Diagnosing pulmonary embolism in outpatients with clinical assessment, D-dimer measurement, venous ultrasound, and helical computed tomography: a multicenter management study.

PURPOSE: To evaluate a diagnostic strategy for pulmonary embolism that combined clinical assessment, plasma D-dimer measurement, lower limb venous ultrasonography, and helical computed tomography (CT). METHODS: A cohort of 965 consecutive patients presenting to the emergency departments of three general and teaching hospitals with clinically suspected pulmonary embolism underwent sequential noninvasive testing. Clinical probability was assessed by a prediction rule combined with implicit judgment. All patients were followed for 3 months. RESULTS: A normal D-dimer level (<500 microg/L by a rapid enzyme-linked immunosorbent assay) ruled out venous thromboembolism in 280 patients (29%), and finding a deep vein thrombosis by ultrasonography established the diagnosis in 92 patients (9.5%). Helical CT was required in only 593 patients (61%) and showed pulmonary embolism in 124 patients (12.8%). Pulmonary embolism was considered ruled out in the 450 patients (46.6%) with a negative ultrasound and CT scan and a low-to-intermediate clinical probability. The 8 patients with a negative ultrasound and CT scan despite a high clinical probability proceeded to pulmonary angiography (positive: 2; negative: 6). Helical CT was inconclusive in 11 patients (pulmonary embolism: 4; no pulmonary embolism: 7). The overall prevalence of pulmonary embolism was 23%. Patients classified as not having pulmonary embolism were not anticoagulated during follow-up and had a 3-month thromboembolic risk of 1.0% (95% confidence interval: 0.5% to 2.1%). CONCLUSION: A noninvasive diagnostic strategy combining clinical assessment, D-dimer measurement, ultrasonography, and helical CT yielded a diagnosis in 99% of outpatients suspected of pulmonary embolism, and appeared to be safe, provided that CT was combined with ultrasonography to rule out the disease.

Diagnostic d'embolie pulmonaire: problématique résiduelle des D-dimères faussement positifs [The unresolved issue of false-positive D-dimer results in the diagnostic workup of pulmonary embolism].

The unresolved issue of false-positive D-dimer results in the diagnostic workup of pulmonary embolism Pulmonary embolism (PE) remains a difficult diagnosis as it lacks specific symptoms and clinical signs. After the determination of the pretest PE probability by a validated clinical score, D-dimers (DD) is the initial blood test in the majority of patients whose probability is low or intermediate. The low specificity of DD results in a high number of false-positives that then require thoracic angio-CT. A new clinical decision rule, called the Pulmonary Embolism Rule-out criteria (PERC), identifies patients at such low risk that PE can be safely ruled-out without a DD test. Its safety has been confirmed in US emergency departments, but retrospective European studies showed that it would lead to 5-7% of undiagnosed PE. Alternative strategies are needed to reduce the proportion of false-positive DD results.

Expression of protease-activated receptors in arthritic synovial tissues

Clinical and experimental evidence suggests that synovial thrombin formation in arthritic joints is prominent and deleterious, leading to exacerbation of rheumatoid arthritis (RA). In this context, cellular effects of thrombin mediated by the protease-activated receptors (PARs) in arthritic joints may be of paramount significance. Four PARs have now been identified. PAR1, PAR3, and PAR4 can all be activated by thrombin whereas PAR2 is activated by trypsin and few other proteases.We first explored PARs expression in RA synovial tissues. Synovial membranes from 11 RA patients were analyzed for PARs expression by RT-PCR and by immunohistology. PAR4 was found in all the biopsies, whereas the expression of PAR1, PAR 2 and PAR3 was more restricted (8/11, 5/11 and 3/11 respectively). In the arthritic synovial membrane of murine antigen-induced arthritis (AIA) we found coexpression of the four different PARs. Next, we explored the functional importance of PAR1 during AIA in vivo using PAR-1 deficient mice. The phenotype of PAR1-deficient mice (n = 22), based on the analysis of arthritis severity (as measured by 99 m tecnetium uptake, histological scoring and intra-articular fibrin measurements) was similar to that of wild-type mice (n = 24). In addition, the in vivo production of antibodies against mBSA was also similar. By contrast, the mBSA-induced in vitro lymph node cell proliferation was significantly decreased in PAR1-deficient mice as compared with controls. Accordingly, mBSA-induced production of interferon-γ by lymph node cells in culture was significantly decreased in PAR1-deficient mice as compared with controls, whereas opposite results were observed for production of IL-10.

Percutaneous Endovascular Salvage Techniques for Implanted Venous Access Device Dysfunction.

PURPOSE: Implanted venous access devices (IVADs) are often used in patients who require long-term intravenous drug administration. The most common causes of device dysfunction include occlusion by fibrin sheath and/or catheter adherence to the vessel wall. We present percutaneous endovascular salvage techniques to restore function in occluded catheters. The aim of this study was to evaluate the feasibility, safety, and efficacy of these techniques. METHODS AND MATERIALS: Through a femoral or brachial venous access, a snare is used to remove fibrin sheath around the IVAD catheter tip. If device dysfunction is caused by catheter adherences to the vessel wall, a new "mechanical adhesiolysis" maneuver was performed. IVAD salvage procedures performed between 2005 and 2013 were analyzed. Data included clinical background, catheter tip position, success rate, recurrence, and rate of complication. RESULTS: Eighty-eight salvage procedures were performed in 80 patients, mostly women (52.5 %), with a mean age of 54 years. Only a minority (17.5 %) of evaluated catheters were located at an optimal position (i.e., cavoatrial junction ±1 cm). Mechanical adhesiolysis or other additional maneuvers were used in 21 cases (24 %). Overall technical success rate was 93.2 %. Malposition and/or vessel wall adherences were the main cause of technical failure. No complications were noted. CONCLUSION: These IVAD salvage techniques are safe and efficient. When a catheter is adherent to the vessel wall, mechanical adhesiolysis maneuvers allow catheter mobilization and a greater success rate with no additional risk. In patients who still require long-term use of their IVAD, these procedures can be performed safely to avoid catheter replacement.