Active clinical trials for "Pulmonary Embolism"

To determine the value of contrast enhanced spiral computed tomography (spiral CT) for the diagnosis of acute pulmonary embolism (PE).

Deep vein thrombosis (DVT) occurs when a blood clot forms in a deep vein, typically in the lower extremities. Pulmonary embolism (PE) occurs when a DVT clot (or fragment) breaks free and travels through the heart to the pulmonary arteries (having to do with the lungs) and lodges in an artery causing a partial or complete blockage. PE is difficult to diagnose due to the non-specific signs and symptoms patients have with this condition such as a cough, shortness of breath, increased heart rate, blood tinged sputum, low oxygen levels. The standard test to diagnose PE is the Pulmonary Computed Tomography Angiogram (CTA). This can be prohibitive with some patients due to the amount of radiation exposure as well as the complications associated with the need to use intravenous (IV) contrast. In this study the investigators are looking at an alternative method of diagnosing PE's in the Emergency Department where the investigators look at the breathing and blood flow to the lungs thru respiratory gated non-contrast CT (commonly called 4DCT). The investigators hypothesize that respiratory induced blood mass change in the lungs will allow the identification of under-perfused lung regions. Cohort 1: An anticipated15 participants will be enrolled with a diagnosis of PE by CTA. Each will receive SPECT/CT and 4DCT imaging on the same day. Respiratory induced blood mass change images will be issued from the 4DCT and compared to the SPECT/CT images. Cohort 2: An anticipated 5 participants will be enrolled under the same criteria and study procedures as Cohort 1. The participants in Cohort 2 will have the addition of Bilevel Positive Airway Pressure (BiPAP) during the 4DCT imaging. This cohort will be used to compare the effect of airway pressure on 4DCT image. Cohort 3: An anticipated 124 participants will be enrolled. Study procedure will be 4DCT only. Participants must be having or have had a CTA to rule in/out PE. This cohort of the study will be using 4DCT to compare negative CTA to positive CTA findings.

The purpose of this study is to perform a pragmatic randomized controlled trial to compare the use of low molecular weight heparin (LMWH, lovenox, enoxaparin) versus acetylsalicylic acid (ASA) for venous thromboembolism (VTE) prophylaxis in patients with high-risk lower extremity fractures.

To evaluate by intravascular OCT study the presence of microvascular pulmonary thrombosis in patients with COVID-19, high D-dimer levels and contrast CT scan negative for pulmonary thrombosis. We'll also evaluate the extension of microvascular pulmonary thrombosis in patients with contrast CT scan positive for pulmonary embolism in areas where contrast CT scan was negative.

Because a missed PE could be potentially lethal, several researches reported that PE is both overinvestigated and overdiagnosed. The diagnostic gold standard for PE is the computed tomographic pulmonary angiogram (CTPA) and has been shown to have clear risks and other downsides. To limit the use of CTPA, two rules were recently reported to be safe to exclude PE: the PERC rule and the YEARS rule. PERC is an 8 item block of clinical criteria that has recently been validated to safely exclude PE in low risk patients. YEARS is a clinical rule that allow to raise the threshold of D-dimer for the order of CTPA. However, whether a modified diagnostic algorithm that includes these two rules combined could safely reduce imaging study use in the ED is unknown. This is a non-inferiority, cluster cross-over randomized, international trial. Each center will be randomized on the sequence of period intervention: 4 months intervention (MOdified Diagnostic Strategy: MODS) followed by 4 months control (usual care), or 4 months control followed by 4 months intervention with 1 month of "wash-out" between the two periods. All centers will recruit adult emergency patients with a suspicion of PE. In the control group (usual strategy), patients will be tested for D-dimer, followed if positive by a CTPA. In the intervention group (MODS) : All included patients will be tested with quantitative D-dimer. The MODS work-up will be based on YEARS rule : - If all YEARS criteria are absent, the threshold of D-Dimer for ordering a CTPA will be raised. If at least one criterion of YEARS is present, then the D-dimer threshold for ordering a CTPA will be as usual.

To evaluate whether there is a difference in symptomatic thromboembolism events in the subset of patients with a history of, or risk factors for thromboembolic disease for topically applied tranexamic acid in total joint arthroplasty.

Hospitalization in pregnancy and childbirth greatly increases the thromboembolic risk of these patients. The application of a protocol for assessing the risk of VTE reduces mortality and morbidity of these phenomena.

The purpose of this study is to show that the use of low volume iso-osmolar non-ionic radio contrast medium (30 cc) in a thoracic CT Scanning procedure in a selected group of patients with chronic kidney disease (CKD) will avoid contrast induced nephropathy (CIN) in comparison to a similar group of patients with CKD who receive no contrast medium..

Study objective: The purpose of this study was to compare the role of the prophylactic protocols N-acetylcysteine (NAC) plus normal saline, sodium bicarbonate (NaHCO3) plus normal saline and intravenous normal saline (NS) alone in the prevention of contrast-induced nephropathy (CIN) after computed tomography pulmonary angiography (CTPA) in emergency patients with suspected pulmonary embolism (PE). Materials and methods: This study was planned as randomized, double blind, placebo controlled clinical research. Patients presenting to the emergency department within a 1-year period, undergoing CTPA on suspicion of PE and having one or more risk factors for development of CIN were included in the study. The NAC group received 1 ml/3 mgr NAC+NS solution 1 h before CTPA and 1 ml/kg per hour for a minimum 6 h after CTPA. The NaHCO3 group received 132 mEq NaHCO3+NS solution for 1 h before CTPA and 1 ml/kg per hour for a minimum of 6h after CTPA. The normal saline (NS) group received 3 ml/kg NS for 1 h before CTPA and 1 ml/kg per hour NS for a minimum 6 h after CTPA. CIN was evaluated as the primary outcome, and moderate renal injury (defined as a 100% increase in serum creatinine levels), severe renal insufficiency requiring hemodialysis or peritoneal dialysis) or in-hospital mortality as secondary outcomes.

Suspected pulmonary embolism (PE) is a frequent clinical problem and remains a diagnostic challenge. The diagnostic approach of PE relies on sequential diagnostic tests, such as plasma D-dimer measurement, multi-slice computed tomography (MSCT) and pulmonary angiography. In addition, the diagnostic workup is usually stratified according to the clinical probability of pulmonary embolism. Clinical probability has a fair predictive accuracy either evaluated implicitly or by clinical prediction rules1 and is useful for identifying patients with a low prevalence of pulmonary embolism who can be usually fully investigated by non invasive tests.The D-dimer test has been extensively evaluated in the exclusion of pulmonary embolism, particularly in outpatients. ELISA D-dimer and second-generation latex agglutination (immuno-turbidimetric tests) have a remarkably high sensitivity and have been proved safe first-line tests in association with clinical probability to rule out pulmonary embolism in outcome studies. The clinical usefulness of D-dimer is defined by the proportion of patients in whom pulmonary embolism may be ruled out by a normal result and it is determined by the specificity. However, ELISA and second-generation latex agglutination (immuno-turbidimetric tests) tests have a quite limited overall specificity of around 35% to 40%. Therefore, many investigators tried to increase the D-dimer thresholds in particular in elderly patients to increase the rate of patients in whom the diagnosis could be excluded by this easy and inexpensive test. Several studies have shown that D-dimer levels increase with age and which turns in a decreased specificity of the D-dimer test at the usual threshold in the elderly, and thus to a less useful test to exclude PE in older patients. Indeed, ELISA D-dimer is able to rule out PE in 60% of patients aged less than 40 years, but in only 5% of patients above the age of 80.8 In this study, raising the cut-off value to various points between 600 ng/ml and 1000 ng/ml increased specificity, but this came at the cost of safety with more false negative test results. In this analysis, however, no stratification was made for clinical probability and the sample was small. Recently, the investigators retrospectively assessed the value of a progressive cut-off adjusted to age in a wide sample of 1712 patients. This "new" cut-off was defined for D-Dimer test positivity in each patient by multiplying patient's age by 10. All patients with a D-Dimer level below 500mg/ml, and all patients above 50 years whose D-Dimer levels were inferior to their age multiplied by 10 were considered as having a negative D-Dimer test. The exact derivation and validation of this "new" D-dimer cut-off is described hereafter. Using the conventional cutoff, the VIDAS® D-Dimer test was negative (below 500 mg/ml) in 512/1712 patients (29.9%) and none had PE during initial workup or the three-month follow-up period. Using the cutoff adjusted to age (cutoff for D-Dimer test positivity equals age multiplied by ten, in mg/ml), the figure was as follows. D-Dimer levels were below the adjusted cutoff in 615/1712 patients (35.9%, number needed to test 2.8). This represented a statistically significant 20.1% increase in the number of patients in whom the D-Dimer test was considered as negative, p=0.0002. Of these 615 patients, 5 had PE during initial workup (0.8%, 95 percent confidence interval 0.4 to 1.9%). These data suggest that adopting this progressive cut-off in patients above 50 years, could increase of about 20% the number of patients in whom PE could be excluded without further testing, with an acceptable safety profile as the three-month thromboembolic rate remained very low. Therefore, the investigators plan a prospective outcome study in which this progressive or "new" cut-off (age X 10 ng/ml) in patients above 50 years will be used. In this multicentre study, clinical probability will be assessed by the simplified revised Geneva revised score (Table 1) and an ELISA D-dimer test will be performed [Vidas D-Dimer Exclusion® test (Biomérieux, Marcy l'Etoile, Paris, France)]. Patients with a non high clinical probability with the simplified revised Geneva score and a normal "new" D-dimer cut-off with the Vidas D-dimer Exclusion®, (Biomerieux, Marcy l'Etoile, France) will be considered as not having PE, and will be followed for three-months to assess possible VTE recurrences. The main outcome will be the rate of thromboembolic events during a formal 3-month follow-up in patients not anticoagulated on the basis of this strategy. Patients with positive D-dimers will be investigated with MSCT as currently admitted.