术前急性高量血液稀释对肿瘤病人围术期T淋巴细胞免疫功能的影响

目的　探讨术前急性高容量血液稀释 (AHH)对肿瘤患者围术期免疫功能的影响。方法　 30例ASAI～II级的胸外科手术病人随机分为AHH组 (n =15 )和对照组 (n =15 )。诱导插管后吸入 2 %～ 2 5 %异氟醚及间断静注维库溴铵维持麻醉 ,在切皮前 ,AHH组输入 6 %羟乙基淀粉液(15ml/kg ,5 0ml/min) ,对照组输入林格氏液 (15ml/kg ,5 0ml/min)。分别于稀释前、稀释后、术后 2 4h和术后 1周抽取静脉血 ,用流式细胞仪测定T淋巴细胞亚群 :CD3 、CD4 、CD8及CD4 /CD8的水平。结果　稀释前两组患者各指标无显著性差异P >0 0 5 ) ;稀释后 ,AHH组CD3 、CD4 明显高于对照组 (P<0 0 1) ,CD8、CD4 /CD8两组比较无显著性差异P >0 0 5 ) ;术后 2 4h和术后第 7dCD3 、CD4 、CD8、CD4 /CD8两组比较均无显著性差异P >0 0 5 )。结论　术前采用 6 %羟乙基淀粉液进行急性高容量血液稀释可以改善肿瘤患者T淋巴细胞的免疫功能 ,对肿瘤患者术后T淋巴细胞的免疫功能无影响。     

曲马多对胃肠道肿瘤患者术中免疫功能的影响

目的 观察曲马多对胃肠道肿瘤患者术中T淋巴细胞亚群和NK细胞数量的影响.方法 30例胃肠道肿瘤行根治手术的患者随机均分为观察组和对照组.观察组麻醉前肌注曲马多1 mg/kg,对照组不使用.于麻醉前、手术1 h和术毕抽取外周静脉血,用流式细胞仪检测T淋巴细胞亚群(CD3+、CD3+CD4+、CD3+CD8+)、活化T细胞(CD3+HLA-DR+)和自然杀伤(NK)细胞(CD3-CDl6+CD56+)数量的变化.结果 两组手术1 h CD3+、CD3+CD4+、CD3+CD4+、CD3+CD8+、CD3+HLA-DR+和NK细胞数量均较麻醉前明显下降,对照组明显低于观察组(P＜0.05);术毕两组各指标有所回升,但对照组仍明显低于麻醉前水平和观察组(P＜0.05).结论 曲马多可减轻胃肠道肿瘤患者术中T淋巴亚群和NK细胞下降的程度,明显改善机体细胞免疫功能的抑制.     

羟乙基淀粉130/0.4急性高容量血液稀释对骨科手术患者内环境的影响

目的探讨硬膜外复合全身麻醉下6%羟乙基淀粉130/0.4急性高容量血液稀释对骨科手术患者内环境的影响。方法选择ASAⅠ或Ⅱ级择期骨科手术患者28例,随机均分为急性高容量血液稀释组(AHH组)和对照组(C组)。均采用硬膜外阻滞复合全身麻醉。AHH组硬膜外阻滞起效后开始血液稀释,快速输入6%羟乙基淀粉130/0.420ml/kg,速率50ml/min;C组常规输液。术中连续监测MAP、HR、SpO2、CVP、ECG和PETCO2。分别于稀释前即刻(T0)、稀释后5min(T1)、120min(T2)采取桡动脉血进行电解质、乳酸(Lac)、血糖(BG)、尿素氮(BUN)、Hct及Hb测定,计算血浆渗透浓度(Posm)。结果AHH组Hct及Hb血液稀释后下降约20%。与C组相比,AHH组患者的MAP、HR较平稳,术中输液量、尿量增多。与T0相比,AHH组T1时CVP升高,T2时pH值降低(P<0.05)。两组患者的BG在T2时增高,且C组高于AHH组(P<0.05)。两组各时点血电解质、Lac、BUN、HCO3-、BE、Posm等各指标差异均无统计学意义。结论硬膜外复合全身麻醉下6%羟乙基淀粉130/0.4急性高容量血液稀释能维持内环境的相对稳定。     

充气式保温毯联合输液加温对全麻食管癌手术苏醒和免疫功能的影响

目的探讨充气式保温毯联合输液加温技术对食管癌手术苏醒和免疫功能的影响。方法择期行食管癌根治术患者50例,随机分为温毯+输液输血加温组(W组)和对照组(C组),每组25例。记录麻醉诱导前(T1)、手术开始2h(T2)、手术结束时(T3)、术后2h(T4)的鼻咽温,及麻醉苏醒时间、术后寒战、术后感染及住院时间;采用流式细胞仪检测T1、T3、术后2d(T5)及5d(T6)外周血T淋巴细胞亚群。结果 C组在T2~T4时的鼻咽温较T1时明显降低(P0.05);W组在T2~T4时的鼻咽温明显高于C组(P0.05);C组患者苏醒时间明显延长、术后寒战发生率明显高于W组(P0.05);与T1时比较,两组T3时CD4+淋巴细胞百分率及CD4+/CD8+均明显下降,CD8+淋巴细胞百分率明显升高(P0.05);在T3时,W组CD4+淋巴细胞百分率及CD4+/CD8+明显高于C组,CD8+淋巴细胞百分率明显低于C组(P0.05)。结论在食管癌根治手术中,采用充气式保温毯联合输液加温技术具有保护患者体温、缩短患者苏醒时间、减少术后寒战的发生,同时有利于保护患者的免疫功能。     

手术联合树突状细胞治疗肾透明细胞癌的效果

目的 观察手术联合树突状细胞治疗肾透明细胞癌的临床效果,为肾癌治疗提供依据.方法 入组患者分为A、B两组,A组(n=33)为术后接受细胞治疗组,B组(n=37)为单纯手术治疗组.所有入组患者分别于手术治疗前8周及治疗后8周采外周血行流式细胞术检测T淋巴细胞亚群(CD3+、CD4+、CD8+、CD4 +/CD8+比值),了解治疗前后机体免疫水平.结果 Ⅰ、Ⅱ期患者A、B组治疗前后T淋巴细胞亚群差异无统计学意义(P＞0.05);Ⅲ期患者A组治疗前后T淋巴细胞亚群差异有统计学意义(P＜0.05),B组治疗前后T淋巴细胞亚群差异无统计学意义(P＞0.05).A组治疗前后T淋巴细胞亚群差异有统计学意义(P＜0.05),B组差异无统计学意义.结论 手术联合树突状细胞治疗可明显提高Ⅲ期肾透明细胞癌患者术后免疫功能,对肾癌治疗具有积极意义.     

瑞芬太尼术后镇痛对肿瘤患者T淋巴细胞亚群的影响

目的观察瑞芬太尼和芬太尼术后镇痛对肿瘤患者T淋巴细胞亚群的影响。方法肿瘤手术患者40例,ASAⅠ或Ⅱ级,随机均分为瑞芬太尼组(R组)和芬太尼组(F组),两组患者均行静-吸复合麻醉。两组术毕分别采用瑞芬太尼或芬太尼行静脉自控镇痛(PCIA),于麻醉前、术后24、48、72 h抽血测定患者T淋巴细胞亚群(CD3+、CD4+、CD8+),并行VAS评分。结果两组患者术后VAS评分差异无统计学意义。术后24 h两组患者CD3+、CD4+、CD4+/CD8+均显著低于麻醉前(P<0.05)。术后48 h R组CD3+、CD4+、CD4+/CD8+已恢复到麻醉前水平,而F组仍明显低于麻醉前和R组(P<0.05)。术后72 h两组T淋巴细胞亚群均恢复至麻醉前水平。结论瑞芬太尼术后静脉自控镇痛能减轻肿瘤患者术后免疫抑制,对机体免疫功能有一定的保护作用。     

不同血液稀释方法对直肠癌患者围术期NK细胞和CIK细胞的影响

目的 比较急性非等容血液稀释(ANIH)和急性高容血液稀释(AHH)联合控制性降压(CH)对直肠癌患者围术期自然杀伤(NK)细胞和细胞因子诱导杀伤(CIK)细胞的影响.方法 择期直肠癌根治术患者45例,随机均分为ANIH组、AHH+CH组和对照组.分别于麻醉前1 h(T1)、术毕即刻(T2)、术后第1天(T3)、第4天(T4)抽取静脉血检测NK和CIK细胞的数量.结果 与T1时比较,T2～T4时AHH+CH组NK细胞明显升高(P＜0.05),T4时ANIH组NK细胞明显升高(P＜0.05),而对照组则明显降低(P＜0.05).与T1时比较,T2时三组CIK细胞均明显降低(P＜0.05),T4时ANIH组和AHH+CH组均明显升高(P＜0.05),且明显高于对照组(P＜0.05).结论 AHH联合CH以及ANIH均能使直肠癌患者NK和CIK细胞增加,AHH联合CH效果更优.     

七氟醚和丙泊酚对HIV感染患者外周静脉血T淋巴细胞亚群的影响

目的探讨七氟醚和丙泊酚全身麻醉对HIV感染患者外周静脉血T淋巴细胞亚群的影响。方法选择全麻下接受妇科及结肠肿瘤手术的HIV感染患者28例,男16例,女12例,年龄28～65岁,体重50～75 kg,ASAⅠ—Ⅲ级。随机分为两组:七氟醚组(S组)和丙泊酚组(P组),每组14例。S组术中持续吸入2%～4%七氟醚,P组持续静脉注射丙泊酚3～6 mg·kg~(-1)·h~(-1),两组均泵注瑞芬太尼0.4～0.6μg·kg~(-1)·min~(-1),调节麻醉深度,维持术中BIS值在40～60。分别于麻醉前30 min(T_0)、气管插管时(T_1)、切皮时(T_2)、手术结束时(T_3)及拔管时(T_4)记录患者生命体征和BIS值以及手术时间和术中出入量。分别于T_0、T_3、术后24 h(T_5)及术后3 d(T_6)抽取患者外周静脉血,检测T淋巴细胞亚群(CD3~+,CD4~+,CD8~+)的含量,计算CD4~+/CD8~+比值,并检测T_0、T_5和T_6时HIV病毒载量。结果与T_0时比较,T_3时两组外周静脉血CD3~+、CD4~+含量和CD4~+/CD8~+比值明显降低,CD8~+含量明显增加(P0.05)。与P组比较,T_3、T_5时S组CD3~+、CD4~+含量和CD4~+/CD8~+比值明显增高,CD8~+含量明显降低(P0.05)。两组HIV病毒载量差异无统计学意义。结论相同麻醉深度下,与丙泊酚比较,七氟醚全身麻醉对HIV感染患者T淋巴细胞亚群抑制较轻且恢复较快。     

局部浸润麻醉对乳腺手术患者外周血T淋巴细胞亚群及应激反应的影响

目的:探讨局部浸润麻醉在乳腺手术中对患者外周血T淋巴细胞亚群及应激反应的影响。方法:选取拟实施乳腺良性肿瘤切除术的120例患者,采用随机数字表法分为A组和B组各60例,A组采用局部浸润麻醉、B组采用硬膜外麻醉,对比两组患者麻醉诱导前(T0)、术毕(T1)、拔管后30 min(T2)时刻的血清皮质醇(Cor)、肾上腺素(E)、去甲肾上腺素(NE)、T淋巴细胞亚群检测结果。结果:T0时刻,A、B组患者的血清Cor、E、NE水平差异无统计学意义(P0.05);T1、T2时刻,两组患者的血清Cor、E、NE水平均较本组T0时刻均显著的升高(P0.05),A组在对应时间点的Cor、E、NE水平均低于B组(P0.05);T0时刻,A、B组患者的外周血CD3~+、CD4~+、CD8~+水平差异无统计学意义(P0.05);T1、T2时刻,B组患者的CD4~+水平较本组T0时刻均显著的降低(P0.05),而CD8~+水平较本组T0时刻显著的升高(P0.05);T1、T2时刻,A组患者的CD4~+水平均高于B组(P0.05),A组患者的CD8~+水平低于B组(P0.05)。结论:乳腺手术中采用局部浸润麻醉较硬膜外麻醉对患者的应激及T淋巴细胞亚群影响更小。     

曲马多对肺癌患者开胸手术围术期免疫功能的影响

目的 探讨曲马多术前应用对肺癌患者开胸手术围术期免疫功能的影响.方法 择期行开胸手术的肺癌患者60例,随机均分为四组,分别在麻醉诱导后使用曲马多1 mg/kg (T组)、恩丹西酮8 mg(O组)、曲马多1 mg/kg+恩丹西酮8 mg(TO组),对照组(C组)不用药.于术前、术毕测定患者血清T淋巴细胞亚群(CD3+、CD4+、CD8+)及NK细胞百分比.结果 四组术毕CD4+细胞显著减低,CD8+细胞显著增高(P＜0.05).T组术毕NK细胞显著增高(P＜0.05),而其它三组明显降低(P＜0.05).结论 肺癌患者使用曲马多更有利于免疫功能的恢复,主要表现为NK细胞百分比增高.     

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.     

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.     

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.