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Background: Evidence-based guidelines advise excluding pulmonary embolism (PE) diagnosis using d-dimer in patients with a lower probability of PE. Emergency physicians frequently order computed tomography (CT) pulmonary angiography without d-dimer testing or when d-dimer is negative, which exposes patients to more risk than benefit. Our objective was to develop a conceptual framework explaining emergency physicians' test choices for PE., Methods: We conducted a qualitative study using in-depth interviews of emergency physicians in Canada. A nonmedical researcher conducted in-person interviews. Participants described how they would test simulated patients with symptoms of possible PE, answered a knowledge test and were interviewed on barriers to using evidence-based PE tests., Results: We interviewed 63 emergency physicians from 9 hospitals in 5 cities, across 3 provinces. We identified 8 domains: anxiety with PE, barriers to using the evidence (time, knowledge and patient), divergent views on evidence-based PE testing, inherent Wells score problems, the drive to obtain CT rather than to diagnose PE, gestalt estimation artificially inflating PE probability, subjective reasoning and cognitive biases supporting deviation from evidence-based tests and use of evidence-based testing to rule out PE in patients who are very unlikely to have PE. Choices for PE testing were influenced by the disease, environment, test qualities, physician and probability of PE., Interpretation: Analysis of structured interviews with emergency physicians provided a conceptual framework to explain how these physicians use tests for suspected PE. The data suggest 8 domains to address when implementing an evidence-based protocol to investigate PE., Competing Interests: Competing interests: Teresa Chan has received stipends from McMaster University and ALiEM LLC, and funding from the PSI Foundation outside the submitted work. No other competing interests were declared., (© 2021 Joule Inc. or its licensors.)

Introduction: Various definitions of bleeding have been used in perioperative studies without systematic assessment of the diagnostic criteria for their independent association with outcomes important to patients. Our proposed definition of bleeding impacting mortality after noncardiac surgery (BIMS) is bleeding that is independently associated with death during or within 30 days after noncardiac surgery. We describe our analysis plan to sequentially 1) establish the diagnostic criteria for BIMS, 2) estimate the independent contribution of BIMS to 30-day mortality and 3) develop and internally validate a clinical prediction guide to estimate patient-specific risk of BIMS., Methods: In the Vascular Events In Noncardiac Surgery Patients Cohort Evaluation (VISION) study, we prospectively collected bleeding data for 16 079 patients aged 45 years or more who had noncardiac inpatient surgery between 2007 and 2011 at 12 centres in 8 countries across 5 continents. We will include bleeding features independently associated with 30-day mortality in the diagnostic criteria for BIMS. Candidate features will include the need for reoperation due to bleeding, the number of units of erythrocytes transfused, the lowest postoperative hemoglobin concentration, and the absolute and relative decrements in hemoglobin concentration from the preoperative value. We will then estimate the incidence of BIMS and its independent association with 30-day mortality. Last, we will construct and internally validate a clinical prediction guide for BIMS., Interpretation: This study will address an important gap in our knowledge about perioperative bleeding, with implications for the 200 million patients who undergo noncardiac surgery globally every year. Trial registration: ClinicalTrials.gov, no NCT00512109., Competing Interests: Competing interests: See the end of the article., (Copyright 2017, Joule Inc. or its licensors.)

Background: Exercise training may have the potential to improve post-thrombotic syndrome, a frequent, chronic complication of deep venous thrombosis. We conducted a randomized controlled two-centre pilot trial to assess the feasibility of a multicentre-based evaluation of a six-month exercise training program to treat post-thrombotic syndrome and to obtain preliminary data on the effectiveness of such a program., Methods: Patients were randomized to receive exercise training (a six-month trainer-supervised program) or control treatment (an education session with monthly phone follow-ups). Levels of eligibility, consent, adherence and retention were used as indicators of study feasibility. Primary outcomes were change from baseline to six months in venous disease-specific quality of life (as measured using the Venous Insufficiency Epidemiological and Economic Study Quality of Life [VEINES-QOL] questionnaire) and severity of post-thrombotic syndrome (as measured by scores on the Villalta scale) in the exercise training group versus the control group, assessed by t tests. Secondary outcomes were change in generic quality of life (as measured using the Short-Form Health Survey-36 [SF-36] questionnaire), category of severity of post-thrombotic syndrome, leg strength, leg flexibility and time on treadmill., Results: Of 95 patients with post-thrombotic syndrome, 69 were eligible, 43 consented and were randomized, and 39 completed the study. Exercise training was associated with improvement in VEINES-QOL scores (exercise training mean change 6.0, standard deviation [SD] 5.1 v. control mean change 1.4, SD 7.2; difference 4.6, 95% CI 0.54 to 8.7; p = 0.027) and improvement in scores on the Villalta scale (exercise training mean change -3.6, SD 3.7 v. control mean change -1.6, SD 4.3; difference -2.0, 95% CI -4.6 to 0.6; p = 0.14). Most secondary outcomes also showed greater improvement in the exercise training group., Interpretation: Exercise training may improve post-thrombotic syndrome. It would be feasible to definitively evaluate exercise training as a treatment for post-thrombotic syndrome in a large multicentre trial.

No single noninvasive test for pulmonary embolism is both sensitive and specific. Some tests are good for "ruling in" pulmonary embolism (e.g., helical CT) and some tests are good for "ruling out" pulmonary embolism (e.g., D-dimer); others are able to do both but are often nondiagnostic (e.g., ventilation-perfusion lung scanning). For optimal efficiency, choice of the initial diagnostic test should be guided by clinical assessment of the probability of pulmonary embolism and by patient characteristics that may influence test accuracy. This selective approach to testing enables pulmonary embolism to be diagnosed or excluded in a minimum number of steps. However, even with the appropriate use of combinations of noninvasive tests, it is often not possible to definitively diagnose or exclude pulmonary embolism at initial presentation. Most of these patients can be managed safely without treatment or pulmonary angiography by repeating ultrasound testing of the proximal veins after one and 2 weeks to detect evolving deep vein thrombosis. Helical CT and MRI are rapidly improving as diagnostic tests for pulmonary embolism and are expected to become central to its evaluation.