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A 40-year-old African-American woman presented to the emergency room (ER) with right upper extremity pain for 3 hours after sleeping overnight on that side. She was diagnosed with basilic vein thrombosis; in the ER, she was tachycardic with minimal ambulation, prompting CT pulmonary angiogram, which confirmed right-sided pulmonary embolism. Bilateral upper and lower extremity venous Dopplers did not show any acute deep venous thrombosis. She received appropriate anticoagulation. Risk factors are a smoker and recently started contraceptive pills.

We have updated recommendations on 12 controversial topics that were published in the 2013 National Consensus on the diagnosis, risk stratification and treatment of patients with pulmonary embolism (PE). A comprehensive review of the literature was performed for each topic, and each recommendation was evaluated in two teleconferences. For diagnosis, we recommend against using the Pulmonary Embolism Rule Out Criteria (PERC) rule as the only test to rule out PE, and we recommend using a D-dimer cutoff adjusted to age to rule out PE. We suggest using computed tomography pulmonary angiogram as the imaging test of choice for the majority of patients with suspected PE. We recommend using direct oral anticoagulants (over vitamin K antagonists) for the vast majority of patients with acute PE, and we suggest using anticoagulation for patients with isolated subsegmental PE. We recommend against inserting an inferior cava filter for the majority of patients with PE, and we recommend using full-dose systemic thrombolytic therapy for PE patients requiring reperfusion. The decision to stop anticoagulants at 3 months or to treat indefinitely mainly depends on the presence (or absence) and type of risk factor for venous thromboembolism, and we recommend against thrombophilia testing to decide duration of anticoagulation. Finally, we suggest against extensive screening for occult cancer in patients with PE.

PURPOSE This study evaluated clinician adherence to the American College of Physicians Best Practice Advice for diagnosis of pulmonary embolism. DESIGN A prospective, single-center, descriptive design was utilized. METHODS A heterogeneous sample of 111 hemodynamically stable adult inpatients with a computed tomography pulmonary angiogram ordered was consented. Electronic medical records were reviewed for demographic and clinical variables to determine adherence. The 6 individual best practice statements and the overall adherence were evaluated by taking the sum of "yes" answers divided by the sample size. RESULTS Overall adherence was 0%. Partial adherence was observed with clinician-recorded clinical decisions rules and obtaining d-dimer (3.6% [4/111] and 10.2% [9/88], respectively) of low/intermediate probability scorers. Age adjustment of d-dimer was not recorded. Computed tomography pulmonary angiogram was the first diagnostic test in 89.7% (79/88) in low/intermediate probability patients. CONCLUSION In hemodynamically stable, hospitalized adults, adherence to best practice guidelines for diagnosis of pulmonary embolism was minimal. Clinical utility of the guidelines in hospitalized adults needs further evaluation. Systems problems (eg, lack of standardized orders, age-adjusted d-dimer values, information technology support) likely contributed to poor guideline adherence.

Background We aimed to identify risk factors and risk scoring models to help identify post-traumatic pulmonary embolisms (PE). Methods We performed a retrospective review (2014–2019) of all adult trauma patients admitted to our Level I trauma center that received a CT pulmonary angiogram (CTPA) for a suspected PE. A systematic literature search found eleven risk scoring models, all of which were applied to these patients. Scores of patients with and without PE were compared. Results Of the 235 trauma patients that received CTPA, 31 (13%) showed a PE. No risk scoring model had both a sensitivity and specificity above 90%. The Wells Score had the highest area under the curve (0.65). After logistic regression, no risk scoring model variables were independently associated with PE. Conclusions In trauma patients with clinically suspected PE, clinical variables and current risk scoring models do not adequately differentiate patients with and without PE.

Background This study was conducted to evaluate the relationship of age-adjusted D-dimer value with different coefficients in diagnosis of pulmonary embolism (PE) in geriatric patients. Methods The emergency admissions of the patients aged 65 and over with suspected PE during 2018 were reviewed retrospectively. The demographic characteristics, laboratory tests and radiologic findings of computed tomography pulmonary angiogram (CTPA) or single photon emission computed tomography ventilation/perfusion scintigraphy (V/Q) were recorded. The characteristics of the patients with PE were statistically compared with the patients without PE. The specificity and sensitivity for higher cut-off levels (age × 10-15) were presented. Results PE was detected in 39.2% (n = 246) of 628 patients aged 65 years and older included in the study. The multivariate analysis revealed that higher D-dimer level (OR = 1,00011; p 0.001) and BUN level (OR = 1.025; p = 0.013) were independent risk factors for PE diagnosis in elderly patients. Diagnostic statistics for D-dimer cut-off levels selected from ROC analysis and calculated values as 10-15 times of age showed that if the D-dimer cut-off value used is chosen higher, lower sensitivity rates are obtained. Our results also indicated that the patients with malignancy, renal failure, central PE on CTPA and PE with high probability on SPECT VQ were presented with higher D-dimer values. Conclusion Our results do not support the use of higher D-dimer cut-off levels such as 15 times the age in geriatric population. The impact of the location of PE and comorbidities on the outcomes of these patients must be clarified for determining cut-offs with higher specificity.

Patients who have undergone a Fontan's procedure have an abnormal circulation that presents a unique challenge when performing computed tomography pulmonary angiograms. In a standard imaging protocol, contrast is injected into the upper limb veins that feed into the superior vena cava. In Fontan's patients the Computed tomography pulmonary angiograms bypasses the heart and preferentially fills the right lung, with only a small amount of mixture of contrast and noncontrast blood in the pulmonary arteries. In this article, we present the case of a 35-year-old female complaining of chest and abdominal pain with oxygen saturations of 85% on room air. Computed tomography pulmonary angiograms showed suboptimal imaging of the left lung and apparent filling defects in the right lung suggesting a radiological diagnosis of a pulmonary embolism. The abnormal flow and distribution of contrast in the pulmonary arteries can result in a false positive diagnosis of pulmonary embolism. To overcome this, experts advise using a dual-injection of contrast via upper and lower limb central veins to achieve optimal imaging.

International audience; Background: There have been reports of procoagulant activity in patients with COVID-19. Whether there is an association between pulmonary embolism (PE) and COVID-19 in the emergency department (ED) is unknown. The aim of this study was to assess whether COVID-19 is associated with PE in ED patients who underwent a computed tomographic pulmonary angiogram (CTPA).Methods: A retrospective study in 26 EDs from six countries. ED patients in whom a CTPA was performed for suspected PE during a 2-month period covering the pandemic peak. The primary endpoint was the occurrence of a PE on CTPA. COVID-19 was diagnosed in the ED either on CT or reverse transcriptase-polymerase chain reaction. A multivariable binary logistic regression was built to adjust with other variables known to be associated with PE. A sensitivity analysis was performed in patients included during the pandemic period.Results: A total of 3,358 patients were included, of whom 105 were excluded because COVID-19 status was unknown, leaving 3,253 for analysis. Among them, 974 (30%) were diagnosed with COVID-19. Mean (±SD) age was 61 (±19) years and 52% were women. A PE was diagnosed on CTPA in 500 patients (15%). The risk of PE was similar between COVID-19 patients and others (15% in both groups). In the multivariable binary logistic regression model, COVID-19 was not associated with higher risk of PE (adjusted odds ratio = 0.98, 95% confidence interval = 0.76 to 1.26). There was no association when limited to patients in the pandemic period.Conclusion: In ED patients who underwent CTPA for suspected PE, COVID-19 was not associated with an increased probability of PE diagnosis. These results were also valid when limited to the pandemic period. However, these results may not apply to patients with suspected COVID-19 in general.

Computed tomography pulmonary angiogram (CTPA) is widely considered the gold standard for diagnosis of pulmonary embolism (PE) with previous studies demonstrating high sensitivity and specificity. Despite this, nondiagnostic and indeterminate CTPA rates of 5%-26% remain a concern. As part of a continuing quality assurance program, a new weight-adjusted contrast dose and increased administration rate CTPA protocol was studied with an aim to improve diagnostic accuracy of PE evaluation.A total of 2,398 CTPA examinations were reviewed to assess pulmonary arterial enhancement and PE yield in this retrospective study. Between 1 August 2014 and 1 August 2015, 1,133 patients received a fixed-volume (60 mL) contrast dose technique at 4 mL/s (protocol A). A new protocol was then implemented as part of a continuing quality assurance program. Between 15 September 2015 and 15 September 2016, 1,265 patients received a weight-adjusted contrast dose (1 mL/kg) and increased administration rate (5 mL/s) CTPA technique (protocol B). Studies were classed into categories based on quality of study; diagnostic: HU211, nondiagnostic: HU211 and PE yield; positive, negative, and indeterminate. These variables were compared with cross-sectional surface area to assess the relationship between patient habitus, CTPA diagnostic quality, and PE yield.A weight-adjusted contrast dose and increased administration rate CTPA protocol (protocol B) resulted in a significant increase in mean PA enhancement (P.0001), 55.23% decrease in nondiagnostic studies and 43.04% decrease in indeterminate studies. Protocol B demonstrated increased positive and negative CTPA rates with decreased indeterminate rates from 12.38% to 7.04%. Comparison with cross-sectional area demonstrated significant increase in proportion of diagnostic studies and reduction in nondiagnostic and indeterminate CTPAs using protocol B in obese patients.A weight-adjusted contrast dose and increased administration rate CTPA protocol can significantly increase PA enhancement, especially in obese patients, resulting in greater high-quality and fewer nondiagnostic and indeterminate CTPA examinations. A CTPA protocol with a higher rate of conclusive examinations can provide greater confidence in PE evaluation for reporting radiologists and accurate clinical decision-making pathways for referring physicians.

COVID-19 patients suffering sudden worsening of clinical conditions have an atypical peripheral pulmonary arterial obstruction at computed tomography pulmonary angiogram (CTPA), poorly associated to deep venous thrombosis (DVT), suspicious for thrombotic in situ nature rather than embolic.

A 52-year-old man presented with palpitations and dyspnea. Extensive bilateral pulmonary emboli (PEs) were identified on computed tomography pulmonary angiogram. Transthoracic echocardiography demonstrated a mobile bi-atrial thrombus straddling the interatrial septum. Consensus decision of a multidisciplinary pulmonary embolus response team was made for emergency thrombectomy of the pulmonary and intra-cardiac clot. Intraoperatively, a patent foramen ovale was identified and repaired. He had an excellent outcome and was discharged home on oral anticoagulation. In this unique case of a bi-atrial thrombus and sub-massive PEs, we demonstrate the utility of dedicated pulmonary embolus response teams in providing rapid and individualized management decisions for complex PE patients.

Pulmonary embolism (PE) care has traditionally been fragmented. The newly introduced Pulmonary Embolism Response Team (PERT) model provides streamlined care based on expedient, multi-disciplinary decision-making. This study aimed to quantify the impact of PERT, as part of a hospital-wide PE treatment protocol, on clinical outcomes.Consecutive adult patients with acute PE diagnosed via computed tomography pulmonary angiogram (CTPA) were included. The PERT and treatment protocol were introduced in January 2015. Patient characteristics, therapies, quality measures of CTPA reporting, and clinical outcomes of PE patients treated for 2 years before and after implementation of these changes were evaluated. Primary endpoints were median length of stay in intensive care (ICU) and survival to discharge.A total of 321 consecutive PE patients were enrolled, of which 154 (treated in 2013-2014) and 167 (2015-2016) patients formed the historical control and study groups, respectively. Implementation of the algorithm was associated with less variance in anticoagulation and improved reporting of right heart strain parameters on CTPA. The ICU stay was reduced from a median of 5 to 2 days (p 0.01). Eligible massive PE patients receiving reperfusion increased from 30% to 92% (p = 0.01), with mean delay from diagnosis to reperfusion decreasing from 763 to 181 minutes (p 0.01). Bleeding complications were not increased, but overall survival to discharge remained unchanged.Introducing a PERT and treatment protocol reduced ICU stay, enhanced quality measures, and improved access of massive PE patients to reperfusion therapies, without increasing bleeding complications or health care costs.

Objective To determine the cause of a markedly raised D-dimer among patients in whom a diagnosis of pulmonary embolism (PE) has been excluded by CT pulmonary angiogram (CTPA) with particular reference to new cases of cancer and aortic dissection. Methods One thousand consecutive patients, suspected of PE, who had undergone CTPA and for whom a D-dimer had been requested, were seen between 2012 and 2016. Retrospectively we examined the case records of all those in the top quintile of the D-dimer distribution whose CTPA was negative for PE. D-dimer in the top quintile ranged from 7.5 to 260 times upper limit normal. Results Eighty-five patients fulfilled our inclusion criteria. The likely causes of their very high D-dimer were infection (n=35, 41.2%), cardiovascular disease (n=12, 14.1% including two patients with previously undiagnosed aortic dissection), surgery or trauma (n=12, 14.1%), new or active cancer (n=9, 10.6% comprising six new cancers and three patients with cancers diagnosed previously that were considered to be active) and miscellaneous causes (n=17, 20.0%). Thirty-five patients (43.5%) died over a 2-year follow-up. Kaplan-Meier survival analysis showed poorer outcomes for patients with new or active cancer, when compared with those with no known cancer (p Conclusions We have shown that a small proportion of patients suspected of PE whose D-dimers are markedly elevated have diagnoses we would not want to miss including previously unsuspected cancer and aortic dissection. Further studies will be required to define the optimal workup of patients with extremely high D-dimer who do not have venous thromboembolism

Introduction Congenital left inferior vena cava (IVC) with hemiazygos continuation and drainage into the superior vena cava (SVC) is a rare IVC variant and is associated with venous thrombo-embolism. This is the report of a case of hemiazygos continuation of the left IVC receiving catheter directed thrombolysis (CDT) for pulmonary embolism. Report A 72 year old woman presented with progressive dyspnoea, and CT images confirmed the diagnosis of pulmonary embolism. The unusual route of the IVC was observed during the right heart catherisation and CDT. CDT was then performed with a left femoral venous approach. The patient tolerated the procedure well, and the follow up pulmonary angiogram showed no residual thrombus. Discussion The use of CDT for pulmonary embolism in patients with left IVC with hemiazygos continuation and drainage into the SVC has been reported rarely. Awareness of this diagnosis is critical during right heart catheterisation to prevent devastating complications. However, with careful manipulation, right heart catheterisation and CDT can be achieved successfully. Pulmonary embolism in patients with left IVC with hemiazygos continuation and drainage into the SVC can be treated with CDT safely and effectively with caution. It is wise to remember the different anatomical variations during IVC catheterisation., Highlights • Congenital left IVC with hemiazygos continuation and draining to the SVC is rare and linked to venous thromboembolism (VTE). • IVC variant related pulmonary embolism can be treated with CDT. CDT through femoral vein access is feasible and safe for IVC variant related pulmonary embolism.

Teaching point: The use of dual-energy instead of conventional single-energy computed tomography pulmonary angiogram can provide additional value concerning the diagnosis of COVID-19 and its complications, especially in the detection of small pulmonary embolism.

Background: COVID-19 (CV19) is a multisystem disease associated with increased risk of coagulopathy and thus, pulmonary embolism (PE). However, detailed PE data remains largely understudied, mainly after hospital discharge. Aim: Evaluate PE occurrence among CV19 pneumonia pts and describe their risk factors and clinical characteristics. Methods: We performed a retrospective analysis (using descriptive statistics, t-Student, Mann-Whitney and Chi-Square tests) of 86 consecutive CV19 pneumonia pts followed in an outpatient setting (CV19 Pulmonology Consultation) post-hospitalization, between 05/2020 and 01/2021. PE diagnosis was based on international guidelines, regardless of the documentation by CT pulmonary angiogram. Clinical, laboratory, radiological and respiratory support data were analysed. Results: Mean age was 57±14 years and the majority was male (54; 63%). PE was diagnosed in 27 cases (31%), with a median time of 9 IQR 6-11 days since CV19 symptoms onset. At PE diagnosis, most pts (16; 59%) were not receiving prophylactic/therapeutic anticoagulant therapy. Patients in PE-group showed higher D-dimers level [1201 IQR 663-7246 vs 834 IQR 554-1317 ng/ml; p

Computed tomographic pulmonary angiography (CTPA) is the gold standard for pulmonary embolism (PE) diagnosis. However, this diagnosis is susceptible to misdiagnosis. In this study, we aimed to perform a systematic review of current literature applying deep learning for the diagnosis of PE on CTPA. MEDLINE/PUBMED were searched for studies that reported on the accuracy of deep learning algorithms for PE on CTPA. The risk of bias was evaluated using the QUADAS-2 tool. Pooled sensitivity and specificity were calculated. Summary receiver operating characteristic curves were plotted. Seven studies met our inclusion criteria. A total of 36,847 CTPA studies were analyzed. All studies were retrospective. Five studies provided enough data to calculate summary estimates. The pooled sensitivity and specificity for PE detection were 0.88 (95% CI 0.803–0.927) and 0.86 (95% CI 0.756–0.924), respectively. Most studies had a high risk of bias. Our study suggests that deep learning models can detect PE on CTPA with satisfactory sensitivity and an acceptable number of false positive cases. Yet, these are only preliminary retrospective works, indicating the need for future research to determine the clinical impact of automated PE detection on patient care. Deep learning models are gradually being implemented in hospital systems, and it is important to understand the strengths and limitations of these algorithms.

Objectives: Patients with COVID-19 may be at high risk for thrombotic complications due to excess inflammatory response and stasis of blood flow. This study aims to assess the incidence of pulmonary embolism among hospitalized patients with COVID-19, risk factors, and the impact on survival. Methods: A retrospective case-control study was conducted at Al-Noor Specialist Hospital in Saudi Arabia between 15 March 2020 and 15 June 2020. Patients with confirmed COVID-19 diagnosis by a real-time polymerase chain reaction (PCR) and confirmed diagnosis of pulmonary embolism by Computed Tomography pulmonary angiogram (CTPA) formed the case group. Patients with confirmed COVID-19 diagnosis by a real-time polymerase chain reaction (PCR) and without confirmed diagnose of pulmonary embolism formed the control group. Logistic regression analysis was used to identify predictors of pulmonary embolism and survival. Results: A total of 159 patients participated were included in the study, of which 51 were the cases (patients with pulmonary embolism) and 108 patients formed the control group (patients without pulmonary embolism). The incidence of PE among those hospitalized was around 32%. Smoking history, low level of oxygen saturation, and higher D-dimer values were important risk factors that were associated with a higher risk of developing PE (p &lt, 0.05). Higher respiratory rate was associated with higher odds of death, and decreased the possibility of survival among hospitalized patients with PE. Conclusions: Pulmonary embolism is common among hospitalized patients with COVID-19. Preventive measures should be considered for hospitalized patients with smoking history, low level of oxygen saturation, high D-dimer values, and high respiratory rate.

OBJECTIVE The purpose of this case series is to evaluate the diagnostic potential of contrast-enhanced ultrasound (CEUS) in patients with clinically suspected pulmonary embolism (PE), suspicious pleural lesions, and negative computed tomography pulmonary angiogram (CTPA). PATIENTS/METHODS Between January 2017 and January 2018, we examined patients with an intermediate or a high-risk Wells score and a negative CTPA with lung B-mode ultrasound (LUS). In a total of six patients, pleural defects were identified and further examined by CEUS. Nonenhancing lesions or those with inhomogeneous enhancement were considered to be suspicious for an embolic event and biopsied for histological validation. The data analysis was retrospective. RESULTS In LUS, the lesions had an average size of 2.4 cm (range 2-3 cm). Five were hypoechoic and one was complex. The shape was wedge shaped (n = 5) or round (n = 1), and the number was solitary (n = 4) or multiple (n = 2) with dorsobasal localization (n = 6). Three lesions were nonenhancing, and three had an inhomogeneous enhancement with areas with complete absence of enhancement. The histological examination showed pulmonary infarction in all six cases, and in one patient also cells of a lung carcinoma. CONCLUSION Our case series demonstrates the diagnostic potential of CEUS for detecting peripheral pulmonary infarction in patients with clinically suspected PE and negative CTPA scan regarding PE. A histological validation or a narrow follow-up might be warranted in some cases.

Background COVID-19 is still a global challenge in regard for management and therapy. Pulmonary embolism (PE) seems to have a higher prevalence in COVID-19 instead of non-COVID patients. Clinical and laboratory parameters related with PE are still unknown. Methods We conducted a retrospective unicentre study in Alto Vicentino Hospital between March 1st, 2020, and January 31st, 2021 in patients admitted for COVID-19 tested with a RT-PCR nasal swab. Data about patients studied with computed tomography pulmonary angiogram (CTPA) because of PE suspicion were collected, as their clinical and laboratory parameters too. Results 2621 patients were admitted for COVID-19 in Alto Vicentino Hospital between March 1st, 2020, and January 31st, 2021 and in 267 of them a CTPA was performed finding 50 PE (18.7%). Only non-Caucasian race (OR = 5.44; 95% CI 1.22–24.35; p = 0.027) and previous VTE (OR = 5.3; 95% CI 1.09–26.17; p = 0.039) were found to be independently associated with PE. Conclusion PE is a frequent complication of COVID-19 and clinician need high degree of suspicion because clinical and laboratoristic parameters cannot drive diagnosis.

Introduction: Covid-19 (CV19) infection is associated with pulmonary embolism (PE). We sought to detail the presence of PE, clinical, laboratory features, and outcomes of those with PE and CV19 compared to CV19 and no PE. Methods: Retrospective analysis of all computed tomography pulmonary angiogram (CTPA) studies undertaken at our hospital during the peak of the pandemic between 29/2-3/5/2020. We included all inpatients with positive CV19 swab or classical or probable features of CV19 on CTPA. All CTPAs were reviewed by certified radiologists. The patient's electronic health records were reviewed for clinical data. Results: Total 132 (45.9%) of CTPAs met inclusion criteria. Presence of PE was 31 (23.5%), with 13 (41.9%) being central, and 18 (58.1%) peripheral. Men (70.4%, P0.04) and white ethnicity (58.1%, P0.03) were significantly associated with PE. No association was seen between CTPA radiographic severity of CV19 and presence of PE. Thromboprophylaxis was administered to 73.2% of the cohort prior to CTPA, no association (P0.29) between administration and diagnosed PE. No difference in vital observations in the 24hrs prior to CTPA as detected. Median Ddimer and Troponin T were significantly elevated (P

IntroductionSARS-CoV-2 infected patients present thrombotic complications caused by direct endothelial cells injury of the microvessels. Pulmonary thromboembolism (PE) has been reported by Computed Tomography pulmonary angiogram (CTPA) in patients with COVID-19 pneumonia with high D-dimer levels.ObjectivesWe present the characteristics of SARS-CoV-2 infected patients diagnosed of PE by CTPA in our hospital. We also present the comparison of these findings with non-infected patients with PE data.MethodsPatients 18 years of age or older with SARS-CoV2 virus infection, and patients with suspected infection at beginning of admission but with negative PCR, were studied with CTPA for suspicion of VTE, during their hospitalization.ResultsDuring the study period, 52 CTPA were performed in our hospital, sixteen in SARS-CoV-2 infected patients. No significant differences in age (p=0.43) and sex (p=0.31) were found between the two groups, infected and non-infected patients. In the infected group, the patients who had PE had a much lower median age (47.8 years) than those without PE (73.3 years). No differences between infected and non-infected patients were detected in the diagnosis of PE with CTPA, 28.6% versus 27.8% (p=1.00). Overall patient mortality was 1.9%; one patient died (6.3%) in the infected group, and none in the non-infected group (p=0.31).ConclusionA considerable incidence of PE diagnosed by CTPA in SARS-CoV-2 infected patients has been observed, despite thrombo-prophylaxis.

Aim: To investigate the diagnostic value of pulmonary embolism severity index (PESI), Simplified PESI (sPESI), Shock Index (SI), Modified SI (MSI), and Age SI (ASI) scores in predicting 30-day mortality in patients diagnosed with pulmonary thromboembolism (PTE) in the emergency department. Materials and Methods: The retrospective study included 257 patients that presented to the emergency department and underwent contrast-enhanced computed tomography pulmonary angiogram (CTPA) due to the suspicion of PTE and were interpreted as PTE by an experienced radiologist between January 1, 2015 and September 20, 2018.The PESI, sPESI, SI, MSI, and ASI scores were calculated for each patient. Results: On univariate logistic regression analysis, 30-day mortality was found to be significantly associated with age, mode of presentation, SBP, DBP, MAP, heart rate, respiratory rate, O2 saturation, temperature, D-dimer, troponin I, high-sensitivity cardiac troponin (hs-cTn), lactate, and SI, MSI, ASI, PESI, and sPESI scores (p

Introduction A Virtual Covid-19 Follow-up Clinic was designed in response to the need to review a large number of in-patients, at a large hospital trust, recovering from Covid-19 but without any significant increase in resources. Methods Patients complete a structured online/telephone symptom and psychological health questionnaire and have a chest x-ray 12 weeks after their illness. These results, and their medical records, are reviewed asynchronously by the medical team in a virtual clinic. Patients are then triaged to further virtual review, telephone review, face to face review, or are discharged. All patients receive comprehensive written information to aid their recovery. Results During the first 8 weeks of the service, 388 patients have completed the questionnaire (63% online) and been reviewed. Current symptoms are shown in figure 1. The questionnaire has identified the holistic needs of patients and allowed triaged follow-up with 122 discharged and 53 urgent face-to-face review appointments completed. 25 CT pulmonary angiogram scans were arranged for patients with typical symptoms of pulmonary emboli; no thromboembolic disease was identified. Conclusion This early experience of a new service has highlighted 5 learning points: Virtual review is not necessarily quicker than clinic review in person, with holistic review taking 15 minutes per patient (excluding phone calls). Patients appreciate clinical contact and this is particularly relevant in the post-Covid era of restricted healthcare attendance. All patients who attend for face to face review are extremely grateful. A multidisciplinary team is necessary bringing together respiratory, cardiology, rheumatology, radiology, psychology and immunology in one holistic review. Patients benefit from therapy input, with 13 of 49 patients assessed by the physiotherapist in clinic diagnosed with breathing pattern disorders. Medical staff redeployment during the pandemic, and the extreme pressures at that time, meant aspects of planned care were not arranged at discharge. Virtual review of medical records has addressed this, for example, re-arranging a referral for a pacemaker and arranging haematological review of a patient newly diagnosed with chronic lymphocytic leukaemia. Regular multi-disciplinary strategy meetings have allowed guidelines to be revised weekly, based on increasing evidence, and experience disseminated.

Introduction Cancer is a strong provoking factor for pulmonary embolism (PE). D-dimer levels are frequently elevated in cancer patients and its specificity decrease with age, hence resulting in frequent unwarranted CT pulmonary angiogram (CTPA). There is growing evidence on the utility of age adjusted d-dimer (AADD) in patients >50 years of age. The objective of this study is to test the efficacy of AADD in ruling out PE in cancer patients when compared to conventional d-dimer cut-off. Methods Retrospective analysis of consecutive patients undergoing CTPA within 48 hours of admission at our institution from 01/04/18 – 30/09/18. Patients Results 807 CTPAs were performed over the 6-month period. 247 patients with cancer were included in further analysis of which 69 (28%) had PE. 60/178 patients (33%) with negative CTPAs had d-dimers positive and AADD negative, whilst only 3/63 CTPAs had positive d-dimers with negative AADD. In essence, 60 patients could have avoided an unnecessary CTPA by using AADD in place of conventional d-dimer, at the expense of missing 3 sub-segmental PE. Conclusion AADD has comparable performance in cancer patients and improves the specificity while retaining sensitivity of d-dimer. It can prevent significant number of inappropriate CTPAs but can potentially miss a few sub-segmental PEs. Further studies are needed to validate its utility before its universal application. Reference Wilts, et al.Thrombosis Research 2017 Apr;152:49–51

Background: Clinical scoring systems for pulmonary embolism (PE) screening have low specificity and contribute to CT pulmonary angiogram (CTPA) overuse. We assessed whether deep learning models using an existing and routinely collected data modality, electrocardiogram (ECG) waveforms, can increase specificity for PE detection. Methods: We use clinical variables, annotated CTPAs, and ECG waveform and morphological parameter data from five hospitals to conduct a retrospective cohort study and develop three models to predict PE likelihood: an ECG model using only ECG waveform data, an EHR model using tabular clinical data, and a Fusion model integrating tabular clinical data and an embedded representation of the ECG waveform. We benchmark the best model against four clinical scores: Wells’ Criteria, Revised Geneva Score, Pulmonary Embolism Rule-Out Criteria, and 4-Level Pulmonary Embolism Clinical Probability Score. Finally, we investigate model robustness through feature sensitivity analyses and assess for demographic subgroup performance parity. Findings: We create a dataset linking 23,793 CTPAs (10·0% PE-positive) and 320,746 ECGs from 21,183 patients for model development and testing. We find that a Fusion model (area under receiver-operating characteristic [AUROC] 0·81 ± 0·01) outperforms both the ECG model (AUROC 0·59 ± 0·01) and EHR model (AUROC 0·65 ± 0·01). On a sample of 100 patients from the test set, the Fusion model has greater specificity (0·18) and performance (AUROC 0·84 ± 0.01) than the all four clinical criteria (AUROC 0·50-0·58, specificity 0·00-0·05). The model also retains superiority over clinical scores in feature sensitivity analyses (AUROC 0·66 to 0·84) and achieves comparable performance across different sex (AUROC 0·81) and racial (AUROC 0·77 to 0·84) subgroups. Interpretation: Integration of electrocardiogram waveforms with traditional clinical variables synergistically increases prediction performance and specificity for PE detection in those who are at least at moderate suspicion for PE. Funding: National Center for Advancing Translational Sciences, National Institutes of Health. Declaration of Interest: All authors declare no competing interests with this study. Ethical Approval: The study was approved by the Mount Sinai Institutional Review Board.

With more than 60,000 deaths annually in the United States, Pulmonary Embolism (PE) is among the most fatal cardiovascular diseases. It is caused by an artery blockage in the lung; confirming its presence is time-consuming and is prone to over-diagnosis. The utilization of automated PE detection systems is critical for diagnostic accuracy and efficiency. In this study we propose a two-stage attention-based CNN-LSTM network for predicting PE, its associated type (chronic, acute) and corresponding location (leftsided, rightsided or central) on computed tomography (CT) examinations. We trained our model on the largest available public Computed Tomography Pulmonary Angiogram PE dataset (RSNA-STR Pulmonary Embolism CT (RSPECT) Dataset, N = 7279 CT studies) and tested it on an in-house curated dataset of N = 106 studies. Our framework mirrors the radiologic diagnostic process via a multi-slice approach so that the accuracy and pathologic sequela of true pulmonary emboli may be meticulously assessed, enabling physicians to better appraise the morbidity of a PE when present. Our proposed method outperformed a baseline CNN classifier and a single-stage CNN-LSTM network, achieving an AUC of 0.95 on the test set for detecting the presence of PE in the study.

A man in his early 50s presented with jaundice, mild shortness of breath on exertion and dark urine. He had had coryzal symptoms 2 weeks prior to admission. Medical history included obstructive sleep apnoea and hypertension. His initial blood tests showed a mild hyperbilirubinaemia and acute kidney injury stage 1. Chest X-ray and CT pulmonary angiogram were negative for features suggestive of COVID-19. He later developed a drop in haemoglobin and repeat bloods showed markedly raised lactate dehydrogenase and positive direct antiglobulin test. These results were felt to be consistent with a haemolytic anaemia. A nasopharyngeal swab came back positive for COVID-19. We suspect the cause of his symptoms was an autoimmune haemolytic anaemia secondary to COVID-19 which has recently been described in European cohorts.

This study's primary goal is to assess the image quality and radiation dose of the low-dose 80kV computed tomography pulmonary angiogram (CTPA) protocol compared to the standard 100kV CTPA protocol for the assessment of pulmonary embolism (PE). The study consisted of 100 patients who had clinically suspected pulmonary embolism and required a CTPA. Patients underwent imaging with a 320-row multi-detector Toshiba Aquilion One Genesis Edition in the absence of the proprietary radiation reduction software known as forward projected model-based Iterative Reconstruction Solution (commercial acronym 'FIRST'). Participants were divided into two groups: A and B. Group A was composed of 50 patients who were allocated to standard CT protocol using a 100 kV exposure setting and all other settings set as a standard by the manufacturer. Group B was composed of 50 patients who were allocated to a CTPA with a low-dose 80kV protocol, standard deviation level 8, an effective mAs of 258, reconstruction algorithm-kernel FC 51 within the lung window, and tube current modulation. A considerable decrease in radiation dose was observed with the low-dose CTPA protocol. The mean radiation dose was also decreased by 66% while using the 80kV protocol than when utilising a standard 100kV technique; this was achieved without compromising this study's diagnostic value. Furthermore, the contrast enhancement was considerably more significant, up to 40% higher when using 80kV. The study found that a low tube voltage of 80kV CTPA protocol resulted in a considerable decrease in radiation dose and improved contrast enhancement without sacrificing the examinations' diagnostic utility.

Category: Reporting quality Background to the audit: Computed tomography pulmonary angiogram (CTPA) studies are the most common investigation for the diagnosis of suspected pulmonary embolism (PE) The National Confidential Enquiry into Patient Outcome and Death (NCEPOD) enquiry into in 2019 identified areas for improvement in the care of patients with new diagnosis of PE One principal recommendation is to standardise CTPA reporting with consideration for reporting proforma to include important positives and negatives Standard: All CTPA reports should comment on the quality/adequacy of study, thrombus burden and the presence/absence of right heart strain Indicator: As above Target: Target: 100% Methodology: Retrospective analysis of CTPA studies from November 2019 Results of first audit round: Total CTPA studies in November 2019: 103 (five were follow-up studies so excluded) CTPA positivity rate 17/98 (17 3%), within accepted standards Of these 17 studies, seven were outsourced for reporting Only 9/17 reports commented on the quality of study (53%) All 17/17 reports commented on thrombus burden (100%) 12/17 reports commented on presence/absence of right heart strain (71%);of the five studies that did not comment on the right heart, two demonstrated massive central PEs No significant difference between onsite radiologist and outsourced reporting First action plan: CTPA reporting template agreed with the consultant body at the departmental audit/governance meeting All positive studies to be reported with template now available on Soliton (radiology information system) Results fed back to Outsourcing company Re-audit at two months Results of second audit round: Awaited (re-audit delayed by COVID-19) References: 1 National Institute for Health and Care Excellence (NICE Guidelines CG144) Venous thromboembolic diseases: diagnosis, management and thrombophilia testing London: National Institute for Health and Care Excellence, 2012 (updated in 2015) 2 The Royal College of Radiologists (RCR: 7th Edition iRefer Guidelines CC04) Suspected Pulmonary Embolism (PE) London: The Royal College of Radiologists, 2012 3 Kingston Hospital (2019) [Blue Book Version 19] Retrieved from: /media/9739/t-secure-department-folders-governance-department-policies-guidelines-publishing-transfer-to-pcg-pdfs-only-patient-care-experience-blue-book-october-2019-v17 pdf 4 National Confidential Enquiry into Patient Outcome and Death Know the score: A review of the quality of care provided to patients aged over 16 years with a new diagnosis of pulmonary embolism London: National Confidential Enquiry into Patient Outcome and Death, 2019 5 Withey S, Tamimi A, CT pulmonary angiogram reporting for pulmonary embolism: are we informing clinical management? ECR Poster C-0835 ECR 2015 doi:10 1594/ecr2016/C-0835 6 www rcr ac uk/audit/appropriateness-usage-computed-tomographypulmonary-angiography-ctpa-investigation-suspected (last accessed 07/04/2019)

Background Hypodense filling defects within the pulmonary veins on computed tomography described as pulmonary vein sign (PVS) have been noted in acute pulmonary embolism and shown to be associated with poor prognosis. We evaluated venous flow abnormalities in chronic thromboembolic pulmonary hypertension (CTEPH) to determine its usefulness in the computed tomography assessment of CTEPH. Methods and Results Blinded retrospective computed tomography analysis of 50 proximal CTEPH cases and 3 control groups—50 acute pulmonary embolism, 50 nonthromboembolic cohort, and 50 pulmonary arterial hypertension. Venous flow reduction was assessed by the following: (1) presence of a filling defect of at least 2 cm in a pulmonary vein draining into the left atrium, and (2) left atrium attenuation (>160 Hounsfield units). PVS was most prevalent in CTEPH. Compared with all controls, sensitivity and specificity of PVS for CTEPH is 78.0% and 85.3% (95% CI, 64.0–88.5 and 78.6–90.6, respectively) versus 34.0% and 70.7% (95% CI, 21.2−48.8 and 62.7–77.8) in acute pulmonary embolism, 8.0% and 62% (95% CI, 2.2–19.2 and 53.7–69.8) in nonthromboembolic and 2.0% and 60% (95% CI, 0.1−10.7 and 51.7−67.9) in pulmonary arterial hypertension. In CTEPH, lobar and segmental arterial occlusive disease was most commonly associated with corresponding absent venous flow. PVS detection was highly reproducible (Kappa=0.96, 95% CI, 0.90–1.01, P Conclusions PVS is easy to detect with higher sensitivity and specificity in CTEPH compared with acute pulmonary embolism and is not a feature of pulmonary arterial hypertension. Asymmetric enhancement of pulmonary veins may serve as an additional parameter in the computed tomography assessment of CTEPH and can be used to differentiate CTEPH from pulmonary arterial hypertension.

A 37-year-old man with a background of bronchiectasis secondary to common variable immunodeficiency (CVID) and pulmonary hypertension presented with dyspnoea, tachycardia and hypoxia. He was investigated with a CT pulmonary angiogram (CTPA) for suspected pulmonary embolus (PE). The CTPA was

Purpose This study evaluated the long-term effectiveness of mandatory assignment of both a clinical decision rule (CDR) and highly sensitive d-dimer in the evaluation of patients with suspected pulmonary embolism (PE). Materials and Methods Institutional guidelines with a CDR and highly sensitive d-dimer were embedded in an order entry menu with mandatory assignment of key components before ordering a CT pulmonary angiogram (CTPA). Data were retrospectively extracted from the electronic health record. Results This was a retrospective review of 1,003 CTPA studies (905 patients, 845 male and 60 female patients, age 63.7 ± 13.5 years). CTPAs were positive for PE in 170 studies (17%), representing an average yield of 15% (year [average]; 2007 [15%], 2008 [18%], 2009 [15%], 2010 [15%], 2011 [17%], 2012 [15%], 2013 [23%]). The increased yield represented efforts of mandatory order entry assignments, educational sessions, and clinical champions. Different d-dimer thresholds with or without age adjustments in combination with the CDR identified about 10% of patients who may have been managed without CTPA. Conclusion Mandatory assignment of a CDR and highly sensitive d-dimer clinical decision pathway can be successfully incorporated into an order entry menu and produce a sustained increase in CTPA yield of patients with suspected PE.

Author(s): Lahham, Shadi; Fox, John C; Thompson, Maxwell; Nakornchai, Tanyaporn; Alruwaili, Badriah; Doman, Ghadeer; May Lee, Shannon; Shafi, Amal; Shniter, Inna; Valdes, Victoria; Zhang, Lishi | Abstract: IntroductionThe imaging standard for evaluation of acute pulmonary embolism (PE) includes a computed tomography pulmonary angiogram. Ultrasonography has shown promise in obtaining the tricuspid annular plane systolic excursion (TAPSE) measurements, which may be of clinical importance in patients with acute PE. The objective of this study is to evaluate the diagnostic capability of TAPSE measurements for patients with suspicion for acute PE.MethodsWe prospectively enrolled patients who came to the emergency department with suspicion of acute PE. Each patient underwent a point-of-care sonogram where a TAPSE measurement was obtained, followed by computed tomography pulmonary angiogram. Based on the computed tomography pulmonary angiogram findings, patients were grouped into 3 categories: no acute PE, clinically insignificant acute PE, or clinically significant acute PE.ResultsWe enrolled 87 patients in this study. Twenty-three (26.4%) of these patients were diagnosed with PE. Of patients with PE, 15 (65%) were found to have a clinically significant acute PE. Analysis of mean TAPSE measurements between patients with clinically significant acute PE and those with insignificant or no PE was 15.2 mm and 22.7 mm, respectively (P ≤ .0001). Following receiver operating characteristic curve analysis, optimum TAPSE measurement to identify clinically significant acute PE is 18.2 mm. A cutoff TAPSE measurement of 15.2 mm shows a sensitivity of 53.3% (95% confidence interval, 26.7%-80%) and a specificity of 100% (95% confidence interval, 100%-100%) for the diagnosis of a clinically significant PE.ConclusionsOur data suggest that TAPSE measurements less than 15.2 mm have a high specificity for identifying clinically significant acute PE.

The hematologic changes which occur during pregnancy make it a hypercoagulable state. Various factors such as hereditary thrombophilia, obesity, etc. increase the risk of venous thromboembolism in these patients. Though the prevalence is low, it can contribute to significant mortality and morbidity. Deep vein thrombosis is the most common type of venous thromboembolism and pulmonary embolism can sometimes be fatal. Various diagnostic modalities like compression duplex ultrasound of leg veins, echo, ventilation-perfusion scan, and computed tomographic pulmonary angiogram can help in diagnosis. Proper treatment can improve both maternal and fetal outcome.

To discuss the value of CT pulmonary angiogram (CTPA) for assessing the treatment outcome of acute pulmonary embolism (APE).CT pulmonary angiogram data and other clinical data were collected for 28 cases diagnosed as APE and analyzed retrospectively. The number and positions of emboli in the pulmonary artery, pulmonary artery obstruction index, right ventricular/left ventricular diameter ratio, main pulmonary artery/ascending aorta diameter ratio and blood oxygen saturation, and pulmonary arterial pressure were compared before and after treatment.Of 28 cases, emboli in the pulmonary artery completely or partially disappeared in 16 and 12 cases, respectively. CPTA indicated that the pulmonary arterial pressure decreased dramatically and the blood oxygen saturation increased after treatment in 26 cases. There were significant differences in the number and positions of pulmonary emboli and in pulmonary artery obstruction index before and after treatment in 28 cases (P .05). However, no significant differences were found in the right ventricular/left ventricular diameter ratio or main pulmonary artery/ascending aorta diameter ratio (P .05).CT pulmonary angiogram proved reliable for assessing the treatment efficacy of APE, providing more clinical information on the patients' status.

Pregnancy increases the risk for thromboembolic disease. CT pulmonary angiogram (CTPA) is widely used for the diagnosis of pulmonary embolus (PE); however, a significant number of scans are suboptimal or non-diagnostic in pregnant patients. This phenomenon is attributed to physiology during the gravid state. The aim of this study is to examine whether all stages of pregnancy are similarly at risk for suboptimal scans. Pregnant patients who had CTPA scans between February 2008 and November 2014 were included. The attenuation in the major pulmonary arteries was compared among patients and controls. An attenuation of 200 Hounsfield units (HU) was used as a cutoff between adequate and suboptimal studies. Statistical analysis compared attenuation means and number of arteries with adequate versus suboptimal attenuation. Forty patients were included in the study. Nine were at or below 13 weeks of pregnancy and 31 between week 14 and term. A control group of 14 non-pregnant women of similar age were also included. All arteries showed a significantly higher attenuation in early pregnancy and in the control group compared to later in pregnancy, p

BACKGROUND Pulmonary embolism is a common and life-threatening condition. Most of the mortality due to pulmonary embolism occurs within the first few hours of the event. Despite improvement in diagnostic techniques, delays in diagnosis of pulmonary embolism are common. As an aetiology of sudden death, massive pulmonary embolism is second only to sudden cardiac death. In current scenario, it is underdiagnosed. Even though, the diagnosis is established, the choice of treatment decides the prognosis. So, using PESI (pulmonary embolism severity index), we can categorise patients into low-risk group and high-risk group and compared it with CTPA (computed tomography pulmonary angiogram) imaging for level of pulmonary artery involvement. MATERIALS AND METHODS This is a retrospective study for a period of 3 years from January 2013 to June 2016. Total of 50 patients were included in this study. In acute pulmonary embolism, patients who underwent CTPA, PESI clinical score was calculated and correlation was done in between these two. RESULTS Out of 50 patients, 38 are in high-risk group and 12 are in low-risk group. Main pulmonary artery, right/left pulmonary artery were involved in 70% of high-risk group patients, which shows a statistically significant association between risk group (class) and involvement of level of arteries by CT pulmonary angiography (p value 0.001). CONCLUSION  By simply using this, 11 variable PESI score, one can predict the patients who are at high risk in the emergency department itself.  We can decide, which patient should undergo thrombolization according to the risk score.  Patients with high-risk score with immediate thrombolysis will have better results.

Pulmonary embolism (PE) is a frequently suspected life-threatening condition that often presents with non-specific signs and symptoms. There is concern that increased availability of computerized tomography pulmonary angiogram (CTPA) is resulting in overuse in the diagnostic workup of patients presenting with cardio-respiratory symptoms. We therefore aimed to determine whether use of CTPA was increasing over time within our institution, with a consequent decrease in the diagnostic yield of PE. Furthermore, we investigated the frequency of alternative (non-PE) pathological findings revealed by CTPA.All patients who underwent CTPA in the first 15 days of eight consecutive years were enrolled retrospectively. Radiology reports and online medical records were examined. In addition, the rates of incidental PE from patients undergoing CT chest for non-suspected PE indications were also examined.An increasing use of CTPA was confirmed (p = 0.04). Despite this, the diagnostic yield of PE also increased (p = 0.03). Similarly, increasing numbers of patients underwent CT chest for non-PE indications, but in this group the rate of incidental PE remained static (~3.4%). In CPTA investigations that were negative for PE, common alternative findings were consolidation, pleural effusion and emphysema, with only 16.7% showing no abnormality.Although CTPA use is increasing, so is the diagnostic yield of PE. In contrast, the rate of incidental PE in those undergoing a CT chest scan for non-PE diagnosis remains relatively low and stable. This suggests that our observed increased use of CTPA is clinically appropriate.

Purpose Optimizing the utilization of CT pulmonary angiogram (CTPA) for the diagnosis and workup of acute chest pain can provide an opportunity to reduce unnecessary radiation and health care system expense. Methods An attempt to improve CTPA utilization began by measuring overall department and clinician-specific utilization. This was bolstered by retrospectively evaluating patient charts for pulmonary embolism scoring criteria and D-dimer utilization so as to better understand gaps in diagnostic workup. The department-wide and individualized metrics were then provided to each emergency department clinician and differences between the pre- and postintervention data were evaluated. Results The percentage of positive CTPAs did not change significantly at 8.7% and 9.2% in the pre- and postintervention groups, respectively. Similarly, the workup of patients based on retrospective PERC and Wells-score criteria did not significantly improve after the intervention. However, the percentage of CTPAs ordered on low D-dimer patients did decrease significantly post-intervention. Further observational analysis uncovered marked variability in clinician ordering behavior and diagnostic rates. Conclusions Overall, such an intervention seems to have a limited, though not insignificant, impact on the workup of suspected pulmonary embolism. Calculating provider-specific utilization metrics allows both the radiologist and clinician to better understand opportunities to improve health care delivery.

A 75-year-old man presented with dyspnea for more than 2 months, with blood test showing low platelet count and cardiac ultrasound showing severe pulmonary hypertension (>54 mm Hg). A CT pulmonary angiogram showed a filling defect in the pulmonary trunk, right and left pulmonary arteries, raising the possibilities of pulmonary embolism or artery sarcoma. FDG PET/CT was performed for further evaluation and showed low uptake in the pulmonary wall, which supported the diagnosis of pulmonary embolism. Patient was treated with anticoagulants with no changes on repeated CT pulmonary angiogram. Patient underwent surgery, and histopatological examination revealed a pulmonary artery sarcoma.

We present a 46-year-old female with pleuritic chest pain on a background of pulmonary embolism diagnosed on a single-photon emission computed tomography (SPECT) ventilation-perfusion (V/Q) imaging 3 years earlier. A SPECT V/Q scan detected a mismatched perfusion defect in the posterior basal segment of the right lower lobe, essentially unchanged from a defect identified 3 years earlier. Given the atypical finding, the patient went on to have a computed tomographic pulmonary angiogram. It revealed an intralobar bronchopulmonary sequestration as the cause of the right lower lobe mismatched perfusion defect. With growing awareness of radiation safety, the number of V/Q imaging studies being undertaken to investigate suspected pulmonary emboli, especially in young female patients, has increased. This case report serves as a timely reminder of the potential pitfalls associated with V/Q scan image interpretation.

Acute pulmonary embolism (PE) can be potentially fatal if not diagnosed and treated early. Mortality in untreated cases can be as high as 30%. Atypical presentation and submassive PE can be missed due to subtle clinical features. Computerized tomography pulmonary angiogram is expensive, exposes to radiation and carries the risk of contrast nephropathy or anaphylactic reactions. On the contrary, McConnell's sign, which is a highly specific sign of PE, can be demonstrated at the bedside with a transthoracic echocardiogram (TTE). Here we discuss two cases where bedside TTE demonstrating McConnell's sign helped in the diagnosis and treatment of PE.

BACKGROUND Venovenous extracorporeal membrane oxygenation in the treatment of severe respiratory failure in adults continues to increase with survival improving; however, it remains associated with serious complications. OBJECTIVE The aim of this study was to evaluate the prevalence of pulmonary embolism (PE) in patients with severe respiratory failure requiring venovenous extracorporeal membrane oxygenation (VV ECMO) and in those managed with conventional mechanical ventilation. METHODS A single-center, observational cohort, retrospective study was undertaken of patients with severe respiratory failure managed with conventional ventilation or requiring ECMO in a tertiary referral university teaching hospital. RESULTS We identified 343 patients with severe respiratory failure between January 2014 and December 2017. VV ECMO was used to support 290 patients and 53 were managed by conventional mechanical ventilation. The prevalence of PE was 9.6% (33/343), of which those supported with VV ECMO was 10% (29/290) and conventional ventilation 7.5% (4/53). There was no difference in survival rates between cohorts with PE versus no PE (ECMO survival to discharge P = .56; conventional ventilation survival to discharge P = .21). CONCLUSIONS The prevalence of pulmonary embolism in severe respiratory failure has important clinical implications for both short and long-term anticoagulation strategies. Routine screening pulmonary angiogram is warranted in this cohort.

Background Pulmonary embolism (PE) is a fatal condition, with a subsequent variety of complications. Although rare, the ensuing presentation of atrial fibrillation (AF) secondary to PE is evident in the literature. However, there has been no report of AF with slow ventricular response requiring a pacemaker as a complication of PE. Case presentation A 78-year-old obese female presented to the emergency room with new onset dyspnea. Computed tomography pulmonary angiogram revealed bilateral PE. Twenty-four hours later, the patient developed new onset AF with slow ventricular response. Therefore, a single chamber pacemaker was implanted. Conclusion PE causing AF with slow ventricular response has not been reported or explained in the literature. The mechanism of this complication is yet to be understood and will require further investigation to explain this newly presented relationship.

A 51-year-old, otherwise well woman, presented with progressive severe dyspnoea. CT pulmonary angiogram (CTPA) demonstrated a large filling defect within the right main pulmonary artery with evidence of right heart strain. She was anticoagulated and discharged home; however, was readmitted with progression of symptoms and hypotension within 1 month. Repeat CTPA demonstrated progression of the filling defect. Formal surgical thrombectomy was performed with removal of an unusual cream-coloured, rubber-like material. Histological analysis revealed intravenous leiomyomatosis (IVL). IVL is a rare benign neoplasm, characterised by smooth muscle cell proliferation in vascular structures that can act aggressively. This case describes the workup, recognition and management of IVL.

Objectives Guidelines and high-quality studies recommend using clinical decision-making (CDM) tools over clinical gestalt when evaluating a patient for pulmonary embolism. The purpose of this study is to investigate our computed tomography pulmonary angiogram (CTPA) utilization patterns and identify causal factors. Methods A retrospective cohort study of CTPA studies ordered by emergency physicians in January, April, July, and October 2017 was undertaken. All necessary information to categorize patients by Wells' score, revised Geneva score, and pulmonary embolism rule-out criteria (PERC) was collected. In addition, various bloodwork, chest radiograph, and computed tomography results were collected. This data was analysed by the Pearson chi-square test or Fisher's exact test for categorical data and independent-samples t test for continuous variables. Results A total of 510 CTPA studies were performed, with a mean age was 61.6 and a 50.6% female population. 136 studies (26.7%) failed to appropriately follow any CDM tool. CDM tool failure rate was dependent on whether the study was ordered from a community (14.9%) or tertiary hospital (University of Alberta Hospital, 27.9% and Royal Alexandra Hospital, 24.6%) ( P = .038). Of these 136 studies, 31 were low/moderate risk and the d-dimer was negative. The remainder were either PERC-negative or low/moderate risk without d-dimer performed. The cumulative positive pulmonary embolism rate was 12.5%. With utilization of a CDM tool, the positive pulmonary embolism rate was 15.0%, compared to 5.9% when using gestalt ( P = .026). Conclusions This study confirms a high rate of CDM tool use failure, and a higher positive CTPA rate for CDM tools compared to clinical gestalt.

Objective To establish the diagnostic value of prespecified ECG changes in suspected pulmonary embolism (PE). Methods Retrospective case–control study in a district general hospital setting. We identified 189 consecutive patients with suspected PE whose CT pulmonary angiogram (CTPA) was positive for a first PE and for whom an ECG taken at the time of presentation was available. We matched these for age±3 years with 189 controls with suspected PE whose CTPA was negative. We considered those with large (n=76) and small (n=113) clot load separately. We scored each ECG for the presence or absence of eight features that have been reported to occur more commonly in PE. Results 20%–25% of patients with PE, including those with large clot load, had normal ECGs. The most common ECG abnormality in patients with PE was sinus tachycardia (28%). S1Q3T3 (3.7%), P pulmonale (0.5%) and right axis deviation (4.2%) were infrequent findings. Right bundle branch block (9.0%), atrial dysrhythmias (10.1%) and clockwise rotation (20.1%) occurred more frequently but were also common in controls. Right ventricular (RV) strain pattern was significantly more commonly in patients than controls, 11.1% vs 2.6% (sensitivity 11.1%, specificity 97.4%; OR 4.58, 95% CI 1.63 to 15.91; p=0.002), particularly in those with large clot load, 17.1% vs 2.6% (sensitivity 17.1%, specificity 97.4%; OR 7.55, 95% CI 1.62 to 71.58; p=0.005). Conclusion An ECG showing RV strain in a breathless patient is highly suggestive of PE. Many of the other ECG changes that have been described in PE occur too infrequently to be of predictive value.

A 30-year-old woman was sent to the emergency room after alcohol and paraquat ingestion. After three sessions of hemoperfusion via the indwelling double-lumen catheter, the patient could tolerate ambient air and her urine output was good. However, on the 10th day of hospitalization, she had a sudden onset of dyspnea and hypoxia. Pulmonary embolism was diagnosed by a computed tomography pulmonary angiogram. The patient recovered after anticoagulation therapy. We could find no reports of dyspnea caused by pulmonary embolism in patients with paraquat intoxication. Here, we present this rare case; the indwelling double-lumen catheter might have been a cause of the pulmonary embolism.