Active clinical trials for "Venous Thrombosis"

The purpose of this study is to compare two diagnostic interventions to improve the way D-dimer blood testing (MDA D-dimer) is used to diagnose first time symptomatic deep vein thrombosis.

To improve the safety of diagnosis and therapy for a set of conditions and undifferentiated symptoms for hospitalized patients, the investigators will employ a set of methods and tools from the disciplines of systems engineering, human factors, quality improvement,and data analytics to thoroughly analyze the problem, design and develop potential solutions that leverage existing current technological infrastructure, and implement and evaluate the final interventions. The investigators will engage the interdisciplinary care team and patient (or their caregivers) to ensure treatment trajectories match the anticipated course for working diagnoses (or symptoms), and whether they are in line with patient and clinician expectations. The investigators will use an Interrupted time series (ITS) design to assess impact on diagnostic errors that lead to patient harm. The investigators will perform quantitative and qualitative evaluations using implementation science principles to understand if the interventions worked, and why or why not.

Asian populations have a lower rate of high-risk gene mutations of venous thrombosis, which means a reasonable perioperative anticoagulant management after hip or knee arthroplasty for Caucasian populations may be too excessive for Asians. So, individual patient risk assessment, rather than a "blanket policy", is considered the best thromboembolism prophylaxis for Asians.The purpose of this study was to evaluate the effectiveness and safety of selective thromboembolism prophylaxis compared with conventional thromboembolism prophylaxis by risk stratification with thromboelastography (TEG) after joint arthroplasty for Asian populations.

The purpose of this study is to determine whether Apixaban, Warfarin and Aspirin Anticoagulation are effective and safe in Prevention of Portal Vein Thrombosis in Liver Cirrhotic Patients after Laparoscopic Splenectomy

The aim of the study is to evaluate efficacy and safety of venous thromboembolism prophylaxis by the combination of graduated compression stockings (GCS), standard doses of low-molecular-weight heparins (LMWH) and sequential compression device (SCD) in the mixed group of surgical patients at high and extremely high risk for venous thromboembolism.

Venous thromboembolism (VTE) encompasses deep venous thrombosis and pulmonary embolus, and is the proximate cause of death in over 100,000 hospitalized patients per year. This project will critically examine the pharmacokinetics of prophylactic doses of enoxaparin in surgical patients, and will evaluate how alteration of enoxaparin dose magnitude and frequency affects peak and trough aFXa levels as well as risk for re-operative hematoma. If subtherapeutic aFXa levels are observed, the study will design, implement and test a clinical protocol to optimize post-operative aFXa levels. Although not an explicit Aim, this study will also provide important preliminary data on VTE rates in surgical patients with in range and out of range aFXa levels.

Knee arthroscopy is the most commonly performed orthopaedic procedure worldwide, with, according to the American Society for Sports Medicine, over 4 million procedures performed each year. The risk of venous thrombosis following this procedure is considerable with rates of symptomatic events varying between 0.9% and 4.6%. It is currently unknown how this high risk comes about considering its short duration and minimal tissue damage caused by the procedure. A factor that may play a role is the use of a tourniquet. A large majority of orthopaedic surgeons prefer to operate within a 'dry field', which is obtained by the use of a tourniquet. Tourniquet applied surgery is not without risks. Although its use during orthopedic surgery is widely accepted and a standard procedure, tourniquet use can lead to loss of muscle functional strength and contractile speed, vessel wall damage and nerve injury, next to the possibly increased risk of venous thrombosis. In the proposed study the investigators will investigate the effect of a tourniquet on local and systemic markers of hypoxia, inflammation, involvement of endothelium, and coagulation activation. A finding of more prominent activation of the coagulation system with tourniquet use than with non-use will create an important opportunity to prevent thromboembolic events in these patients, as it has been shown that knee arthroscopy can be performed adequately without the use of a tourniquet. Furthermore, it will increase the understanding of the pathophysiology of thrombosis.

Blood clots that form in the extremities (deep venous thrombosis) and lungs (pulmonary embolus) are feared complications of reconstructive surgery. One in ten patients with symptomatic pulmonary embolus will be dead in 60 minutes. Patients with deep venous thrombosis can develop the post-thrombotic syndrome, known to be a major driver of poor quality of life. These phenomena, broadly known as venous thromboembolism (VTE), have substantial downstream ramifications, and the US Surgeon General and the American Society of Plastic Surgeons (ASPS), among others, have underscored the importance of VTE prevention in surgical patients. Reconstructive surgery, most commonly performed to fix traumatic injuries or defects after cancer excision, often involves borrowing tissue from adjacent or distant areas on the body; reconstructive surgery patients can routinely have surgical injury involving 20% or more of their total body surface area. Injury and resultant inflammation are known to increase metabolism of certain drugs, including those used to prevent VTE after surgery. Enoxaparin is a blood-thinning medication that decreases likelihood of blood clot formation. Previous research has shown that reconstructive surgery patients who are given enoxaparin after surgery are less likely to develop VTE. However, despite receiving of a standard dose of enoxaparin, many patients still develop this life-threatening complication. The investigators believe that patients metabolize enoxaparin differently based on the degree of surgical injury created during reconstruction, and seek to critically examine enoxaparin metabolism in reconstructive surgery patients. The proposed research will evaluate how enoxaparin affects the blood based on standard, ASPS-recommended dosing after reconstructive surgeries; the investigators will also examine whether the extent of surgical injury alters metabolism as well. Enoxaparin effectiveness will be tracked using anti-Factor Xa (aFXa) levels. If subtherapeutic aFXa levels are observed, the study will also design, implement and test a clinical enoxaparin dose-adjustment protocol to achieve appropriate post-operative aFXa levels. Further research based on these data will examine reduction in VTE risk when aFXa-driven enoxaparin dosing is used.

The purpose of this study is to determine if weight-based heparin infusions at a rate of 10 units/kg/hour are sufficient to maintain a target anti-Xa of 0.1-0.35 IU/mL for VTE prophylaxis in patients undergoing microvascular surgery. Additionally, a pilot protocol has been developed to titrate these heparin infusions to ensure patients have sufficient VTE prophylaxis. All patients will be enrolled in the observational arm of the study and receive anti-Xa level monitoring. Patients with out-of-range anti-Xa levels will cross over to the interventional arm of the study and receive real time heparin infusion dose adjustments per the pilot protocol. The primary outcome measured will be the percentage of patients with anti-Xa levels in the target range of 0.1-0.35 IU/mL while on a heparin infusion at 10 units/kg/hour.

Pregnant and recently postpartum women are at significantly higher risk of developing a blood clot in their arms or legs known as a deep venous thrombosis (DVT) and/or a blood clot in their lungs known as a pulmonary embolism (PE) compared to their non pregnant counterparts. It is estimated that this risk increases anywhere from 4 to 50 times higher in pregnant versus non-pregnant women and further increases almost 11 fold in the post partum period. This risk is almost doubled when the patient undergoes cesarean delivery. In 2011, the American College of Obstetricians and Gynecologists (ACOG) issued updated guidelines stating that for patients undergoing cesarean delivery with additional risk factors for clot or thromboembolism, protective (prophylactic) treatment with low molecular weight heparin (LMWH) a type of blood thinner should be considered. However, no specific guidelines about which risk factors should be considered, or what medication doses should be used were provided. The American College of Chest Physicians (ACCP) Evidence-Based Clinical Practice Guidelines published in 2012 delineated who should be given prophylaxis based on various risk factors, however acknowledged that the recommendations were based on weak quality evidence. ACOG endorses either once or twice a day dosing for high risk patients after delivery and states that adjustments for obese women should be made on a case by case basis. However, there are limited studies on the dosing of LMWH in specific subpopulations including post operative patients, pregnant patients and obese patients. All of these studies have urged further investigation of the correct dosing for these high risk subjects due to changes associated with pregnancy and the level of medication in the blood that may put these patients at higher risk of venous thromboembolism. Many previous studies have shown that women in these high risk categories do not achieve protective levels of the medication measured with a laboratory test; anti Xa level. The investigators hypothesize that due to their dual risk, obese post-operative recently pregnant women may not be adequately protected with the daily fixed dose and might need more frequent dosing to protect them. The objective of this study is to assess what proportion of women achieve the desired anti Xa level with the fixed daily dose versus twice daily weight based dosing (0.5 mg/kg).