锁定钢板与人工肱骨头置换治疗肱骨近端粉碎性骨折临床疗效比较

[目的]比较分析锁定钢板和人工肱骨头置换治疗肱骨近端粉碎性骨折的中短期疗效.[方法]回顾性分析本院骨科2009年1月～2011年6月采用肱骨近端锁定钢板和人工肱骨头置换治疗Neer 3、4部分肱骨近端骨折患者61例,按随机数字表法分为2组,分别为应用锁定钢板内固定治疗组(内固定组,n =35)和人工肱骨头置换治疗组(置换组,n =26).其中内固定组含Neer 3部分骨折23例,4部分骨折12例;置换组含Neer 3部分骨折5例,4部分骨折21例.比较分析两组手术时间、术中出血量及一次性住院费用,同时采用Neer评分标准从关节疼痛、活动、功能等方面评定两组临床疗效.[结果]两组随访时间相仿,平均随访时间为20.5个月(12 ～36个月).内固定组手术时间平均为(60±5)min,术中出血量平均为(300±10) ml,一次性住院费用平均为(37 940±3 500)元,Neer评分优良率为86.2％;置换组手术时间平均为(50 ±5) min,术中出血量平均为(350±20) ml,一次性住院费用平均为(38 850±4 800)元,Neer评分优良率为90.0％.两组手术时间、术中出血量、一次性住院费用以及术后随访Neer评分比较差异均无统计学意义(P＞0.05).[结论]锁定钢板与人工肱骨头置换治疗肱骨近端粉碎骨折的手术时间、出血量及住院费用相仿,术后均能达到满意的临床疗效.2种手术方式的选择取决于筛选正确的适应证,对于年龄较轻同时可争取术中复位的肱骨近端骨折,锁定钢板内固定是最佳选择;而对于骨折严重粉碎无法重建的肱骨近端骨折,尤其伴有严重骨质疏松的老年患者,人工肱骨头置换则是最佳选择.     

肱骨近端锁定接骨板治疗肱骨近端外展嵌插四部分骨折的疗效分析

目的 探讨肱骨近端锁定接骨板治疗肱骨近端外展嵌插四部分骨折的疗效.方法2005年11月至2006年12月经j角肌胸大肌入路采用AO肱骨近端锁定接骨板治疗18例肱骨近端外展嵌插四部分骨折患者,男8例,女10例;平均年龄66.4岁(57～74岁).骨折Neer分型:均为肱骨近端外展嵌插四部分骨折.受伤至手术时间平均为6.3 d(5～11 d).记录术中手术时间和出血量.末次随访时采用Constant-Murley肩关节评分标准评定患者肩关节功能.结果本组患者手术时间为70～125min,平均95 min;术中出血量为200～400 mL,平均350 mL.18例患者术后获35～45个月(平均40.6个月)随访.骨折均获愈合,临床愈合时间平均为12周(10～14周).2例患者发生Ⅱ～Ⅲ期肱骨头缺血性坏死,1例发生Ⅳ期肱骨头缺血性坏死.末次随访时Constant-Murley肩关节评分平均为84.2分(67～94分);其中优9例,良6例,一般3例,优良率为83.3%.肩关节活动度:前屈上举平均为164.0°±29.0°,体侧外旋平均为40.5°±21.3°,内旋达T7～T8(L2～T5).结论 肱骨近端锁定接骨板固定是治疗肱骨近端外展嵌插四部分骨折较理想的方法,其固定确切,保护了肱骨头及骨折端的血供.     

3D打印技术辅助肱骨近端锁定钢板内固定治疗肱骨近端骨折的疗效观察

目的探讨采用3D打印技术辅助肱骨近端锁定钢板内固定治疗肱骨近端骨折的临床效果。方法回顾性分析自2015-01—2015-07诊治的60例肱骨近端骨折,采用3D打印技术辅助肱骨近端锁定钢板内固定治疗30例(观察组),采用切开复位肱骨近端锁定钢板内固定治疗30例(对照组)。比较2组手术时间、术中出血量、术中透视次数,以及术后1年肩关节功能Neer评分。结果观察组手术时间较对照组短,术中出血量、透视次数较对照组少,差异有统计学意义(P0.05)。60例均获得随访,随访时间平均14.2(12~16)个月。观察组术后1年时肩关节功能Neer评分高于对照组,差异有统计学意义(P0.05)。结论 3D打印技术辅助肱骨近端锁定钢板内固定治疗肱骨近端骨折使得骨折复位更加可靠,内固定置入更加精确,在一定程度上减小了手术对患者的损伤,更有利于患者术后功能恢复。     

人工肱骨头置换术与锁定钢板内固定治疗肱骨近端骨折的疗效分析

目的探讨人工肱骨头置换术与肱骨近端锁定钢板内固定治疗肱骨近端骨折的临床疗效并分析并发症发生情况。方法回顾性分析自2014-01—2017-06诊治的35例肱骨近端骨折,15例Neer三部分骨折及7例Neer四部分骨折采用肱骨近端锁定钢板内固定治疗(锁定钢板组),13例Neer四部分骨折采用人工肱骨头置换术治疗(肱骨头置换组)。结果 35例均获得随访,随访时间平均8.4(7～39)个月。2组手术时间、术中出血量比较差异无统计学意义(P0.05);肱骨头置换组术后6个月Neer评分高于锁定钢板组,差异有统计学意义(P 0.05)。术后6个月疗效采用Neer评分标准评定:锁定钢板组优6例,良10例,可4例,差2例;肱骨头置换组优4例,良6例,可2例,差1例。内固定组2例出现肩关节僵硬,活动受限;1例出现肱骨头缺血性坏死及螺钉切出,二期行肱骨头置换术。肱骨头置换组1例出现关节半脱位。结论年龄70岁、基础条件尚可的Neer三部分及部分四部分肱骨近端骨折患者首选锁定钢板内固定治疗,而高龄、骨质疏松严重、不能耐受二次手术的Neer四部分骨折患者首选人工肱骨头置换术治疗。     

肱骨近端锁定接骨板治疗肱骨近端外展嵌插四部分骨折的疗效分析

目的 探讨肱骨近端锁定接骨板治疗肱骨近端外展嵌插四部分骨折的疗效.方法2005年11月至2006年12月经j角肌胸大肌入路采用AO肱骨近端锁定接骨板治疗18例肱骨近端外展嵌插四部分骨折患者,男8例,女10例;平均年龄66.4岁(57～74岁).骨折Neer分型:均为肱骨近端外展嵌插四部分骨折.受伤至手术时间平均为6.3 d(5～11 d).记录术中手术时间和出血量.末次随访时采用Constant-Murley肩关节评分标准评定患者肩关节功能.结果本组患者手术时间为70～125min,平均95 min;术中出血量为200～400 mL,平均350 mL.18例患者术后获35～45个月(平均40.6个月)随访.骨折均获愈合,临床愈合时间平均为12周(10～14周).2例患者发生Ⅱ～Ⅲ期肱骨头缺血性坏死,1例发生Ⅳ期肱骨头缺血性坏死.末次随访时Constant-Murley肩关节评分平均为84.2分(67～94分);其中优9例,良6例,一般3例,优良率为83.3%.肩关节活动度:前屈上举平均为164.0°±29.0°,体侧外旋平均为40.5°±21.3°,内旋达T7～T8(L2～T5).结论 肱骨近端锁定接骨板固定是治疗肱骨近端外展嵌插四部分骨折较理想的方法,其固定确切,保护了肱骨头及骨折端的血供.     

3D打印技术在PHILOS内固定肱骨近端骨折内侧距支撑重建中的应用

目的探讨3D打印技术在肱骨近端锁定接骨板(PHILOS)内固定肱骨近端骨折内侧距支撑重建中的应用效果。方法回顾性分析自2015-01—2017-01行PHILOS内固定治疗的42例肱骨近端骨折,21例术前采用3D打印技术辅助模拟肱骨近端骨折内侧距支撑重建(3D打印组),21例进行常规手术(常规组)。结果 42例均获得随访,随访时间平均10.5(6.0~12.5)个月。与常规组比较,3D打印组手术时间更短,肱骨颈干角更大,肱骨头内翻角更小,肱骨头高度丢失更少,末次随访时肩关节功能Neer评分更高,差异有统计学意义(P0.05);但2组骨折愈合时间比较差异无统计学意义(P0.05)。结论采用3D打印技术可以辅助肱骨近端骨折分型及进行术前模拟手术,术中精确放置钢板固定肱骨内侧距,从而使患者获得更好的肩关节功能康复效果。     

经皮微创钢板内固定术治疗肱骨近端骨折的疗效观察

[目的]总结应用经皮微创与切开复位钢板内固定治疗肱骨近端骨折的临床效果。[方法]对2014年1月~2014年12月手术治疗并获得随访的57例肱骨近端骨折患者进行回顾性分析,其中27例行经皮微创钢板内固定,男9例,女18例;年龄70.5(51.4~89.5)岁,按照Neer分型,二部分骨折14例,三部分骨折11例,四部分骨折2例;30例行切开复位钢板内固定,男11例,女19例,年龄69.5(52.3~86.8)岁,按照Neer分型,二部分骨折13例,三部分骨折14例,四部分骨折3例。从手术相关指标、患侧Neer肩关节功能评分及术后并发症情况3个方面对两种治疗方法进行比较分析。[结果]:57例患者获得随访,时间13~24个月,平均17.8个月。术后出现感染、腋神经损伤、肱骨头坏死各1例,内固定失效3例。经皮微创组手术切口长度、术中出血量、住院天数、骨折愈合时间均优于切口组,两组间差异有统计学意义(P<0.05),而手术时间比较两组差异无统计学意义(P>0.05)。术后并发症的发生率两组比较差异无统计学意义(P>0.05),术后12个月的肩关节功能Neer评分两组比较差异无统计学意义(P>0.05)。[结论]:经皮微创钢板内固定治疗肱骨近端骨折具有创伤小、骨折愈合快等特点。     

肱骨近端锁定钢板与髓内钉内固定治疗Neer 3部分肱骨近端骨折的比较

目的比较肱骨近端锁定钢板与髓内钉内固定治疗Neer 3部分肱骨近端骨折的临床疗效。方法回顾性分析自2010-09—2016-05诊治的127例Neer 3部分肱骨近端骨折,采用肱骨近端锁定钢板内固定治疗64例(锁定钢板组),采用肱骨近端髓内钉内固定治疗63例(髓内钉组)。比较2组手术时间、术中出血量、术中透视次数、住院时间、骨折愈合时间,以及术后6、12个月肩关节功能Neer评分及ASES评分。结果髓内钉组在手术时间、术中出血量、住院时间方面优于锁定钢板组,差异有统计学意义(P0.05);2组术中透视次数、骨折愈合时间比较差异无统计学意义(P0.05)。127例均获得随访,随访时间平均14.1(13~16)个月。末次随访时X线片显示所有骨折均达到骨性愈合。髓内钉组术后6个月肩关节功能Neer评分、ASES评分优于锁定钢板组,差异有统计学意义(P0.05);术后12个月时,2组肩关节功能Neer评分、ASES评分差异无统计学意义(P0.05)。结论肱骨近端锁定钢板与髓内钉内固定治疗Neer 3部分肱骨近端骨折均可取得满意的临床疗效,但髓内钉内固定创伤更小,术后肩关节功能恢复更快。     

手术与非手术治疗老年肱骨近端骨折的疗效分析

目的 探讨手术与非手术治疗老年肱骨近端骨折的临床疗效. 方法 2006年8月至2010年8月共收治24例肱骨近端骨折患者,男19例,女5例;年龄56～67岁,平均59.5岁.骨折按Nee分型:二部分骨折17例,三部分骨折7例,均为闭合骨折.其中15例采用手术治疗(手术组),9例采用非手术治疗(非手术组).分别于骨折术后3、6、12个月摄X线片、查体记录患者的肩关节疼痛和功能障碍指数(SPADI). 结果 24例患者术后获14 ～36个月(平均23.2个月)随访.手术组出血量平均为(550±80)mL,手术时间平均为(115±20) min,术后无切口感染、神经损伤.全部患者术后12个月时骨折均获骨性愈合,未出现肱骨头坏死.全部患者术后3、6个月时SPADI评分比较差异有统计学意义(P＜0.05),术后12个月时比较差异无统计学意义(P＞0.05),手术组评价优于非手术组. 结论 对于老年肱骨近端骨折二或三部分骨折,可根据患者的个体情况选择治疗方式,手法复位满意的患者术后配合积极的康复锻炼也能获得较好的临床效果.     

肱骨近端锁定钢板与近端锁定钢板联合内侧普通钢板治疗肱骨近端骨折合并中段骨折的疗效分析

目的比较肱骨近端锁定钢板与肱骨近端锁定钢板联合内侧普通钢板治疗肱骨近端骨折合并中段骨折的疗效。方法肱骨近端骨折合并中段骨折患者18例,将18例患者分为两组:单钢板组10例,单使用肱骨近端锁定钢板;双钢板组8例,使用肱骨近端锁定钢板联合内侧普通钢板。从手术时间、术中出血量、住院时间、骨折愈合时间以及术后半年、1年Neer评分方面评估两种治疗方法的临床疗效。结果随访12~18个月,平均15个月,两组患者术中出血量、手术时间、住院时间、术后半年Neer评分比较,差异无统计学意义(P0.05);双钢板组骨折愈合时间、术后1年Neer评分优于单钢板组,两组比较差异有统计学意义(P0.05)。结论肱骨近端锁定钢板联合内侧普通钢板较单用肱骨近端锁定钢板固定可靠,可进一步提供内侧柱支撑,便于早期功能锻炼,且术中肌肉止点剥离少,更有利于骨折愈合以及功能恢复。     

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.     

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.     

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.