡因20 ml。C组直接行麻醉诱导。于术前1 d和术后第7天采用神经心理组合量表评估患者的认知功能，记录术中舒芬太尼用量和术后早期认识功能障碍(POCD)的发生情况。记录麻醉诱导后切皮前5 min、术后24、72 h的S100β蛋白浓度。记录入手术室、麻醉诱导后切皮前5 min、锯胸骨时、CPB开始后30 min、CPB结束后30 min、出手术室时的HR和MAP。分别于麻醉诱导后切皮前5 min、CPB开始后30 min、CPB结束后30 min、术后24、72 h检测血清IL-6、TNF-α浓度；检测麻醉诱导后切皮前5 min、CPB结束后30 min、术后72 h的血糖和胰岛素浓度并计算各时点的胰岛素抵抗（IR）指数。记录术后24、72 h的VAS疼痛评分、机械通气时间和ICU滞留时间。
结果 与C组比较，T组术中舒芬太尼用量明显减少、术后第7天POCD的发生率（45% vs 21%）明显降低（P＜0.05），术后24、72 h血清S100β蛋白浓度明显降低（P＜0.05），锯胸骨时HR明显减慢、MAP明显降低（P＜0.05），CPB开始后30 min、CPB结束后30 min和术后24 h血清IL-6浓度明显降低（P＜0.05），CPB开始后30 min、CPB结束后30 min血清TNF-α浓度明显降低（P＜0.05），CPB结束后30 min和术后24 h的IR指数明显降低（P＜0.05），术后24 h的VAS疼痛评分明显降低、机械通气时间和ICU滞留时间明显缩短（P＜0.05）。
结论 TTP阻滞可有效降低老年患者CPB下瓣膜置换术后早期POCD的发生率，有利于维持术中血流动力学稳定、减轻围术期炎症反应、改善IR指数，从而促进患者术后早期康复。     

右美托咪定对老年患者冠状动脉旁路移植术后认知功能的影响

目的 观察右美托咪定对老年患者冠状动脉旁路移植术(coronary artery bypass graft,CABG)后认知功能的影响. 方法 择期行CABG的老年患者60例,年龄60岁～70岁,美国麻醉医师协会(ASA)分级Ⅱ或Ⅲ级,采用随机数字表法分为两组,右美托咪定组(D组)和生理盐水对照组(C组),每组30例.D组患者于麻醉诱导前静脉注射右美托咪定0.6 μg/kg(15 min),随后以0.2 μg· kg-1·h.速率输注至术毕;C组给予等容量生理盐水;其余麻醉措施两组相同.于麻醉后手术前(T1)、心肺转流(cardiopulmonary bypass,CPB)开始后30 min(T2)、CPB结束后30 min(T3)、术后6(T4)、24 h(T5)测定颈内静脉球部血清肿瘤坏死因子(tumor necrosis factor,TNF)-α、白细胞介素(interlukin,IL)-6水平及S100β蛋白浓度.分别于术前1d及术后第1、4、7天对患者进行简易精神状态量表(mini-mental state examination,MMSE)测验. 结果 T2～T5时,D组血清TNF-α、IL-6水平及S100β蛋白浓度明显低于C组(P＜0.05).与T1比较,T2～T5两组血清TNF-α、IL-6水平及S100β蛋白浓度均明显升高(P＜0.05).D组患者MMSE评分术后第4天[(25.2±1.4)分]、第7天[(26.6±13)分]明显低于术前1 d[(29.3±0.8)分],C组患者MMSE评分术后第4天[(23.2±1.0)分]、第7天[(25.6±1.3)分]也较术前1 d[(29.4±1.0)分]明显降低(P＜0.05).术后第4、7天,术后认知功能障碍(postoperative cognitive dysfunction,POCD)的发生率D组(36.7％、30％)均明显低于C组(46.7％、36.7％)(P＜0.05).结论 右美托咪定可降低CPB下行CABG的老年患者POCD的发生率,其机制可能与抑制炎性反应以及S100β蛋白表达有关.     

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.     

The analgesic effect of racemic ketamine in patients with chronic ischemic pain due to lower extremity arteriosclerosis obliterans

Background : Ketamine in sub-dissociative doses has been shown to have analgesic and phantom-Limb pain, where conventional treatment has often failed. Chronic ischemic pain due to lower extremity arteriosclerosis obliterans often responds poorly to analgesics, and the pain-generating mechanisms are not well understood.
Methods : Eight patients with rest pain in the lower extremity due to arteriosclerosis obliterans were given sub-dissociative doses of 0.15, 0.30, or 0.45 mg/kg racemic ketamine and morphine 10 mg as a 5-min infusion on four separate days in a cross-over, double-blind, randomised protocol. Plasma levels of (S)- and (R)-ketamine and their nor-metabolites were analysed with an enantioselective high-performance liquid chromatography (HPLC) method. Pain levels were evaluated with a visual analogue scale (VAS).
Results : Individual pain levels were highly variable during and after all the infusions but the pooled pain levels showed a dose-dependent analgesic effect of ketamine with a transient but complete pain relief in all patients at the highest dose (0.45 mg/ kg). Side-effects, mainly disturbed cognition and perception, were pronounced and dose-dependent. Morphine 10 mg had an analgesic peak at 20 min and 5/8 patients had complete pain relief. The remaining 3 patients also had high baseline pain scores, indicating a higher analgesic potency for the 0.30 and 0.45 mg/ kg ketamine doses than for morphine 10 mg.
Conclusion : We have demonstrated a potent dose-dependent analgesic effect of racemic ketamine in clinical ischemic pain. Due to a narrow therapeutic window, this analgesic effect is probably best utilised in combination with other analgesics.