体外循环冠状动脉旁路移植术围手术期血浆脑钠肽的变化及其临床意义

目的观察体外循环冠状动脉旁路移植术（CABG）围手术期血浆脑钠肽（brain natriuretic peptide,BNP）的变化规律。方法2005年7～10月我院收治20例CABG患者,分别于麻醉诱导后,主动脉开放前,开放后20min,进入ICU,术后12h,24h和48h测量血浆BNP浓度,分析围手术期BNP的变化规律,以及BNP与心功能、血流动力学指标及术后血浆肌酸激酶同工酶（CK-MB）、肌钙蛋白（TNT）等的相关关系。结果麻醉诱导后BNP与左心室射血分数（LVEF）呈明显负相关（r=-0.912,P=0.000）,与左心室舒张期末内径（r=0.714,P=0.000）,肺毛细血管楔压（PCWP,r=0.809,P=0.000）,中心静脉压（r=0.787,P=0.000）呈明显正相关。手术前后BNP浓度的差异有统计学意义（F=42.259,P〈0.01）,从主动脉钳开放后逐步上升,并在术后24h达峰值。进入ICU,术后12h,24h的BNP浓度与PCWP呈明显正相关（r=0.602,P=0.005;r=0.554,P=0.011;r=0.631,P=0.003）,与CK-MB浓度呈明显正相关（r=0.528,P=0.017;r=0.638,P=0.002;r=0.882,P=0.000）;但与TNT浓度的相关性不明显。结论冠心病患者术前血浆BNP浓度能正确反映术前的心功能状态;心肌缺血-再灌注损伤是术后BNP大量释放的原因;术后BNP监测能正确及时地反映患者的心功能状态,特别是前负荷状态。     

造血干细胞动员对移植静脉近期通畅率的影响

目的 研究造血干细胞动员对移植静脉近期通畅率和吻合口内膜增生程度的影响.方法 将24只新西兰大白兔随机分为实验组和对照组,每组12只,每只兔建立双侧颈动-静脉移植模型,其中一侧移植静脉于移植前采用0.25%胰蛋白酶去内皮细胞处理.实验组兔静脉移植后24h开始皮下注射分泌型基因重组人粒细胞集落刺激因子(rhG-CSF,100μg/kg),连续10d;对照组兔注射等量生理盐水.术后观察造血干细胞动员情况,包括外周血有核细胞计数,单个核细胞比率,移植静脉的近期通畅和吻合口内膜增生情况.结果 实验组术后5d外周血有核细胞计数(t=8.406,P=0.000)和单个核细胞比率(t=31.267,P=0.000)较对照组明显增加.两组内皮完整移植静脉均有较高的通畅率;去内皮移植静脉的通畅率明显降低,实验组通畅率高于对照组(67%vs.30%).实验结束实验组去内皮移植静脉吻合口搏动指数(PI)明显低于对照组(t=2.958,P=0.009).术后4周病理检查显示,两组移植静脉吻合口内膜均有不同程度地增生,去内皮移植静脉内膜增生程度较重,实验组去内皮移植静脉再内皮化完全,吻合口内膜增生程度明显轻于对照组(t=3.413,P=0.004).结论 造血干细胞动员对移植静脉有保护作用,可促进移植静脉的再内皮化,提高近期通畅率,预防吻合口内膜增生引起的再狭窄.     

非体外循环与改良灌注体外循环下冠状动脉旁路移植术对心肌损伤影响558例的回顾性队列研究

目的探讨体外循环下冠状动脉旁路移植术(ONCAB)与非体外循环冠状动脉旁路移植术(OPCAB)对心肌损伤的差异。方法2017~2019年北京安贞医院对558例冠状动脉粥样硬化性心脏病患者施行了冠状动脉旁路移植术,根据是否应用改良灌注的体外循环,将患者分为两组。OPCAB组(OP组):465例,男282例、女183例,年龄(63.58±7.87)岁;ONCAB组(ON组):93例,男64例、女29例,年龄(63.91±7.51)岁。观察两组患者术前24 h、术后30 min、12 h、36 h、48 h和6 d的肌酸激酶MB(CK-MB)及心肌损伤特异性指标—肌钙蛋白(c Tn I)。结果全部患者无围术期死亡。ON组术后12 h CK-MB(5.00 ng/m L vs.8.60 ng/m L,Z=–2.189,P=0.029)、c Tn I(3.00 ng/m L vs.7.80 ng/m L,Z=–5.307,P=0.000),术后36 h CK-MB(5.00 ng/m L vs.5.60 ng/m L,Z=–2.280,P=0.023)、c Tn I(0.10 ng/m L vs.1.02 ng/m L,Z=–6.418,P=0.000),术后48 h c Tn I(0.07 ng/m L vs.0.81 ng/m L,Z=–1.946,P=0.032),均低于OP组。结论ONCAB较OPCAB对心肌损伤更小。     

腹腔镜筋膜内子宫切除术对机体免疫功能影响的随机对照研究

目的探讨腹腔镜筋膜内子宫切除术(classical intrafascial supracervical hysterectomy,CISH)对机体免疫功能的影响.方法选择因良性疾病须行子宫切除术60例,随机分为2组,每组各30例,分别行CISH和开腹子宫切除术(abdominal hysterectomy,AH).测定2组术前、术后1 d血白细胞计数、中性粒细胞百分数,术前1 d和术后1 d、4 d外周血淋巴细胞亚群(CD3、CD4、CD8)、IL-2、IL-10水平.结果 2组术后1 d外周血CD3、CD4浓度较术前均有不同程度的下降(CISH组:qCD3=6.033,qCD4=4.763;AH组:qCD3=11.043,qCD4=9.202;P<0.05),但AH组上述指标显著低于CISH组(tCD3=4.509,PCD3=0.000;tCD4=2.494,PCD4=0.016),术后4 d CISH组CD3、CD4与术前无显著差异(qCD3=1.046,qCD4=0.238,P>0.05),AH组仍明显低于术前(qCD3=6.531,qCD4=5.269,P<0.05),2组比较差异有显著性(tCD3=4.251,PCD3=0.000;tCD4=3.389,PCD4=0.001); 2组CD8浓度术后均稍有下降,但无统计学意义(CISH组:F=0.98,P=0.379;AH组:F=0.29,P=0.752).CISH组术后1 d、4 d外周血 IL-10较术前无明显升高(F=2.24,P=0.113),而AH组术后明显升高(q1-2=20.182,q1-3=15.933, P<0.05),2组比较差异有显著性(术后1 d t =-11.632,P=0.000;术后4 d t = -7.745,P= 0.000).外周血IL-2浓度:CISH组术后1 d明显降低(q=5.465,P<0.05),术后4 d与术前相比差异无显著性(q=2.484,P>0.05),AH组术后1 d、4 d较术前均明显降低(q1-2=11.187,q1-3=5.404,P<0.05),2组间差异有显著性(术后1 d t =5.281,P= 0.000;术后4 d t = 2.806,P=0.007).AH组术后1 d血 WBC和中性粒细胞百分数明显升高(t=-17.476,P=0.000; t=-16.851,P=0.000),CISH组亦明显高于术前(t=-10.685,P=0.000; t=-9.624,P=0.000),2 组比较差异有显著性(t=-7.020,P=0.000;t=-6.181,P=0.000).结论 CISH与AH相比,创伤轻,对机体免疫功能影响小,一定程度上保护了机体的免疫功能.     

国人非体外循环冠状动脉旁路移植术前阿司匹林治疗策略分析

目的观察国人术前不停用阿司匹林对非体外循环冠状动脉旁路移植术(OPCAB)后早期临床结果的影响。方法回顾性分析北京大学人民医院心外科2011~2012年354例择期行OPCAB术患者的临床资料。2011年132例,术前停用阿司匹林≥5 d,定义为停用组,其中男93例、女39例,年龄36~83(61.70±8.74)岁;2012年222例,术前不停用阿司匹林,定义为不停用组,其中男162例、女60例,年龄37~82(63.26±8.94)岁。比较两组术后总引流量、因出血二次开胸、并发症及住院死亡情况,并比较两组术后4~6 h、12~18 h及24~48 h血清心肌肌钙蛋白I(c Tn I)水平。结果两组术前一般资料差异无统计学意义(P0.05)。停用组移植桥血管数少于不停用组[(3.00±0.89)支vs.(3.43±0.93)支,P=0.001]。两组患者术后总引流量[(1 063.75±511.50)ml vs.(1 131.35±460.13)ml,P=0.201]、因出血二次开胸(0例vs.1例,P=1.000)、围术期心肌梗死(2例vs.1例,P=0.647)、术后急性肾功能衰竭(4例vs.7例,P=1.000)、术后脑卒中(1例vs.4例,P=0.726)、术后呼吸机辅助时间[(41.46±85.50)h vs.(52.07±143.59)h,P=0.441]、术后ICU滞留时间[(81.46±116.90)h vs.(79.07±136.43)h,P=0.867]及住院死亡率(0.8%vs.0.9%,P=1.000)差异均无统计学意义。两组间术后4~6 h血清c Tn I水平差异无统计学意义(P=0.506);术后12~18 h及24~48 h血清c Tn I水平差异有统计学意义(P=0.002,P=0.000)。不停用组术后12~18 h及24~48 h血清c Tn I4.0 ng/ml者比例显著低于停用组(5.4%vs.16.7%,P=0.001;5.9%vs.17.4%,P=0.000)。结论 OPCAB术前不停用阿司匹林并不增加术后出血风险,对术后并发症发生率和手术死亡率无显著影响,可以减少OPCAB术后的心肌损伤。     

腹腔镜胆囊切除术对机体炎症免疫反应的影响

目的对比研究腹腔镜胆囊切除术(laparoscopic cholecystectomy,LC)和开腹胆囊切除术(open cholecystectomy,OC)对机体炎症免疫反应的影响. 方法监测胆囊结石或胆囊息肉样病变患者(LC、OC各30例)术前、术后1 h、1 d、2 d的外周血T淋巴细胞亚群、WBC计数、C反应蛋白(C-reactive protein,CRP)及白细胞介素-6(IL-6)的变化并进行比较.酶联免疫吸附法(ELISA)检测IL-6,流式细胞仪检测T细胞亚群. 结果 OC组术后2 d,成熟T淋巴细胞(CD3)(q=5.822,P<0.05)、辅助性T淋巴细胞(CD4)(q=10.636,P<0.05)较术前显著下降,2组CD4/CD8在术后1、2 d无统计学差别(P＞0.05).OC组术后2 d, WBC计数(t=4.904,P=0.000)、CRP(t=9.409,P=0.000)、IL-6(t=6.471,P=0.000)均明显高于LC组. 结论 LC对机体炎症免疫反应影响小,有利于术后恢复.     

不同动员方案对异基因造血干细胞移植临床疗效的影响

目的 探讨异基因造血干细胞移植中不同动员方案的临床效果.方法 回顾性分析71例异基因外周血造血干细胞移植的临床资料,根据供者采用动员剂的不同分为G-CSF动员组(G组,有24例受者)和G-CSF联合GM-CSF动员组(G+M组,有47例受者).比较两组供者的动员效果及移植物细胞成分,观察受者术后造血功能重建的情况和GVHD的发生情况,观察供者应用动员剂后的不良反应.结果 动员4 d后,G组供者的外周血白细胞计数为(49.6±19.5)×109/L,明显高于G+M组供者的(25.4±10.4)×109/L(P＜0.05).两组间CD34+细胞占单个核细胞比例的差异无统计学意义(P＞0.05),但G+M组CD34+CD38-细胞占CD34+细胞的比例为(37.7±5.7)%,明显高于G组的(31.4±4.5)%(P＜0.05).两组供者经过1～3次采集均能获取足够的CD34+细胞,两组采集的供者淋巴细胞计数及其亚群分布的差异均无统计学意义(P＞0.05).两组受者间CD34+细胞、CD34+CD38-细胞及T淋巴细胞亚群输入量的差异均无统计学意义(P＞0.05).术后所有受者的造血功能均顺利重建.术后对受者进行2～55个月的随访,无论是急性还是慢性GVHD,其发病率和严重程度在两组间的差异均无统计学意义(P＞0.05).术后共有17例受者死于原发病复发,10例死于GVHD和感染等移植相关并发症,G组和G+M组分别有14例(58.3%)和31例(66.0%)受者存活.在使用动员剂后,供者出现的主要不良反应为骨骼肌酸痛和发热,多发生在用药后36 h,给予解热镇痛药后缓解.结论 单用G-CSF与联合应用G-CSF和M-CSF进行动员的临床效果相当,但后者对CD34+CD38-细胞的选择性较强,而在异基因造血干细胞移植输入较多的CD34+细胞和CD34+CD38-细胞有利于受者造血功能的快速重建.     

非体外循环冠状动脉旁路移植术术前单次他汀强化负荷减轻术后心肌损伤的随机对照试验

目的探讨非体外循环冠状动脉旁路移植术(OPCAB)术前单次他汀强化负荷的安全性及其对术后心肌保护的作用。方法纳入江苏省人民医院2010年2月至2011年8月期间140例择期行OPCAB的患者,于术前12 h用统计软件产生随机序列,将患者分为对照组和单次负荷80 mg阿托伐他汀的他汀负荷组,每组70例。检测入院时、术后6 h、术后12 h、术后24 h、术后48 h、术后72 h、术后96 h和术后120 h 8个时间点心肌损伤标志物[肌钙蛋白T(Tn T)、心肌型肌酸激酶同工酶(CK-MB)、肌红蛋白(Mb)],以及术前2 d、术后1 d、术后4 d、术后7 d和出院前等5个时间点的肝脏功能[谷丙转氨酶(ALT)、谷草转氨酶(AST)和总胆红素(TBIL)]、血脂[总胆固醇(TC)、甘油三酯(TG)和低密度脂蛋白胆固醇(LDL-C)]以及超敏C反应蛋白(hs CRP)。结果所有患者均手术顺利,康复出院。两组患者术前临床资料及上述指标差异无统计学意义(P0.05)。围手术期两组ALT和AST水平差异无统计学意义,且术后ALT(4.29%vs.5.71%,P=1.000)和AST(4.29%vs.0%,P=0.245)大于3倍正常值上限的发生率差异无统计学意义。与对照组比较,他汀负荷组术后Tn T[(0.23±0.27)ng/ml vs.(0.16±0.24)ng/ml,P=0.011]、CK-MB[(29.57±30.04)U/L vs.(17.73±14.07)U/L,P=0.001]、hs CRP[(31.85±22.89)mg/L vs.(20.81±10.96)mg/L,P=0.001)峰值显著降低。他汀负荷组Tn T大于正常值上限的发生率(47.1%vs.65.7%,P=0.041)及大于5倍正常值上限的发生率(8.6%vs.22.9%,P=0.037)均低于对照组。他汀负荷组CK-MB大于正常值上限的发生率低于对照组(20.0%vs.54.3%,P=0.000)。结论 OPCAB术前单次他汀强化负荷安全,且有减轻术后心肌损伤的作用。     

腹部手术后早期血浆白蛋白及炎症介质变化的研究

目的 探讨不同腹部手术后早期是否存在血浆白蛋白含量降低及术后早期血浆白蛋白含量变化是否与炎症介质水平相关.方法 选取2008年8月至2009年3月择期行不同腹部手术的患者45例,按手术方式不同将患者分为胆囊切除组(A组)、胆囊切除+胆道探查组(B组)、消化道肿瘤根治切除组(C组).每组均为15例.3组于术前、术后12、24、48 h及72 h测定血浆白蛋白含量、血清IL-6、TNF-α浓度.结果 白蛋白含量:A组术后各检测时间点较术前无明显降低(P＞0.05);术后各检测时间点B、C组患者血浆白蛋白含量较术前降低(P＜0.01),C组下降更明显.血清IL-6、TNF-α:A组患者术后12、24、48 h较术前升高(P＜0.01);B、C组患者术后各检测时间点较术前升高(P＜0.01);术前3组间比较差异无统计学意义(P＞0.05).术后各检测时间点3组间比较差异有统计学意义(P＜0.01).血浆白蛋白含量与IL-6、TNF-α浓度呈负相关;(r=-0.376,P=0.000;r=-0.772,P=0.000).结论 腹部中大手术后早期患者出现血浆白蛋白含量降低;腹部手术后早期炎症介质有不同程度的升高;腹部手术后早期白蛋白含量与炎症介质浓度呈负相关.     

胃癌组织中CD133的表达及其临床意义

目的研究胃癌组织中CD133表达的相互关系,重点明确术前、术后外周血单核细胞中CD133mRNA表达的临床意义及其与胃癌原发灶CD133表达的关系。方法 50例胃癌、10例胃溃疡穿孔及10名健康自愿者入组研究。胃癌患者术前和术后1周抽外周静脉血各4 ml,密度梯度离心法分离单核细胞,半定量逆转录聚合酶链反应(RT-PCR)检测CD133 mRNA表达水平。胃溃疡穿孔患者术前抽外周静脉血、健康自愿者抽晨血各4 ml。胃癌原发灶及癌旁正常胃黏膜组织分别行RT-PCR、免疫组织化学染色检测CD133 mRNA和蛋白的表达。分析CD133表达对各临床病理特征和预后的影响。结果健康自愿者及术前胃溃疡患者及胃癌患者外周血中CD133 mRNA的半定量值分别为0.029±0.060、0.059±0.099及0.270±0.163(P=0.000)。胃癌患者术前外周血CD133 mRNA表达与肿瘤组织分化程度、淋巴管浸润、肿瘤浸润深度、淋巴结转移及TNM分期均有关(P<0.05)。相关分析显示,胃癌患者术前外周血中CD133 mRNA半定量值与淋巴结转移率(rs=0.422,P=0.002)、癌转移淋巴结枚数(rs=0.398,P=0.004)呈正相关,并与胃癌原发灶中CD133 mRNA的表达呈正相关(rs=0.337,P=0.017)。胃癌原发灶中CD133蛋白表达阳性者,术前外周血中CD133 mRNA的半定量值较CD133蛋白表达阴性者高(Z=-2.539,P=0.011)。50例胃癌患者行胃癌根治术后1周,其外周血中CD133 mRNA半定量值明显高于术前CD133 mRNA的表达水平(P=0.021)。胃癌浸润深度较深者,术后CD133 mRNA表达升高更明显(Z=-1.978,P=0.039)。术后外周血中CD133 mRNA高表达者较低表达者预后更差(χ2=6.193,P=0.013)。结论胃癌患者术前外周血高表达CD133 mRNA,其与肿瘤分化程度、淋巴管浸润、肿瘤浸润深度、淋巴结转移、TNM分期及胃癌原发病灶CD133蛋白表达有关,且与淋巴结转移率、癌转移淋巴结枚数及胃癌原发灶中CD133 mRNA的表达呈正相关。术后患者外周血中CD133 mRNA半定量值较术前明显升高,这一升高提示肿瘤浸润程度较深,患者预后较差。     

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.     

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.     

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.     

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.     

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.