Suspected Pulmonary Embolism Patients Research Articles

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.

Trends in the utilization of computed tomography chest for acute pulmonary embolism in the emergency department and the yield in treatment

Background: Acute pulmonary embolism (PE) is a life-threatening condition with high mortality rates. Prompt and accurate diagnosis is crucial to prevent morbidity and mortality. Overutilizing computed tomography pulmonary angiography (CTPA) in low-risk patients can lead to unnecessary health-care costs and radiation exposure. Proper pretest probability assessment is recommended to guide the use of CTPA. Aim: This study aimed to evaluate the utilization of CTPA in the diagnosis of acute PE in the emergency department, with a focus on the application of pretest probability assessment (modified Wells score [MWS] and D-dimer). The primary objectives were to assess the extent of CTPA usage in low-risk patients, determine the effectiveness of D-dimer levels and the MWS in predicting PE, and identify areas for potential improvement in CTPA utilization to reduce unnecessary imaging and enhance patient care. In addition, the study aimed to evaluate the appropriateness of anticoagulant treatment in patients diagnosed with acute PE, particularly in cases of segmental/subsegmental PE. Settings and Design: A retrospective analysis was done on all suspected PE patients in the emergency room at our facility who underwent CTPA over 5 years. Patient demographic information, presenting complaints, physical examination findings, laboratory test results, and imaging findings were all included in the data collection. Materials and Methods: A retrospective review of 758 patient records at a tertiary hospital was conducted over 5 years. Data included demographics, presenting symptoms, test results, and imaging findings. D-dimer levels and the MWS were used for pretest probability evaluation. Anticoagulant treatment and appropriateness were also assessed. Statistical Analysis: Statistical analysis was carried out using RStudio (R version 4.3.0). Numerical variables were expressed as median (interquartile range), and frequencies and percentages were used to present categorical variables. A Fisher’s exact test was applied to assess the differences between patients who received anticoagulants and those who did not, as well as patients with PE statuses across D-dimer levels, Wells score categories, and receiving anticoagulants. A Kruskal–Wallis test explored the time to read reports between PE categories. P <0.05 indicated statistical significance. Results: Among 758 patients, 18.8% had acute PE, with 6.2% being segmental/subsegmental PE. The majority of cases (79.8%) were negative for PE. A high rate of CTPA utilization was observed, especially in low-risk patients. Sixty-eight percent of low-risk patients had negative PE results. Among patients with acute PE, lobar PE (36.4%) and segmental/subsegmental PE (32.9%) were the most common locations. D-dimer and MWS were underutilized. Conclusions: By identifying low-risk patients who might not need CTPA, compliance with pretest probability evaluation using the MWS and D-dimer levels can help minimize unnecessary imaging and its associated risks. The results showed that efforts should be made to adhere to guidelines and recommendations, especially if the patients were categorized as low risk based on MWS or normal D-dimer levels. This will eventually improve patient outcomes and lower health-care costs.

A nomogram for predicting the risk of pulmonary embolism in neurology department suspected PE patients: A 10-year retrospective analysis.

The purpose of this retrospective study was to establish a numerical model for predicting the risk of pulmonary embolism (PE) in neurology department patients. A total of 1,578 subjects with suspected PE at the neurology department from January 2012 to December 2021 were considered for enrollment in our retrospective study. The patients were randomly divided into the training cohort and the validation cohort in the ratio of 7:3. The least absolute shrinkage and selection operator regression were used to select the optimal predictive features. Multivariate logistic regression was used to establish the numerical model, and this model was visualized by a nomogram. The model performance was assessed and validated by discrimination, calibration, and clinical utility. Our predictive model indicated that eight variables, namely, age, pulse, systolic pressure, hemoglobin, neutrophil count, low-density lipoprotein, D-dimer, and partial pressure of oxygen, were associated with PE. The area under the receiver operating characteristic curve of the model was 0.750 [95% confidence interval (CI): 0.721-0.783] in the training cohort and 0.742 (95% CI: 0.689-0.787) in the validation cohort, indicating that the model showed a good differential performance. A good consistency between the prediction and the real observation was presented in the training and validation cohorts. The decision curve analysis in the training and validation cohorts showed that the numerical model had a good net clinical benefit. We established a novel numerical model to predict the risk factors for PE in neurology department suspected PE patients. Our findings may help doctors to develop individualized treatment plans and PE prevention strategies.

Diagnostic yield of CT pulmonary angiography for pulmonary embolism in clinically suspected patients.

Pulmonary embolism (PE) is a common medical problem. Its diagnostic criteria must be reviewed to determine the need for confirmatory testing. Computed tomography pulmonary angiography (CTPA) is the current standard of care, which provides accurate diagnosis with rapid turnaround. This study aimed to estimate the diagnostic yield of CTPA in clinically suspected PE patients in a tertiary care hospital in Saudi Arabia.Radiology records of all patients with clinically suspected PE who underwent CTPA between January 1, 2012 and September 30, 2018 were reviewed retrospectively. A radiologist with 10 years of professional experience interpreted and reported all cases. The Wells score with 2 tiers (likely and unlikely) was used to raise the clinical suspicion of PE.Positive results for PE were reported in 177 out of 534 clinically suspected cases (33%). Among the positive PE cases, 143 were acute (81%) and 34 (19%) were chronic. Bilateral, right-sided, and left-sided PE were found in 115 (65%), 37 (21%), and 25 (14%) cases, respectively. Involvement of the segmental branches, subsegmental branches, and the pulmonary trunk were noted in 152 (86%), 70 (40%), and 9 cases (5%), respectively. Saddle PE was found in (4%) of the cases. The lower lobe branches (right 55%, left 53%) and the upper lobe branches (right 47%, left 41%) were the most common sites of involvement.CTPA had a higher positive detection rate for PE among clinically suspected cases than its published diagnostic yield. Adequate clinical evaluation when selecting patients for CTPA is emphasized to minimize unjustified exposure of the patients to radiation and intravenous contrast administration. It is crucial for radiologists to provide detailed reports commenting on all relevant findings, including pertinent negatives. A template for reporting radiological findings for CTPA can be recommended for this purpose.

D-dimer can help differentiate suspected pulmonary embolism patients that require anti-coagulation.

ObjectivesDetermine whether D-dimer concentration in the absence of imaging can differentiate patients that require anti-coagulation from patients who do not require anti-coagulation.MethodsData was obtained retrospectively from 366 hemodynamically stable adult ED patients with suspected pulmonary embolism (PE).Patients were categorized by largest occluded artery and aggregated into: ‘Require anti-coagulation’ (main, lobar, and segmental PE), ‘Does not require anti-coagulation’ (sub-segmental and No PE), ‘High risk of deterioration’ (main and lobar PE), and ‘Not high risk of deterioration’ (segmental, sub-segmental, and No PE) groups.Wilcoxon rank-sum test was used for 2 sample comparisons of median D-dimer concentrations. Receiver operating characteristic (ROC) curve analysis was utilized to determine a D-dimer cut-off that could differentiate ‘Require anti-coagulation’ from ‘Does not require anti-coagulation’ and ‘High risk of deterioration’ from ‘Low risk of deterioration’ groups.ResultsThe ‘Require anti-coagulation’ group had a maximum area under the curve (AUC) of 0.92 at an age-adjusted D-dimer cut-off of 1540 with a specificity of 86% (95% CI, 81–91%), and sensitivity of 84% (79–90%). The ‘High risk of deterioration’ group had a maximum AUC of 0.93 at an age-adjusted D-dimer cut-off of 2500 with a specificity of 90% (85–93%) and sensitivity of 83% (77–90%).ConclusionsAn age-adjusted D-dimer cut-off of 1540 ng/mL differentiates suspected PE patients requiring anti-coagulation from those not requiring anti-coagulation. A cut-off of 2500 differentiates those with high risk of clinical deterioration from those not at high risk of deterioration. When correlated with clinical outcomes, these cut-offs can provide an objective method for clinical decision making when imaging is unavailable.

P5019Derivation and validation of a new probability score in pulmonary embolism suspicion allowing safely reduction of imaging testing: PEPS (Pulmonary Embolism Probability Score)

Abstract Background In pulmonary embolism (PE) suspicion, several strategies based on clinical criteria and D-dimer (Dd) measurement have been developed in order to reduce resource utilization. However, they used different clinical probability (CP) assessment methods limiting their combination. Purpose To develop and validate a unique probability score integrating most of previous proposals to allow safely reduction of imaging testing. Methods 4 CP levels were previously defined in order to obtain a false negative rate <1.9%: 1) without Dd test: very low CP (PE prevalence <1.9%), 2) with Dd <1000 μg/L: low CP (<15%), 3) with Dd <500 or age x10μg/L: moderate CP (<60%) and 4) precluding PE exclusion on Dd: high CP. We used individual data from 4 prospective cohorts of suspected PE patients in Europe and America (n=11 066) for derivation and internal validation. The variables significantly associated with PE in univariate analysis were included in a multivariate logistic regression model. Points were assigned according to the regression coefficients. The score was validated in two external independent cohorts (n=1554, n=1669). Results PEPS comprised 13 variables: age <50 years (−2), age 50–64 years (−1), heart rate <80 beats/min (−1), chronic lung disease (−1), chest pain and recent dyspnea (+1), syncope (+1), male sex (+1), previous venous thromboembolism (+2), medical or orthopaedic immobilization (+2), estrogenic treatment (+2), oxygen saturation <95% (+3), unilateral lower limb pain (+3) and PE is the most likely diagnosis (+ 5). The rates of false negative and avoidable imaging tests if the PEPS strategy would have been applied were 0.6% [95% CI: 0.3–1.1] and 22.7% [20.2–25.3] in the first external validation cohort, and 0.85 [0.5–1.45] and 26.6% [23.5–29.9] in the second one. Applied retrospectively, PEPS strategy compared favourably with other strategies and combinations. Derivation Int. validation Ext. validation 1 Ext. validation 2 nPE/N % [95% CI] nPE/N % [95% CI] nPE/N % [95% CI] nPE/N % [95% CI] TOTAL 615/5588: 11.0% [10.2–11.9] 432/3726: 11.6% [10.6–12.7] 327/1546: 21.2% [19.2–23.2] 196/1669: 11.7% [10.3–13.4] Very low CP PEPS<0 16/1445: 1.1% [0.7–1.8] 16/946: 1.7% [1.0–2.7] 3/118: 2.5% [0.7–6.8] 5/347: 1.4% [0.6–3.3] Low CP 0≤PEPS<5 127/2620: 4.9% [4.1–5.7] 106/1805: 5.9% [4.9–7.1] 49/611: 8.0% [6.1–10.4] 61/647: 7.2% [5.7–9.1] Moderate CP 5≤PEPS<12 347/1334: 26.0% [23.7–28.4] 243/867: 28.0% [25.1–31.1] 206/715: 28.8% [25.6–32.2] 107/430: 24.9% [21.0–29.2] High CP 12≤PEPS 125/179:69.8% [62.8–76.1] 67/108: 62.0% [52.6–70.6] 69/102: 67.7% [58.1–76.2] 23/45: 51.1% [37.0–65.0] AUC 0.84 [0.83–0.86] 0.82 [0.80–0.84] 0.79 [0.76–0.82] 0.77 [0.74–0.80] CP: Clinical probability; PEPS: Pulmonary Embolism Probability Score. Conclusions A strategy based on the proposed score may lead to a safely substantial reduction of imaging testing. It should now be tested in an outcome interventional study.

309 D-Dimer in Children With a Radiographically Diagnosed Pulmonary Embolism

Pulmonary embolism (PE) is an important cause of morbidity and mortality. Guidelines for the diagnosis and treatment of PE in adults use D-dimer testing to aid in risk stratification. Currently, the usefulness of D-dimer assays for PE in children is unknown. This study aims to evaluate the use of D-dimer in pediatric patients with a radiographically diagnosed PE and suspected PE. This is a sub-analysis of a retrospective chart-review of patients ≤ 21 years, presenting with a PE diagnosed by CTA or high-probability VQ. Data was collected from 1 ED/hospital from 1996 to 2016 and from another 3 ED/hospitals across 2 states from 2013-2016. D-dimer results from pediatric patients with a PE were compared with a control group of high-risk pediatric patients being evaluated for suspected PE by CTA. Out of 144 patients, 45.1% (65/144) had a radiographically confirmed PE and 54.9% (79/144) had suspected but negative PE by CTA. Of patients with a radiographically confirmed PE, 96.9% (63/65) were diagnosed by CTA and 3.08% (2/65) high-probability VQ. There were no significant differences in demographics for PE versus suspected PE patients: median age 19.3 (range 13.5-21.9) versus 18.9 (range 10.0-21.9), female 70.8% (46/65) versus 69.6% (55/79), Caucasian 56.9% (37/65) versus 53.2% (42/79), African American 36.9% (24/65) versus 27.8% (22/79), and other 4.62% (3/65) versus 3.80% (3/79). D-dimers drawn less than 4 days from onset of symptoms were obtained in 69.2% (45/65) of patients with PE and 98.7% (78/79) patients without PE. Elevated D-dimers (>500 ng/mL FEU) were found in 88.9% (40/45) of patients with PE and 87.2% (68/78) with suspected PE. Median D-dimer with PE 1,825 (range 99-19,980) versus no PE 721 (range 99-6,140) (p=0.0002*). D-dimers were falsely-negative in 11.1% (5/45) patients with PE. PE were located in the central pulmonary artery in 31.1% (14/45) and peripheral arteries 68.9% (31/45). Central PE D-dimer 4,075 median (range 460-35,201) versus peripheral 3,160 (range 99-19,980) (p=0.0015*) versus No PE 715 (range 99-6,140) (p=<0.001*). Ultrasound was ordered for 67.7% (44/65) of patients with PE. DVT concurrent with PE was present in 20.5% (9/44). Unilateral extremity DVT was present in 66.7% (6/9) and 33.3% (3/9) had bilateral extremity DVT. D-dimer in pediatric patients with PE had a sensitivity and specificity of 88.9% and 12.8% respectively with a positive predictive value of 37.0% compared to a negative predictive value of 66.7%. Although D-dimers were higher in pediatric patients with PE than in high-risk suspected PE patients, there was a high incidence of false-negative (11.1%) as well as false-positives (87.2%). Patients with central PE had higher D-dimers than those with peripheral PE. D-dimer in pediatric patients with PE is sensitive but not specific.Tabled 1Characteristics of patients with a false-negative D-dimerD-dimer ng/mL FEUAge (years)SexChief complaintHistory9916.1FAcute onset SOBOCP 20-year-old cousin died from a blood clot13721.3FAcute onset pleuritic CP, palpitationsCongenital adrenal hyperplasia19021.9FAcute SOB, non-pleuritic CP, hemoptysisInjectable hormonal birth-control46018.5FNon-pleuritic CP, hemoptysisOCP Brother: sickle-cell trait49916.9MAcute onset SOBCongenital pulmonary stenosisGrandfather died of HCM Open table in a new tab

Diagnostic characteristics of lower limb venous compression ultrasonography in suspected pulmonary embolism: a meta‐analysis

Essentials Lower limb ultrasonography (CUS) could be useful in suspected pulmonary embolism (PE). We performed a metaanalysis on the diagnostic characteristics of CUS in suspected PE. With a sensitivity of 41%, proximal CUS would be positive in one of every 7.3 patients. Complete CUS has a higher sensitivity but specificity for PE is too low to use it in suspected PE. Background Diagnosis of pulmonary embolism (PE) is commonly based on D-dimer measurement and computed tomography (CT) angiography. Lower limb vein compression ultrasonography (CUS) for diagnosing deep vein thrombosis may be of interest in patients with suspected PE. Objectives We aimed to summarize the data on thediagnostic characteristics of CUS in suspected PE patients. Patients/Methods We conducted a literature review by using PUBMED and EMBASE and included 15 prospective studies in which CUS was performed in consecutive patients with suspected PE. Results Of the 6991 included patients, 2001 (30%) had pulmonary embolism. Eight of the 15 studies included only outpatients, two included hospitalized patients and five involved both in- and outpatients. In 13 studies, only proximal CUS was performed. Two studies analyzed the added value of distal CUS including the calf veins (whole-leg CUS). Pooled estimate of proximal CUS sensitivity was 41% (95% confidence interval [CI], 36-46%) with strong heterogeneity (I square, 79%). Specificity of proximal CUS was 96% (95% CI, 94-98%). The overall positive likelihood ratio for proximal CUS was 11.9 (95% CI, 7.1-19.8), whereas the overall negative likelihood ratio was 0.6 (95% CI, 0.5-0.7). The sensitivity of whole-leg CUS was 79% (95% CI, 24-98%) and specificity was 84% (95% CI, 76-90%). Conclusions Proximal CUS has low sensitivity and cannot be used to rule out PE. Nevertheless, its high specificity allows confirming PE, which may be useful in patients with contraindications to CT angiography. Whole-leg CUS has a higher sensitivity but low specificity for PE and can therefore not be recommended.

The analysis of risk factors of pulmonary embolism in patients with negative D-dimer

Objective To analyze the risk factors of pulmonary embolism in patients with negative D- dimer in serum in order to determine the need of pulmonary computed tomography angiograph (CTA) to confirm the final diagnosis in those patients for avoidance of misdiagnosis. Methods A retrospective analysis of 106 patients suspected to suffer from pulmonary embolism (PE) with serum negative D-dimer checked with pulmonary CTA was carried out. According to the results of CTA, the patients were divided into two groups, namely PE group (n=41) and non-PE group (n=65). The difference in clinic presentation, the time elapsed from onset to visit, N-terminal pro-brain natriuretic peptide (NT-proBNP) , high risk factors (such as immobilization for 3 weeks, leg swelling and pain to palpation, history of deep vein thrombosis, malignancy) and Wells score (≥4 points indicates probability of PE). And logistic regression analysis was made to investigate the risk factors in PE with negative D-dimer. Results The analysis study showed that 38.6% of total patients suspected to suffer from PE with serum negative D-dimer were checked by CTA to confirm the presence of PE. One important characteristics of the D-dimer negative PE patients was the longer time consumed from onset to visit [(9.51±2.01) d vs. (4.01±1.92) d, P <0.05] , and majority of the CTA positive patients suspected to suffer from PE with negative D-dimer had high risks of PE (P <0.01). Compared with the non-PE group, the Wells score ≥4 points and the level of serum NT-proBNP significantly increased in the PE group (P <0.01). Logistic regression analysis revealed that dyspnea, high NT-proBNP level and Wells sore ≥4 points were risk factors for D-dimer negative PE. Conclusion Delayed treatment was the main cause of misdiagnosis of D-dimer negative PE. Dyspnea, high NT-proBNP level and Wells sore ≥4 points were risk factors for suspected PE patients with negative D-dimer, and these patients should be confirmed by pulmonary CTA. On the contrary, PE could be excluded if patients with D-dimer negative had no these risk factors. Key words: D-dimer; Negative; Risk factor; N-terminal pro-brain natriuretic peptide; Pulmonary embolism

Evaluation of the usefulness of a D dimer test in combination with clinical pretest probability score in the prediction and exclusion of Venous Thromboembolism by medical residents.

IntroductionVenous thromboembolism (VTE) requires urgent diagnosis and treatment to avoid related complications. Clinical presentations of VTE are nonspecific and require definitive confirmation by imaging techniques. A clinical pretest probability (PTP) score system helps predict VTE and reduces the need for costly imaging studies. d-dimer (DD) assay has been used to screen patients for VTE and has shown to be specific for VTE. The combined use of PTP and DD assay may improve exclusion of VTE and safely avoid imaging studies.Materials and methodsWe prospectively used the Wells PTP score and a DD test to evaluate 230 consecutive patients who presented with VTE symptoms. The receiver operating characteristic curve was used to identify a new DD cutoff value, which was applied to VTE diagnosis and compared with the upper limit of locally established reference range for prediction of thrombosis alone and in combination with the clinical PTP score.ResultsWe evaluated 118 patients with VTE symptoms fulfilling the inclusion criteria, 64 (54.2%) with clinically suspected deep vein thrombosis (DVT) and 54 (45.8%) with symptoms of pulmonary embolism (PE). The PTP was low in 28 (43.8%) and moderate/high in 36 (56.25%) of the suspected DVT patients, and low in 29 (53.7%) and moderate/high in 25 (46.3%) of the suspected PE patients. Eighteen cases were confirmed by imaging studies: 9 DVT and 9 PE. The agreement between confirmed cases and PTP was significant with PE but not DVT. The negative predictive value for both DVT and PE with current DD cutoff value of <250 μg/L DDU was 100%, whereas with the calculated cutoff the NPV was 88%.ConclusionsWe confirm that PTP score is valuable tool for medical residents to improve the detection accuracy of VTE, especially for PE. The DD cutoff value of 250 μg/L FEU is ideal for excluding most cases of low PTP; however, the calculated cutoff was less specific for the exclusion of VTE.

P165 Ambulatory Management Of Suspected Pulmonary Embolism At A Districtgeneralhospital. A 2 Year Review

Background Studies have suggested that outpatient (OP) management of suspected pulmonary embolism (PE) is feasable. 1 At our DGH (popn 289400) in 2012 we found that over a 2 month period most suspected PE patients (suitable for ambulatory care) were being identified resulting in significant (17 nights) bed savings. 2 The aims of repeating our study were 1) to ascertain the proportion of patients who had a CTPA that were managed as OP and subsequent nights saved 2) to identify any further patients that could have been managed as OP and potential nights saved 3) a comparison with 2012 Methods RADIS was used to collect all CTPA’s performed between 1st Jan 2014 and 28th February 2014. Inclusion criteria: Ambulatory, normal heart rate, respiratory rate, blood pressure and oxygen saturations, any patient who was managed as an OP. Simpflified PESI Score 2 weeks, sPESI Score >1, clinical concern. Results For the above period 102 CTPA’s were performed (105 in 2012). Average time from request to CTPA was 4.7 h (0.5–24 h. 4.1 hrs in 2012) Figure 1 shows the excluded patients.9 patients were included;7 were female, average age 47 years (23–66 years). All had a sPESI score Conclusion The number of ambulatory patients investigated for PE has reduced from 2012 to 2014 which probably reflects an increased acute physician presence at our DGH but some bed savings (7 nights over our 2 month period) were still made. Over 2 years approximately 180 ambulatory patients have been investigated and managed for PE at our DGH with no adverse incidents to date. References Hogg K et al . Emerg Med J 2006;23:123–127 Benjamin JA et al . Thorax 2012;67:A123

P141 Outpatient Management of Suspected Pulmonary Embolism at a District General Hospital; A Two Month Review

BackgroundStudies have suggested that outpatient (OP) management of suspected pulmonary embolism (PE) is feasible.1 At our DGH (popn 289,400) the decision to manage a suspected PE as an OP is...

Venous Thromboembolism: Classification, Risk Factors, Diagnosis, and Management

Venous thromboembolism (VTE) is categorised as deep venous thrombosis (DVT) and pulmonary embolism (PE). VTE is associated with high morbidity and causes a huge financial burden on patients, hospitals, and governments. Both acquired and hereditary risks factors contribute to VTE. To diagnose VTE, noninvasive cost-effective diagnostic algorithms including clinical probability assessment and D-dimer measurement may be employed followup by compression ultrasonography for suspected DVT patients and multidetector computed tomography angiography for suspected PE patients. There are pharmacological and mechanical interventions to manage and prevent VTE. The pharmacological approaches mainly target pathways in coagulation cascade nonspecifically: conventional anticoagulants or specifically: new generation of anticoagulants. Excess bleeding is one of the major risk factors for pharmacological interventions. Hence, nonpharmacological or mechanical approaches such as inferior vena cava filters, graduated compression stockings, and intermittent pneumatic compression devices in combination with pharmacological interventions or alone may be a good approach to manage VTE.

The additional use of end-tidal alveolar dead space fraction following D-dimer test to improve diagnostic accuracy for pulmonary embolism in the emergency department

PurposeTo determine the diagnostic performance of bedside assessment of end-tidal alveolar dead space fraction (ADSF) for pulmonary embolism (PE) and whether the use of additional ADSF assessment following D-dimer assay...

A New Quantitative D-dimer Assay Appropriate in Emergency: Reliability of the Assay for Pulmonary Embolism Exclusion Diagnosis

Plasma D-dimers, degradation products of cross-linked fibrin, are elevated in several thrombotic diseases. In the last decade, their measurement has been performed with specific monoclonal antibody based ELISA assay, with a high negative predictive value of such pathologies. However these methods have a low clinical impact since they cannot be used in emergency because they are time consuming and require series. Recently, rapid tests have been proposed with similar accuracy and are feasible for use in emergency conditions. The aim of our study was to evaluate the potential value of a new quantitative rapid assay, based on agglutination of latex microparticles coated with two monoclonal antibodies specific for D-dimers (Liatest D-Di, Diagnostica Stago), in the exclusion diagnosis of pulmonary embolism (PE). Eighty-five consecutive suspected PE patients were included in the study. D-dimer determination was performed with both standard ELISA and Liatest D-Di just before pulmonary scintigraphy. Sixty-nine patients were free of PE and 16 had PE. Our results confirm the excellent sensitivity and negative predictive values of the conventional D-dimer ELISA. Using a cut-off value of 500 ng/ml, the sensitivity and the negative predictive values of Liatest D-Di were 94% and 96%, respectively. Only one case of PE had a D-dimer value at 480 ng/ml, close to the cut-off value. This study demonstrates that the Liatest D-Di assay is sensitive enough to be used as the first step in the assessment of PE. However, the best cut-off value has to be determined to get an exclusion diagnosis with certainty.