Real-time Anti-Factor Xa Measurements in Surgical Patients to Examine Enoxaparin Metabolism and...
Deep Venous ThrombosisPulmonary Embolus1 moreVenous 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.
Twice Daily Enoxaparin Prophylaxis in Reconstructive Surgery Patients
Venous ThromboembolismDeep Venous Thrombosis1 moreBlood 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.
Analysis of a Training Intervention for Pulmonary Embolism Diagnosis in Emergency Department (APEED)...
Pulmonary EmbolismThe purpose of this study is to analyze the clinical impact of an educational intervention on adherence to Clinical Practice Guidelines in an Emergency Department (ED), by using a standardized training, for improving diagnostic sensibility and reducing unnecessary scans, adverse effects and stays in the ED.
Evaluation of Anti-Xa Levels in Surgery Patients Receiving Weight-based Heparin
Deep Vein ThrombosisPulmonary Embolism1 moreThe 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.
Comparing Anti-XA Levels in Post-Cesarean Patients Undergoing Enoxaparin Thromboprophylaxis
ObesityObesity6 morePregnant 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).
VenaTech Convertible Vena Cava Filter U.S. Multi-Center Clinical Trial
Pulmonary EmbolismThe investigation is designed to verify that clinical use of the vena cava filter does not raise new questions of safety or effectiveness compared to currently-marketed permanent filters.
Safer Warfarin Treatment
Atrial FibrillationVenous Thrombosis2 moreThe study is a national multicenter prospective observational study, including 200 patients. The main purpose of this study is to explore in more detail the influence of genetic variability (CYP enzymes and vitamin K dependent proteins) and dietary vitamin K status on warfarin dosing, clinical effect and adverse events with emphasis on the initial phase of treatment. The hypothesis is that genetic variability concerning CYP enzymes and vitamin K dependent proteins predict dosing and adverse events during warfarin treatment. The main aim is to individualize warfarin therapy and establish a treatment algorithm based on genotype and dietary vitamin K status to make the anticoagulation therapy with warfarin more secure.
A Pivotal Study to Evaluate the Safety and Effectiveness of RMT Medical Technology's SafeFlo® Vena...
Pulmonary EmbolismTo determine the safety and effectiveness of the SafeFlo filter for permanent protection against pulmonary emboli. All patients will be selected to receive the filter according to the stated inclusion / exclusion criteria after consultation between the attending physician and interventional radiologist. Patients with a permanent implantation will be followed for up to 6 months. Clinical success will be defined as no occurrences of any of the following events: recurrent pulmonary embolism, IVC occlusion or filter embolization. The proportion of permanent filter patients considered to be a clinical success will be the primary efficacy parameter.
Screening for Occult Malignancy in Patients With Idiopathic Venous Thromboembolism
Venous ThromboembolismDeep Vein Thrombosis1 moreBlood clots in leg veins (deep vein thrombosis) or lung arteries (pulmonary embolism) that happen for no reason (i.e. unexplained) are both called "unprovoked venous thromboembolism" (VTE). These unexplained blood clots can be the first symptom of cancer. Up to 10% of patients with unexplained blood clots will be diagnosed with cancer within one year of their blood clot diagnosis. These cancers can be found anywhere in the body although the relationship appears stronger with the pancreas, ovary and liver. Cancer testing in patients with blood clots is controversial. There is presently a wide variety of expert opinions and practices. Previous studies showed that a limited cancer screen including a medical history, physical examination, basic blood work and chest X-ray, will find about 90% of cancers. More recent and better designed studies showed that the limited cancer screen misses many cancers and needs to be improved. More extensive cancer testing may find more cancers but is potentially uncomfortable for patients, costs a lot of money and involves a lot of people. The "comprehensive computed tomography" is less uncomfortable, inexpensive, radiological test made to find many cancers at once. Thus, the scientific question to be asked is: Does a "comprehensive computed tomography" miss less cancers than a limited cancer screen in patients with blood clots? The main goal of this study is to find out if a "comprehensive computed tomography" misses less cancers than a limited cancer screen in patients with unexplained blood clots. The second goal of the study is 1) to find out if a "comprehensive computed tomography" finds more "curable" cancers than the limited cancer screen; 2) to find out if the patients diagnosed with cancer are still alive and cancer-free after one year (i.e. the patients with curable cancer were treated and are doing well); 3) to prove that a negative "comprehensive computed tomography" means that the patient will not have cancer and; 4) to find out if a "comprehensive computed tomography" is well tolerated and safe for patients.
Study of Apixaban for the Prevention of Thrombosis-related Events Following Knee Replacement Surgery...
Deep Vein ThrombosisPulmonary EmbolismThe purpose of this study is to learn if apixaban can prevent blood clots in the leg (deep vein Thrombosis [DVT]) and lung (pulmonary embolism [PE]) that sometimes occur after knee replacement surgery and to learn how apixaban compares to enoxaparin (Lovenox®) for preventing these clots. The safety of apixaban will also be studied.