低分子肝素与普通肝素在血液透析中心静脉导管封管中并发症的比较

目的 探讨低分子肝素应用于血液透析患者中心静脉导管封管预防相关并发症的效果。方法 将本院血透中心140例患者分为低分子肝素组（ n ＝78）和普通肝素组（ n ＝62）,低分子肝素组采用低分子肝素封管,普通肝素组用普通肝素封管,比较两组封管中并发症的发生情况。结果 透析结束7d内低分子肝素组的穿刺压迫点时间（5．6±1．54） min、潜血转阴时间（4．1±1．12）d和皮肤黏膜出血停止时间（4．7±1．43） d均短于普通肝素组[（9．6±1．49） min ,（8．6±1．71） d ,（7．9±1．25） d],差异有统计学意义（ P＜0．05）;1年内低分子肝素组18例发生出血倾向（23．1％）,普通肝素组有36例发生出血倾向（58．1％）,低分子肝素组出血并发症发生率显著低于肝素组。结论 低分子肝素用于血液透析中心静脉导管封管中的并发症发生率显著低于普通肝素封管,封管更为安全。     

低分子肝素的药理作用研究进展低分子肝素的药理作用研究进展

低分子肝素（LMWH）由普通肝素（UFH）酶解或化学降解的方法而得其相对分子质量为2000～10000Da，平均为5000Da左右的混合物。LMWH与UFH相比具有皮下注射吸收好、半衰期长、生物利用度高、同质性较好、抗凝作用大致相同或更优、抗血栓作用强、副反应少、不需实验室监测等优势，因此，LMWH颇受临床医师的青睐，临床应用的适应证不断扩大。在欧洲及北美某些地区对LMWH的应用大有取代UFH之势。我们就LMWH在药理作用研究进展作一综述。     

低分子肝素抗凝疗效观察

对低分子肝素抗凝疗效观察总结如下。     

大鼠颈动脉血管成形术模型的实验研究

目的通过建立大鼠颈动脉血管成形术模型,观察大鼠损伤血管的增生及再狭窄变化。方法用2F Fogarty球囊导管损伤大鼠左颈总动脉,分别在不同时间点取材,观察术后不同时间点血管壁的变化。结果大鼠颈总动脉损伤后引起血管内皮细胞剥脱,新生内膜形成并增生,导致管腔狭窄。结论大鼠颈动脉血管成形术造成血管再狭窄,其造模成功率高,操作简便,疾病模型接近人类,能够为进一步研究提供理想的动物模型。     

低分子肝素与普通肝素在冠状动脉介入治疗中的安全性和有效性观察

低分子肝素（LMWH）在药代动力学及药理学方面较普通肝素（UFH）有许多优势,已广泛应用于心血管疾病的抗凝治疗。既往研究证明,在预防急性冠状动脉综合征（ACS）并发症方面,LMWH优于UFH。而且其应用领域不断拓宽。在经皮冠状动脉介入治疗（PCI）术中,LMWH是否会取代UFH,目前尚无定论。我们观察了LMWH在冠状动脉介入治疗术中应用的安全性及有效性。     

普通肝素与低分子量肝素治疗难治性增生性肾炎的疗效比较

有资料显示肝素除了具有良好的抗凝效应外 ,尚从多种机制上发挥抑制肾小球系膜增生的作用[1,2 ] ,而系膜增生是增生性肾炎的共同病理特点 ,它的进行性发展是肾小球逐渐硬化、纤维化 ,肾功能进行性减退的重要环节。近年低分子量肝素 (ＬＭＷＨ)在临床许多领域开始取代普通肝素 (Ｈｅｐ) ,本文对比观察了两者治疗难治性增生性肾炎中对减少尿蛋白排泄、延缓肾功能进行性减退两个主要方面的疗效差别 ,报道如下。1　材料与方法1.1　病例选择及分组　本院肾内科 1997年 6月至2 0 0 0年 6月住院病人 4 0例 ,男 2 4例 ,女 16例 ,年龄2 7.3± 11.8岁 …     

瑞舒伐他汀对Medtronic球囊导管损伤大鼠颈动脉平滑肌细胞增殖及凋亡的影响

背景:球囊扩张及支架置入后再狭窄、管腔丢失等问题制约了支架置入治疗的进一步发展,血管内膜增殖和凋亡在再狭窄中的作用及干预方法尚在积极探索中.目的:采用Medtronic球囊建立大鼠颈动脉球囊损伤模型,观察瑞舒伐他汀对球囊损伤大鼠颈动脉平滑肌细胞增殖及凋亡的影响.方法:将雄性SD大鼠随机数字表法分为球囊损伤组和治疗组.均采用Medtronic球囊建立大鼠颈动脉球囊损伤模型,并取球囊损伤组大鼠的右侧颈总动脉(未行球囊损伤)作为正常对照.治疗组于球囊损伤前3 d始连续给予瑞舒伐他汀5 mg/(kg·d)灌胃,球囊损伤组给予9 g/L氯化钠溶液灌胃.术后7,14 d取颈总动脉进行苏木精-伊红染色,免疫组织化学检测SM α-actin、增殖细胞核抗原,采用TUNEL法检测平滑肌细胞凋亡情况.结果与结论:与球囊损伤组比较,治疗组造模后14 d,损伤血管新生内膜面积、新生内膜,中膜面积比值明显减少(P<0.05),管腔面积增加26%;增殖细胞核抗原阳性细胞率降低,凋亡阳性细胞率增高(P相似文献   

前房灌注加压制作大鼠视网膜急性损伤模型

目的：成功制作大鼠视网膜急性损伤模型。方法：前房灌注加压至110 mm Hg,维持60 min。结果：12只大鼠均成功做成视网膜急性损伤模型,形态学观察也证实模型成功。结论：以针体开侧孔的针头,在手术显微镜下操作,成功地制作了大鼠视网膜急性损伤模型,且避免并发症发生。     

大鼠脑局灶性缺血再灌注后梗死体积变化与低分子肝素的保护效应

目的:观察低分子肝素对大鼠脑缺血再灌注后不同时间点脑梗死体积的影响。方法:实验于2005-03/2005-06在华北煤炭医学院动物实验中心完成。①选用雄性SD大鼠90只,体质量280～330g。应用随机数字表法将大鼠分为3组:假手术组、缺血再灌注组、低分子肝素组,每组30只。假手术组:只游离右侧颈总动脉、颈内动脉、颈外动脉。缺血再灌注组和低分子肝素组:均采用改良Longa法制作大鼠右侧大脑中动脉闭塞局灶性脑缺血再灌注模型。缺血2h后分别腹腔注射生理盐水1mL和皮下注射低分子肝素(200IU/kg)生理盐水稀释液1mL。2组均于缺血2.5h后开始再灌注3,6,12,24,48h,每个时间点取6只进行观察。②分别称重应用四氮唑红染色法染成白色的梗死组织与染成红色的正常组织,以梗死组织占全脑湿重的百分比表示脑梗死体积。③采用两样本均数的t检验对两组间数据进行分析。结果:大鼠90只均进入结果分析。缺血再灌注组大鼠脑缺血再灌注3,6,12,24,48h时脑梗死体积分别为(17.28±2.69)%,(22.66±2.16)%,(30.17±4.17)%,(38.83±4.54)%,(43.75±2.66)%,低分子肝素组分别为(12.54±1.35)%,(19.83±2.32)%,(23.83±3.19)%,(30.33±2.50)%,(36.25±2.54)%,假手术组均为0。随着缺血再灌注时间的延长,缺血再灌注组脑梗死体积逐渐增大,低分子肝素组梗死体积较缺血再灌注同一时间组明显缩小(t=-2.376,-2.191,-2.96,-4.019,-4.446,P<0.05)。结论:脑缺血再灌注损伤随再灌注时间延长而加重,低分子肝素能减少脑梗死体积,缩小梗死范围,对大鼠脑缺血再灌注损伤后具有保护作用。     

老年慢性肾衰患者长期血透中低分子肝素与普通肝素的比较

随着我国人口老龄化进程的加快,〉60岁老年人口逐年增加,我国〉60岁的老年人每10万人中有15.43人为慢性肾衰竭［1］。维持性血液透析是终末期肾脏病老年患者赖以生存的治疗模式,抗凝治疗是血液透析技术的重要组成部分［2］。作者通过观察40例血液透析使用LMWH与UFH的老年患者在抗凝效果、透析充分性、营养状态、骨代谢、对血小板影响情况,得出合理治疗方案。报道如下。     

Low-molecular-weight heparin in outpatient treatment of DVT

Patients with a diagnosis of acute deep venous thrombosis have traditionally been hospitalized and treated with unfractionated heparin followed by oral anticoagulation therapy. Several clinical trials have shown that low-molecular-weight heparin is at least as safe and effective as unfractionated heparin in the treatment of uncomplicated deep venous thrombosis. The use of low-molecular-weight heparin in an outpatient program for the management of deep venous thrombosis provides a treatment alternative to hospitalization in selected patients. Use of low-molecular-weight heparin on an outpatient basis requires coordination of care, laboratory monitoring, and patient education and participation in treatment. Overlapping the initiation of warfarin permits long-term anticoagulation. Advantages include a decreased incidence of heparin-induced thrombocytopenia and fewer episodes of bleeding complications. Future clinical trials evaluating the safety and efficacy of low-molecular-weight heparin in the treatment of complicated deep venous thrombosis will further define appropriate indications for use and strategies for outpatient management.     

Low-molecular-weight heparin in preventing and treating DVT

Low-molecular-weight heparin is a relatively recent addition to the list of therapies for prophylaxis and treatment of deep venous thrombosis (DVT). As a prophylactic, low-molecular-weight heparin is as effective as standard heparin or warfarin and does not require monitoring of the activated partial thromboplastin time or the International Normalized Ratio. Traditionally, treatment for DVT required patients to be hospitalized for administration of intravenous heparin. With subcutaneous injections of low-molecular-weight heparin, treatment of DVT can be initiated or completed in the outpatient setting with no increased risk of recurrent thromboembolism or bleeding complications. Low-molecular-weight heparin is an attractive option for use in patients with a first episode of DVT, no risk factors for bleeding and the ability to administer injections with or without the help of a visiting nurse or family member.     

Postoperative anticoagulation in vascular surgery: part 1. A retrospective comparison of clinical outcomes for unfractionated heparin versus low-molecular-weight heparin.

The use of postoperative anticoagulation is not uncommon for patients undergoing vascular procedures, whether for adjunctive therapy to the surgical procedure or for resumption of preoperative anticoagulation. Longer postoperative length of stay is necessary to achieve an adequate therapeutic international normalized ratio with traditional protocols that call for the use of unfractionated heparin. We retrospectively examined 195 cases to determine whether low-molecular-weight heparin, specifically enoxaparin, was an effective postoperative replacement for intravenous unfractionated heparin, with the impact on postoperative length of stay. There was no difference in the frequency of complications except for increased incidence of return to surgery for graft thrombosis (n = 11) in patients who received traditional intravenous unfractionated heparin with adjusted-dose warfarin daily (n = 139, P <.02). For all 195 vascular procedures combined, the average postoperative length of stay with use of enoxoparin was shortened with use of enoxaparin (P <.0008). There was a 2-day reduction in the average postoperative length of stay for the femoral-distal procedure group (n = 18, P <.004). In the first part of the article, we summarize our findings and offer new applications and ideas for vascular nurses to consider when postoperative anticoagulation is indicated after vascular procedures. Factors contributing to safe and efficacious postoperative anticoagulation with use of low-molecular-weight heparin, specifically enoxaparin, are presented to the vascular nurse. In the second part, we discuss the roles of members of the vascular team, as well as our experience with use of enoxaparin as implemented in the clinical setting.     

A controlled trial of low-molecular-weight heparin (dalteparin) versus unfractionated heparin as anticoagulant during continuous venovenous hemodialysis with filtration.

OBJECTIVE: To compare the efficacy, safety, and cost of fixed-dose low-molecular-weight heparin (dalteparin) with adjusted-dose unfractionated heparin as anticoagulant for continuous hemofiltration. DESIGN: Prospective, randomized, controlled clinical trial. SETTING: University-affiliated adult intensive care unit PATIENTS: All patients requiring continuous hemofiltration for acute renal failure or systemic inflammatory response syndrome (SIRS) were eligible. Fifty-seven patients were enrolled. Eleven were excluded, seven because of major protocol violations and four died before hemofiltration. INTERVENTIONS: Patients received continuous venovenous hemodialysis with filtration with prefilter replacement at 500 mL/hr and countercurrent dialysate at 1000 mL/hr. Filters were primed with normal saline containing anticoagulant. Dalteparin-treated patients received a commencement bolus of 20 units/kg and a maintenance infusion at 10 units/kg/hr. Heparin-treated patients received a commencement bolus of 2000-5000 units and a maintenance infusion at 10 units/kg/hr, titrated to achieve an activated partial thromboplastin time in the patient of 70-80 secs. MEASUREMENTS AND MAIN RESULTS: The primary outcome measure--time to failure of the hemofilter--was compared using survival analysis. Twenty-two patients (13 with acute renal failure and nine with SIRS; total, 41 filters) were randomized to heparin. Twenty-five patients (16 with acute renal failure and nine with SIRS; total, 41 filters) were randomized to dalteparin. Mean (SE) activated partial thromboplastin time in the heparin group was 79 (4.3) secs. Mean (SE) anti-factor-Xa activity in the six patients given dalteparin who were assayed was 0.49 (0.07). Mean (SE) prehemofiltration platelet count was 225 (35.5) x 10(9) for heparin and 178 (18.1) x 10(9) for dalteparin (p = .24, unpaired Student's t-test). Mean (SE) prehemofiltration hemoglobin was 11.4 (0.61) g/dL for heparin and 10.6 (0.38) g/dL for dalteparin (p = .31, unpaired Student's t-test). PRIMARY OUTCOME: There was no significant difference in the time to failure between the two groups (p = .75, log rank test). For dalteparin, Kaplan-Meier (K-M) mean (SE) time to failure of the hemofilter was 46.8 (5.03) hrs. For heparin, K-M mean (SE) time to failure was 51.7 (7.51) hrs. The 95% CI for difference in mean time to failure was -13 to 23 hrs. The power of this study to detect a 50% change in filter life was >90%. SECONDARY OUTCOMES: Mean (SE) reduction in platelet count during hemofiltration was 63 (25.8) x 10(9) for heparin and 41.8 (26.6) x 10(9) for dalteparin (p = .57, unpaired Student's t-test). Eight patients given dalteparin and four patients given heparin had screening for heparin-induced thrombocytopenia; three of the dalteparin patients and one of the heparin patients were positive (p = 1.0, Fisher's exact test). There were three episodes of trivial bleeding and two episodes of significant bleeding for dalteparin, and there were three episodes of trivial bleeding and four episodes of significant bleeding for heparin (p = .53, chi-square test). The mean (SE) decrease in hemoglobin concentration during hemofiltration was 0.51 (0.54) g/dL for heparin and 0.28 (0.49) g/dL for dalteparin (p = .75, unpaired Student's t-test). The mean (SE) packed-cell transfusion volume during hemofiltration was 309 (128) mL for heparin and 290 (87) mL for dalteparin (p = .90, unpaired Student's t-test). Daily costs, including coagulation assays, of hemofiltration were approximately 10% higher using dalteparin than with heparin. CONCLUSIONS: Fixed-dose dalteparin provided identical filter life, comparable safety, but increased total daily cost compared with adjusted-dose heparin. Unfractionated heparin remains our anticoagulant of choice for continuous hemofiltration in intensive care.     

肝素对急性肺损伤大鼠基质金属蛋白酶2和9活性的影响

目的 探讨肝素对急性肺损伤( ALI)大鼠体内基质金属蛋白酶(MMP-2、MMP-9)蛋白及mRNA表达的影响.方法 18只雄性Wistar大鼠,按随机数字表法分成3组,每组6只.经尾静脉注射脂多糖(LPS)6 mg/kg复制ALI大鼠模型;肝素组在注射LPS前15 min经尾静脉注射普通肝素100 U/kg,对照组注射等量生理盐水.分别于制模后1、3、6h取股静脉血,采用酶联免疫吸附试验(ELISA)测定血清中MMP-2、MMP-9蛋白表达;制模后6h处死动物,取左肺,应用实时荧光定量聚合酶链反应(qRT-PCR)检测肺组织中MMP-2及MMP-9的mRNA表达.结果 与对照组比较,ALI组血清MMP-2( μg/L)、MMP-9( μg/L)蛋白表达增高,6h达到高峰(MMP-2:2.86±0.40比1.21±0.24,MMP-9:2.54±0.29比1.15±0.34,均P＜0.01);应用肝素后在6h时MMP-2、MMP-9蛋白表达明显降低(MMP-2:1.92±0.31比2.86±0.40,MMP-9:1.82±0.26比2.54±0.29,均P＜0.05).制模后6h,ALI组肺组织MMP-2、MMP-9的mRNA表达明显高于对照组(MMP-2 mRNA:1.88±0.09比1.00±0.10,MMP-9 mRNA:3.15±0.47比1.00±0.17,均P＜0.01);肝素组MMP-2、MMP-9的mRNA表达较ALI组明显降低(MMP-2 mRNA:1.26±0.14比1.88±0.09,P＜0.01;MMP-9 mRNA:2.06±0.68比3.15±0.47,P＜0.05),但仍高于对照组(均P＜0.05).结论 ALI大鼠体内MMP-2、MMP-9表达增加,肝素能够减少血清及肺组织中MMP-2、MMP-9的表达,从而减轻肺损伤.     

Alternatives to unfractionated heparin for anticoagulation in cardiopulmonary bypass

Despite the progress made in the development of cardiopulmonary bypass (CPB) equipment, systemic anticoagulation with unfractionated heparin and post-bypass neutralization with protamine are still used in most perfusion procedures. However, there are a number of situations where unfractionated heparin, protamine or both cannot be used for various reasons. Intolerance of protamine can be addressed with extracorporeal heparin removal devices, perfusion with (no) low systemic heparinization and, to some degree, by perfusion with alternative anticoagulants. Various alternative anticoagulation regimens have been used in cases of intolerance to unfractionated heparin, including extreme hemodilution, low molecular weight heparins, danaparoid, ancrod, r-hirudin, abciximab, tirofiban, argatroban and others. In the presence of heparin-induced thrombocytopenia (HIT) and thrombosis, the use of r-hirudin appears to be an acceptable solution which has been well studied. The main issue with r-hirudin is the difficulty in monitoring its activity during CPB, despite the fact that ecarin coagulation time assessment is now available. A more recent approach is based on selective blockage of platelet aggregation by means of monoclonal antibodies directed to GPIIb/IIIa receptors (abciximab) or the use of a GPIIb/IIIa inhibitor (tirofiban). An 80% blockage of the GPIIb/IIIa receptors and suppression of platelet aggregation to less than 20% allows the giving of unfractionated heparin and running CPB in a standard fashion despite HIT and thrombosis. Likewise, at the end of the procedure, unfractionated heparin is neutralized with protamine as usual and donor platelets are transfused if necessary. GPIIb/IIIa inhibitors are frequently used in interventional cardiology and, therefore, are available in most hospitals.