200例心房颤动患者病因及抗凝治疗临床分析

【目的】探讨房颤患者的病因及抗凝治疗的特点。【方法】回顾性分析200例房颤患者的-临床资料。【结果】房颤患者病因组成前四位依次为风心病41．5％；冠心病24．5％；高血压病15．5％；特发性8．5％。治疗多以地高辛为主控制心率125例，应用阿司匹林抗血小板聚集172例，使用华法令28例。【结论】房颤患者病因以风心病、冠心病、高血压最多见。治疗上应注意控制心率并使用阿司匹林抗血小板聚集，华法令应用不足，血栓栓塞事件发生率高。     

脓毒症抗凝治疗策略应用现状：一项多中心横断面调查

目的 了解国内临床医师对脓毒症患者凝血功能的评估手段以及在不同情况下抗凝策略的选择。方法由复旦大学附属中山医院急诊科通过“问卷星”设计问卷，自2022年7月30日至2022年9月4日通过微信、电子邮件等方式推送至国内多家急诊、重症医学中心参与脓毒症患者诊治的临床医师，回收答卷后进行分析。结果 回收问卷157份，其中约半数医师的医疗机构未开展特殊凝血标志物检测。对于脓毒症患者，临床医师较多选用低分子肝素抗凝(72.6%～80.9%)，并根据临床情况（如手术、发生弥散性血管内凝血、出血、术前口服抗凝药物等）进行调整。当发生或既往存在肝素诱导的血小板减少症（heparin-induced thrombocytopenia,HIT）Ⅱ型时，45.2%～61.1%的临床医师未选择非肝素类抗凝药物；对于术前服用华法林或直接口服抗凝药物（direct oral anticoagulant,DOAC）的术后患者，30.6%～45.2%的临床医师选择不抗凝或低分子肝素抗凝。结论 临床医师一般给予脓毒症患者抗凝治疗，应用最广泛的药物为低分子肝素。对于发生HIT的脓毒症患者，抗凝决策常不符合指南；对于术前服...     

早期静脉溶栓治疗急性心肌梗死60例临床观察

【目的】评估早期静脉溶栓联合抗凝、抗血小板聚集、调脂综合治疗急性心肌梗死（AMI）的疗效。【方法】对60例发病至治疗时间≤6h的AMI患者进行尿激酶溶栓联合低分子肝素、氯比格雷、舒降之治疗，并对其疗效进行分析。【结果】发病≤4h以内接受治疗45例，血管再通者36例，占80％。发病4h～6h以内接受治疗15例，血管再通者11例，占73．3％。60例中6h内再通者47例，占总例数78．3％。【结论】早期静脉溶栓联合抗凝、抗血小板聚集、调脂治疗AMI，其越早应用效果越佳，血管再通率达78．3％，在无心脏介入及冠状动脉搭桥术的情况下，只要认真选择好适应证，行早期静脉溶栓治疗，有助于抢救治疗AMI患者。     

采血管材质及血样抽取后存放时间对血小板激活的影响

【目的】评估采血管材质及血样抽取后存放时间对血小板激活的影响。【方法】抽取50例健康人群的双份静脉血标本分别于EDTA—K2塑料管、EDTA—K2玻璃管中抗凝，采用BayerADVIA-2120全自动血细胞分析仪于血样抽取后0．5h、2h、4h、24h检测血小板平均浓度（MPC）、血小板平均体积（MPV）。【结果】玻璃采血管与塑料采血管对MPC测定值的影响无统计学意义（P〉0．05）。MPC、MPV测定值在标本抽取后0．5h与2h间比较无统计学意义（P〉0．05），与4h及24h组比较有统计学意义（P〈0．05），且MPC随标本抽取后贮放时间的延长而呈进行性下降，MPV则增大，两者间有良好的负相关（R=-0．65，P〈0．001，n=50）。【结论】为避免血小板体外激活，保证MPC检测的准确性，MPC测定宜在2h内进行。     

静电自组装壳聚糖/肝素多层膜修饰的聚对苯二甲酸丁二醇酯表面对红细胞及血小板的影响

目的评价静电自组装壳聚糖和肝素固定于聚苯二甲酸丁二醇酯(PBT)膜表面对红细胞及血小板的影响。方法首先将PBT浸泡于聚乙烯亚胺溶液中氨解使其表面带氨基呈正电性,然后多次交替吸附带负电的肝素和带正电的壳聚糖,形成以肝素为最外层的多层膜结构;对该聚电解质多层膜的理化性能做表征,再做溶血率、红细胞变形性、红细胞渗透脆性、血小板黏附、血小板功能等评价实验。以未接触材料的红细胞或血小板为对照组,实验组分别为未改性PBT以及不同层数的静电自组装改性PBT膜,血小板黏附每组的标本数为5,其余指标每组标本数为9。结果水接触角、zeta电位、原子力显微镜等测量观察:PBT膜表面壳聚糖/肝素多层膜逐渐形成;不同层数的多层膜溶血率5%,随组装层数增加,红细胞变形指数逐渐增加,10层静电自组装PBT膜与对照组相近,分别为0.545 7±0.010 7 vs 0.546 1±0.013 1(P0.05);10层静电自组装PBT膜的红细胞渗透脆性与对照组相比明显降低,分别为4.270 1±0.089 5 vs 4.338 8±0.076 2(P0.05),说明红细胞对低渗溶液的抵抗力增大。扫描电镜显示:未改性PBT膜表面黏附的血小板数明显多于改性膜表面,且观察到明显的伪足,随组装层数的增加,血小板在多层膜表面的黏附数减少。未改性PBT膜与2/5/10层静电自组装PBT膜表面黏附的血小板数分别为722 7±222 2 vs 468 2±158 5 vs 327 3±185 0 vs 227 3±103 1(P0.05),未改性PBT膜与对照组的血小板最大聚集率(%)为82.36±2.11 vs87.22±2.10(P0.05),低渗休克相对变化率(HSR)(%)为77.12±1.09 vs 79.33±1.27(P0.05),CD62p表达率(%)为17.45±1.25 vs 9.78±0.58(P0.05);随组装层数的增加,血小板最大聚集率(%)增加,HSR增大,CD62p表达率降低。其中,10层静电自组装PBT膜与未改性PBT膜相比,血小板最大聚集率(%)增加,分别为82.35±1.91 vs94.79±1.84(P0.05),HSR相似,分别为77.32±0.95 vs 76.76±2.35(P0.05),CD62p表达率降低,分别为17.67±1.25 vs 14.67±1.15(P0.05)。结论壳聚糖/肝素静电自组装修饰PBT后,PTB膜亲水性改善,减少了血小板的黏附且对血小板功能和红细胞无明显影响。     

心房颤动复律前经食管超声心动图检测左心房血栓的临床意义

目的 评价经食管超声心动图(TEE)在非瓣膜性心脏病心房颤动患者药物或电复律治疗中的作用。方法 43例心电图证实的非瓣膜性心脏病心房颤动患者接受抗血小板或抗凝治疗并在复律治疗前24～48h行经胸超声心动图和TEE检查。结果 TEE发现左心耳血栓2例和左心房自发声影3例，经抗凝或抗血小板治疗后39例接受复律治疗，其中31例药物复律(成功19例，失败12例)，8例接受电复律(成功6例，失败2例)。所有患者在治疗期间均无血栓栓塞性并发症。结论 心房颤动患者早期接受复律治疗前，TEE探测心房血栓可作为指导抗凝治疗、降低血栓栓塞风险的一项必要的常规检查。     

直接MAIPA对免疫性和非免疫性血小板减少性紫癜的鉴别诊断

目的检测免疫性与非免疫性血小板减少患者血小板膜糖蛋白特异性自身抗体，评价该方法在免疫性和非免疫性血小板减少性紫癜鉴别诊断中的价值。方法应用改良直接单克隆抗体俘获血小板抗原技术(MAIPA)检测血小板膜糖蛋白(GPⅡh／Ⅲa、GP I b和GPI a／Ⅱa)特异性自身抗体。结果免疫性血小板减少患者自身抗体阳性率(76．4％)显著高于非免疫性血小板减少患者(3．6％)(P＜0．05)。直接MAIPA诊断免疫性血小板减少的敏感性为76．4％，特异性为96．4％，阳性预测值为97．1％。GPⅡh／Ⅲa特异性自身抗体阳性的免疫性血小板减少患者血小板计数与自身抗体吸光度比值呈显著负相关(r=-0．338，P＜0．05)。结论直接MAIPA检测血小板膜糖蛋白特异性自身抗体对于鉴别免疫性与非免疫性血小板减少有一定意义。     

内镜逆行胰胆管造影治疗前服用抗凝药物患者出血原因分析与护理

通过对7例内镜逆行胰胆管造影治疗前服用抗凝药物术后发生出血患者的出血原因进行回顾性分析，总结高危人群行内镜逆行胰胆管造影治疗的护理要点。术前做好常规检查，尤其是对血红蛋白、凝血功能、血小板的检测，术前停用抗凝药；术中尽可能减少出血风险较大的操作；术后加强生命体征的监测，对患者的引流液、呕吐物、大便颜色的观察，可以及时发现，及时处理，以减轻术后因出血导致的严重后果。     

不同抗凝技术在连续性静脉-静脉血液滤过中的应用评价

目的 对连续性静脉-静脉血液滤过治疗过程中不同抗凝技术进行评价。方法 选择危重患者48例行连续性静脉-静脉血液滤过（CVVH）治疗，其中出血倾向12例，设为A组，采用局部枸橼酸钠抗凝法；活动性出血者17例，设为B组，采用无肝素抗凝技术；其余患者19例。设为C组，采用低分子肝素钙抗凝。3组置换液速度均为3000ml／h，持续时间12h／d，碳酸氢盐置换液前稀释方式输入。计算溶质下降率，治疗前后检测电解质、酸碱指标、凝血指标；记录心率、平均动脉压、跨膜压及滤器寿命。结果 3组治疗后血尿素氮、肌酐均显著下降，但组间比较溶质下降率差异无显著性（P〉0．05）；电解质、酸碱指标在治疗后均趋于稳定。A、B组各凝血指标在治疗后无显著改变，C组部分凝血活酶时间显著延长（P〈0．05）。整个治疗过程中，3组患者心率、平均动脉压均较稳定。跨膜压明显升高的时间点：A组〉C组〉B组。滤器平均寿命：A组〉C组〉B组（P〈0.05）。结论 CVVH中3种抗凝技术各有优缺点，只有个体化地选择抗凝技术，才能使CVVH更安全有效地应用于危重患者的治疗。     

TEG技术在血小板保存过程中功能评价的应用研究

本研究旨在通过血栓弹力图（thmmbelastography，TEG）技术探讨血小板保存过程中功能的变化。随机选择各项指标均符合国家标准的单供者机采血小板12个单位并在（22±2）℃条件下振荡保存。分别在保存1、2、3、4、5天检测血栓弹力图参数，包括反应时间（R）、凝血时间（K）、α角（ANG）和最大振幅（MA），同时检测血小板计数、平均血小板体积、低渗休克反应（HSR）水平、CD62p阳性率及凝血酶激活CD62p再表达率的变化，综合评价血小板保存过程中体外功能的变化情况。结果显示：平均血小板体积随保存时间延长而轻度增大，但无统计学差异（p〉0．05）；血小板膜表面CD62p表达率随保存时间延长而显著升高（P〈0．01）；凝血酶激活后CD62p再表达率随保存时间的延长而显著下降（p〈0．01）；血小板低渗休克反应水平在1-5天无明显变化（P〉0.05）；R值随保存时间延长而明显延长（P〈0．01），K值无明显变化（P〉0.05），α角虽呈轻度下降趋势，但无显著差异（P〉0．05）；MA值在保存1-4天无显著变化，保存5天时仅有轻度下降（P〈0．05）。结论：虽然血小板随保存时间延长激活率明显升高，但反映血小板综合凝血功能的最大振幅（MA值）和HSR水平在整个保存期内并无显著变化，说明保存期末的血小板仍然具有良好的止血功能；血栓弹力图参数MA值可以作为一项重要指标用于血小板保存过程中的功能评价。     

Pyrophosphate as a novel anticoagulant for storage of whole blood: A proof-of-concept study

Background

Citrate is the only anticoagulant currently Food and Drug Administration (FDA)-approved for the long-term storage of blood for transfusion. Citrate inhibits phosphofructokinase and may play a pro-inflammatory role, suggesting that there may be an advantage to using alternative anticoagulants. Here, we examine the use of pyrophosphate as an anticoagulant.

Study design and methods

Whole blood samples from healthy donors were anticoagulated either with citrate–phosphate–adenine–dextrose (CPDA-1) or our novel anticoagulant mixture pyrophosphate-phosphate–adenine–dextrose (PPDA-1). Samples were assessed for coagulation capacity by thromboelastography immediately after anticoagulation (T0) with and without recalcification, as well as 5 hours after anticoagulation (T1) with recalcification. Complete blood counts were taken at both timepoints. Flow cytometry to evaluate platelet activation as well as blood smears to evaluate cellular morphology were performed at T1.

Results

No clotting was detected in samples anticoagulated with either solution without recalcification. After recalcification, clotting function was restored in both groups. R-Time in recalcified PPDA-1 samples was shorter than in CPDA-1 samples. A reduction in platelet count at T1 compared to T0 was observed in both groups. No significant platelet activation was observed in either group at T1. Blood smear indicated platelet clumping in PPDA-1.

Conclusion

We have shown initial proof of concept that pyrophosphate functions as an anticoagulant at the dose used in this study, though there is an associated loss of platelets over time that may limit its usefulness for blood storage. Further dose optimization of pyrophosphate may limit or reduce the loss of platelets.     

Inhibition of activated protein C by platelets.

Activated protein C (APC), an anticoagulant that acts by inactivating Factors Va and VIIIa, is dependent on a suitable surface for its action. In this study we examined the ability of human platelets to provide this surface and support APC-mediated anticoagulant effects. The activity of APC was examined in three systems: the Factor Xa recalcification time of Al(OH)3 adsorbed plasma, studies of thrombin generation in recalcified plasma, and assessment of the rate of inactivation of purified Factor Va. In comparison with phospholipid, intact platelets required significantly greater concentrations of APC to achieve a similar degree of anticoagulation. When washed platelet membranes were substituted for intact platelets, adequate support of APC was observed and the anticoagulant effect was similar to that obtained with phospholipid. Platelet releasate obtained by stimulation of platelets with thrombin and epinephrine contained an inhibitor that interfered with the ability of phospholipid and washed platelet membranes to catalyze the anticoagulant effects of APC. A noncompetitive inhibition was suggested by Dixon plot analysis of the interaction between platelet releasate and APC. The activity of the platelet APC inhibitor was immediate and was not enhanced by heparin, distinguishing it from the circulating protein C inhibitor. The presence of this inhibitor in the platelet and its release with platelet stimulation emphasizes the procoagulant role of this cell.     

Polyphosphate as a general procoagulant agent

Summary. Background: Polyphosphate is secreted by activated platelets and we recently showed that it accelerates blood clotting, chiefly by triggering the contact pathway and promoting factor (F) V activation. Results: We now report that polyphosphate significantly shortened the clotting time of plasmas from patients with hemophilia A and B and that its procoagulant effect was additive to that of recombinant FVIIa. Polyphosphate also significantly shortened the clotting time of normal plasmas containing a variety of anticoagulant drugs, including unfractionated heparin, enoxaparin (a low molecular weight heparin), argatroban (a direct thrombin inhibitor) and rivaroxaban (a direct FXa inhibitor). Thromboelastography revealed that polyphosphate normalized the clotting dynamics of whole blood containing these anticoagulants, as indicated by changes in clot time, clot formation time, alpha angle, and maximum clot firmness. Experiments in which preformed FVa was added to plasma support the notion that polyphosphate antagonizes the anticoagulant effect of these drugs via accelerating FV activation. Polyphosphate also shortened the clotting times of plasmas from warfarin patients. Conclusion: These results suggest that polyphosphate may have utility in reversing anticoagulation and in treating bleeding episodes in patients with hemophilia.     

New antithrombin-based anticoagulants

Clinically used anticoagulants are inhibitors of enzymes involved in the coagulation pathway, primarily thrombin and factor Xa. These agents can be either direct or indirect inhibitors of clotting enzymes. Heparin-based anticoagulants are indirect inhibitors that enhance the proteinase inhibitory activity of a natural anticoagulant, antithrombin. Despite its phenomenal success, current anticoagulation therapy suffers from the risk of serious bleeding. The need for safer and more effective antithrombotic agents clearly exists. The past decade has seen enormous effort directed toward discovering and/or designing new molecules with anticoagulant activity. These new molecules can be classified into (a). antithrombin and its mutants, (b). natural polysaccharides, (c). synthetic modified heparins and heparin-mimics, (d). synthetic oligosaccharides, and (e). synthetic non-sugar antithrombin activators. This review focuses on these efforts in designing or discovering new molecules that act through the antithrombin pathway of anticoagulation.     

Surface hemocompatible modification of polysulfone membrane via covalently grafting acrylic acid and sulfonated hydroxypropyl chitosan

In this study, acrylic acid (AA) and sulfonated hydroxypropyl chitosan (SHPCS) were covalently grafted on the PSf membrane surface to improve its hemocompatibility. First, the modified AA-PSf membrane was obtained through the Friedel–Craft reaction between acrylic acid and the PSf membrane surface. Then, the modified SHPCS-AA-PSf membrane was prepared by grafting SHPCS onto the AA-PSf membrane surface via the dehydration acylation of the carboxyl group of the AA-PSf membrane with the amino group of SHPCS. ATR-FTIR and XPS measurements confirmed that the –COOH group and SHPCS were successfully grafted onto the surface of the PSf membrane. The modified PSf membranes showed suppressed platelet adhesion and lower protein adsorption (161 μg cm⁻²) compared with the pristine PSf membrane (341 μg cm⁻²). Hemocompatibility testing showed that modified membrane materials had a prolonged clotting time, plasma recalcification time (PRT), activated partial thromboplastin time (APTT), thrombin time (TT), and prothrombin time (PT). All of these results indicated that the surface modification of the PSf membrane with acrylic acid and SHPCS had good hemocompatibility and anticoagulant property.

In this study, acrylic acid (AA) and sulfonated hydroxypropyl chitosan (SHPCS) were covalently grafted on the PSf membrane surface to improve its hemocompatibility.     

Citrate anticoagulation and the dynamics of thrombin generation

BACKGROUND: Sodium citrate has been used as an anticoagulant to stabilize blood and blood products for over 100 years, presumably by sequestering Ca(++) ions in vitro. Anticoagulation of blood without chelation can be achieved by inhibition of the contact pathway by corn trypsin inhibitor (CTI). OBJECTIVE: To evaluate the influence of citrate anticoagulation on the performance of blood, platelet-rich and platelet-poor plasma assays. METHODS: Blood was anticoagulated in three ways: by collection into citrate, CTI and citrate with CTI. Plasma was prepared using each anticoagulation regimen. Functional analyses included calibrated automated thrombography, thromboelastography, plasma clotting, the synthetic coagulation proteome and platelet aggregation. Coagulation reactions were initiated with tissue factor-phospholipid and Ca(++) (when indicated). RESULTS: In all cases, citrate anticoagulation resulted in reaction dynamics significantly altered relative to blood or plasma stabilized with CTI alone. Subsequent experiments showed that calcium citrate itself impairs coagulation dynamics. CONCLUSION: Coagulation analyses using blood that has been exposed to citrate and recalcified do not yield reliable depictions of the natural dynamics of blood coagulation processes.     

Current Strategies for the Management of Bleeding Associated with Direct Oral Anticoagulants and a Review of Investigational Reversal Agents

BackgroundThe management of life-threatening bleeding in patients who are receiving direct oral anticoagulants (DOACs) is a serious medical concern.ObjectiveThis review provides a concise, balanced overview of the current and future approaches for reversing the anticoagulation effects of DOACs, particularly factor Xa (FXa) inhibitors.DiscussionThe anticoagulant activity of the direct thrombin inhibitor dabigatran can be reversed by idarucizumab, but until recently, options for the management of major bleeding in patients who were receiving FXa inhibitors were limited to nonspecific strategies, including supplementation of clotting factors with prothrombin complex concentrates (PCCs) or activated PCCs for attenuating anticoagulation effects. They appear as a treatment option in many hospital guidelines despite the lack of approval by the U.S. Food and Drug Administration and the lack of rigorous medical evidence supporting their use in this setting. The development of specific reversal agents may provide improved strategies for the management of bleeding. Andexanet alfa is a modified FXa molecule approved in the United States to reverse the anticoagulant effects of FXa inhibitors (rivaroxaban and apixaban) in patients with life-threatening or uncontrolled bleeding. Ciraparantag is a small-molecule inhibitor of multiple anticoagulants that has been investigated in healthy subjects.ConclusionThe current guidelines for management of DOAC-associated bleeding are being updated to reflect that the reversal agent for rivaroxaban and apixaban is now available. For other FXa inhibitors, in the absence of a reversal agent, nonspecific strategies that include PCCs are recommended. The population of patients anticoagulated with DOACs is growing, and we hope that specific reversal agents will improve the approach to management of major bleeding in this population.     

不同标本类型间髓过氧化物酶水平的检测分析

目的探讨不同标本类型间髓过氧化物酶(MPO)检测结果的差异性、抗凝剂的选择及检测结果的比对。方法同时采集165例健康体检人群含乙二胺四乙酸二钾(EDTA-K2)、肝素钠两种抗凝剂的血浆标本及不含抗凝剂的普通生化管的血清标本,分别检测3种标本类型中MPO水平,并对各组检测结果进行统计学分析。结果同一例体检者不同抗凝剂的血浆标本间及与不含抗凝剂的血清标本间MPO检测结果差异有统计学意义(P0.05)。结论不同标本类型对血液标本中MPO水平检测结果差异较大,建议各个实验室检测时根据不同抗凝剂制订相应的参考区间;由于EDTA-K2抗凝血浆不受体外白细胞中MPO释放的影响,推荐采用EDTA-K2抗凝血作为检测MPO水平的首选。     

Continuous haemofiltration with r-hirudin (lepirudin) as anticoagulant in a patient with heparin induced thrombocytopenia (HIT II)

A 60-year-old man was admitted to the hospital with aortic dissection. An operative excision and replacement with a Y-graft was performed. Postoperatively he developed multiple organ dysfunction and required intermittent haemofiltration (anticoagulation with heparin). An ischemia of the left leg occurred at the third postoperative day. The initial platelet count was 99,000/microliter. Continuous haemofiltration (CVVH) was started three days later. Thrombotic obstructions of haemodialysis filters and catheters occurred frequently and heparin-induced thrombocytopenia (HIT II) was suspected. Antibodies against heparin were found in the HIPA test. Despite heparin free citrate dialysis and anticoagulation with danaparoid thrombotic obstructions of filters and catheters continued. Therefore the anticoagulation therapy during CVVH was changed to recombinant hirudin (lepirudin). Starting dose was a bolus of 0.01 mg/kg bw followed by the same amount as maintenance dose per hour. Anticoagulation was adjusted to an increase of aPTT (activated partial thromboplastin time) to 1.5-2 times its normal value. A dose of 0.005 mg/kg bw/h lepirudin was sufficient to maintain adequate anticoagulation. After changing to lepirudin no further catheter obstructions were observed and the platelets recovered slowly. Renal function improved and five weeks after admission endogenous creatinine clearance showed a value of 25 ml/min. We conclude that lepirudin is an effective anticoagulant during CVVH in patients with HIT II. In partly permeable polysulfon filters a dose of 0.005 mg/kg bw/h lepirudin is sufficient to maintain adequate anticoagulation. Monitoring anticoagulation by measuring the increase of aPTT (factor 1.5-2.0) seems to be safe. However, optimally the r-hirudin concentration should be measured directly using the Ecarin clotting time.