View clinical trials related to Thrombosis.
Filter by:The purpose of this study is to evaluate the effect of Low Molecular Weight Heparin (LMWH) (Fragmin, dalteparin) versus Unfractionated Heparin (UFH) on the primary outcome of proximal leg Deep Vein Thrombosis (DVT) diagnosed by compression ultrasound, and the secondary outcomes of Pulmonary Embolism (PE), bleeding, Heparin-Induced Thrombocytopenia (HIT), and objectively confirmed venous thrombosis at any site.
Currently, most emergency physicians have limited access to obtaining formal radiology ultrasound studies, particularly overnight. Many are forced to adopt risky and expensive strategies in managing their patients with suspected deep venous thrombosis (DVT) who present during off-hours: for low risk patients, discharging without anticoagulation and arranging for outpatient studies; for moderate to high risk patients, empirically anticoagulating and admitting to the hospital to await definitive testing. If emergency physicians could reliably perform an accurate ultrasound exam for DVT, such risks could be obviated. This is a prospective, observational cohort study assessing the accuracy of emergency physician diagnosis of proximal DVT using compact ultrasound equipment and a simplified compression technique. The value of color flow doppler and augmentation will also be assessed. Outcomes (sensitivity, specificity, positive likelihood ratio and negative likelihood ratio) will be assessed at 30 days. Prior to enrolling patients in the study, emergency physicians will undertake a 2 hour training course on the performance of the simplified compression technique for the diagnosis of lower extremity DVT. Emergency physicians will perform the DVT ultrasound exam on study subjects with suspected DVT. Clinical management of the study subjects will not be altered; all subjects will proceed to receive a formal DVT ultrasound study by the radiology department which will serve as the criterion reference for the study.
To study the safety and efficacy of early administration of Low Molecular Weight Heparin to patients with traumatic brain injury.
The purpose of this study is to: - Create a database including a description of the patient population that undergoes total hip replacement with special emphasis on orthopedic and cardiovascular complications and the quality of life 1 year postoperatively. - Characterise the patient at risk for the above mentioned events - Create methods for predicting patients at risk for short-term (90 days) and long term (1 year) complications in relation to hip replacement surgery.
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.
This study examines whether low intensity, dose adjusted warfarin prolongs the time to mechanical failure of hemodialysis catheters without resulting in an unacceptable rate of bleeding.
To determine whether treatment and further investigation can be safely withheld in patients who present with suspected recurrent deep vein thrombosis (DVT) and have either a (i) negative D-Dimer or (ii) a positive D-Dimer with normal serial compression ultrasound.
Excessive prolongation of the international normalized ratio (INR) occurs frequently in patients taking warfarin; in fact, about one in six INR values is above the desired range. Excessive prolongation of the INR is clinically important because the risk of bleeding approximately doubles for each one point increase in the INR beyond the usual therapeutic range. Thus, treatment strategies which rapidly and reliably lower an excessively prolonged INR into the desired range have the potential to reduce bleeding. When taken by patients with INR values between 4.5 and 10, a small dose of oral vitamin K (1 mg to 2.5mg) reduces the INR into the desired INR range in about 75% of cases within 24 hours of its administration. If warfarin is simply withheld, and no vitamin K is given, about 25% of patients will have an INR in the desired range at 24 hours. However, vitamin K is rarely given to such patients. In a recent survey carried out by our group, less than 20% of such patients would have been given low dose oral vitamin K by a group of physicians who regularly supervise warfarin therapy. The most common treatment for excessive prolongation of the INR is to simply withhold warfarin and allow the INR to fall into the therapeutic range. Although this strategy is effective its safety has never been adequately examined. In fact, recent evidence suggests that patients with INR values of more than 6.0 who are treated with simple warfarin withdrawal have a risk of major bleeding of 4% in the two weeks after they develop their prolonged INR. When asked why they did not give oral vitamin K to a non-bleeding patient who has an excessively prolonged INR, physicians generally give one of three reasons: (1)They are not convinced that oral vitamin K reduces bleeding. (2) They are concerned that oral vitamin K may cause thrombosis. (3) In contrast with simply withholding warfarin, giving oral vitamin K requires a patient to visit the physician, and the physician must have a supply of vitamin K. The investigators hypothesize that the routine practice of not administering oral vitamin K to patients with excessively prolonged INR values is causing patients to have major, life-threatening and fatal bleeds. To convince physicians that oral vitamin K should be administered to all non-bleeding patients with INR values of more than 4.5, the investigators propose a study which the investigators anticipate will demonstrate that oral vitamin K reduces bleeding, does not cause thrombosis, and can be administered at home without direct physician supervision. To accomplish these goals, the investigators propose a multinational, double-blind, placebo-controlled trial. The investigators will randomize patients with INR values between 4.5 and 10.0 to receive 1.25 mg of oral vitamin K or placebo and follow them for bleeding and thrombosis. Patients with INR values of more than 10.0 will receive a single 1.25 mg dose of oral vitamin K. Successful completion of this study will establish a treatment standard supported by clinical data which will, in turn, change the way that patients taking warfarin who present with an excessively prolonged INR are treated.
The purpose of this study is to determine whether elastic compression stockings used for 2 years are effective in preventing the post-thrombotic syndrome in patients with symptomatic proximal deep venous thrombosis.
The assessment of patients with suspected deep vein thrombosis (DVT) is a common clinical scenario that, despite major advances in diagnostic testing, continues to be challenging. The diagnosis of DVT remains problematic in: - patients with suspected first DVT who have a moderate or high pre-test probability (PTP) for DVT and a normal compression ultrasound (CUS); - patients with suspected recurrent DVT; and - patients in whom CUS or contrast venography is technically difficult or not feasible due to patient characteristics. In patients with suspected first DVT who have a moderate or high PTP and a normal CUS, DVT occurs in up to 10% of cases. Thus, additional diagnostic testing is required, such as venography or serial CUS, so that DVT is not missed, but these approaches are costly and invasive. In patients with suspected recurrent DVT, currently used diagnostic approaches are problematic because they all have limitations in differentiating old disease from true recurrent disease. CUS is technically difficult in selected patients, particularly those who are obese. Contrast venography is the gold standard diagnostic test for DVT to which all other diagnostic venous imaging modalities for DVT are compared and judged. The Food and Drug Administration (FDA) requires that a new diagnostic test for DVT be assessed against venography. [99mTc] ThromboView® is a novel diagnostic test based on a 99mTc-labeled monoclonal antibody specific for D-dimer fragments of cross-linked fibrin that are found in acute DVT. After intravenous injection of [99mTc] ThromboView®, there is uptake of the monoclonal antibody by acute, D-dimer rich, venous thrombi. This is visualized with nuclear medicine imaging as an area of increased radioisotope activity that corresponds to the location of DVT. Based on the biologic and imaging characteristics of [99mTc] ThromboView®, this diagnostic test has the potential to: - identify small non-occlusive proximal DVT or distal DVT in patients with a moderate or high PTP and normal CUS; - differentiate old from new DVT in patients with suspected recurrent DVT; - diagnose or exclude DVT in patients in whom CUS is not technically feasible; and - provide an alternative to venography that is non-invasive, has no contrast-related toxicity and is easily administered. The present study is the first phase II clinical trial of [99mTc] ThromboView® in patients with suspected initial or recurrent DVT in whom DVT has been confirmed or excluded by venography. A phase II clinical trial to investigate the diagnostic accuracy of [99mTc] ThromboView® is justified because: - ThromboView® was well tolerated, with no significant toxicity in studies involving animals and healthy volunteers; and - it has shown promise in Phase I trials as a non-invasive diagnostic test for acute DVT.