听觉诱发电位指数在老年高血压患者异氟醚麻醉中的应用

目的　研究听觉诱发电位指数 (AEPI)调控异氟醚麻醉深度对老年高血压患者手术中血压控制的可行性。方法　择期行胃切除术合并高血压的老年患者 2 8例 ,ASAⅡ～Ⅲ级 ,随机分两组 ,每组 14例。Ⅰ组通过AEPI监测对麻醉深度行反馈调控 ;Ⅱ组不用AEPI调控 ,仅根据血液动力学的变化来调整麻醉深度。两组患者麻醉诱导均用芬太尼、丙泊酚和琥珀胆碱 ;麻醉维持用氧化亚氮、异氟醚吸入。记录基础值、插管时、插管后 5min、切皮时、术中探查时、停药时、睁眼时和拔管时 8个时间点的HR、SBP、DBP、MAP和AEPI。结果　Ⅰ、Ⅱ组在插管时的SBP、DBP和MAP均显著低于基础值 (P <0 0 5 )。但插管后 5min时与基础值比较 ,Ⅱ组血压有回升 ,Ⅰ组仍降低 (P <0 0 5 )。术中切皮时、探查时、停药时 ,Ⅰ组血液动力学变化较为平稳 ,且低于基础值 (P <0 0 5 ) ;而Ⅱ组中 ,在切皮时和探查时明显上升 (P <0 0 5 )。两组患者在基础值、睁眼时及拔管时的AEPI值均无明显差异 ;但术中各时点Ⅰ组明显低于Ⅱ组 (P <0 0 5 )。结论　在老年高血压患者手术中 ,通过AEPI的监测调节异氟醚麻醉深度可维持稳定的血液动力学 ,有利于保障患者的安全     

七氟醚与异氟醚麻醉用于支撑喉镜下声带息肉摘除术的比较

目的探讨七氟醚与异氟醚麻醉在支撑喉镜下声带息肉摘除术的临床效果。方法支撑喉镜下声带息肉摘除术患者40例,ASAⅠ～Ⅱ级,随机分为七氟醚组（S组）与异氟醚组（Ⅰ组）,每组20例。两组静注异丙酚2mg／kg、维库溴胺0．05mg／kg,随即S组吸入8％七氟醚或Ⅰ组吸入4．5％异氟醚2min后行气管插管术,术中分别以七氟醚或异氟醚维持麻醉。监测围术期血压、心率、心电图及脉搏氧饱和度等生命体征,记录术毕自主呼吸恢复、拔管及认知恢复的时间。结果麻醉诱导后,S组与Ⅰ组平均动脉压均明显降低,心率加快（P〈0．01）;气管插管后MAP、HR均升高（P〈0．05或P〈0．01）。七氟醚或异氟醚维持麻醉均满足手术要求,两组麻醉苏醒顺利,不良反应少,但S组自主呼吸恢复、拔管及认知恢复的时间均快于Ⅰ组（P〈0．01）。结论七氟醚或异氟醚全麻均适用于支撑喉镜下声带息肉摘除术,七氟醚的麻醉苏醒比异氟醚快。     

右美托咪定用于腹腔镜胆囊切除术中的临床观察

目的 探讨右美托咪定用于腹腔镜胆囊切除术中的安全性和有效性.方法 ASA Ⅰ或Ⅱ级择期行腹腔镜胆囊切除术的患者32例,随机均分为右美托咪定组(D组)和生理盐水对照组(C组).D组和C组于气管插管后手术开始前10 min分别静脉泵注右美托咪定0.6μg/kg和生理盐水(泵注时间为10 min).两组均以吸入异氟醚维持麻醉.观察记录患者入室及切皮和拔管时的血压、心率以及术中维持麻醉时异氟醚的肺泡气浓度和拔除气管导管的时间.结果 与入室时比较,切皮时和拔管时C组血压明显升高和心率明显增快(P＜0.05),D组血压,心率无明显变化.D组术后烦躁的发生率显著低于C组(P＜0.05).结论 右美托咪定可使腹腔镜胆囊切除术患者的血流动力学更稳定,术后苏醒迅速而完全.     

七氟醚与丙泊酚用于小儿烧伤手术麻醉维持的比较

目的比较七氟醚与丙泊酚用于小儿烧伤手术麻醉维持的效果。方法择期手术烧伤患儿60例,随机分为丙泊酚组(P组)和七氟醚组(S组),每组30例。气管插管后P组泵注丙泊酚3~8 mg.kg-1.h-1维持麻醉,S组吸入1%~4%七氟醚维持麻醉;需要时均间断静注芬太尼和阿曲库铵。术毕前5 min停用丙泊酚和七氟醚。记录术中血流动力学指标以及术毕患儿自主呼吸恢复时间、苏醒时间、拔管时间、苏醒时躁动情况。结果气管拔管后P组SpO2明显降低,且低于S组(P<0.05)。S组患儿自主呼吸恢复时间、拔管时间和苏醒时间均明显短于P组(P<0.01)。结论七氟醚用于小儿烧伤手术麻醉维持循环稳定,术毕自主呼吸恢复快、苏醒迅速,拔管及时,躁动发生率低,麻醉效果优于丙泊酚。     

异氟醚和七氟醚麻醉对患者心率变异性的影响

目的研究异氟醚和七氟醚麻醉对患者心率变异性(HRV)的影响。方法60例择期颅脑手术患者,用动态心电图仪记录麻醉诱导前、插管后10 min、停药时、停药后1、2 h和4 h的HRV。结果ISO1组(异氟醚,年龄<60岁)和ISO2组(异氟醚,年龄≥60岁)插管后10 min、停药时、停药后1、2 h的低频功率(LF)、高频功率(HF)值均显著低于麻醉诱导前(P<0.05)。SEV1组(七氟醚,年龄<60岁)和SEV2组(七氟醚,年龄≥60岁)的LF、HF值在插管后10 min、停药时、停药后1 h均显著低于麻醉诱导前(P<0.05)。ISO组插管后各时点的LF、HF值均显著低于SEV组(P<0.05)。结论异氟醚对患者的交感神经和迷走神经都有明显的抑制作用,而对于交感神经和副交感神经活性的均衡性没有显著的影响。异氟醚对于交感神经和迷走神经的抑制作用比七氟醚更为明显。     

瑞芬太尼用于小儿先天性唇腭裂修复术麻醉的观察

目的:观察瑞芬太尼用于小儿先天性唇腭裂修复术麻醉时的血流动力学变化、苏醒时间和苏醒质量.方法:选择先天性唇腭裂修复术小儿30例,随机分成瑞芬太尼组(R组,n=15)和芬太尼组(F组,n=15).麻醉诱导R组用瑞芬太尼1～2μg/kg,F组用芬太尼2～3μg/Kg,插管后行机械通气,R组持续输注瑞芬太尼0.2～0.25μg.Kg-1.min-1,F组每隔15～20min缓慢静注芬太尼1μg/Kg.两组均持续吸入1%异氟烷.监测指标包括患者诱导前、诱导后2min、气管插管后2min、手术开始后1Omin的血流动力学变化,连续记录有创动脉压力(IBP)、心率(HR).血氧饱和度(SPO2).术毕停药后患者自主呼吸恢复时间、睁眼时问、拔管时问及躁动情况. 结果:两组诱导后血压、心率均降低,无显著性差异(P>O.05).R组插管后血流动力学平稳,而F组插管后2min血压升高、心率加快(P<0.05).手术开始后1Omin,R组血压.心率低于F组(P<0.05).两组患儿自主呼吸恢复时间、睁眼时间、拔管时间R组少于F组(P<0.05).躁动R组多于F组,两组比较有显著性差异(P<0.05). 结论:瑞芬太尼复合异氟烷麻醉用于小儿先天性唇腭裂修复术可使血流动力学稳定、苏醒迅速、并发症少,是一种安全、有效的麻醉方法.     

氯胺酮对腹部手术患者七氟醚MAC_(BAR)的影响

目的 评价氯胺酮对七氟醚抑制50%腹部手术患者切皮时应激反应的最低肺泡有效浓度(MAC_(BAR))的影响.方法 择期腹部手术患者44例,ASA Ⅰ或Ⅱ级,年龄30～60岁,随机分为2组(n=22):对照组(K_0组)和氯胺酮组(K_1组).麻醉诱导:静脉注射异丙酚2 mg/kg、芬太尼3 μg/kg和顺阿曲库铵0.15 mg/kg,气管插管后行机械通气.K_0组吸入七氟醚,K_1组吸入七氟醚的同时静脉输注氯胺酮14 μg·kg~(-1)·min~(-1).初始七氟醚呼气末浓度为3.0%.采用改良的序贯法进行试验,切皮时患者的心率或平均动脉压升高幅度≥基础值的15%定义为阳性反应,记录平衡点后各个由阳性反应到阴性反应的中点的浓度,取其平均值,即为MAC_(BAR),并计算其95%可信区间.结果 K_0组七氟醚MAC_(BAR)为3.25%(95%可信区间为3.05%～3.45%);K_1组七氟醚MAC_(BAR)为2.20%(95%可信区间为1.96%～2.44%),K_1组七氟醚MAC_(BAR)低于K_0组(P<0.05).结论 静脉输注氯胺酮14 μg~(-1)·min~(-1)可降低腹部手术患者七氟醚MAC_(BAR),增强七氟醚抑制应激反应的效应.     

全麻复合高位硬膜外阻滞对冠心病病人肌钙蛋白Ⅰ的影响

目的比较观察冠心病病人行胸部手术时采用全麻复合高位硬膜外阻滞能否减轻心肌的损伤.方法 32例冠心病病人随机分为两组,每组16例,Ⅰ组为安氟醚复合高位硬膜外阻滞;Ⅱ组为单纯安氟醚麻醉.两组病人入室后测心率(HR)、平均动脉压(MAP).Ⅰ组病人在行安氟醚全麻前行T3～4或T4～5硬膜外麻醉,5 min后开始诱导插管,安氟醚全麻;Ⅱ组病人直接行安氟醚全麻.两组病人在诱导前和诱导插管后8 h分别抽取血样测定肌钙蛋白I(cTnI)浓度.结果Ⅰ组病人插管后1、5 min及拔管时HR、MAP比麻醉前低(P＜0.05);Ⅱ组病人比麻醉前高(P＜0.05),两组病人插管后1、5 min及拔管时HR、MAP相比有显著差异(P＜0.05).两组病人插管后8 h cTnI浓度均高于诱导前(P＜0.05),但Ⅰ组插管后8 h cTnI浓度比Ⅱ组为低(P＜0.05).结论全麻复合高位硬膜外阻滞麻醉能够减轻冠心病病人手术期的心肌损伤.     

七氟醚复合全麻对上腹部手术应激反应的影响

目的 探讨吸入七氟醚全麻基础上复合硬膜外阻滞或瑞芬太尼靶控输注对上腹部手术患者应激反应的影响。方法选择60例ASAⅠ～Ⅱ级拟行上腹部手术患者随机分为3组（n=20）：对照组（七氟醚维持）、瑞芬太尼组（七氟醚＋瑞芬太尼靶控输注）、硬外组（七氟醚＋硬膜外阻滞）。所有患者入室后常规监护ECG、血压、血氧饱和度,行中心静脉穿刺及桡动脉穿刺测压后,快速诱导插管。记录三组麻醉前（T1）、插管后即刻（T2）、手术开始即刻（T3）、手术开始后30min（T4）及术毕（T5）的平均动脉压（MAP）、心率（HR）、脑电双频谱指数（BIS）及测量末梢血糖（Glu）、乳酸（Lac）、血浆皮质醇（Cor）浓度。记录拔管时间及术后恶心呕吐。结果硬膜外组及瑞芬组术中皮质醇浓度均较对照组低,术后皮质醇浓度瑞芬组低于对照组及硬膜外组。结论七氟醚复合瑞芬太尼靶控输注或硬膜外阻滞的全麻比单用七氟醚更有效减轻术中应激反应。     

七氟醚静吸复合麻醉与全凭静脉麻醉用于小儿手术的比较

目的 比较七氟醚静吸复合麻醉与丙泊酚、芬太尼全凭静脉麻醉用于小儿手术的临床效果.方法 60例4～14岁ASA Ⅰ级择期行外科手术的小儿,随机均分为丙泊酚、芬太尼全凭静脉麻醉组(丙泊酚组)和七氟醚静吸复合麻醉组(七氟醚组).丙泊酚组静脉麻醉诱导,静脉麻醉药物维持.七氟醚组七氟醚麻醉诱导,七氟醚麻醉维持.记录术中血流动力学变化,术后麻醉恢复情况.结果 两组诱导方法都能实现快速诱导,且丙泊酚组麻醉诱导起效更快,意识消失时间、插管时间较七氟醚组缩短(P＜0.01).而七氟醚组麻醉诱导对心率的影响更小,诱导更平稳.七氟醚组苏醒时间、拔管时间、定向力恢复时间和PACU滞留时间均短于丙泊酚组(P＜0.01).结论 七氟醚静吸复合麻醉后术中循环稳定,术后清醒迅速、平稳,可安全有效地应用于小儿手术.     

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.     

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.