腺苷A1受体激动剂预处理对保存心脏效果的影响

目的探讨腺苷A1受体激动剂预处理延迟效应对低温St.Thomas液保存大鼠心脏的影响及其与心肌ATP敏感性钾通道的关系。方法Wistar大鼠随机分6组,A、C、D组在缺血前24h以高选择性A1受体激动剂CCPA预处理,B、E注射生理盐水;而D、F组在缺血前应用ATP敏感性钾通道阻滞剂氯磺环己脲。然后A、B组4℃St.Thomas液保存4h,复灌1h,而另4组低温缺血3h,复灌1h。观测心功能、CKMB、ATP含量等。结果A组左室内压上升与下降最大速率恢复率(±dp/dtmax,%)为62.83±17.27,66.81±18.99,心肌ATP含量(10-3μmol/wet.g)3.67±1.42;而B组分别为40.41±18.29,44.70±25.14,1.46±0.54;A组都明显高于B组,差异都有统计学意义(P<0.01或P<0.05)。C组±dp/dtmax恢复率、ATP含量都明显高于D、E、F组(P<0.01或P<0.05),而D、E、F组间差异无统计学意义(P>0.05)。结论以腺苷A1受体激动剂可诱导预处理的延迟效应,改善低温St.Thomas液保存离体大鼠心脏的保存效果,而该效应与心肌ATP敏感性钾通道开放有关。     

腺苷A1受体激动剂诱导心脏缺血预处理延迟效应的实验研究

目的探讨腺苷A1受体激动剂能否诱导心脏缺血预处理的延迟保护及其与锰-超氧化物歧化酶(Mn-SOD)表达的关系.方法按随机数字表法将60只鼠分为6组,每组10只.A组:用腺苷A1受体激动剂2-氯环戊腺苷(CCPA)预处理; B组:为缺血对照,静脉注射生理盐水;C组:注射反义全巯代磷酸化寡核苷酸(ODN)后再注射生理盐水;D组、E组和F组在预处理前分别静脉注射Mn-SOD反义ODN、意义ODN、错配ODN.观察左心室压力变化最大速率(±dp/dtmax)的恢复率,肌酸激酶同工酶(CK-MB)释放活性,心肌三磷酸腺苷(ATP)、丙二醛(MDA)含量和Mn-SOD活性.结果 A组、E组和F组±dp/dtmax恢复率、心肌ATP含量和Mn-SOD活性均高于B组、C组和D组(P<0.05,0.01),而CK-MB释放活性和MDA含量均低于B组、C组和D组(P<0.05).结论腺苷A1受体激动剂可诱导预处理的延迟效应,减轻心肌缺血-再灌注损伤,其机制与Mn-SOD的高表达有关.     

腺苷与单磷酯A联合预处理对供心保存的实验研究

目的　探讨腺苷与单磷酯A联合预处理对供心保存的效果。方法　健康大白兔 39只 ,随机分为 4组。A、B组以单磷酯A预处理 2 4h后 ,制成离体心脏 ,A组再用腺苷预处理 ;C组用腺苷作经典预处理 ;D组仅注射生理盐水作对照。各组预处理后 ,用 4℃改良St.Thomas液诱导心脏停搏 ,低温保存 4h ,复灌 1h。观察心功能恢复率、心肌三磷酸腺苷 (ATP)和丙二醛 (MDA)含量、心肌磷酸肌酸激酶 (CK mb)释放量等。结果　A、B、C、D组心功能恢复率 (+dp/dtmax ,% )分别为 :70 .97± 17.92 ,6 5 .5 4± 2 2 .6 2 ,6 4 .36± 16 .10 ,39.0 7± 13.78;A组高于B、C、D组 ,并与D组的差异有显著性 (P <0 .0 1)。A、B、C、D组心肌组织ATP含量 (10 -3 μmol/g湿重 )分别为 :5 .4 6± 1.37,3.97± 1.0 4 ,4 .4 5± 1.2 9,2 .0 7± 0 .74 ;A组高于B、C、D组 ,差异有显著性 (P <0 .0 5orP <0 .0 1)。结论　用单磷酯A和腺苷联合预处理 ,对供心有一定的保护效果。     

腺苷预处理保存供心的实验研究

目的　本研究探讨腺苷预处理早发效应对供心的保护效果。方法　大白兔制成离体心脏 ,以腺苷预处理后 4℃改良St .Thomas液诱导心脏停搏 ,置于该液中低温保存 4h ,再灌注 1h。观察心功能恢复率、心肌ATP、Ck -mb释放量。另设缺血预处理组和单纯改良St .Thomas液保存对照组。结果　缺血和腺苷预处理心功能恢复率 ( +dp/dtmax % )分别为 ( 74.5 6± 14 .3 8) ,( 68.3 8± 10 .47) ,均高于对照组 ( 3 2 .45± 9.46) ,差异有显著性 (P <0 .0 5 )。结论　腺苷预处理早发效应能改善供心保存效果。     

超氧化物歧化酶介导腺苷延迟预处理的研究

目的 探讨以腺苷介导延迟预处理与锰-超氧化物歧化酶(Mn-SOD)的关系。方法大鼠随机分 6组,B组以腺苷 A1受体激动剂 CCPA预处理,24 h后制成离体心脏,低温缺血 3 h,复灌1h。观测心功能、SOD等。A组为缺血对照;C、E、F组在预处理前分别静注Mn-SOD反义、意义、错配寡核苷酸(ODN)。结果 B、C组左室压力上升最大速率恢复率(％)分别为 72.62±16.28,50.00±17.02、Mn-SOD活性(IU/mg.prot)分别为67.81±19.12,35.70±15.02,B组都高于C组,差异有显著性(P<0.05)。结论 Mn-SOD参与腺苷 A1受体介导的延迟预处理。     

二氮嗪心脏停搏液对供心的保护作用

目的探讨二氮嗪(diazoxide)心脏停搏液对冷保存供心细胞凋亡的作用。方法用单纯随机抽样法将32只新西兰大耳白兔随机分成4组(每组8只):二氮嗪组(KH液加入50μmol/L二氮嗪),STH组(St.Thomas液),5-HD组(KH液中加入50μmol/L二氮嗪和100μmol/L 5-hydroxydecanoic acid)和KH组(KH液)。兔心分别在相应的心脏停搏液中冷保存(4℃)6h,应用Langendorff灌注模型,在保存前后测左心室发展压(LVDP)、左心室内压上升最大速率(+dp/dtmax),以保存前LVDP、+dp/dtmax值作基数计算保存后的恢复率。用原位末端标记法(TUNEL)检测保存后心肌细胞凋亡,测定保存后心肌组织中三磷酸腺苷(ATP)、丙二醛(MDA)的含量。结果二氮嗪组的LVDP、+dp/dtmax恢复率和心肌组织中ATP含量明显高于其他3组(P<0.05),而心肌细胞凋亡率、心肌MDA含量均明显低于其他3组(P<0.05)。结论二氮嗪心脏停搏液对离体心脏有保护作用,其作用可能与线粒体钾通道(mitochondrial KATP)开放有关;线粒体钾通道阻滞剂5-HD可取消二氮嗪的心肌保护作用。     

腺苷A_1受体激动剂后处理对兔心肌缺血-再灌注损伤的影响

目的 探讨腺苷A1受体激动剂(2-氯环戊腺苷,CCPA)后处理对兔心肌缺血-再灌注损伤的保护作用.方法 32只兔随机均分为四组:假手术组(S组,开胸后仅行左冠状动脉套线而不阻断160min)、缺血-再灌注组(IR组,行左冠状动脉前降支阻断40 min,再灌注120 min)、缺血后处理组(lPC组,结扎左冠状动脉前降支40 min,再通30 s,结扎30 s,重复3次,再灌注120 min)和CCPA后处理组(APC组,结扎左冠状动脉前降支40 min,开放左冠状动脉1 min内予以静推CCPA100 μg/kg,冉灌注120 min).分别于左冠状动脉前降支阻断前20 min(T1)、左冠状动脉前降支阻断20 min(T2)、左冠状动脉前降支阻断40 min(T3)、心肌再灌注1 h(T4)和心肌再灌注2 h(T5)抽取颈内动脉血测定血清心肌肌钙蛋白I(cTnI)含量.再灌注末抽血离心测定超氧化物歧化酶(SOD)、丙二醛(MDA),测定心肌梗死面积.结果 和IR组相比,IPC组和APC组再灌注各个时间点cTnI均降低(P<0.05);IPC组和APC组梗死面积均小于IR组(P<0.05);IPC组和APC组血清中sOD的活性高于IR组,MDA的含量低于IR组(P<0.05).结论 腺苷A1受体激动剂后处理具有类似缺血后处理的心肌保护作用.其机制可能是通过减少氧自山基的生成,增强心肌抗氧化能力.     

老年心肌缺血再灌注损伤中M受体途径的作用

目的　通过模拟手术过程对老年心肌与青年心肌M受体途径影响的对比研究 ,探讨老年心肌的缺血再灌注损伤机制。方法　成年犬 1 0只 (3～ 4岁 ,A组 )、老年犬 1 0只 (7～ 8岁 ,B组 )。常规建立犬体外循环模型。应用MPA 2 0 0 0生物信号分析系统 ,记录LVEDP、±dp/dt。分别于复跳即刻、复跳后 0 5、1h取左室心肌 ,测定心肌M受体密度、G蛋白含量、cGMP、鸟苷酸环化酶活性。结果　 (1 )在各个时段B组的LVEDP均大于A组 ,而A组的±dp/dtmax均大于B组。在体外循环后 ,随着时间的推移 ,两组手术前后的LVEDP无明显变化 ,但±dp/dtmax均有下降。与A组相比 ,B组下降更为明显。 (2 )在复跳 0 5、1h ,B组的M受体密度较A组明显升高。 (3)A组的Gs复跳前后均变化不大 ,而Gi在复跳后则下降明显 ;B组中复跳后Gs较前有较大下降 ,而Gi则下降较少。Gi/GsB组仍较A组明显升高。 (4)在再灌注后的各个时相 ,B组cGMP的含量以及鸟苷酸环化酶活性明显上升。结论　心脏手术后在老年心肌中由于M受体途径信号强度增强 ,并且与心脏功能呈负相关 ,从而加重了老年心肌的缺血再灌注损伤。     

二氮嗪改善供心超时冷保存效果的实验研究

目的　研究二氮嗪在离体大鼠心脏冷保存中的作用,探讨线粒体ATP敏感性钾通道(Mito chondrialATP sensitivepotassiumchannel,MitoKATPC)开放剂在改善供心功能中的可能机制,及超时(超过公认5h)冷保存供心的有效性。方法　SD大鼠随机分7组。对照组、二氮嗪(DE)组,以上两组又各分为冷保存3、5、10h组和DE +5 羟基葵酸盐(5 HD)组。采用Langendorff离体鼠心灌注法,复灌6 0min ,观察心脏血流动力学、冠脉流出液心肌酶漏出量及心肌水含量变化,并做心肌超微结构检查。结果　(1)冷保存3、5、10h后,DE组LVDP、±dp/dtmax、CF恢复率在多个复灌时间点上均优于对照组,且心肌酶漏出量明显减少。(2 )5、10h保存组中,DE处理后LVEDP的变化明显小于对照组。(3)与对照组相比,保存10h后DE组的心肌水含量明显降低,且心肌超微结构优于对照组。(4)与保存5h对照组相比,保存10h后DE组在复灌期可显著抑制LVEDP的增高;仅LVDP和-dp/dtmax恢复率较保存5h对照组低。(5 )DE的上述作用可被Mi-toKATPC的特异性阻断剂5 HD抵消。结论　Celsior保存液中加入DE能明显改善离体大鼠心脏冷保存效果,且供心的冷缺血安全时间可安全延长至10h,其保护机制涉及MitoKATPC的开放     

常温缺血预处理对幼兔未成熟心肌的保护作用

目的研究常温缺血预处理(IP)对幼兔未成熟心肌的保护作用。方法将24只幼兔分为四组。组1IP1次;组2IP2次;组3IP3次;对照组。应用Langendorff心脏灌注方法,对3～4周龄幼兔离体心脏实施不同次数的5分钟缺血、5分钟再灌注的常温IP,常温缺血45分钟,再灌注30分钟。于平衡灌注末、缺血前、再灌注3分钟、5分钟、10分钟、20分钟和30分钟分别测定左心室发展压(LVDP)、左心室最大上升及下降速率(±dp/dtmax),再灌注末测定心肌组织三磷酸腺苷(ATP)含量、丙二醛(MDA)含量和超氧化物歧化酶(SOD)活性。结果再灌注30分钟时,组1和组2LVDP、+dp/dtmax恢复率显著高于对照组（P<0.05,P<0.01）,组3LVDP、±dp/dtmax的恢复率与对照组比较差别无显著性意义。再灌注末组1、组2和组3心肌ATP含量显著高于对照组（P<0.05）。组2MDA含量显著低于组1、组3和对照组（P<0.05）。结论IP对未成熟心肌具有保护作用,其中2次IP的保护作用最好,而3次的保护作用减弱,表明IP对未成熟心肌的保护作用具有饱和效应和累计现象。     

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.     

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.     

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.     

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.