瑞芬太尼复合异丙酚在高血压患者腹腔镜胆囊切除术的应用

目的探讨瑞芬太尼复合异丙酚全凭静脉麻醉用于高血压患者腹腔镜胆囊切除术对血流动力学的影响。方法择期ASAⅠ-Ⅱ级腹腔镜胆囊切除术高血压患者40例，均为Ⅰ～Ⅱ期高血压患者。A组用异丙酚和瑞芬太尼持续静脉泵入维持麻醉；B组以异氟醚吸入维持麻醉，间断辅以芬太尼静注。监测血流动力学参数、拔管时间、清醒时间。结果与气腹前比，A组无明显变化，B组气腹后10min的SBP、DBP、HR及术毕HR明显高于气腹前，A组的清醒时间及拔管时间均短于B组。结论瑞芬太尼复合异丙酚全凭静脉麻醉用于高血压患者腹腔镜胆囊切除术是一种安全、有效的全麻方法。     

异丙酚复合芬太尼或瑞芬太尼靶控静脉麻醉与静吸复合麻醉的比较

目的将异丙酚复合芬太尼或瑞芬太尼进行靶控静脉麻醉与传统的静吸复合麻醉的麻醉效果进行比较分析,观察其临床效果。方法将ASAⅠ-Ⅱ级择期手术的150例患者随机分成A组(异丙酚复合芬太尼靶控静脉麻醉),B组(异丙酚复合瑞芬太尼靶控静脉麻醉)和C组(静吸复合麻醉)3组。每组各50例,对比3组的临床麻醉效果。结果进行麻醉时的数据显示,C组患者的SBP、DBP和HR在诱导时的最低值比较差异无统计学意义(P0.05)。A、C组的插管反应率高于B组,差异有统计学意义(P0.05)。C组的OAAS评分明显高于A组和B组,差异有统计学意义(P0.05)。结论与静吸复合麻醉比较,异丙酚复合瑞芬太尼靶控静脉麻醉更稳定,患者更易于恢复意识,应当在临床推广使用。     

腹腔镜胆囊切除术瑞芬太尼-异丙酚全凭静脉麻醉与地氟醚静吸复合麻醉效果的比较

目的比较腹腔镜胆囊切除术（laparascopic cholecystectomy，LC）瑞芬太尼-异丙酚全凭静脉麻醉与静吸复合麻醉的临床效果。方法择期LC手术40例，随机分为对照组和实验组，每组20例。麻醉维持，对照组用10%地氟醚吸入，实验组按异丙酚6 mg/（kg.h）和瑞芬太尼0.5μg/（kg.min）的速度用微量泵输入。记录麻醉诱导前（T0）、气腹前（T1）和气腹后10min（T2），气腹毕（T3），术毕（T4）的收缩压（SBP）、舒张压（DBP）、心率（HR）、血氧饱和度（SPO2）、呼之睁眼时间，拔管时间，清醒程度及不良反应。结果对照组T2、T3、T4时HR、T2时SBP及DBP均显著高于T0时基础值（P〈0.05），实验组各时点指标无明显变化；两组比较对照组T2、T3、T4时HR、SBP及T2、T3时DBP均明显高于实验组（P〈0.05）；两组患者拔管时间，清醒程度均无显著性差异；实验组镇静评分（OAAS评分）明显高于对照组（P〈0.05）；实验组的术后恶心呕吐发生率显著低于对照组（P〈0.05）。结论与常规静吸复合麻醉下行LC比较，异丙酚复合瑞芬太尼全凭静脉麻醉围术期麻醉更平稳，并发症较少。     

瑞芬太尼与氯胺酮复合异丙酚静脉麻醉用于重睑术中的疗效对比

目的:对比分析瑞芬太尼复合异丙酚和氯胺酮复合异丙酚静脉麻醉在重睑术中的麻醉效果及安全性,为重睑术麻醉方案的选择提供参考。方法:纳入笔者医院2014年1月-2017年12月符合条件的重睑术就医者108例作为研究对象,按照手术顺序编号,采用数字随机表法分为2组,每组54例。瑞芬太尼组采用瑞芬太尼复合异丙酚静脉麻醉,氯胺酮组采用氯胺酮复合异丙酚麻醉,记录两组就医者围手术期氧合状态、通气状况及脑功能指标变化[平均动脉压(MAP)、心率(HR)、呼吸频率(BR)、血氧饱和度(SpO_2)、呼气末二氧化碳分压(PETCO_2)],及围手术期并发症发生情况等。结果:两组患者入室后即刻、局麻后20min MAP、HR、BR、SpO_2、PETCO_2比较差异无统计学意义(P0.05),但瑞芬太尼组静脉麻醉即刻、局麻即刻、局麻后10min MAP、HR、BR均明显低于氯胺酮组,差异有统计学意义(P0.05)。瑞芬太尼组Ramsay镇静评分(2~4分)率为88.89%明显高于氯胺酮组的70.37%,差异有统计学意义(P0.05)。瑞芬太尼组BCS舒适评分为(2.81±0.93)分明显高于氯胺酮组的(2.41±0.72)分,差异有统计学意义(P0.05)。瑞芬太尼组围手术期并发症发生率为11.11%明显低于氯胺酮组的22.22%,差异有统计学意义(P0.05)。结论:瑞芬太尼复合异丙酚用于重睑术麻醉综合效果优于氯胺酮复合异丙酚麻醉方案,为手术创造了更优的麻醉效果,具有较高的临床价值。     

妇科腹腔镜手术全凭静脉麻醉与异氟醚吸入麻醉的对比研究

目的观察瑞芬太尼靶控输注复合异丙酚全凭静脉麻醉与异氟醚吸入麻醉在妇科腹腔镜手术中的应用效果。方法随意选择2008年1～12月择期妇科腹腔镜手术60例,ASA分级Ⅰ～Ⅱ级,分为2组：靶控输注瑞芬太尼复合异丙酚全凭静脉麻醉组（T组,n=30）,采用咪唑安定0.05 mg/kg,瑞芬太尼1μg/kg,异丙酚2～2.5 mg/kg及维库溴铵0.1 mg/kg快速诱导后,经口明视气管插管,维持采用瑞芬太尼靶浓度4～8 ng/ml,异丙酚4～8 mg.kg-1.h-1;异氟醚组（I组,n=30）,采用芬太尼2μg/kg,异丙酚2～2.5 mg/kg,维库溴铵0.1 mg/kg诱导,经口明视插管后,维持采用1∶1的氧气和异氟醚（维持呼气末浓度0.8～1.2 MAC）吸入麻醉。术中监测收缩压（SBP）、舒张压（DBP）、心率（HR）等指标。结果在插管后1 min（T3）,I组病人DBP、HR与基础值（T1）比较明显升高（P〈0.05）,T组病人DBP、HR则基本恢复到T1水平,2组比较差异有显著性（t=-4.277,P=0.000;t=-3.286,P=0.002）。清醒拔管时（T6）与T1比较,I组SBP、DBP、HR明显升高（P〈0.05）,而T组SBP、DBP、HR则无明显变化（P〉0.05）,2组比较差异有显著性（t=-5.461,P=0.000;t=-2.287,P=0.000;t=-4.382,P=0.000）。T组病人诱导时间、苏醒时间、拔管时间均显著短于I组（t=-6.386,P=0.000;t=-4.876,P=0.000;t=-6.632,P=0.000）。结论瑞芬太尼靶控输注复合异丙酚全凭静脉麻醉在妇科腹腔镜手术中既满足了手术要求又提高了麻醉药的可控性。     

不同剂量瑞芬太尼复合依托咪酯麻醉诱导时腹部手术患者心血管反应及血流动力学变化

目的:探讨不同剂量的瑞芬太尼复合依托咪酯麻醉诱导时腹部手术患者心血管反应和血流动力学的变化情况,从而有效的为患者选取合适的剂量进行麻醉诱导.方法:将我院2010年1月到2010年12月进行腹部手术治疗的90例患者随机的分为三组,A组给予1.0ug/L瑞芬太尼,B组给予2.0ug/L瑞芬太尼,C组给予3.0ug/L瑞芬太尼进行复合依托咪酯麻醉诱导,观察三组的患者血流动力学的变化和心血管的反应情况.结果:C组患者在插管后观察点的SBP和DBP以及HR较诱导前比较具有明显的降低,差异有统计学意义(P＜0.05).但是在插管后的SBP和DBP以及HR变化无明显的差异(P＞0.05);而A组和B组患者在插管后1min的SBP和DBP以及HR较诱导前有明显的升高,差异有统计学意义(P＜0.05).而插管后3min和5min的SBP和DBP以及HR变化也明显的降低,但高于C组插管后3min、5min的SBP、DBP及HR变化情况,差异有统计学意义(P＜0.05).结论:不同剂量的瑞芬太尼复合依托咪酯在腹部手术患者的麻醉诱导中,均具有抑制心血管应激反应.而且临床中采取3.0ug/L的瑞芬太尼复合依托咪酯麻醉诱导的稳定性较好,能够有效的稳定患者的血流动力学变化,但是在采取这种剂量诱导时,做好预防严重的心血管抑制情况发生.     

喉罩麻醉中靶控输注异丙酚复合瑞芬太尼效果观察

目的观察靶控输注异丙酚复合瑞芬太尼实施喉罩麻醉的效果。方法随机将86例接受喉罩麻醉的患者分为2组,各43例。对照组给予异丙酚靶控输注。观察组应用异丙酚复合瑞芬太尼靶控输注。比较2组患者(1)麻醉前(T_0)、喉罩置入前(T_1)、喉罩置入后1 min(T_2)、停药时(T_3)的SBP、DBP、HR。(2)术中不良反应例数、患者苏醒时间及异丙酚用量。结果 T_0、T_3时2组SBP、DBP及HR差异无统计学意义(P0.05)。T_1、T_2时点观察组SBP、DBP及HR的波动幅度优于对照组,术中不良反应、苏醒时间及异丙酚的用量少于对照组,差异均有统计学意义(P0.05)。结论与单纯应用异丙酚比较,靶控输注异丙酚复合瑞芬太尼实施喉罩麻醉,对患者血液动力学影响较小,不良反应发生率低,苏醒快及异丙酚的用量少,效果满意。     

老年结直肠癌患者腹腔镜手术不同麻醉方式的比较

目的 比较三种不同麻醉方式在老年结直肠癌腹腔镜手术中的应用效果.方法 120例老年结直肠癌腹腔镜手术患者随机分为硬膜外阻滞组(A组)、全麻组(B组)和全麻复合硬膜外阻滞组(C组),每组40例.观察和比较三组患者的SBP、DBP、HR变化及术中肌松效果、躁动及术后恶心呕吐情况.结果 气腹后10 min三组SBP,A、B组DBP明显高于麻醉前(P＜0.05),A、B组SBP、DBP明显高于C组(P＜0.05);气腹后60 min A、B组SBP、DBP明显高于麻醉前和C组(P＜0.05);放气后20min三组患者SBP、DBP均恢复正常.A组术中肌松欠佳及躁动发生率明显多于B、C组(P＜0.05);B组患者术后24 h内恶心、呕吐发生率明显多于A、C组(P＜0.05).结论 全麻复合硬膜外阻滞麻醉应用于老年结直肠癌腹腔镜手术,患者术中循环呼吸较平稳,麻醉并发症较少.     

丙泊酚与瑞芬太尼静吸复合麻醉对腹腔镜胆囊切除术后认知功能的影响

目的 探讨丙泊酚与瑞芬太尼静吸复合麻醉与靶控静脉麻醉对老年腹腔镜下胆囊切除术患者术后认知功能的影响.方法选取择期行腹腔镜下胆囊切除术老年患者79例,以随机数字表法将患者分为A组34例和B组35例.B组予以丙泊酚与瑞芬太尼静脉麻醉复合吸入七氟烷麻醉,A组予以丙泊酚与瑞芬太尼靶控静脉麻醉.比较两组患者的手术时间、自主呼吸恢复时间、苏醒时间、拔管时间与定向力恢复时间;采用意识状态评分法（OAAS）评价患者拔管后即刻,拔管后1小时、3小时和24小时的意识状态;采用简易精神状态量表（MMSE） 评价患者术前24小时,拔管后1小时、3小时和24 小时的认知功能.结果两组患者手术时间、苏醒时间、拔管时间比较,差异均无统计学意义（t＝0.11～0.21,P＞0.05）;B组患者自主呼吸恢复时间、定向力恢复时间均短于A组,差异均具有统计学意义（t＝4.77和4.07,P＜0.05）.B组拔管后即刻OAAS评分高于A组（t＝3.67,P＜0.05）,拔管后1小时 MMSE评分高于A组（t＝4.61,P＜0.05）;其余各时点两组OAAS、MMSE评分比较,差异均无统计学意义（t＝0.07～1.07,P＞0.05）.结论丙泊酚与瑞芬太尼静吸复合麻醉用于老年腹腔镜下胆囊切除术患者具有满意的麻醉效果,较好的稳定了患者的术后意识状态及认知功能,对术后认知功能的影响较小,其效果优于丙泊酚与瑞芬太尼靶控静脉麻醉,对老年腹腔镜下胆囊切除术患者的手术麻醉具有一定的指导借鉴意义.     

小儿腹腔镜疝内环扎术应用氯胺酮异丙酚复合静脉麻醉分析

目的　探讨氯胺酮异丙酚复合静脉麻醉用于小儿腹腔镜疝内环扎术的可行性、安全性、实用性。　方法40例行腹腔镜疝内环扎术患儿 ,随机分为全麻插管组 (A组 2 0例 )和非插管组 (B组 2 0例 ) ,连续监测HR、SBP、DBP、SPO2 ,分时段抽动脉血行血气分析。　结果　两组气腹时HR均增快 ,但无统计学意义 ,放气后逐渐恢复至气腹前水平。B组气腹后 10min ,PaCO2 、HCO3-均明显高于麻醉前 (P <0 .0 5 )但尚在正常范围 ,组间比较亦无明显差异 (P >0 .0 5 ) ;A组气腹后 10min ,PaO2 明显高于麻醉前及B组 (P <0 .0 5 )。　结论　氯胺酮异丙酚复合静脉麻醉在小儿腹腔镜疝内环扎手术中是一种可行的麻醉方法 ,但手术时间如大于 1h仍以气管内插管控制呼吸为宜     

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 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.     

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.