逆行性灌注浅低温氧合血心脏不停跳与冷血心脏停搏液对cTn I的影响

目的　对比研究逆行性灌注浅低温氧合血心脏不停跳与低温冷血心脏停搏液对外周血清心肌肌钙蛋白 I(c Tn I)的影响。　方法　将 18例双瓣膜置换术患者分为心脏不停跳组和心脏停搏组 ,观察围手术期外周血清c Tn I、肌酸激酶 (CK)、肌酸激酶同工酶 (CK- MB)及主动脉阻断前后用透射电子显微镜观察心肌超微结构变化。结果　心脏不停跳组主动脉开放后各个时相点 CK虽略低于心脏停搏组 ,但差别无显著性意义 (P>0 .0 5 ) ;主动脉开放后 6小时 CK- MB明显低于心脏停搏组 (P<0 .0 5 ) ,主动脉开放后各个时相点心脏不停跳组 c Tn I明显低于心脏停搏组 (P<0 .0 5 )。两组患者主动脉阻断前心肌超微结构均有轻度改变 ,主动脉阻断 90分钟心脏停搏组心肌超微结构损伤较心脏不停跳组明显。　结论　逆行性灌注浅低温氧合血心脏不停跳围手术期外周血清 c Tn I较低 ,可能与该方法使体外循环期间发生不可逆损伤的心肌细胞较少 ,心肌超微结构损伤较轻有关。     

超极化停搏对家猫体外循环时心肌细胞膜脂区域流动性的影响

目的 探讨超极化停搏对猫体外循环(CPB)时心肌细胞膜脂区域流动性的影响.方法 家猫75只,体重3～4 kg,随机分为3组(n=25),CPB组:CPB建立后不阻断上腔静脉、下腔静脉和主动脉,仅行CPB 150 min;去极化停搏组:主动脉阻断60 min,再灌注60 min,心脏停搏液使用高钾St Thomas液;超极化停搏组:心脏停搏液使用含吡那地尔的低钾St Thomas液,余处理与去极化停搏组相同.应用自旋标记-电子自旋共振技术测定CPB时心肌细胞膜脂区域流动性.结果 与CPB组比较,去极化停搏组主动脉阻断30 min后心肌细胞膜脂S和τc均升高,超极化停搏组主动脉阻断60 min后心肌细胞膜脂S和τc均升高(P＜0.01);与去极化停搏组比较,超极化停搏组主动脉阻断30 min后心肌细胞膜脂S和τc均降低(P＜0.01).结论 与去极化停搏相比,超极化停搏能够更好地维持家猫CPB时心肌细胞膜脂的区域流动性.     

逆行灌注心脏不停跳双瓣膜置换术围术期心肌细胞凋亡及Bcl-2,Bax的表达

目的观察逆行灌注心脏不停跳双瓣膜置换术围术期心肌细胞凋亡及Bcl-2，Bax蛋白表达的变化。方法将26例风湿性心脏病患者分为两组，实验组：14例，阻断主动脉后浅低温逆行灌注持续给予氧合血，使心脏缓慢跳动（40～50次／分）；对照组：12例，中度低温阻断主动脉后根部灌注高钾含血停搏液，待心脏停搏后改为逆行灌注。术中多时点检测血浆肌酸激酶同工酶（CK-MB）、心肌肌钙蛋白T（cTnT）的含量；分别于体外循环（CPB）前，CPB后30min留取右心房标本，检测心肌凋亡细胞及免疫组化法测定心肌细胞Bcl-2和Bax蛋白表达。结果与CPB前比较，主动脉阻断30min时两组CK-MB、cTnT和心肌细胞凋亡数明显升高（P〈0．01），Bax表达明显降低（P〈0．01），实验组Bcl-2表达降低不明显（P〉0．05），而对照组Bcl-2表达降低明显（P〈0．01）。与对照组比较，主动脉阻断30min后实验组CK-MB、cTnT和心肌细胞凋亡数明显降低（P〈0．05），Bcl-2表达明显升高（P〈0．01）。结论逆行灌注心脏不停跳双瓣膜置换术与心脏停搏手术相比较，对心肌细胞凋亡的影响较小，可能与维持Bcl-2蛋白表达水平，抑制Bcl-2／Bax基因向Bax偏移等因素有关。     

吡那地尔预处理对体外循环犬心肌的保护效果

目的 探讨ATP敏感性钾通道开放剂(KCOs)吡那地尔(Pinacidil)药物预处理对常温及低温犬体外循环(CPB)晶体高钾停搏液间断灌注心肌的保护效果。方法 18条犬随机分为三组,每组6条,分别建立犬的常温及低温CPB全心缺血Pinacidil预处理模型。对照组(A组):低温CPB,主动脉根部灌注4℃St.Thomas停搏液(K~+16mmol/L)10ml/kg,阻断30min复灌一次(1/2首量);B组:常温CPB,主动脉根部灌注37℃含氧Pinacidil液(0.083mg/kg);C组:低温CPB,主动脉根部灌注液同B组。三组心脏均接受60min缺血和30min再灌注。阻断主动脉前,开放后15min、30min测血液动力学改变;并循环5min,阻断循环30min、60min及开放循环20min于左心室取心肌组织,测定心肌腺苷酸含量。结果 再灌注期间C组的血液动力学指标明显好于A、B组(P<0.01),而B组又较A组好(P<0.01)。缺血及再灌注期间C组心肌的ATP含量也明显高于A、B组(P<0.01),B组又高于A组(P<0.01)。结论 Pinacidil预处理时对CPB下缺血心肌具有良好的保护效果,低温的效果优于常温。     

不同剂量谷胱甘肽对体外循环下心内直视手术患儿心肌损伤的影响

目的 评价不同剂量谷胱甘肽(GSH)对体外循环(CPB)下心内直视手术患儿心肌损伤的影响.方法 择期CPB下行室间隔缺损修补术患儿48例,年龄2～5岁,ASA分级Ⅱ或Ⅲ级,采用随机数字表法,将患儿随机分为4组(n＝12):对照组(C组)和不同剂量GSH组(G1-3组).G1～3组分别于含血停搏液中加入GSH 50、75、100 mg/kg,C组单用含血停搏液.分别于切皮前即刻(T0)、主动脉开放后30 min(T1)、停CPB后6、12、24 h(T2-4)时取颈内静脉血样,测定血浆心肌肌钙蛋白Ⅰ(cTnI)浓度.于主动脉阻断前即刻及主动脉开放后15 min取心肌组织,观察心肌超微结构,对心肌细胞行线粒体量化评分.结果 与C组比较,G1,2组T3,4时、G3组T1～4时血浆cTnI浓度降低(P<0.05);与G1组和G2组比较,G3组T1～4时血浆cTnI浓度降低(P<0.05);与C组和G1,2组比较,G3组主动脉开放后15 min时心肌细胞线粒体量化评分降低(P<0.05).G3组心肌损伤程度较C组明显减轻.结论 GSH可呈剂量依赖性地减轻CPB下心内直视手术患儿心肌损伤,剂量100 mg/kg时效果较好.     

瑞芬太尼后处理对犬心肺转流后心肌缺血-再灌注损伤的影响

目的研究瑞芬太尼后处理对心肺转流(CPB)犬缺血-再灌注心肌的保护作用及机制。方法 18只成年雄性犬,随机均分为缺血-再灌注组(C组)、缺血后处理组(I组)和瑞芬太尼后处理组(R组)。建立犬CPB模型,阻断升主动脉血流60min。主动脉阻断55min时自主动脉根部进行温血再灌注;I组在开放主动脉之前给予开放30s/再阻断30s三个循环;R组随温血输注瑞芬太尼4μg·kg-1·min-1,持续5min。测定CPB前5min(T0)、开放升主动脉5min(T1)、停CPB30min(T2)和120min(T3)时血浆肌钙蛋白I(cTnI)、丙二醛(MDA)浓度和超氧化物歧化酶(SOD)活性,停CPB120min后测定心肌含水率并观察心肌组织超微结构改变。结果与T0时比较,T1～T3时三组血浆cTnI和MDA浓度均明显升高(P<0.01),而SOD活性明显降低(P<0.01)。T1～T3时I组和R组cTnI和MDA浓度均低于C组(P<0.01),SOD活性高于C组(P<0.01)。I组和R组心肌含水率和超微结构改变均低于或轻于C组(P<0.01),I组和R组各指标差异无统计学意义。结论瑞芬太尼后处理减轻犬CPB后心肌缺血-再灌注损伤,其机制可能与减少活性氧生成并增加SOD活性进而减轻氧化应激有关。     

冷血心脏停搏液及低温心室颤动法在冠状动脉旁路移植术中心肌保护的效果

目的　评价冷血心脏停搏液和低温心室颤动法在冠状动脉旁路移植术 (CABG)中心肌保护的临床效果。方法　根据不同的心肌保护方法 ,将 2 0 13例患者分为两组 ,冷血心脏停搏液组 :5 96例采用冷血心脏停搏液保护心肌 ;低温心室颤动组 :1417例采用低温心室颤动法保护心肌。两组均为单纯、择期 CABG手术 ,观察心肺转流术(CPB)时间 ,升主动脉阻断时间 ,ICU监护期 ,住院死亡率 ,主动脉内气囊泵 (IABP)使用率 ,中枢神经系统并发症及肾功能衰竭发生率。　结果　术中冷血心脏停搏液组与低温心室颤动组旁路移植血管支数无差异 ,冷血心脏停搏液组CPB时间、升主动脉阻断时间明显长于低温心室颤动组 (P<0 .0 1)。术后 ICU监护期、中枢神经系统和肾功能衰竭并发症及术后住院死亡率两组间无差异。　结论　单纯、择期 CABG手术患者 ,低温心室颤动法仍是一种安全、有效的心肌保护方法 ,其临床效果可能优于冷血心脏停搏液法。     

雷米芬太尼后处理对心肺转流诱导犬心肌损伤和炎症因子的影响

目的 探讨雷米芬太尼后处理对心肺转流(CPB)诱导犬心肌损伤和炎症因子的影响.方法 健康成年雄性犬12只,随机均分为雷米芬太尼组(R组)和对照组(C组).两组动物经麻醉和开胸后,建立CPB心肌缺血-再灌注模型,阻断升主动脉60 min.R组于主动脉阻断55 min时自主动脉根部随温血灌注液持续输注雷米芬太尼5 min,速度为4μg·kg-1·min-1,灌注液输注速率2 ml·kg-1·min-1持续5 min.C组于相同时点行温血再灌注,灌注液输注速率同R组.分别于CPB前5 min(T0)、阻断升主动脉后30 min(T1)、开放升主动脉后5 min(T2)、停CPB 30 min(T3)和停CPB 2 h(T4)采集股动脉血,检测心肌肌钙蛋白I(cTnI)的浓度和血浆肿瘤坏死因子α(TNF-α)、白细胞介素-6(IL-6)、IL-8.记录主动脉开放后心脏自动复跳情况,电镜下观察心肌组织超微结构改变.结果 与T0时比较,两组cTnI、TNF-α在CPB后各时点均明显升高(P＜0.05或P＜0.01),升主动脉开放后各时点IL-6、IL-8均明显升高(P＜0.01).R组升主动脉开放后各时点cTnI、TNF-α、IL-6、IL-8均明显低于C组(P＜0.01).R组心肌组织结构损伤程度轻于C组.结论 雷米芬太尼后处理可抑制犬CPB诱导促炎细胞因子的释放,减轻心肌再灌注损伤.     

冷晶体间断灌注与联合温血诱导停搏及终末再灌注的对比研究

目的　对比温氧合血诱导停搏及终末再灌注和 4℃冷晶体心脏停搏液间断灌注的心肌保护作用。　方法将 4 0例风湿性心脏病患者随机等分成温血组和冷晶体组 ,观察心脏自动复跳率 ,测定停搏前、复跳后 0小时、6小时、12小时、18小时、2 4小时和 4 8小时的血浆心肌肌钙蛋白 I(c Tn I) ,对心肌线粒体作量化计分。　结果　温血组心脏自动复跳率明显高于冷晶体组 ;体外循环后温血组 c Tn I明显低于冷晶体组 ,温血组 c Tn I高峰出现时间较早 ;线粒体量化计分分数反映复跳后温血组心肌损伤较轻。　结论　温氧合血诱导停搏及终末再灌注的心肌保护效果较好。     

左-卡尼汀心脏停搏液对心脏瓣膜置换术患者心肌细胞凋亡的影响

目的研究左-卡尼汀心停搏液对心脏瓣膜置术患者心肌细胞凋亡的影响。方法24 例体外循环(CPB)下拟行心脏瓣膜置换术患者,随机分为2组:治疗组和对照组,每组12例,治疗组于4℃ST.ThomasⅡ停搏液中按6g/L 加入左-卡尼汀作为心脏停搏液,对照组给予等量生理盐水。升主动脉阻断期间每30 min灌注停搏液一次,每次15 ml/kg,末次灌注氯化钾浓度减为半量。术前1 d和术后7 d作心脏彩超,测定心脏指数(CI)和左心室射血分数(LNEF);记录开放升主动脉后心脏自动复跳情况。CPB转流前和停机后即刻取心房心肌组织一块,用原位末端脱氧核糖核苷酸转移酶标记法检测心肌凋亡细胞;免疫组化法测定心肌细胞Bax和Bcl-2蛋白表达,计算Bcl-2蛋白与Bax蛋白的比值(Bcl-2/Bax)。结果与对照组比较,治疗组开放升主动脉后心脏自动复跳率升高,术后7 d CI和LVEF 升高,停机后心肌细胞凋亡指数降低(P<0.05或0.01);与转流前比较,两组停机后Bax蛋白表达增强,对照组Bcl-2蛋白表达减弱(P<0.05或0.01);与对照组比较,治疗组停机后Bax蛋白表达减弱, Bcl-2蛋白表达增强,Bcl-2/Bax升高(P<0.05或0.01)。结论左-卡尼汀通过调整Bcl-2与Bax蛋白表达的平衡,从而减少了CPB诱导的心肌细胞凋亡,对心肌起到一定程度的保护作用。     

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.     

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.     

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.     

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.     

Intrathecal administration of sameridine to patients subjected to arthroscopic knee joint surgery

Background: Sameridine, a new substance with both local anesthetic and opioid effects, was administered intrathecally for the first time to humans, i. e. in patients subjected to arthroscopic knee joint surgery.
Method: A dose-escalating (10, 15, 20 and 25 mg), open study was performed in 33 patients. Only two patients were included in the 25 mg group.
Results: Sameridine provided good quality of surgical anesthesia in all patients except those receiving 10 mg. The maximum level of sensory block, Th5–Th7, was reached within 30 min with a median duration of 3.6–3.9 h. The motor block was more profound with increasing dose, but never lasted longer than the sensory block. The influence on heart rate and blood pressure was minor and atropine and ephedrine were needed in four patients. No clinically significant ECG-changes were detected and no arrhythmias were recorded. Oxygen saturation and respiratory rate did not decrease in a clinically significant way and were not affected by concomitant morphine given i. v. postoperatively. There were few side-effects, the most frequent being mild pruritus (10/33).
Conclusion: Sameridine provided clinically adequate anesthesia for the patients receiving the doses of 15, 20 and 25 mg. Further studies are needed to evaluate the substance and it is of great interest to clinically investigate the opioid component with respect to postoperative analgesia.     

Reduction of Plasma Fibrinogen, Immunoglobulin G, and Immunoglobulin M Concentrations by Immunoadsorption Therapy with Tryptophan and Phenylalanine Adsorbents

Abstract Immunoadsorption (1A) therapy with tryptophan (TR-350) or phenylalanine (PH-350) adsorbents has been used to reduce the concentration of serum antibodies in human lymphocyte antigen (HLA)-immunized patients. Other forms of plasma purification have been reported to reduce the level of fibrinogen, which affects the blood properties. In this study we investigated the effects of IA therapy using both adsorbents on plasma fibrinogen and immunoglobulins G and M in 13 patients (8 patients were treated with TR-350, and 5 patients were treated with PH-350). During each session 1 plasma volume (2.8 ± 0.4 L of plasma) was processed through the immunocolumn and then returned to the patient together with the blood cells. Compared with the pretreatment values, the plasma fibrinogen, IgG, and IgM concentrations were significantly reduced after IA therapy (p < 0.01 for TR-350; p < 0.04 for PH-350). There was a positive correlation between the degree of reduction of plasma proteins and the number of IA treatments given. A nonpara-metric test (Wilcoxon's signed-rank test or the Mann-Whitney test) was used for statistical analysis. We conclude from our study that IA therapy effectively lowers the plasma levels of fibrinogen, IgG, and IgM and thus can be considered a valuable alternative to other blood purification methods.