Suspected Pulmonary Embolism Research Articles

Diagnosis of Suspected Pulmonary Embolism During Pregnancy: A Narrative Review

Diagnosis of Suspected Pulmonary Embolism During Pregnancy: A Narrative Review

Effectiveness of the YEARS Algorithm Added to Classical Clinical Decision-making Rules in Suspected Pulmonary Embolism

Effectiveness of the YEARS Algorithm Added to Classical Clinical Decision-making Rules in Suspected Pulmonary Embolism

Overuse of Computed Tomography Pulmonary Angiography and Low Utilization of Clinical Prediction Rules in Suspected Pulmonary Embolism Patients at a Regional Australian Hospital.

A pulmonary embolism (PE) is an obstruction in the pulmonary arterial system and may include non-specific signs and symptoms. Clinical prediction rules (CPRs) assess the pretest probability (PTP) of a PE to prevent the overuse of computed tomography pulmonary angiography (CTPA). CTPA overuse results in patient harm and health system waste. This study aimed to evaluate CTPA usage in an Australian regional hospital through analyzing CTPA encounters. A retrospective chart analysis was undertaken of 100 CTPAs conducted at an Australian regional hospital from April to May 2023. Analysis was undertaken for parameters including risk factors, signs and symptoms, investigations, and the use of CPRs. Overall, 86% of patients had signs and/or symptoms of a PE within a week of examination, and 6% of the population had signs of deep vein thrombosis. More than half of the population had no risk factors, while the most prevalent risk factors were a recent history of immobilization/trauma and/or having surgery that required general anesthesia in the last 4 weeks. The most common co-morbidity was chronic lung disease (11%). For the pre-test diagnostic workup, the ECG was the most ordered investigation. The Wells' score was used at 10%, while most patients did not have any CPRs applied. The prevalence of PEs discovered on CTPAs was 9%. CPRs were under-utilized in this Australian regional hospital. The D-dimers for ruling out subjects with low PTP derived from CPRs were also underused. This led to the inappropriate overordering of CTPAs, resulting in negative implications for patients and unnecessary costs to the health system.

Ten-Year Trend in Advanced Imaging Utilization for Suspected Pulmonary Embolism in Pregnancy

PurposeAdvanced imaging is essential to diagnose pulmonary embolism (PE) in pregnancy, but there are associated maternal and fetal radiation risks. The purpose of this study was to evaluate the 10-year trend in advanced imaging utilization for the evaluation of suspected PE in pregnancy. MethodsThe authors evaluated pregnant women with advanced imaging using CT pulmonary angiography (CTPA) or lung scintigraphy (LS) for evaluation of suspected PE presenting to two tertiary hospitals from 2007 to 2016. The rate of imaging was evaluated relative to positive PE rate and local pregnancy rate. positive PE was defined as a new acute PE finding on any advanced imaging within 3 days of first advanced imaging test. Local pregnancy rates were defined per 1,000 pregnancies in the county serviced by both hospitals. Chi-square testing was used to evaluate statistical significance (P < .05) in the utilization trend of advanced imaging and relative to local pregnancy rates and evaluations positive for PE. ResultsA total of 707 pregnant patients were identified, of whom 92.5% (n = 654) underwent CTPA and 7.5% (n = 53) underwent LS. Regression analysis showed an average increase of 5.2 advanced imaging studies per year (P < .001), with 61 and 105 studies performed in 2007 and 2016, respectively. Additionally, there was an average increase of 0.08 (P < .001) advanced imaging studies per 1,000 local pregnancies per year, doubling from 0.7 in 2007 to 1.4 in 2016 (P < .001). Finally, there was a decrease of 0.004 (P = .009) in advanced imaging positive for PE, from 3% (2 of 61) in 2007 to 0% (0 of 100) in 2016. ConclusionsAdvanced imaging utilization increased by 72% over the 10-year window, driven by higher use of CTPA. Although the detection rate of PE on advanced imaging has decreased, the utilization rate among pregnant patients doubled during this period. These results highlight the need to consider the radiation risks and costs of advanced imaging in specific patient populations.

How Tasmanian Emergency Departments 'Choose Wisely' When Investigating Suspected Pulmonary Embolism.

Overuse of computed tomography pulmonary angiograms (CTPAs) for diagnosis of pulmonary embolism (PE) has been recognised as an issue for over ten years, with Choosing Wisely Australia recommending that CTPAs only be ordered if indicated by a clinical practice guideline (CPG). This study aimed to explore the use of evidence-based practice within regional Tasmanian emergency departments in relation to CTPA orders by determining whether CTPAs were ordered in accordance with validated CPGs. We conducted a retrospective medical record review of all patients who underwent CTPA across all public emergency departments in Tasmania between 1 August 2018 and 31 December 2019 inclusive. Data from 2758 CTPAs across four emergency departments were included. PE was reported in 343 (12.4%) of CTPAs conducted, with yield ranging from 8.2% to 16.1% between the four sites. Overall, 52.1% of participants had neither a CPG documented, nor a D-dimer conducted before their scan. A CPG was documented before 11.8% of scans, while D-dimer was conducted before 43% of CTPAs. The findings presented in this study indicate that Tasmanian emergency departments are not consistently 'Choosing Wisely' when investigating PE. Further research is required to identify explanations for these findings.

Temporal Trends in the Use of Computed Tomographic Pulmonary Angiography for Suspected Pulmonary Embolism in the Emergency Department : A Retrospective Analysis.

Recently, validated clinical decision rules have been developed that avoid unnecessary use of computed tomographic pulmonary angiography (CTPA) in patients with suspected pulmonary embolism (PE) in the emergency department (ED). To measure any resulting change in CTPA use for suspected PE. Retrospective analysis. 26 European EDs in 6 countries. Patients with CTPA performed for suspected PE in the ED during the first 7 days of each odd month between January 2015 and December 2019. The primary end points were the CTPAs done for suspected PE in the ED and the number of PEs diagnosed in the ED each year adjusted to an annual census of 100 000 ED visits. Temporal trends were estimated using generalized linear mixed regression models. 8970 CTPAs were included (median age, 63 years; 56% female). Statistically significant temporal trends for more frequent use of CTPA (836 per 100000 ED visits in 2015 vs. 1112 in 2019; P<0.001), more diagnosed PEs (138 per 100000 in 2015 vs. 164 in 2019; P= 0.028), a higher proportion of low-risk PEs (annual percent change [APC], 13.8% [95% CI, 2.6% to 30.1%]) with more ambulatory management (APC, 19.3% [CI, 4.1% to 45.1%]), and a lower proportion of intensive care unit admissions (APC, -8.9% [CI, -17.1% to -0.3%]) were observed. Data were limited to 7 days every 2 months. Despite the recent validation of clinical decision rules to limit the use of CTPA, an increase in the CTPA rate along with more diagnosed PEs and especially low-risk PEs were instead observed. None specific for this study.

Diagnostic Strategy for Suspected Pulmonary Embolism in Emergency Departments Based on the 4-Level Pulmonary Embolism Clinical Probability Score: Study Protocol of SPEED&PEPS Trial.

Introduction: Several strategies have been devised to safely limit the use of thoracic imaging in patients suspected of pulmonary embolism (PE). However, they are based on different rules for clinical probability (CP) assessment, rendering their combination difficult. The four-level pulmonary embolism probability score (4PEPS) allows the combination of all other strategies using a single CP assessment. Methods and analysis: Pragmatic cluster-randomized trial in 20 EDs. Patients with suspected PE will be included and followed for 90 days (number of patients to be included: 2560, 1280 in each arm). Ten centers will be allocated to the control group where physicians will be free to do as they see fit but they will be given the recommendation to apply a validated strategy. Ten centers will be allocated to the interventional group where the physicians will be given the recommendation to apply the 4PEPS strategy. The primary objective will be to demonstrate that the application of the 4PEPS strategy by the emergency physicians, in comparison to current practices, (i) does not increase the risk of serious events related to diagnostic strategies and (ii) significantly reduces the use of thoracic imaging. Ethics and dissemination: The study will be submitted for approval to an institutional ethics review board for all participating centers. If successful, the SPEED&PEPS trial will have an important impact for patients suspected of PE limiting their irradiation and for public health in substantial savings in terms of the direct cost of diagnostic investigations and the indirect cost of hospitalizations due to waiting times or delayed harmful effects. Funding: This work is funded by a French Public Health grant (PREPS-N 2019). The funding source plays no role in the study design, data collection, analysis, interpretation or the writing of the manuscript. Trial registration: ongoing. Trial status: not started.

Diagnostic Accuracy of a Bespoke Multiorgan Ultrasound Approach in Suspected Pulmonary Embolism.

Purpose The aims of this study were to prospectively assess the diagnostic accuracy of a bespoke multiorgan point-of-care ultrasound approach for suspected pulmonary embolism and evaluate if this model allows reduced referral to further radiation diagnostics while maintaining safety standards. Materials and Methods Patients with suspected pulmonary embolism referred for CT pulmonary angiography or ventilation/perfusion scintigraphy were included as a convenience sample. All patients were subject to blinded ultrasound investigation with cardiac, lung, and deep venous ultrasound. The sensitivity and specificity of applied ultrasound signs and the hypothetical reduction in the need for further diagnostic workup were calculated. Results 75 patients were prospectively enrolled. The Wells score was below 2 in 48 patients, between 2 and 6 in 24 patients, and above 6 in 3 patients. The prevalence of pulmonary embolism was 28%. The most notable ultrasound signs were presence of a deep venous thrombus, at least two hypoechoic pleural-based lesions, the D-sign, the 60/60-sign, and a visible right ventricular thrombus which all had a specificity of 100%. Additionally, a multiorgan ultrasound investigation with no findings compatible with pulmonary embolism yielded a sensitivity of 95.2% (95%CI: 76.2-99.9). CT or scintigraphy could be safely avoided in 70% of cases (95%CI: 63.0-83.1%). Conclusion The findings of our study suggest that implementation of a multiorgan ultrasound assessment in patients with suspected pulmonary embolism may safely reduce the need for CT or scintigraphy by confirming or dismissing the suspicion.

60 Temporal Trends in the Use of Computed Tomographic Pulmonary Angiography for Suspected Pulmonary Embolism in the Emergency Department

In recent years, several clinical decision rules, including age-adjusted D-dimer threshold, PERC, YEARS, and PEGeD, have been derived to safely limit the use of computed tomographic pulmonary angiography (CTPA) in patients with suspected pulmonary embolism (PE) in the emergency department (ED). The hypothesis of this study is that this has led to a subsequent reduction in CTPA use.

Predictive Value of Coronary Artery Calcium in Patients Receiving Computed Tomography Pulmonary Angiography for Suspected Pulmonary Embolism in the Emergency Department.

Coronary artery calcium (CAC) is a frequent incidental finding on computed tomography pulmonary angiogram (CTPA) in the evaluation of pulmonary embolism (PE) in the emergency department (ED); however, its prognostic value is unclear. In this study, we interrogate the prognostic value of CAC identified on CTPA in predicting adverse outcomes in the evaluation of PE in the ED. In this retrospective cohort study, we identified 610 patients presenting to the ED in 2013 and evaluated with CTPA for suspected PE. Ordinal CAC scores were evaluated as absent (0), mild (1), moderate (2), or severe (3) in each of the 4 main coronary arteries. Composite CAC scores were subsequently compared against adverse clinical outcomes, defined as intensive care unit admission, hospital stay longer than 72 hours, or death during hospital course or at 6-month follow-up, using univariate and multivariate logistic regression analyses. Relevant exclusion criteria included a history of cardiovascular disease. In all, 365 patients met the inclusion criteria (231 women, mean age 56±16 y) with 132 patients (36%) having some degree of CAC and 16 (4%) having severe CAC. Known malignancy was present in 151 (41%) patients and composite adverse clinical outcomes were observed in 98 patients (32%). Age, presence of acute PE, malignancy, and presence of CAC were significant predictors of adverse outcomes on both univariate and multivariate analyses. CAC was not an independent predictor of short-term adverse outcomes on multivariate analysis ( P =0.06) when all patients were considered. However, when patients with known malignancy were excluded, CAC was an independent predictor of short-term adverse outcomes (odds ratio=2.5, confidence interval=1.1-5.5, P =0.03) independent of age and presence of PE. The presence of CAC on CT PA was predictive of adverse outcomes in patients without known cardiac disease presenting to the ED with suspected PE.

Is it possible to reduce overutilization of computed tomographic pulmonary angiography in a real-world population with suspected acute pulmonary embolism?

Introduction: Computed tomographic pulmonary angiography (CTPA) is the basic examination in the diagnosis of acute pulmonary embolism (PE), however, it is overused many times in emergency units. The aim of this study was to assess the percentage of CTPA which is possible to avoid in patients considered for radiological imaging due to suspected PE. Material and methods: The retrospective analysis of clinical data and the calculation of PE probability rules (Wells score, Geneva score, blood D-dimer concentration, ECG) were performed in 700 consecutive patients who underwent CTPA due to suspected PE in a single university center between January 2017 and January 2020. Results: Suspected PE was confirmed by CTPA in 22.7% of considered patients. The independent risk factors for PE diagnosis in CTPA were: history of DVT, diagnosis of DVT on admission, and “PE-likely” score according to simplified Wells scale. Blood D-dimer concentration was associated with the lowest diagnostic accuracy of PE. The combination of simplified Geneva “PE-likely” score with standard or age-adjusted D-dimer cut-offs achieved 100% negative predictive value for PE. In relation to studied PE pre-test probability rules, use YEARS algorithm was associated with the greatest number of CTPAs which could be avoided (9.3%) with the risk &lt; 1% of false-negative categorization. Conclusions: The combination of simplified Geneva “PE-likely” score with age-adjusted D-dimer cut-offs and YEARS algorithm were more effective than the PERC, original and simplified Wells and Geneva rules in safe exclusion of PE, which might reduce the absolute number of unnecessary CTPA.

Comparison of Guidelines for Evaluation of Suspected Pulmonary Embolism in Pregnancy: A Cost-effectiveness Analysis

Pulmonary embolism (PE) remains a leading cause of maternal mortality, yet diagnosis remains challenging. International diagnostic guidelines vary significantly in their recommendations, making it difficult to determine an optimal policy for evaluation. Which societal-level diagnostic guidelines for evaluation of suspected PE in pregnancy are an optimal policy in terms of its cost-effectiveness? We constructed a complex Markov decision model to evaluate the cost-effectiveness of each identified societal guidelines for diagnosis of PE in pregnancy. Our model accounted for risk stratification, empiric treatment, diagnostic testing strategies, as well as short- and long-term effects from PE, treatment with low-molecular-weight heparin, and radiation exposure from advanced imaging. We considered clinical and cost outcomes of each guideline from a US health care system perspective with a lifetime horizon. Clinical effectiveness and costs were measured in time-discounted quality-adjusted life years (QALYs) and US dollars, respectively. Strategies were compared using the incremental cost-effectiveness ratio (ICER) with a willingness-to-pay threshold of $100,000/QALY. One-way, multiway, and probabilistic sensitivity analyses were performed. We identified six international societal-level guidelines. Base-case analysis showed the guideline proposed by the American Thoracic Society and Society of Thoracic Radiology (ATS-STR) yielded the highest health benefits (22.90 QALYs) and was cost-effective, with an ICER of $7,808 over the guidelines proposed by the Australian Society of Thrombosis and Haemostasis and the Society of Obstetric Medicine of Australia and New Zealand (ASTH-SOMANZ). All remaining guidelines were dominated. The ATS-STR guideline-recommended strategy yielded an expected additional 2.7 QALYs/100 patients evaluated over the ASTH-SOMANZ. Conclusions were robust to sensitivity analyses, with the ATS-STR guidelines optimal in 86%of probabilistic sensitivity analysis scenarios. The ATS-STR guidelines for diagnosis of suspected PE in pregnancy are cost-effective and generate better expected health outcomes than guidelines proposed by other medical societies.

2021 RSNA Outstanding Researcher

HomeRadiologyVol. 302, No. 1 PreviousNext CommunicationsFree AccessSpecial Communications2021 RSNA Outstanding ResearcherMary C. MahoneyMary C. MahoneyMary C. MahoneyPublished Online:Nov 30 2021https://doi.org/10.1148/radiol.219024MoreSectionsPDF ToolsImage ViewerAdd to favoritesCiteTrack CitationsPermissionsReprints ShareShare onFacebookTwitterLinked In Pamela K. Woodard, MDDownload as PowerPointOpen in Image Viewer A leading researcher in cardiothoracic imaging and a generous mentor, Pamela K. Woodard, MD, specializes in cardiac CT and MRI techniques and in translating novel cardiovascular PET radiotracers into human subjects.“Dr Woodard is truly an outstanding researcher,” said RSNA President Mary C. Mahoney, MD. “She is respected not only for her enormous success in funded research, but her generous mentoring of so many of our future leaders in imaging research.”Dr Woodard is the Hugh Monroe Wilson professor of radiology and professor of biomedical engineering at the Mallinckrodt Institute of Radiology, Washington University in St Louis, Mo, where she is also the senior vice chair and division director of Radiology Research Facilities. In this role, she provides administrative oversight to the directors of the department’s 10 National Institutes of Health (NIH) research facilities, including the preclinical and clinical imaging PET and MRI research facilities and the Cyclotron Facility. She is also director of the Center for Clinical Imaging Research, head of Cardiac MR/CT, director of the Radiology Research Resident Track, and the program director of the NIH-funded T32 TOP-TIER (Training Opportunities in Translational Imaging Education and Research) clinician-scientist training program in translational imaging research.Dr Woodard received her undergraduate degree from Duke University in Durham, NC, and her medical degree from the Duke University School of Medicine. She completed her internship in internal medicine at the University of North Carolina at Chapel Hill, a residency in diagnostic radiology at Duke University, and a fellowship in cardiothoracic imaging at the Mallinckrodt Institute of Radiology.Following early success in securing grant funding, including a 1996 Siemens Medical Solutions/RSNA Research Fellow Grant and a 1999 Carestream Health/RSNA Research Scholar Grant, Dr Woodard secured multiple NIH grants. Early in her career, she was a principal investigator (PI) on the landmark NIH-funded PIOPED II project, published in the New England Journal of Medicine, which established multi-detector CT as the principal method for pulmonary embolism diagnosis. She also led a key project on the Washington University NIH contract, Programs of Excellence in Nanotechnology, which developed a receptor-targeted radiotracer for atherosclerotic plaque imaging.Dr Woodard currently leads her own research program and is a PI or MPI on three NIH R01 grants for the translation of cardiovascular radiotracers into humans. She has nearly 200 peer-reviewed manuscripts, several patents, and has served as a charter member on NIH study sections, including Clinical and Integrative Cardiovascular Sciences (CICS) and Medical Imaging (MEDI), and chair of the NIH study section, Imaging Guided Interventions and Surgery. She has received numerous awards for her work, including being named an Academy of Radiology and Biomedical Imaging Research (ARBIR) Distinguished Investigator.A revered leader in organized radiology, Dr Woodard serves on the board of directors of ARBIR and the Missouri Radiological Society. She also serves on the American College of Radiology (ACR) Board of Chancellors as the ACR chair of the Commission on Research. She is a past president of the North American Society for Cardiovascular Imaging. Her expertise has informed the R&E Foundation Research Grant Study Section and the Quantitative Imaging Biomarkers Alliance.Article HistoryPublished online: Nov 30 2021Published in print: Jan 2022 FiguresReferencesRelatedDetailsRecommended Articles Linda Moy, MD, Named New Editor of RadiologyRadioGraphics2022Volume: 42Issue: 2pp. E37-E38Linda Moy, MD, Named New Editor of RadiologyRadiology2022Volume: 303Issue: 1pp. 3-4David A. Bluemke, MD, PhD, Named Editor of RadiologyRadiology2016Volume: 282Issue: 1pp. 10-11David A. Bluemke, MD, PhD, Named Editor of RadiologyRadioGraphics2017Volume: 37Issue: 1pp. 5-62020 RSNA Outstanding ResearcherRadiology2020Volume: 298Issue: 1pp. 1See More RSNA Education Exhibits Imaging of Suspected Pulmonary Embolism and Deep Venous Thrombosis in Obese PatientsDigital Posters2020Clinical Aspects Relating to Acute Pulmonary Embolism ImagingDigital Posters2018Acute Pulmonary Embolism: The Role of the Radiologist from Diagnosis to TreatmentDigital Posters2018 RSNA Case Collection Acute pulmonary embolismRSNA Case Collection2022Carotid WebRSNA Case Collection2020Pulmonary Embolism with Right Heart StrainRSNA Case Collection2020 Vol. 302, No. 1 Metrics Altmetric Score PDF download

Recommended D-Dimer Use in Suspected Pulmonary Embolism Is Insufficient to Curb the Long-Term Overutilization of CT Pulmonary Angiography.

The aim of this study was to determine whether the authors' emergency medicine department has seen a significant change in CT pulmonary angiography (CTPA) utilization or positive rates for pulmonary embolism (PE) over a 10-year period for the 2 years before and 8 years after the implementation of patient population-specific D-dimer recommendations. A retrospective chart review was performed among all patients belonging to a geographically isolated health maintenance organization who underwent CTPA for the evaluation of acute PE in the emergency department between 2010 and 2019. The positive rate for acute PE among these studies was calculated and stratified by serum D-dimer value collected within 48 hours previously. A total of 6,013 CT pulmonary angiographic studies were reviewed, of which 40.2% had serum D-dimer ≥ 1.0 μg/mL (positive rate 10.6%), 42.5% did not have serum D-dimer drawn (positive rate 7.3%), and 17.2% had serum D-dimer < 1.0 μg/mL (positive rate 0.6%). There was a significant increase in positivity on CTPA in 2012 with the health group's formal recommendation of a D-dimer cutoff of 1.0 μg/mL. This improvement also corresponded with fewer orders for CTPA after a negative D-dimer result. However, in the following years, CTPA utilization and percentage positivity were found to be reverting to the prerecommendation statistics. The failure to mandate the use of serum D-dimer with a higher threshold value for patients who are to undergo CTPA for possible PE has resulted in poor lasting compliance despite promising early results. A firmer approach is likely necessary to yield positive long-term outcomes.

Derivation and Validation of a 4-Level Clinical Pretest Probability Score for Suspected Pulmonary Embolism to Safely Decrease Imaging Testing

Pulmonary embolism (PE) poses a diagnostic challenge to Emergency Medicine physicians because the signs and symptoms of PE are extremely common and unspecific. Multiple decisions tools have been created to help rule out this diagnosis and curb the overuse of imaging, particularly computed tomography pulmonary angiography (CTPA). Unnecessary CTPA places patients at risk for allergic reaction, renal failure, and long term radiation accumulation related diseases. Despite these efforts, there has been a large increase in the use of imaging to rule out PE.

Derivation and Validation of a 4-Level Clinical Pretest Probability Score for Suspected Pulmonary Embolism to Safely Decrease Imaging Testing

Pulmonary embolism (PE) poses a diagnostic challenge to Emergency Medicine physicians because the signs and symptoms of PE are extremely common and unspecific. Multiple decisions tools have been created to help rule out this diagnosis and curb the overuse of imaging, particularly computed tomography pulmonary angiography (CTPA). Unnecessary CTPA places patients at risk for allergic reaction, renal failure, and long term radiation accumulation related diseases. Despite these efforts, there has been a large increase in the use of imaging to rule out PE.

Derivation and Validation of a 4-Level Clinical Pretest Probability Score for Suspected Pulmonary Embolism to Safely Decrease Imaging Testing

In patients with suspected pulmonary embolism (PE), overuse of diagnostic imaging is an important point of concern. To derive and validate a 4-level pretest probability rule (4-Level Pulmonary Embolism Clinical Probability Score [4PEPS]) that makes it possible to rule out PE solely on clinical criteria and optimized D-dimer measurement to safely decrease imaging testing for suspected PE. This study included consecutive outpatients suspected of having PE from US and European emergency departments. Individual data from 3 merged management studies (n = 11 114; overall prevalence of PE, 11%) were used for the derivation cohort and internal validation cohort. The external validation cohorts were taken from 2 independent studies, the first with a high PE prevalence (n = 1548; prevalence, 21.5%) and the second with a moderate PE prevalence (n = 1669; prevalence, 11.7%). A prior definition of pretest probability target values to achieve a posttest probability less than 2% was used on the basis of the negative likelihood ratios of D-dimer. Data were collected from January 2003 to April 2016, and data were analyzed from June 2018 to August 2019. The rate of PE diagnosed during the initial workup or during follow-up and the rate of imaging testing. Of the 5588 patients in the derivation cohort, 3441 (61.8%) were female, and the mean (SD) age was 52 (18.5) years. The 4PEPS comprises 13 clinical variables scored from -2 to 5. It results in the following strategy: (1) very low probability of PE if 4PEPS is less than 0: PE ruled out without testing; (2) low probability of PE if 4PEPS is 0 to 5: PE ruled out if D-dimer level is less than 1.0 μg/mL; (3) moderate probability of PE if 4PEPS is 6 to 12: PE ruled out if D-dimer level is less than the age-adjusted cutoff value; (4) high probability of PE if 4PEPS is greater than 12: PE ruled out by imaging without preceding D-dimer test. In the first and the second external validation cohorts, the area under the receiver operator characteristic curves were 0.79 (95% CI, 0.76 to 0.82) and 0.78 (95% CI, 0.74 to 0.81), respectively. The false-negative testing rates if the 4PEPS strategy had been applied were 0.71% (95% CI, 0.37 to 1.23) and 0.89% (95% CI, 0.53 to 1.49), respectively. The absolute reductions in imaging testing were -22% (95% CI, -26 to -19) and -19% (95% CI, -22 to -16) in the first and second external validation cohorts, respectively. The 4PEPS strategy compared favorably with all recent strategies in terms of imaging testing. The 4PEPS strategy may lead to a substantial and safe reduction in imaging testing for patients with suspected PE. It should now be tested in a formal outcome study.

PaCO2-EtCO2 Gradient and D-dimer in the Diagnosis of Suspected Pulmonary Embolism.

Background:The diagnosis of pulmonary embolism (PE) because of nonspecific clinical presentation remains as a challenge for emergency physicians. Arterial to end-tidal partial pressure of carbon dioxide (P(a-Et) CO2) gradient may be useful in the evaluation of PE. This aimed to define the diagnostic role of P(a-Et)CO2 gradient by sidestream capnography, as a noninvasive method, and D-dimer in patients with PE.Materials and Methods:Two hundred and three patients with chest pain or dyspnea who attend the hospital emergency ward were enrolled over a study period at a single academic center. PE was confirmed by multidetector computed tomography (MDCT) scans. PaCO2, EtCO2, and D-dimer were measured within 24 h of MDCT by capnograph.Results:The combination of P(a-Et)CO2 gradient (cutoff >9.2 ng/ml) and D-dimer (cutoff >3011 ng/ml) with sensitivity and specificity of 30.2% and 87.2% showed a significant diagnostic value in detecting PE (area under the curve = 0.577, P = 0.045) but not alone (P > 0.05).Conclusion:As the results show, the combination of P(a-Et)CO2 gradient and D-dimer can show an acceptable diagnostic value in detecting PE, although it suggests further research on evaluating the diagnostic value of P(a-Et)CO2 gradient and combining it with other diagnostic criteria to achieve a definite and generalizable result.

Trends in Imaging for Suspected Pulmonary Embolism Across US Health Care Systems, 2004 to 2016

In response to calls to reduce unnecessary diagnostic testing with computed tomographic pulmonary angiography (CTPA) for suspected pulmonary embolism (PE), there have been growing efforts to create and implement decision rules for PE testing. It is unclear if the use of advanced imaging tests for PE has diminished over time. To assess the use of advanced imaging tests, including chest computed tomography (CT) (ie, all chest CT except for CTPA), CTPA, and ventilation-perfusion (V/Q) scan, for PE from 2004 to 2016. Cohort study of adults by age group (18-64 years and ≥65 years) enrolled in 7 US integrated and mixed-model health care systems. Joinpoint regression analysis was used to identify years with statistically significant changes in imaging rates and to calculate average annual percentage change (growth) from 2004 to 2007, 2008 to 2011, and 2012 to 2016. Analyses were conducted between June 11, 2019, and March 18, 2020. Rates of chest CT, CTPA, and V/Q scan by year and age, as well as annual change in rates over time. Overall, 3.6 to 4.8 million enrollees were included each year of the study, for a total of 52 343 517 person-years of follow-up data. Adults aged 18 to 64 years accounted for 42 223 712 person-years (80.7%) and those 65 years or older accounted for 10 119 805 person-years (19.3%). Female enrollees accounted for 27 712 571 person-years (52.9%). From 2004 and 2016, chest CT use increased by 66.3% (average annual growth, 4.4% per year), CTPA use increased by 450.0% (average annual growth, 16.3% per year), and V/Q scan use decreased by 47.1% (decreasing by 4.9% per year). The use of CTPA increased most rapidly from 2004 to 2006 (44.6% in those aged 18-64 years and 43.9% in those ≥65 years), with ongoing rapid growth from 2006 to 2010 (annual growth, 19.8% in those aged 18-64 years and 18.3% in those ≥65 years) and persistent but slower growth in the most recent years (annual growth, 4.3% in those aged 18-64 years and 3.0% in those ≥65 years from 2010 to 2016). The use of V/Q scanning decreased steadily since 2004. From 2004 to 2016, rates of chest CT and CTPA for suspected PE continued to increase among adults but at a slower pace in more contemporary years. Efforts to combat overuse have not been completely successful as reflected by ongoing growth, rather than decline, of chest CT use. Whether the observed imaging use was appropriate or was associated with improved patient outcomes is unknown.

VTE in ICU Patients With COVID-19

VTE in ICU Patients With COVID-19