Current trends in venous thromboembolism among persons hospitalized with acute traumatic spinal cord injury: does early access to rehabilitation matter?

Selassie AW, Varma A, Saunders LL. Current trends in venous thromboembolism among persons hospitalized with acute traumatic spinal cord injury: does early access to rehabilitation matter?

Objective

To determine the incidence of venous thromboembolism (VTE) among patients with traumatic spinal cord injury (TSCI) in acute care settings that is attributable to extended length of stay (LOS), insurance status, and access to rehabilitation.

Design

Population-based, retrospective cohort study.

Setting

Levels I through III and undesignated trauma centers.

Participants

Patients with acute TSCI (N=3389) discharged from all acute care hospitals in South Carolina from 1998 through 2009, and a representative sample of patients with TSCI (n=186) interviewed 1 year later.

Interventions

Not applicable.

Main Outcome Measure

VTE while in acute care.

Results

Annual incidence of TSCI is 67.2 per million in the state of South Carolina, while the cumulative incidence of VTE is 4.1%. Patients with TSCI who developed VTE were nearly 4 times more likely (odds ratio [OR], 3.98; 95% confidence interval [CI], 2.57–6.17) to have been those who stayed 12 days or longer in acute care after adjusting for covariates. The adjusted mean LOS in acute care was 32.0 days (95% CI, 27.7–37.2) for patients with TSCI who had indigent insurance versus 11.3 days (95% CI, 4.9–17.6) for Medicare, and 18.5 days (95% CI, 14.5–22.5) for commercial insurance after adjusting for VTE, disposition, and year of discharge. Only 20% of the persons under indigent care received rehabilitation from accredited rehabilitation facilities in contrast to 60% under commercial insurance.

Conclusions

Fewer patients with TSCI under indigent care received postacute rehabilitation compared with Medicare or commercial insurance. Insurance status remains a major barrier to timely transfer to rehabilitation, leading to protracted LOS in acute care with increased risk of VTE.     

Venous thromboembolism in patients with cancer. Part I. Survey of oncology nurses' attitudes and treatment practices for ambulatory settings

Patients with cancer have a higher incidence of venous thromboembolism (VTE). Little information currently exists on VTE and the understanding and beliefs of oncology nurses. Therefore, the attitudes and treatment practices of ambulatory oncology nurses were surveyed to determine the current knowledge base of VTE in patients with cancer. Survey results are presented along with a thorough literature review of thromboembolism and the unique risk factors for this frequent complication in patients with cancer. The causes of VTE in this patient population often are multifactorial and include hypercoagulability, stasis, and vascular endothelial damage from procedures or the neoplastic process itself. In particular, chemotherapy administration can increase the risk of thrombosis considerably. New therapies, including thalidomide, require oncology nurses caring for these patients to have heightened awareness of the potential for thrombogenic complications. This is the first of two articles that address the problem of thromboembolism in patients with cancer, including the survey results. (See part II on page 465.) Oncology nurses are essential in the care of VTE in patients with cancer and can help with patient identification, treatment, and compliance for improved patient outcomes.     

Is long-term low-molecular-weight heparin acceptable to palliative care patients in the treatment of cancer related venous thromboembolism? A qualitative study

Venous thromboembolism (VTE) is common in patients with terminal cancer. Current treatment practice with warfarin has a high incidence of complications, including bleeding, poor control and recurrent VTE. Long-term low-molecular-weight heparin (LMWH) therapy is safer and more efficacious in this patient group, but there are concerns that daily therapy may have a negative impact on quality of life. A qualitative study was carried out to determine whether LMWH was acceptable in palliative care patients, both in the community and in-patient units. Forty palliative care patients receiving LMWH for VTE were interviewed. Participants found LMWH to be an acceptable intervention, allowing them freedom from blood tests and optimism regarding their care. It was considered a preferable therapy to warfarin, which had a negative impact on participant's quality of life. The findings of this study support the use of LMWH, first line in the treatment of established VTE in the palliative care setting.     

Venous Thromboembolism: Exploring Incidence and Utility of Screening in Individuals With Brain Injury

ObjectiveTo determine the incidence of VTE in the population with brain injuries (BIs) using ultrasonography, and to assess the risk of pulmonary embolism (PE) development and/or bleeding complications related to anticoagulation.DesignRetrospective study.SettingAcute rehabilitation hospital.Participants238 individuals with moderate to severe BI who were routinely screened for VTE with ultrasonography on admission to rehabilitation (N=238).InterventionsNot applicable.Main Outcome MeasuresRetrospective chart review was performed to identify individuals who were diagnosed with VTE at the following 3 time points: in acute care prior to admission to rehabilitation, at the time of admission diagnosed via screening examination, and after admission to rehabilitation. Additionally, risk factors for VTE, PE, and incidence of bleeding complications related to therapeutic anticoagulation were assessed.Results123 deep vein thromboses (DVTs) were identified with 38.2% in acute care (n=47), 69.1% on admission to rehabilitation (n=85), and 7.3% during the course of rehabilitation stay (n=9). Risk factors for development of VTE included age at injury, body mass index, injury etiology, history of neurosurgical procedure, and surgery during inpatient rehabilitation. Of those who were placed on therapeutic anticoagulation due to admission diagnosis of VTE (n=50), 2% developed recurrent DVT and 2% had bleeding complications. There was zero incidence of PE.ConclusionWe demonstrated a high prevalence of VTEs identified on screening ultrasonography on admission to inpatient rehabilitation among individuals with moderate to severe BIs, and low complications related to anticoagulation. Given the findings of this study, prospective research in ultrasonography screening for VTE in moderate to severe BI is needed.     

Treatment and secondary prevention of venous thromboembolism in cancer patients. Current strategies and new therapeutic options

Cancer is a major and independent risk factor of venous thromboembolism (VTE). In clinical practice, a high number of VTE events occurs in patients with cancer, and treatment of cancer-associated VTE differs in several aspects from treatment of VTE in the general population. However, treatment in cancer patients remains a major challenge, as the risk of recurrence of VTE as well as the risk of major bleeding during anticoagulation is substantially higher in patients with cancer than in those without cancer. In several clinical trials, different anticoagulants and regimens have been investigated for treatment of acute VTE and secondary prophylaxis in cancer patients to prevent recurrence. Based on the results of these trials, anticoagulant therapy with low-molecular-weight heparins (LMWH) has become the treatment of choice in cancer patients with acute VTE in the initial period and for extended and long-term anticoagulation for 3-6 months. New oral anticoagulants directly inhibiting thrombin or factor Xa, have been developed in the past decade and studied in large phase III clinical trials. Results from currently completed trials are promising and indicate their potential use for treatment of VTE also in cancer patients. However, the role of the new oral thrombin and factor Xa inhibitors for VTE treatment in cancer patients still has to be clarified in further studies specifically focusing on cancer-associated VTE. This brief review will summarize the current strategies of initial and long-term VTE treatment in patients with cancer and discuss the potential use of the new oral anticoagulants.     

Cancer and venous thromboembolism: a multidisciplinary approach

In this paper, we briefly review the relation between cancer and venous thromboembolism (VTE), an association that has been recognized for more than a century. In particular we focus on VTE as predictor and prognostic factor for cancer and the antineoplastic potential of antithrombotic treatment. Cancer may cause disturbances in the haemostatic system by numerous mechanisms that can lead to an increased risk of VTE. Patients with known cancer are at increased risk of VTE; however, VTE may also be a predictor of subsequent cancer in the years afterwards. Furthermore, cancer patients with VTE are more likely to have advanced disease and a worse prognosis than cancer patients without a VTE episode. These findings may have implications for the clinical care of patients with VTE in terms of screening for cancer. However, extensive cancer screening programs are not recommended in general for patients with VTE. A wide range of antithrombotic drugs including heparin, oral anticoagulants, and platelet inhibitors have been examined in order to study the effect on the prevention and treatment of various cancers. These efforts have resulted in a considerable amount of useful data from animal models and a number of promising reports from retrospective analyses and small-scale trials linking antithrombotic treatment with an increased survival in cancer patients and even a lower risk of primary cancer. However, the clinical implications of these findings must await properly designed and conducted randomized clinical trials.     

The use of long-term low-molecular weight heparin for the treatment of venous thromboembolism in palliative care patients with advanced cancer: a case series of sixty two patients

The advantages of low-molecular weight heparin (LMWH) over warfarin, in the treatment of cancer associated venous thromboembolism (VTE) are well reported. However the studies supporting LMWH include few patients representative of the palliative care population. Although LMWH has advantages over warfarin it is still unclear, within the palliative care environment, how long anticoagulation should be continued, what dose of LMWH should be used and whether palliative care patients experience different complication rates such as bleeding, heparin-induced thrombocytopenia and osteoporosis.We report a case series of 62 patients with advanced malignancy and VTE treated with long-term LMWH according to either the CLOT (full dose) or Montreal (reduced dose) regime. Seventy-four percent of patients self-administered LMWH, whereas 24% had it given by a carer and 2% by the district nurse. LMWH was given for median duration of 97 days; the most common reason for discontinuation of therapy being admission to die or commencement of the care pathway (n = 50, 81%). A further 11% (n = 7) stopped after 6 months of treatment. Of these 3 (43%) developed clinical symptomatic recurrence of VTE. The overall minor bleeding rate was 8.1% (95% confidence interval 3.5-17.5%), and this was not associated with NSAID or steroid use. No major bleeding events were observed. No patients developed evidence of heparin-induced thrombocytopenia or osteoporosis.Long-term LMWH appears effective in treatment of VTE in the palliative care population with advanced cancer. A randomised control trial is required to identify the best dose required to ensure optimum efficacy and safety.     

The underutilization of venous thromboembolism prophylaxis in medical patients

Venous thromboembolism (VTE), long been recognized as a preventable complication of hospitalization, is becoming more widely recognized as a risk for both medical and surgical patients. Recommendations exist for VTE prophylaxis (PPX) in medical patients, but current research shows that the utilization of these guidelines is suboptimal. The rates of VTE PPX are lower than recommended rates, and in those patients receiving PPX, the type, dosage, or duration is not in accordance with recognized recommendations. The recommendations and protocols for medical patients that are currently available should be followed, and as new research is developed and reviewed, current practice should be changed to reflect it. The clinical nurse specialist is in a unique position to assimilate the current recommendations into practice and to enhance patient care by virtue of having multiple spheres of influence, capable of influencing institution policy, patient, family, nurse, and physician education, and direct patient care. The VTE PPX is not overused, but underused, and institutions, physicians, and nurses all need to be cognizant of patient risk for VTE with the need to treat prophylactically and initiate PPX according to the American College of Chest Physicians guidelines.     

Rehabilitation outcomes for veterans with polytrauma treated at the Tampa VA

Returning soldiers from Iraq and Afghanistan who have sustained polytrauma have a combination of complex physical and mental morbidities that require extensive therapy and rehabilitation. This study examined the effect of rehabilitation on 116 polytrauma patients with service-connected injuries treated at the Tampa VA; improvements in functional and cognitive abilities were measured using the Functional Independence Measure (FIM) scores and healthcare costs for rehabilitation treatment were also assessed. Intensive rehabilitation therapy increased functional ability in this cohort with an average improvement in total FIM scores of 23 points. Total inpatient costs for these patients exceeded $4 million in approximately 3 years. Rehabilitation nurses face challenges providing quality care to this target patient population, including characterizing war-related polytrauma, providing surveillance, coordinating care, synchronizing care for patients with multiple injuries, and conducting evidence-based pain management.     

Venous thromboembolism prophylaxis guidelines: use by primary care physicians

Venous thromboembolism (VTE), a prevalent, costly medical condition, is one of the most common causes of death in the United States. Although risk factors for VTE are well known, thromboembolic events cannot be predicted because patients are asymptomatic and screening methods have limitations. Anticoagulant therapy (eg, low-molecular-weight heparin, unfractionated heparin, selective factor Xa inhibitors) has proved effective for preventing thromboembolism, including deep vein thrombosis and pulmonary embolism. While quality care for VTE entails prophylaxis for all relevant patients, many high-risk patients are undertreated or treated incorrectly. Both primary and secondary prevention of VTE remain inadequate for several reasons, including lack of awareness of the American College of Chest Physicians guidelines, of the seriousness of VTE, of the benefits of prophylaxis, and of the relatively low risk of bleeding complications. To provide appropriate treatment, physicians must assess the numbers and types of risk factors for each patient, the underlying illness or surgical procedure, and the benefits and risks of possible therapies. The problem of VTE will grow as the US population ages, as surgery is performed on increasingly sick patients, and as the length of hospital stays continues to decrease.     

Factors influencing hospice thromboprophylaxis policy: a qualitative study

Despite level 1 evidence supporting the use of low-molecular weight heparin thromboprophylaxis in hospitalised cancer patients, only 7% of specialist palliative care units (SCPU) have thromboprophylaxis guidelines. The reasons for this are unclear. To explore specialist palliative care units (SPCU) directors' views on thromboprophylaxis in the inpatient unit, audiotaped semi-structured interviews were conducted with SCPU medical directors to explore factors influencing thromboprophylaxis practice. Purposive sampling of units known not to have thromboprophylaxis guidelines was conducted (as identified from previous research). The hospice directory was used to sample from units in each region of Great Britain and Ireland to ensure representation across the specialty. Interviews were transcribed and analysed using interpretative phenomenological analysis (IPA). Four major and four sub themes were identified. Participants were progressive in their attitudes to palliative care and comfortable with instigating active interventions for patient benefit. Symptomatic venous thromboembolism (VTE) was rarely seen and therefore not considered important enough to warrant guidelines. There was concern that evidence informing thromboprophylaxis guidelines in the general population was not transferable to the advanced cancer population and that the outcome measures from these studies were less meaningful to a palliative care patient. Thromboprophylaxis was considered a life prolonging intervention which may result in a poorer death than one because of VTE. Nevertheless, participants were receptive to change if presented with convincing evidence derived from a representative population. Until the true prevalence and symptomatic burden of VTE is known, the role of thromboprophylaxis in the SPCU setting will remain controversial. There is a need for a well-designed study to explore the utility of thromboprophylaxis in the palliative care inpatient setting. However, this will require meaningful outcome measures to be used within a clinically applicable population.     

Management of venous thromboembolism in the palliative care setting

Recent literature has highlighted the unique challenges facing professionals involved with the management of venous thromboembolism (VTE) in cancer patients. Although research favours the use of low molecular weight heparin (LMWH) rather than warfarin, no studies have been conducted exclusively in the palliative care population. Likewise, active treatment may not always be appropriate in the advanced cancer patient. This paper highlights the issues to be considered when facing a palliative care patient and suspected VTE. In particular, consideration must be given to the practicalities and acceptability of investigating suspected VTE, the dose and length of anticoagulation, and management of the patient nearing death. An understanding of the current evidence must be applied to the individual patient, taking into account their needs and wishes.     

Evaluation of a thromboprophylaxis quality improvement project in a palliative care unit

ContextThe benefits of anticoagulation treatment for primary prophylaxis in patients with advanced progressive diseases are unclear. Moreover, there are no empirically based guidelines on thromboprophylaxis for palliative care patients.ObjectivesTo prospectively evaluate a quality improvement protocol on the use of thromboprophylaxis on a 36-bed palliative care unit (PCU).MethodsA protocol was developed to guide and standardize practice related to venous thromboembolic events (VTE) and anticoagulation medication use on the PCU in patients with a life expectancy of less than six months. Through a prospective audit, data were collected for consecutively admitted patients over a period of four months.ResultsOf the 127 patients admitted to the PCU, 41 (32.3%) were on thromboprophylaxis on admission. All but one of these patients had come from an acute care hospital. Thromboprophylaxis was discontinued in 36 (87.8%) of these patients; one patient went on to develop a VTE. Of the 71 patients admitted without thromboprophylaxis, none of the patients were started on thromboprophylaxis and six went on to develop a VTE.ConclusionIn this quality improvement study of patients admitted to a PCU largely for end-of-life care, thromboprophylaxis was discontinued in most patients without a significant increase in the incidence of symptomatic VTE. The validity of recommendations extrapolated from the general hospitalized cancer population supporting routine thromboprophylaxis and applied to these patients can be challenged. A policy that requires thromboprophylaxis in all hospitalized cancer patients may run the risk of indiscriminately including patients who are in the terminal phase of their lives.     

Venous thrombosis and cancer: from mouse models to clinical trials

Cancer patients have a ~4 fold increased risk of venous thromboembolism (VTE) compared with the general population and this is associated with significant morbidity and mortality. This review summarizes our current knowledge of VTE and cancer, from mouse models to clinical studies. Notably, the risk of VTE varies depending on the type and stage of cancer. For instance, pancreatic and brain cancer patients have a higher risk of VTE than breast and prostate cancer patients. Moreover, patients with metastatic disease have a higher risk than those with localized tumors. Tumor‐derived procoagulant factors and growth factors may directly and indirectly enhance VTE. For example, increased levels of circulating tumor‐derived, tissue factor‐positive microvesicles may trigger VTE. In a mouse model of ovarian cancer, tumor‐derived IL‐6 and hepatic thrombopoietin have been linked to increased platelet production and thrombosis. In addition, mouse models of mammary and lung cancer showed that tumor‐derived granulocyte colony‐stimulating factor causes neutrophilia and activation of neutrophils. Activated neutrophils can release neutrophil extracellular traps (NETs) that enhance thrombosis. Cell‐free DNA in the blood derived from cancer cells, NETs and treatment with cytotoxic drugs can activate the clotting cascade. These studies suggest that there are multiple mechanisms for VTE in patients with different types of cancer. Preventing and treating VTE in cancer patients is challenging; the current recommendations are to use low‐molecular‐weight heparin. Understanding the underlying mechanisms may allow the development of new therapies to safely prevent VTE in cancer patients.     

基于移动健康平台的延续护理对静脉血栓栓塞症出院患者延续治疗知信行的影响

目的探讨基于移动健康平台的延续护理对静脉血栓栓塞症(VTE)出院患者延续治疗知识、态度、行为的影响。方法采用方便抽样法,选取2017年2月—2018年1月重庆市某三甲医院出院的342例VTE患者作为研究对象,根据住院号随机分为对照组(169例)和观察组(173例)。对照组采用常规出院健康指导方式,观察组基于移动健康平台实施延续性康复护理健康指导模式。采用自制的VTE出院患者延续治疗问卷调查表比较两组患者的VTE延续治疗知信行情况。结果干预6个月后,观察组患者的VTE相关知识、延续治疗态度及依从行为得分均高于对照组,差异有统计学意义(P<0.01)。结论基于移动健康平台对VTE出院患者实施延续护理健康指导,有利于提高VTE出院患者延续治疗知识、态度水平,改善依从行为。     

The use of oral anticoagulants for the treatment of venous thromboembolic events in an ED

Venous thromboembolism (VTE) is a disease spectrum that ranges from deep vein thrombosis (DVT) to pulmonary embolism (PE). Rapid diagnosis and treatment of VTE by emergency care providers are critical for decreasing patient mortality, morbidity, and the incidence of recurrent events. Recent American College of Chest Physicians guidelines recommend initial treatment with unfractionated heparin, low–molecular weight heparin, or fondaparinux overlapped with warfarin for a minimum of 5 days for the treatment of VTE in most cases. Warfarin monotherapy is thereafter continued for 3, 6, or 12 months. These guidelines were published before the approval of target-specific oral anticoagulants (TSOACs), and they have yet to be updated to reflect these new treatment options. For some patients, TSOACs, which act by directly inhibiting factor IIa or factor Xa, may provide safer, more convenient alternatives to warfarin. Their advantages include ease of use, reduced monitoring requirements, and lower bleeding risk than traditional therapy. Additionally, clinical trials have established noninferiority of TSOACs to warfarin for the prevention of recurrent VTE. These trials have demonstrated that TSOACs exhibit similar or lower bleeding rates, particularly intracranial bleeding rates compared with warfarin. Anticoagulation therapy with TSOACs may allow early discharge or outpatient management options for low-risk patients with DVT and PE. This review addresses the importance of early diagnosis and treatment of VTE, outcomes of VTE risk assessment, key efficacy and safety data from phase 3 clinical trials for the various TSOACs for the treatment of DVT and PE, and the corresponding considerations for clinical practice.     

Superficial vein thrombosis and recurrent venous thromboembolism: a pooled analysis of two observational studies

Summary. Background: The management strategies for symptomatic isolated superficial vein thrombosis (SVT) (without concomitant deep vein thrombosis [DVT] or pulmonary embolism [PE]) have yet to achieve widespread consensus. Concerns have been raised regarding the usefulness of prescribing anticoagulant treatments to all patients with isolated SVT. Determining the isolated SVT subgroups who have the highest risks of venous thromboembolism (VTE) recurrence (composite of DVT, PE, and new SVT) may facilitate the identification of patients who are likely to benefit from anticoagulant treatment. Design and methods: We performed a pooled analysis on individual data from two observational, multicenter, prospective studies, to determine predictors for VTE recurrence and their impact in an unselected population of symptomatic isolated SVT patients. Results: One thousand and seventy‐four cases of symptomatic isolated SVT were followed up at 3 months. VTE recurrence was observed in 3.9% of the patients; 16.2% of the patients did not receive anticoagulants, and 0.6% experienced a VTE recurrence. Cancer, personal history of VTE and saphenofemoral/popliteal involvement significantly increased the risk of subsequent VTE or DVT/PE in univariate analyses. Only male sex significantly increased the risk of VTE or DVT/PE recurrence in multivariate analyses. Twelve per cent of the patients had cancer or saphenofemoral junction involvement, and were at higher risk of DVT/PE recurrence than patients without those characteristics (4.7% vs. 1.9%, P = 0.06). Conclusions: In patients with symptomatic SVT, only male sex significantly and independently increased the risk of VTE recurrence. Cancer or saphenofemoral junction involvement defined a population at high risk for deep VTE recurrence. Some SVTs might be safely managed without anticoagulants.     

Ethical concerns in isolating patients with methicillin-resistant Staphylococcus aureus on the rehabilitation ward: a case report

Concern about methicillin-resistant Staphylococcus aureus (MRSA) is increasing in rehabilitation facilities. Those affected are often isolated to prevent the spread of MRSA to other patients. Because this isolation often interferes with the traditional rehabilitative approach, rehabilitation team members find themselves in an ethical dilemma as to how to approach these patients. Some patients may feel that strict isolation protocols violate their rights. We report a case showing the ethical dilemmas that an MRSA-positive patient brings to the rehabilitation setting. Isolation techniques make it difficult to treat rehabilitation patients using the current standards of care without compromising the medical ethics principles of autonomy and beneficence. Further study is required to establish protocols for patients with MRSA in the rehabilitation setting.     

Anticoagulants in cancer

Summary. Cancer patients are at high risk for venous thromboembolism (VTE), which results in substantial morbidity and mortality. In this narrative review, we present evidence for the use of anticoagulants in the treatment and prevention of VTE in cancer patients. The benefit of perioperative anticoagulant prophylaxis following cancer surgery is well established. However, the risk‐benefit trade‐offs in non‐surgical hospitalized cancer patients and among outpatients receiving chemotherapy are more complex. Emerging evidence suggests that the use of low molecular weight heparin (LMWH) may confer a small survival benefit in cancer patients without VTE. However, specific patient populations that may derive the most benefit have yet to be defined. Guidelines endorse LMWH as the preferred treatment for acute VTE, on the basis of high‐quality clinical trial data, but the optimal duration of treatment remains unclear, and practical issues may limit its use outside the clinical trial setting. Novel oral anticoagulants may provide additional treatment and prophylaxis options, but their efficacy and safety in this population have not been established. Despite the significant impact of VTE on the lives of cancer patients and the large body of existing literature regarding treatment and prevention, important unanswered clinical questions remain, emphasizing the need for additional high‐quality clinical trial data.     

Prévention de la maladie veineuse thromboembolique en réanimation : Quand ? Pourquoi ? Comment ?

The occurrence of venous thromboembolism(VTE) in critically ill patients represents an important cause of increased morbidity and mortality. Because the incidence of VTE in the intensive care unit (ICU) is about 30% without thromboprophylaxis, patients hospitalized in these units should be considered at high risk for thrombosis and should receive a prophylactic treatment. Besides conventional risk factors for VTE (age, cancer, surgery, obesity…), specific factors present in ICU patients may also contribute to VTE, including mechanical ventilation, vasopressors, and central venous lines. Despite these observations, there are few rigorous studies evaluating thromboprophylaxis specifically in the ICU. Low-molecular weight heparins and unfractionated heparin appear effective in preventing VTE. However, the impact of certain clinical characteristics of critically ill patients (oedema, renal insufficiency, or vasopressor) on the risk/benefit of these drugs needs to be clarified. Mechanical devices, elastic stockings, and intermittent pneumatic compression are recommended for critical care patients who are at high risk for bleeding; however, they have never been evaluated in any clinical trial in ICU patients. Further studies are needed to better understand the reasons of VTE occurrence in ICU patients in order to improve management of their thromboprophylaxis.