Anticoagulation in pregnancy and neuraxial blocks

The peripartum management of the anticoagulated parturient represents a significant clinical challenge to both the obstetrician and the anesthesiologist. This review discusses the causes of thrombosis in the pregnant population, the anticoagulants used for prophylaxis, and treatment of these disorders, along with recommendations for neuraxial blockade in parturients who receive peripartum anticoagulation.     

Deep venous thrombosis and pulmonary embolism

All surgical patients are at risk for the development of deep venous thrombosis and subsequent pulmonary embolism or postphlebitic syndrome. The evolution of ultrasonographic imaging has increased the awareness of prevention, diagnosis, and treatment of deep venous thrombosis. Duplex imaging and Doppler color flow imaging have made the diagnosis of deep venous thrombosis relatively simple, painless, inexpensive, and definitive. These procedures have gained acceptance by both patients and physicians. Several risk factors have been identified that increase the chance of the development of deep venous thrombosis. These factors include a history of deep venous thrombosis, presence of a malignant process, increasing age, cigarette smoking, obesity, prolonged bed rest, and general anesthesia. The greater the number of risk factors, the more aggressive prophylaxis should be. Means of prophylaxis have improved, and surgeons now generally agree that some form of prophylaxis is required. Heparin and intermittent compression devices appear to be equally effective in preventing deep venous thrombosis. The addition of venous monitoring in high-risk patients permits immediate identification of the presence of deep venous thrombosis. During the last decade, the treatment of patients with deep venous thrombosis has changed little. Heparin followed by warfarin remains the treatment of choice. A small group of patients receive fibrinolytic therapy for deep venous thrombosis. Although the incidence of postoperative deep venous thrombosis has decreased during the last decade, it remains a significant complication.     

Recomendaciones de consenso SEDAR-SEMICYUC sobre el manejo de las alteraciones de la hemostasia en los pacientes graves con infección por COVID-19

The infection by the coronavirus SARS-CoV-2, which causes the disease called COVID-19, mainly causes alterations in the respiratory system. In severely ill patients, the disease often evolves into an acute respiratory distress syndrome that can predispose patients to a state of hypercoagulability, with thrombosis at both venous and arterial levels. This predisposition presents a multifactorial physiopathology, related to hypoxia as well as to the severe inflammatory process linked to this pathology, including the additional thrombotic factors present in many of the patients.In view of the need to optimise the management of hypercoagulability, the working groups of the Scientific Societies of Anaesthesiology-Resuscitation and Pain Therapy (SEDAR) and of Intensive, Critical Care Medicine and Coronary Units (SEMICYUC) have developed a consensus to establish guidelines for actions to be taken against alterations in haemostasis observed in severely ill patients with COVID-19. These recommendations include prophylaxis of venous thromboembolic disease in these patients, and in the peripartum, management of patients on long-term antiplatelet or anticoagulant treatment, bleeding complications in the course of the disease, and the interpretation of general alterations in haemostasis.     

Thrombolytic therapy for acute deep venous thrombosis: how much is enough?

Twenty-eight patients treated with thrombolytic therapy for acute deep venous thrombosis were monitored prospectively with non-invasive testing every 12–24 h during treatment to evaluate thrombus response and whether duration of therapy was appropriate. Some 75% (21 of 28) of patients demonstrated improvement with lytic therapy with 36% (10 of 28) demonstrating complete lysis; 95% of responders (20 of 21) initiated lysis within 24 h. Some 33% (7 of 21) of all responders and 64% (7 of 11) of those having partial lysis had treatment terminated during thombus resolution but before maximal lysis. Non-invasive testing indicated that thrombolytic therapy for acute deep venous thrombosis is frequently terminated before maximal lysis of the thrombus. Monitoring thrombus response with venous duplex imaging should be part of the treatment strategy of deep venous thrombosis if thrombolytic therapy is used. This approach should increase efficacy and potentially reduce complications of thrombolytic therapy for acute deep venous thrombosis.     

Surveillance for venous thromboembolic disease after total knee arthroplasty.

The value of deep venous thrombosis screening after total knee arthroplasty is controversial. The purpose of the current study was to examine the value of routine surveillance for venous thrombosis after total knee arthroplasty done with modern operative and perioperative treatment. Computerized search engines were used to identify papers published between 1985 and July 2000 relevant to the purpose of the study. Papers that met the inclusion criteria for review were categorized as follows: the frequency of deep venous thrombosis; the natural history of deep venous thrombosis; the accuracy of screening methods for venous thrombosis; and efficacy of screening in reducing morbidity attributable to venous thromboembolism after total knee arthroplasty. Several studies have shown a low complication rate related to venous thromboembolic disease when compression ultrasound is used for screening as part of a clinical algorithm after knee arthroplasty. However, the only large prospective randomized trial evaluating ultrasound screening failed to show a reduction in morbidity with a surveillance protocol. The benefits of surveillance depend on factors specific to each surgeon's practice including the type and duration of venous prophylaxis, the rate of symptomatic and asymptomatic thromboembolic disease associated with that protocol, and the accuracy of screening tests used for surveillance.     

Current assessment of thromboembolic disease and pregnancy.

This study was undertaken to assess incidence of deep venous thrombosis and pulmonary emboli in an inner-city pregnant population. Thromboembolic disease is believed to occur in 0.05 to 0.1 per cent of all pregnancies. Historically, postpartum thromboembolic disease was more common; decreased hospital stay may shift the thromboembolic disease to the antepartum period. A 5-year retrospective review of 4910 births assessed for incidence of thromboembolic disease, methods of diagnosis and treatment, and risk factors. A total of 4910 deliveries with 3978 transvaginal resulted in 30 episodes of deep venous thrombosis and five pulmonary emboli. All incidences of deep venous thrombosis but one were left-sided; four of five pulmonary emboli were postpartum. Of the epidsodes of deep venous thrombosis 17 per cent were first trimester, 50 per cent second trimester, 27 per cent third trimester, and 6 per cent postpartum. The diagnosis was confirmed by duplex scan in 24 of 30 patients. Heparin was the standard treatment. Deep venous thrombosis in pregnancy is most common in the second trimester; pulmonary emboli remain most common postpartum.     

Treatment alternatives for axillary-subclavian vein thrombosis: long-term follow-up

Sponteneous axillary-subclavian vein thrombosis in young patients produces long-term disability. Patients with secondary axillary-subclavian vein thrombosis usually require prolonged venous catheterization for chemotherapy or pacemaking. This study aimed to compare the early and late results of lytic versus anticoagulant therapy in the treatment of axillary-subclavian vein thrombosis, both spontaneous and secondary to central venous cannulation. Nine patients underwent conventional treatment (heparin and warfarin) (group 1), and 10 had initial lytic therapy followed by heparin and warfarin (group 2). Three patients had cervical or first rib resection. Thirteen patients had spontaneous thrombosis and six were secondary to central venous catheterization. The mean follow-up was 36 months. Two of nine patients (22%) in group 1 and eight of 10 patients (80%) in group 2 had total venous recanalization and symptom resolution (P = 0.018). In the spontaneous axillary-subclavian vein thrombosis.subset, one of six patients (17%) in group 1 and five of seven patients (71%) in group 2 had total venous recanalization and symptom resolution (P = 0.078). The average difference in cost per patient between groups 1 and 2 was $19 039. In conclusion, lytic therapy appears superior to anticoagulation in the treatment of axillary-subclavian vein thrombosis. However, such treatment is more expensive and its benefits should be carefully weighed against the cost in each case. Copyright © 1996 The International Society for Cardiovascular Surgery.     

Rapid-inflation intermittent pneumatic compression for prevention of deep venous thrombosis

BACKGROUND: Current treatment regimens that are designed to prevent deep venous thrombosis in patients undergoing orthopaedic procedures rely predominantly on drug prophylaxis alone. The purpose of this randomized clinical study was to evaluate the effectiveness of a mechanical adjunct to chemoprophylaxis that involves intermittent compression of the legs. METHODS: During a twenty-two month period, 1803 patients undergoing a variety of orthopaedic procedures were prospectively randomized to receive either chemoprophylaxis alone or a combination of chemoprophylaxis and mechanical prophylaxis. Nine hundred and two patients were managed with low-molecular-weight heparin alone, and 901 were managed with low-molecular-weight heparin and intermittent pneumatic compression of the calves for varying time periods. Twenty-four percent of the patients underwent total hip or knee joint replacement. Screening for deep venous thrombosis was performed on the day of discharge with duplex-color-coded ultrasound. RESULTS: In the chemoprophylaxis-only group, fifteen patients (1.7%) were diagnosed with a deep venous thrombosis; three thromboses were symptomatic. In the chemoprophylaxis plus intermittent pneumatic compression group, four patients (0.4%) were diagnosed with deep venous thrombosis; one thrombosis was symptomatic. The difference between the groups with regard to the prevalence of deep venous thrombosis was significant (p = 0.007). In the chemoprophylaxis plus intermittent pneumatic compression group, no deep venous thromboses were found in patients who received more than six hours of intermittent pneumatic compression daily. CONCLUSIONS: Venous thrombosis prophylaxis with low-molecular-weight heparin augmented with a device that delivers rapid-inflation intermittent pneumatic compression to the calves was found to be significantly more effective for preventing deep venous thrombosis when compared with a treatment regimen that involved low-molecular-weight heparin alone.     

脾切除术后肠系膜上静脉血栓形成八例诊治分析

目的　探讨脾切除术后肠系膜上静脉血栓形成的诊断及治疗。方法　回顾性分析1990年 1月～ 2 0 0 0年 8月收治的 8例患者诊治资料。结果　 6例痊愈 ,2例死亡。结论　脾切除术为肠系膜上静脉血栓形成的易患因素。彩色超声、CT、选择性血管造影对该病早期诊断具有重要意义。早期手术及持续有效地抗凝治疗是降低本病死亡率的关键。     

Factors predictive of venous thrombotic complications in patients with isolated superficial vein thrombosis

OBJECTIVE: Superficial vein thrombosis may be complicated with venous thromboembolism. We examined factors predictive of venous thromboembolism in superficial vein thrombosis, which, to our knowledge, had not been prospectively studied before. DESIGN AND METHODS: We performed post hoc analysis of the STENOX trial, a prospective randomized controlled trial that investigated various antithrombotic therapies in 427 hospitalized patients with objectively confirmed symptomatic isolated superficial vein thrombosis. The value of various baseline characteristics as predictive factors of venous thrombotic complications at 3 months was studied with logistic regression. Venous thrombotic complications were defined as deep vein thrombosis or pulmonary embolism, or recurrence or proximal extension of superficial vein thrombosis. RESULTS: Venous thrombotic complications occurred in 78 patients. Independent predictive factors for complications were superficial vein thrombosis of recent onset (odds ratio [OR], 3.01; 95% confidence interval [CI], 1.44-6.27), severe chronic venous insufficiency (OR, 2.75; CI, 1.10-6.89), male gender (OR, 2.17; CI, 1.28-3.68), and history of venous thromboembolism (OR, 2.07; CI 1.06-4.04). Deep vein thrombosis or pulmonary embolism occurred in 19 patients. Only severe chronic venous insufficiency was an independent predictor of this complication (OR, 4.50; CI, 1.30-15.61). CONCLUSIONS: After symptomatic isolated superficial vein thrombosis, venous thrombotic complications are relatively frequent, and are more likely to occur in men, in patients with a history of venous thromboembolism or with severe chronic venous insufficiency, or in whom superficial vein thrombosis is recent. Knowledge of such predictive factors may be useful for determining appropriate treatment in patients with superficial vein thrombosis and for designing future phase III clinical trials.     

Treatment and outcome of pancreatic venous graft thrombosis after kidney--pancreas transplantation

BACKGROUND: Pancreas venous graft thrombosis after transplantation is the main non-immunological cause of graft failure and usually results in pancreatectomy. Duplex Doppler ultrasonography is the primary imaging technique for monitoring vascular patency after pancreas transplantation. This study reports the results of rescue treatments for pancreas graft thrombosis after simultaneous pancreas--kidney transplantation. METHODS: One hundred and ninety-six patients with insulin-dependent diabetes mellitus received a simultaneous pancreas--kidney transplantation. Venous graft thrombosis was diagnosed in 25 of these patients based on Doppler ultrasonographic findings. RESULTS: Total venous graft thrombosis was diagnosed in 20 symptomatic patients, of whom 14 required graft pancreatectomy. Surgical thrombectomy was attempted in six patients with preserved arterial supply and was successful in four. Partial venous graft thrombosis was diagnosed in five asymptomatic patients; one also had partial splenic artery thrombosis. Rescue graft procedures included systemic anticoagulation (one patient), arterial thrombolysis (one) and venous thrombolysis and/or mechanical venous thrombectomy (four episodes in three patients). Graft rescue was achieved in three patients treated by venous thrombolysis/thrombectomy. CONCLUSION: Doppler ultrasonography allows the appropriate selection of rescue treatment based on the findings of total or partial thrombosis.     

急性髂股静脉血栓形成时腔内治疗技术的选用与评价

急性髂股静脉血栓形成（AIFVT）是常见的静脉血栓栓塞性疾病,易并发致命性肺栓塞（PE）。近年来导管溶栓的应用不断增加,但不推荐常规应用。当溶栓治疗不满意或者使用溶栓治疗受到限制时,可采用抽栓导管负压抽吸血栓。超声消融不能作为深静脉血栓形成的单一治疗手段,多联合手术取栓及球囊扩张、支架植入术。AIFVT治疗的关键是早期诊断、早期治疗。     

Frequency of venous thrombosis in patients with an exacerbation of chronic obstructive lung disease

The presence or absence of venous thrombosis was determined in 29 patients with an acute exacerbation of chronic obstructive lung disease by the technique of autologous platelet labelling with indium-111. Deep venous thrombosis was diagnosed in 13 patients and in nine of these patients thrombosis was located proximal to the knee--that is, in areas associated with an appreciable risk of pulmonary embolism. One patient died; pulmonary emboli were found at postmortem examination. The incidence of venous thrombosis seen in this study is high enough to suggest that these patients may benefit from prophylactic antithrombotic treatment.     

下肢深静脉血栓并发急性肺栓塞的肺内血栓分布特点及血管腔内治疗的临床效果

目的探讨下肢深静脉血栓并发急性肺栓塞的肺内血栓分布特点及血管腔内治疗的临床效果。方法对8例患者首先行下腔静脉滤器置入术以防止下肢深静脉血栓再次脱落,在此基础上行肺动脉造影,观察肺动脉血栓分布情况,利用导丝导管迅速开通栓塞血管,恢复栓塞血管内血流,每24h给予50万U尿激酶,连续72h肺动脉小剂量置管溶栓,24h后行肺动脉造影,观察残留血栓分布,及时调整溶栓导管位置。72h时再行肺动脉造影,观察肺动脉血流恢复情况并拔管,根据DSA图像应用血管造影机自带容量测量软件工具计算血栓残留量;对下肢深静脉血栓有症状者利用导丝导管对栓塞血管迅速开通,观察血栓开通后下肢症状缓解变化。治疗期间每隔24h抽血行血凝分析1次,观察患者术后是否有渗血、出血增加的现象。结果对8例患者共栓塞肺动脉分支24支,其中双肺动脉4个大分支栓塞患者1例,双肺动脉3个大分支栓塞者6例,双肺动脉2个大分支栓塞者1例。治疗后72h肺动脉造影显示血栓残留量20%者20支,20%~50%者2支,50%者2支。患侧下肢深静脉血栓经血管腔内治疗后下肢肿胀、疼痛均有不同程度缓解,72h后症状基本缓解。治疗期间8例患者的活化部分凝血活酶时间、国际标准化比率均在正常范围之内,未出现渗血、出血增加的现象。结论下肢深静脉血栓并发急性肺栓塞得到及时治疗的患者血栓分布以肺动脉3支分支血栓多见,血管腔内治疗及小剂量置管溶栓治疗是一种安全有效的治疗方法。     

骨折术后深静脉血栓的防治

目的 探讨骨折术后合并深静脉血栓的临床特点和防治措施。方法 抗凝治疗下肢深静脉血栓5例。结果 5例经及时诊断和抗凝治疗后均获得好转。结论 深静脉血栓具有隐蔽性临床征象，容易延误早期治疗。对高危患者应重点预防。围手术期采用3种预防方法能够显著减少深静脉血栓的发生率。     

溶栓配合肝素间歇疗法治疗静脉血栓形成——附40例临床分析

目的:探讨溶栓配合肝素间歇疗法治疗静脉血栓形成的临床疗效。方法:40例患者予尿激酶和肝素钙交替静滴,疗程为4周,根据临床症状和体征及彩色多普勒结果判断疗效。结果:40例患者中,临床痊愈14例,显效26例,均未发生严重内脏出血;出凝血和血流变指标较治疗前显著改善(P<0.01)。结论:溶栓配合肝素间歇疗法在临床显示了较好的安全性和有效性。     

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??Evaluation of transluminal therapy in acute iliofemoral venous thrombosis CHEN Zhong. Department of Vascular Surgery, Beijing Anzhen Hospital ,Capital University of Medical Science, Beijing 100029, China
Abstract Acute iliofemoral venous thrombosis (AIFVT) is a common disease in venous thromboembolism. In recent years, the application of catheter-directed thrombolysis was increasing,but not recommended routine applications. when treatment of catheter-directed thrombolysis was not satisfied or limited, can adopt thrombus extraction. Ultrasonic ablation was not single treatment of deep venous thrombosis, it must joint thrombectomy, balloon angioplasty and peri-operative. The key of AIFVT treatment was the early diagnosis and early treatment.     

下肢静脉超声检出肌肉骨骼系统病变的临床价值

目的探讨下肢静脉超声检出肌肉骨骼系统病变的临床价值。方法回顾性收集因临床疑诊或需除外下肢深静脉血栓接受下肢静脉超声检查的8 288例患者的资料,分析下肢静脉超声检查对于肌肉骨骼系统病变的检出率及合并深静脉血栓等超声表现。结果下肢静脉超声检出肌肉骨骼系统病变134例,以腘窝囊肿(90/134,67.16%)最常见,其后依次为血肿(31/134,23.13%)、肌肉撕裂(5/134,3.73%)、脓肿(2/134,1.49%)、肿瘤(2/134,1.49%)、肌层囊肿(2/134,1.49%)、腘窝术后积液(1/134,0.75%)及膝关节滑膜增生(1/134,0.75%)。不同肌肉骨骼系统病变超声表现各异。腘窝未破裂囊肿最大径大于破裂囊肿(F=5.266,P=0.024)。134例中20例合并下肢深静脉血栓,其中肌肉撕裂患者最易合并血栓(1/5,20.00%)。结论下肢静脉超声检查可在判别有无深静脉血栓的同时检出肌肉骨骼系统病变,有助于修正或补充临床诊断及治疗方案,具有较高临床价值。     

全髋关节置换术后深静脉血栓形成

目的：探讨全髋关节置换术后下肢深静脉血栓形成（DVT）的发生情况及预防治疗措施。方法：对220例（244髋）全髋关节置换患者围手术期皮下注射低分子肝素来预防治疗下肢深静脉血栓形成。术后第7天行彩色多普勒超声检查。结果：58例发生下肢深静脉血栓，其中远端血栓33例，近端血栓14例，全静脉血栓11例，DVT发生率26．4％，未发生1例肺栓塞。结论：围手术期低分子肝素应用可降低全髋关节置换术后DVT发生率，且安全可靠。     

Pharmacological prophylaxis of venous thrombo-embolism.

The pathogenesis of venous thrombosis is briefly discussed as a basis for the understanding of preventive measures used in this condition. Prophylaxis in venous thrombosis is then reviewed with emphasis on pharmacological treatment, and more particularly on heparin.