常规与非体外循环冠状动脉旁路移植术治疗冠状动脉多支病变的对比分析

目的　评价非体外循环下冠状动脉旁路移植术 (OPCAB)与常规体外循环下冠状动脉旁路移植术(CCABG)相比是否具有优越性。　方法　将 170例 2支以上血管病变行冠状动脉旁路移植术 (不包括瓣膜手术或室壁瘤切除等合并手术的病例 )患者分为 OPCAB组和 CCABG组 ,OPCAB组通过胸骨正中切口 ,在非体外循环心脏不停跳下完成冠状动脉旁路移植术 ;CCABG组建立常规体外循环 ,心脏停搏下完成冠状动脉旁路移植术。对两组病例的术前和术后各项指标进行对比分析。　结果　两组患者术前的一般情况无差异 ,OPCAB组与 CCABG组间曾行溶栓或经皮腔内冠状动脉成形术治疗和 3支病变的比例分别为 31.8%比 18.3%和 5 9%比 78% ,移植旁路血管分别为3.6± 0 .8支比 4.3± 1.0支 (P<0 .0 1) ,但所用的血管材料两组间无差异。OPCAB组术后呼吸机辅助时间和外科住院时间较短 ,住院费用较低 (P<0 .0 5 )。但术后并发症如二次开胸止血、伤口感染、心律失常、围术期心肌梗死、肺部并发症等的发生率 OPCAB组为 9.8% ,CCABG组为 14.6 % ;OPCAB组无手术死亡 ,CCABG组死亡 1例 (P>0 .0 5 )。　结论　 OPCAB治疗冠心病多支病变的初期结果显示可以减少患者术后辅助呼吸时间和外科住院时间 ,降低住院费用。但目前尚不能替代 CCABG,其近、远期效果仍     

常规与非体外循环下冠状动脉3支病变旁路移植血管通畅性对比分析

目的　评价非体外循环下冠状动脉旁路移植术 (OPCAB)与体外循环下冠状动脉旁路移植术 (CCABG)治疗冠状动脉三支病变术中旁路早期通畅性。方法　 6 0例 3支血管病变的病人分为OPCAB组和CCABG组 ,每组各 30例。行冠状动脉旁路移植术 ,OPCAB组胸骨正中切口 ,在非体外循环心脏不停跳下完成手术 ;CCABG组建立常规体外循环 ,心脏停跳下完成手术。术中应用即时血流测量技术对旁路血管进行流量测量。对比分析两组术前、术后的各项指标及各血管旁路流量、搏动指数和血流波形。结果　两组病人术前一般情况差异无统计学意义。OPCAB组与CCABG组移植旁路血管分别为 (3 6±0 6 )支与 (4 3± 0 9)支 (P <0 0 1) ;两组前降支及右冠状动脉旁路血流量、搏动指数差异无显著性。CCABG组回旋支序贯旁路和远端吻合口多 ,血流量较OPCAB组高。两组弥漫病变血管旁路血流量小。结论　OPCAB与CCABG治疗 3支病变 ,两组血管旁路早期通畅性差异无显著性。     

体外循环和非体外循环冠状动脉旁路术围手术期心肌损伤程度的对比研究

目的　对比研究常规体外循环下冠状动脉旁路术 (CCABG)和非体外循环心脏跳动下冠状动脉旁路术 (OPCAB)围手术期心肌肌钙蛋白I(cTnI)动态变化规律 ,以明确心肌损伤的程度。方法　 5 9例不稳定心绞痛患者 ,射血分数 (EF) 0 35～ 0 5 6 ,其中 34例行OPCAB ,患者平均年龄 (5 9 1± 1 7)岁 ,平均搭桥数 1 0～ 5 0支 ,平均 (2 90± 0 8)支 ;2 5例行CCABG ,患者平均年龄 (5 6 5± 1 8)岁。搭桥数 2 0～ 5 0支 ,平均 (3 2± 0 7)支。分别在术前 ,术后第 8、2 4、48、72、96、12 0h时 ,采集患者静脉血标本 ,离心后取血浆测定cTnI值。cTnI的测定采用自动双抗体夹心酶联免疫荧光测定法 ,仪器检测灵敏度cTnI 0 35 μg/L。　 结果　术前 2组患者cTnI差异无显著性意义 (P >0 0 5 )。OPCAB手术组cTnI值在术后观察期内均低于CCABG组 ,差异有显著性意义 (t=1 9432 ,P =0 0 0 7)。全组患者无死亡 ,均痊愈出院。　结论　cTnI是诊断心肌损伤的良好指标。OPCAB手术心肌损伤程度显著低于CCABG手术。     

心肌脂肪酸结合蛋白变化与OPCAB后心肌梗死

目的 探讨心肌型脂肪酸结合蛋白(H-FABP)与非体循环外冠状动脉旁路移植术(OPCAB)后心肌损伤及心肌梗死的关系.方法 59例首次单纯行OPCAB的患者,分别于麻醉诱导后、CABG手术结束(最后1支旁路血管吻合完毕)、入ICU即刻、2、4、8h及术后l天抽取中心静脉血检测H-FABP含量;于术前、入ICU 4、8h、术后1、2天分别常规化验cTnI、CK-MB.根据术后8h的cTnI值及心电图的改变将患者分为正常组(I组,cTnI＜0.1 ng/ml)、心肌损伤组(Ⅱ组,cTnI 0.1～ 1.0 ng/ml)、心肌梗死组(Ⅲ组,cTnI＞1 ng/ml).结果 心肌梗死组的H-FABP显著高于心肌损伤组及正常组(P＜0.01),H-FABP与cTnI、CK-MB有良好的相关性.H-FABP在入ICU 2 h达峰值,显著早于cTnI、CK-MB(P＜0.01),且入ICU 4 h即开始下降,术后1天回到基线水平.而cTnI、CK-MB达峰值的时间分别是术后8h和1天,且术后2天仍维持在较高水平.结论 H-FABP与OPCAB围手术期心肌梗死有良好的相关性,且与“金标准”cTnI比较具有一定的优越性,早期监测H-FABP对诊断围手术期心肌梗死具有较为突出的应用价值.     

糖尿病病人行OPCAB与CCABG的早期结果对比

目的 比较糖尿病病人非体外循环和经典体外循环冠状动脉旁路移植(OPCAB和CCABG)的术后早期临床结果.方法 1999年4月至2008年1月,318例糖尿病病人行冠状动脉旁路移植术(CABG).OPCAB 210例,CCABG 108例.两组术前总体情况差异无统计学意义.OPCAB在非体外循环、心脏跳动下完成,CCABG在体外循环、心脏停跳下完成.正中开胸,胸膜外游离带蒂左乳内动脉(LIMA),与左前降支(LAD)吻合,大隐静脉(GSV)与其他靶血管吻合,吻合口超过2个采用序贯吻合.术前口服降糖药或皮下注射胰岛素将血糖控制在6 mmol/L以下,术后早期在ICU时持续泵入胰岛素,将血糖控制在6～8mmol/L.结果 两组共5例(1.57%)死亡,7例(2.20%)发生并发症.两组均达到完全再血管化,平均移植旁路血管OPCAB组(2.6±1.1)支,低于CCABG组的(3.1±1.3)支,P＜0.05.OWCAB组死亡1例(0.48%),明显低于CCABG组4例(3.70%),P＜0.05.OPCAB组发生并发症5例(2.30%),CCABG组2例(1.85%),组间差异无统计学意义,P＞0.05.结论 糖尿病者冠状动脉旁路移植手术围术期严格控制血糖至接近正常水平,住院病死率和并发症率低.OWAB术后早期病死率明显低于CCABG.     

体外循环与非循环冠状动脉旁路移植术对老年冠心病病人脏器损伤的影响

目的分析体外循环与非循环冠状动脉旁路移植术对老年冠心病病人脏器损伤的影响。方法老年冠心病病人144例,遵循随机对照试验原则行盲法分组,对照组72例,采取体外循环冠状动脉旁路移植术(CCABG),观察组72例,实施非体外循环冠状动脉旁路移植术(OPCAB)治疗,比较两组临床手术指标和并发症,监测术后不同时间节点心(CK-MB、cTnI),肺(IO),肾(BUN、SCr),肝(AST、ALT)等脏器组织及颅脑(S100B蛋白)损伤情况,随访记录术后12个月心功能(LVEF、LVEDD)改善效果,以SF-36量表评估生活质量。结果两组手术手术操作时间、搭桥数目、术后24小时内引流量比较,差异无统计学意义(P0.05),观察组血浆、全血输注量、呼吸机应用、ICU入住时间及住院恢复时间、并发症低于对照组(P0.05);观察组术毕即刻(T2)、术后24小时(T3)、术后48小时(T4)等时间节点AST、ALT、BUN、CK-MB、SCr、cTn I、S100B蛋白均低于对照组,OI高于对照组(P0.05);两组术后12个月LVEF、LVEDD比较差异无统计学意义(P0.05),观察组GH、RE、MH评分均高于对照组(P0.05)。结论 OPCAB与CCABG治疗老年冠心病均可造成脏器组织损伤,OPCAB对病人肺、心肌、肾、肝脏器及颅脑组织损伤程度均较CCABG治疗者更小,预后更佳。     

合并慢性肾功能不全患者的冠状动脉旁路移植术

目的　探讨冠状动脉粥样硬化性心脏病 (冠心病 )合并慢性肾功能不全患者行冠状动脉旁路移植术(CABG)时手术方式的选择。　方法　 15例冠心病合并慢性肾功能不全患者根据施行的术式不同分为两组 ,常规CABG(CCABG)组 :9例患者 ,在体外循环下行 CCABG。OPCAB组 :6例患者 ,行非体外循环冠状动脉旁路移植术(OPCAB)。术后观察两组肾功能情况、心律失常、呼吸和神经系统并发症、移植血管支数、呼吸机辅助时间、术后出血量和输血量等临床指标。　结果　全组无手术死亡 ,CCABG组患者术后早期肾功能较术前差 (P<0 .0 5 ) ;OPCAB组患者术后早期肾功能较术前无明显变化 (P>0 .0 5 ) ,术后并发症比 CCABG组低 ,手术时间、ICU时间和术后呼吸机辅助时间均比 CCABG组短 ,术后出血量和输血量比 CCABG组少 (P<0 .0 5 )。　结论　冠心病术前合并肾功能不全的患者 ,采用 OPCAB术式明显优于 CCABG,经围术期的积极处理 ,大多数患者可渡过肾功能衰竭关。     

老年人非体外循环冠状动脉旁路移植术的心肌保护作用

目的比较70岁以上老年人非体外循环冠状动脉旁路移植术(OPCAB)和体外循环冠状动脉旁路移植术(CABG)围术期心肌损伤程度,探讨OPCAB的心肌保护效果。方法30例老年患者分为两组,A组15例,为CABG组,B组15例,为OPCAB组。分别于术前、术中30min、术中1h、术后6h、12h、24h、72h、120h取静脉血标本,分别测定心肌肌钙蛋白I(cTnI)水平和CKMB活性;另外记录围手术期各项临床指标。结果OPCAB组术后辅助呼吸时间较CABG组短(P<0.01),而且主动脉球囊反搏和输血例数较低(P<0.05)。CABG组与OPCAB组cTnI、CKMB的术前水平相,术后6hcTnI即有升高而后下降,术后30min至72h均较OPCAB组明显升高(P<0.05或0.01)。结论与CABG相比,OPCAB的心肌损伤较轻,心肌保护效果较好。     

70岁以上患者冠状动脉旁路移植术

目的 总结70岁以上患者冠状动脉旁路移植术的经验,就伴发疾病的处理、手术适应证、手术技术及效果进行分析. 方法 2004年3月至2008年3月,采用冠状动脉旁路移植术治疗70岁以上高龄患者91例,年龄70～83岁.75岁以上者22例.心肺转流冠状动脉旁路移植组(CCABG组)72例,非体外循环冠状动脉旁路移植组(OPCAB组)19例.两组术前临床资料无明显差异.其中CCABG组术前植入颈动脉支架2例,肾动脉支架2例;OPCAB组植入颈动脉支架2例,肾动脉支架1例.全组左侧胸廓内动脉使用率为96.7%;CCABG组心肺转流时间(108±34)min;主动脉阻断时间(70±22)min;搭桥数(3.5±0.8)支.OPCAB组搭桥数(2.9±0.7)支. 结果 全组住院死亡2例,均为慢性阻塞性肺疾病合并肺感染.CCABG组有1例脑梗死,2例肺部感染,但与OPCAB组相比差异无统计学意义.两组在呼吸机辅助时间、ICU时间、呼吸衰竭、急性肾功能衰竭、二次开胸等方面无明显差异.但CCABG组搭桥支数高于OPCAB组(P<0.01).术后随访3～36个月,OPCAB组1例复发心绞痛,药物控制有效. 结论 处理好伴发疾病,充分再血管化,最大限度改善心肌供血,70岁以上CABG患者也可以取得满意疗效.是否在心肺转流下手术,预后并无明显差异.     

70岁以上患者的冠状动脉旁路移植术

目的介绍70岁以上高龄患者行冠状动脉旁路移植术(CABG)的结果和围术期处理策略. 方法对70岁以上患者行CABG 121例,119例(98.3%)为不稳定型心绞痛,113例(93.4%)合并其他疾病.80例(66.1%)采用非体外循环心脏不停跳CABG(OPCAB),41例(33.9%)选择常规体外循环CABG(CCABG);胸膜外技术游离左乳内动脉(LIMA),保持胸膜腔完整,常规将LIMA与左前降支(LAD)吻合,其余桥用大隐静脉(SV).术中使用即时超声血流仪(TTFM)测量移植血管血流,保证吻合口通畅.术后加强物理治疗和营养支持,严格控制血糖于6～10 mmol/L.结果行CCABG患者移植血管3.08±0.75支, OPCAB患者2.24±0.82支,110例(90.9%)使用LIMA.全组死亡1例(急诊手术),死亡率0.8%,死于多器官功能衰竭;发生并发症4例(3.3%).术后呼吸机使用时间OPCAB患者10.04±5.68小时,CCABG患者21.46±14.54小时;住ICU 时间2.65±1.45天,术后12.22±5.56天出院. 结论充分评估手术风险,选择恰当的手术方案,经过缜密的围术期处理,高龄患者亦可取得良好的手术效果.     

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.     

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.