Computed Tomography Pulmonary Angiography Research Articles

Clinical predictors of pulmonary embolism for inpatients: are computed tomography pulmonary angiograms being requested appropriately?

The heterogeneity of inpatient pulmonary embolism (PE) presentations may lead to computed tomography pulmonary angiograms (CTPA) being over-requested. Current clinical predictors for PE, including Wells criteria and Pulmonary Embolism Rule-out Criteria (PERC), have predominantly focussed on outpatient and emergency department populations. To determine the clinical indicators for ordering inpatient CTPA and the predictors of positive scans for PE. Consecutive inpatient CTPA (performed >24 h after admission) from January 2017 to December 2017 were retrospectively reviewed. Variables including baseline characteristics, vital signs and risk factors for PE were extracted. A total of 312 CTPA was reviewed (average patient age 67 years; 46% male) and 36 CTPA were positive for PE (11.5%). The average time to inpatient CTPA request was 7 days. Clinical indicators associated with positive scans were hypoxia (odds ratio (OR) 2.4; 95% confidence interval (CI) 1.1-5.6), tachypnoea (OR 2.5; 95% CI 1.2-6.0), recent surgery or immobilisation (OR 2.7; 95% CI 1.2-6.4), S1Q3T3 pattern on electrocardiogram (ECG; OR 7.2; 95% CI 1.4-35.7) and right bundle branch block pattern on ECG (OR 4.7; 95% CI 1.6-13.1). Hypotension, fever and malignancy were not significant. Both PERC and Wells criteria had poor positive predictive value (12% and 27% respectively), but the negative predictive value for PERC and Wells was 100% and 95.8% respectively. Inpatient CTPA appear to be over-requested and can potentially be rationalised based on a combination of clinical predictors and Wells criteria and/or PERC rule. Further prospective studies are needed to develop accurate clinical decision tools targeted towards inpatients.

Subsegmental pulmonary embolism and anticoagulant therapy: the impact of clinical context.

Anticoagulation for subsegmental pulmonary embolism (SSPE) is controversial. To assess the impact of clinical context on anticoagulation and outcomes of SSPE. We electronically searched computed tomography pulmonary angiogram reports to identify SSPE. We extracted demographic, risk factor, investigations and outcome data from the electronic medical record. We stratified patients according to anticoagulation and no anticoagulation. From 1 January 2017 to 31 December 2019, we identified 166 patients with SSPE in 5827 pulmonary angiogram reports. Of these, 123 (74%) received anticoagulation. Compared with non-anticoagulated patients, such patients had a different clinical context: higher rates of previous venous thromboembolism (11% vs 0%; P = 0.019), more recent surgery (26% vs 9%; P = 0.015), more elevated serum D-dimer (22% vs 5%; P = 0.004), more lung parenchymal abnormalities (76% vs 61%; P = 0.037) and were almost twice as likely to require inpatient care (76% vs 42%; P < 0.001). Such patients also had twice the all-cause mortality at 1 year (32% vs 16%). SSPE is diagnosed in almost 3% of pulmonary angiograms and is associated with high mortality, regardless of anticoagulation, due to coexistent disease processes rather than SSPE. Anticoagulation appears dominant but markedly affected by the clinical context of risk factors, alternative indications and illness severity. Thus, the controversy is partly artificial because anticoagulation after SSPE is clinically contextual with SSPE as only one of several factors.

Pulmonary embolism in patients with COVID-19 and D-dimer diagnostic value: A retrospective study.

BackgroundD-dimer levels are significantly higher in COVID-19 patients with Pulmonary Thromboembolism (PTE) as compared to those without PTE, but its clinical utility is still uncertain.PurposeTo determine the D-dimer performance for ruling out PTE in patients with COVID-19. We also assessed clinical and laboratory factors associated with the presence of PTE on CT Pulmonary Angiogram (CTPA).MethodsRetrospective study involving all patients who presented at a tertiary care hospital from March 2020 to May 2021 with severe acute respiratory syndrome from COVID-19, who underwent CTPA and had D-dimer collected within 48 hours from CTPA. The D-dimer ability to classify patients with or without PTE according to CTPA was evaluated.ResultsA total of 697 patients [382 (54.8%) men; mean (SD) age, 59 (20.5) years] were included, of which 71.5% required intensive care admission, 32.4% had PTE, and 35.6% died during hospitalization. PTE was independently associated with mortality [42.5% vs. 32.3%; p = 0.038]. D-dimer levels were higher in patients with PTE [9.1 (3.9; 20) vs. 2.3 (1.2; 5.1); p < 0.001]. Using the D-dimer cutoff of 0.5 μg/mL or above, sensitivity was 98.2% and specificity 5.7%. The 0.3 μg/mL threshold was associated with 100% of sensitivity for the presence of PTE, with which 99.1% of patients had increased values. ROC curve AUC was 0.77, demonstrating moderate discriminative power of D-dimers to detect PTE.ConclusionsD-dimer levels are higher among COVID-19 hospitalized patients with PTE as compared to those without PTE and have moderate discriminative power to detect PTE, but its use to exclude PTE in this population may have limited clinical utility.

Comparison of COVID-19 disease severity and PE rates between Kent B1.1.7 lineage versus other lineages on CTPA

Category: ThoracicPurpose:To compare radiologically determined COVID-19 disease severity and pulmonary embolism (PE) rates on initial computed tomography pulmonary angiogram (CTPA), clinical severity and outcomes of patients infected with B1.1.7 lineage compared with those infected with remaining strains.Methods and materials:Single-centre retrospective analysis on a cohort of 139 consecutive patients with polymerase chain reaction (PCR)-confirmed COVID-19 infection who underwent CTPA and viral genome sequencing between 1 December 2020 and 7 January 2021.Two radiologists undertook blinded analysis of the first CTPA since admission and scored out of 25 for lung involvement to produce a CT severity score (CTSS). Pulmonary embolism rates were determined on radiological report. Clinical, biochemical and outcome data was collected with a median follow up of 61 days.Results:88/139 patients infected with B1.1.7 lineage.A significant difference in venous thromboembolism (VTE) rate was observed between B1.1.7 (1.1%, 1/88) and non-B1.1.7 (13.7%, 7/51) controlling for age, gender, anticoagulation on admission and comorbidities (adjusted p=0.0104).No difference in CTSS or clinical severity (determined by ventilatory requirements or oxygen saturations), hospital length of stay, admission to critical care or death between B1.1.7 and non-B1.1.7.However, significantly higher C-reactive protein (CRP) was found in non-B1.1.7 versus B1.1.7 (mean CRP 179 versus 134, adjusted p<0.0001).Conclusion:Although B1.1.7 variant has been shown to associate with increased mortality and disease severity, we did not demonstrate a difference in CT severity score nor in clinical severity or outcomes. Further, patients with non-B.1.1.7 had a significant higher rate of pulmonary embolism and higher maximal CRP. Category: Thoracic Purpose: To compare radiologically determined COVID-19 disease severity and pulmonary embolism (PE) rates on initial computed tomography pulmonary angiogram (CTPA), clinical severity and outcomes of patients infected with B1.1.7 lineage compared with those infected with remaining strains. Methods and materials: Single-centre retrospective analysis on a cohort of 139 consecutive patients with polymerase chain reaction (PCR)-confirmed COVID-19 infection who underwent CTPA and viral genome sequencing between 1 December 2020 and 7 January 2021. Two radiologists undertook blinded analysis of the first CTPA since admission and scored out of 25 for lung involvement to produce a CT severity score (CTSS). Pulmonary embolism rates were determined on radiological report. Clinical, biochemical and outcome data was collected with a median follow up of 61 days. Results: 88/139 patients infected with B1.1.7 lineage. A significant difference in venous thromboembolism (VTE) rate was observed between B1.1.7 (1.1%, 1/88) and non-B1.1.7 (13.7%, 7/51) controlling for age, gender, anticoagulation on admission and comorbidities (adjusted p=0.0104). No difference in CTSS or clinical severity (determined by ventilatory requirements or oxygen saturations), hospital length of stay, admission to critical care or death between B1.1.7 and non-B1.1.7. However, significantly higher C-reactive protein (CRP) was found in non-B1.1.7 versus B1.1.7 (mean CRP 179 versus 134, adjusted p<0.0001). Conclusion: Although B1.1.7 variant has been shown to associate with increased mortality and disease severity, we did not demonstrate a difference in CT severity score nor in clinical severity or outcomes. Further, patients with non-B.1.1.7 had a significant higher rate of pulmonary embolism and higher maximal CRP.

Acute Massive and Submassive Pulmonary Embolism: Historical Considerations/Surgical Techniques of Pulmonary Embolectomy/Novel Applications in Donor Lungs with Pulmonary Emboli.

Pulmonary embolectomy has a chequered history but the quest to surgically treat a patient diagnosed with pulmonary embolism effectively spurred the development of cardiopulmonary bypass and a new dawn for cardiac surgery. The advent of cardiopulmonary bypass, extracorporeal membrane oxygenation, and computed tomography pulmonary angiogram has allowed rapid diagnosis and made surgical pulmonary embolectomy a relatively safe procedure that should be considered when indicated. Pulmonary emboli in donor lungs, often get rejected for transplantation. Ex vivo lung perfusion is among newly available technology with the ability to not only recondition marginal lungs but also treat donor lung pulmonary embolisms, effectively increasing the donor pool.

COVID-19 CT severity score on CT pulmonary angiography (CTPA): Correlation with clinical disease severity and short-term prognosis

COVID-19 CT severity score on CT pulmonary angiography (CTPA): Correlation with clinical disease severity and short-term prognosis

D-Dimer Levels and Prognostic Features in Pulmonary Embolism

Background: The aim of our study is to investigate the efficacy of D-dimer marker in patients who applied to the emergency department with a preliminary diagnosis of pulmonary embolism. &#x0D; Materials and methods: This study was conducted retrospectively at Bursa Uludağ University Faculty of Medicine Hospital between January 2018 and December 2018. Patients whose D-dimer levels were checked considering the preliminary diagnosis of pulmonary embolism were included in the study. &#x0D; Results: A total of 3411 patients were included in the study. In all patients, the diagnosis of PE was made by computed tomography pulmonary angiography. Examination of 1968 patients with (+) D-dimer revealed new diagnosis in 702 patients (35.67%). Pulmonary embolism was diagnosed in a total of 74 patients (10.54%) whereas the most common alternative diagnoses was 33.62% (n=236) pneumonia. On examination of 1443 patients with negative D-dimer levels, pulmonary embolism was diagnosed in 7 (3.14%) patients whereas the most common other diagnoses was 44.84% (n=100) Acute Coronary Syndrome. However, in the D-dimer positive patient group, the rate of newly diagnosed patients requiring clinical and intensive care hospitalization was found to be significantly higher. &#x0D; Conclusion: In conclusion, even if pulmonary embolism is not detected in D-dimer positive cases, it is thought that these patients need further investigation, considering the frequency of serious conditions requiring clinical and intensive care unit admission.

Using barium as an internal radioprotective shield for pregnant patients undergoing CT pulmonary angiography: A retrospective study

PurposeThe purpose of our retrospective study was to assess the effect of barium sulfate contrast medium on radiation dose and diagnostic quality of CT Pulmonary Angiography (CTPA) in an in-vivo study of pregnant patients. MethodsOur retrospective study included 33 pregnant patients who underwent CTPA to exclude pulmonary embolism. The patients received oral 40% w/v barium solution just prior to the acquisition of their planning radiograph. All CTPA were performed on 64-slice, single-source CT scanners with AEC with noise index = 28.62–31.64 and the allowed mA range of 100–450. However, only 5/33 patients had mA modulation (AEC 100–450 mA range), while 28/33 patients had mA maxed out at the set maximum mA of 450 over the entire scan range. We recorded CTDIvol (mGy), DLP (mGy.cm) and scan length. The same information was recorded in weight-and scanner-matched, non-pregnant patients. Statistical tests included descriptive data (median and interquartile range) and Mann-Whitney test. ResultsThere were no significant differences in CTDIvol and DLP between the barium and control group patients (p > 0.1). The median mA below the diaphragm was significantly higher in each patient with barium compared to the weight and scanner-matched patient without barium. Evaluation of lung and subsegmental lower lobe pulmonary arteries was limited in 85% barium group. Due to thin prospective section thickness (1.25 mm), most patients were scanned at maximum allowed mA for AEC. ConclusionUse of AEC with thick barium in pregnant patients undergoing CTPA as an internal radioprotective shield produces counterproductive artifacts and tube current increments.

Predictive ability of viscoelastic testing using ClotPro® for short-term outcome in patients with severe Covid-19 ARDS with or without ECMO therapy: a retrospective study

BackgroundSARS-CoV-2 infections are suspected to trigger the coagulation system through various pathways leading to a high incidence of thromboembolic complications, hypercoagulation and impaired fibrinolytic capacity were previously identified as potentially mechanisms. A reliable diagnostic tool for detecting both is still under discussion. This retrospective study is aimed to examine the prognostic relevance of early viscoelastic testing compared to conventional laboratory tests in COVID-19 patients with acute respiratory distress syndrome (ARDS).MethodsAll mechanically ventilated patients with COVID-19 related ARDS treated in our intensive care unit (ICU) between January and March 2021 were included in this study. Viscoelastic testing (VET) was performed using the ClotPro® system after admission to our ICU. Prevalence of thromboembolic events was observed by standardized screening for venous and pulmonary thromboembolism using complete compression ultrasound and thoracic computed tomography pulmonary angiography at ICU admission, respectively. We examined associations between the severity of ARDS at admission to our ICU, in-hospital mortality and the incidence of thromboembolic events comparing conventional laboratory analysis and VET. ECMO related coagulopathy was investigated in a subgroup analysis. The data were analyzed using the Mann–Whitney U test.ResultsOf 55 patients enrolled in this study, 22 patients required treatment with ECMO. Thromboembolic complications occurred in 51% of all patients. Overall hospital mortality was 55%. In patients with thromboembolic complications, signs of reduced fibrinolytic capacity could be detected in the TPA assay with prolonged lysis time, median 460 s (IQR 350–560) vs 359 s (IQR 287–521, p = 0.073). Patients with moderate to severe ARDS at admission to our ICU showed increased maximum clot firmness as a sign of hypercoagulation in the EX-test (70 vs 67 mm, p < 0.05), FIB-test (35 vs 24 mm, p < 0.05) and TPA-test (52 vs 36 mm, p < 0.05) as well as higher values of inflammatory markers (CRP, PCT and IL6). ECMO patients suffered more frequently from bleeding complications (32% vs 15%).ConclusionAlthough, the predictive value for thromboembolic complications or mortality seems limited, point-of-care viscoelastic coagulation testing might be useful in detecting hypercoagulable states and impaired fibrinolysis in critically ill COVID-19 ARDS patients and could be helpful in identifying patients with a potentially very severe course of the disease.

Constructing custom-made radiotranscriptomic signatures of vascular inflammation from routine CT angiograms: a prospective outcomes validation study in COVID-19

BackgroundDirect evaluation of vascular inflammation in patients with COVID-19 would facilitate more efficient trials of new treatments and identify patients at risk of long-term complications who might respond to treatment. We aimed to develop a novel artificial intelligence (AI)-assisted image analysis platform that quantifies cytokine-driven vascular inflammation from routine CT angiograms, and sought to validate its prognostic value in COVID-19.MethodsFor this prospective outcomes validation study, we developed a radiotranscriptomic platform that uses RNA sequencing data from human internal mammary artery biopsies to develop novel radiomic signatures of vascular inflammation from CT angiography images. We then used this platform to train a radiotranscriptomic signature (C19-RS), derived from the perivascular space around the aorta and the internal mammary artery, to best describe cytokine-driven vascular inflammation. The prognostic value of C19-RS was validated externally in 435 patients (331 from study arm 3 and 104 from study arm 4) admitted to hospital with or without COVID-19, undergoing clinically indicated pulmonary CT angiography, in three UK National Health Service (NHS) trusts (Oxford, Leicester, and Bath). We evaluated the diagnostic and prognostic value of C19-RS for death in hospital due to COVID-19, did sensitivity analyses based on dexamethasone treatment, and investigated the correlation of C19-RS with systemic transcriptomic changes.FindingsPatients with COVID-19 had higher C19-RS than those without (adjusted odds ratio [OR] 2·97 [95% CI 1·43–6·27], p=0·0038), and those infected with the B.1.1.7 (alpha) SARS-CoV-2 variant had higher C19-RS values than those infected with the wild-type SARS-CoV-2 variant (adjusted OR 1·89 [95% CI 1·17–3·20] per SD, p=0·012). C19-RS had prognostic value for in-hospital mortality in COVID-19 in two testing cohorts (high [≥6·99] vs low [<6·99] C19-RS; hazard ratio [HR] 3·31 [95% CI 1·49–7·33], p=0·0033; and 2·58 [1·10–6·05], p=0·028), adjusted for clinical factors, biochemical biomarkers of inflammation and myocardial injury, and technical parameters. The adjusted HR for in-hospital mortality was 8·24 (95% CI 2·16–31·36, p=0·0019) in patients who received no dexamethasone treatment, but 2·27 (0·69–7·55, p=0·18) in those who received dexamethasone after the scan, suggesting that vascular inflammation might have been a therapeutic target of dexamethasone in COVID-19. Finally, C19-RS was strongly associated (r=0·61, p=0·00031) with a whole blood transcriptional module representing dysregulation of coagulation and platelet aggregation pathways.InterpretationRadiotranscriptomic analysis of CT angiography scans introduces a potentially powerful new platform for the development of non-invasive imaging biomarkers. Application of this platform in routine CT pulmonary angiography scans done in patients with COVID-19 produced the radiotranscriptomic signature C19-RS, a marker of cytokine-driven inflammation driving systemic activation of coagulation and responsible for adverse clinical outcomes, which predicts in-hospital mortality and might allow targeted therapy.FundingEngineering and Physical Sciences Research Council, British Heart Foundation, Oxford BHF Centre of Research Excellence, Innovate UK, NIHR Oxford Biomedical Research Centre, Wellcome Trust, Onassis Foundation.

Diagnosis, Diagnostic Tools, and Risk Stratification for Contemporary Treatment of Pulmonary Embolism.

Pulmonary embolism (PE) is quite common and is associated with significant morbidity and mortality. It is estimated that it is the cause of approximately 100,000 annual deaths in the United States. With great variability in presenting symptoms of PE, poor recognition of PE can be fatal. As such, many risk scores have been created to identify the sickest patients. Choosing the appropriate imaging modality is also critical. Invasive pulmonary angiography was once the gold standard to establish the diagnosis. With the advent of nuclear imaging, V/Q scans, invasive angiography has been phased out for diagnosing acute PE. At present, the standard for diagnosis of acute PE is computed tomography pulmonary angiography. In select patient cohorts, nuclear studies remain the modality of choice. Once the diagnosis of acute PE is established, there is a broad spectrum of severity in outcome which has led to substantial focus and development of risk stratification prediction models. We will discuss making the proper diagnosis with contemporary diagnostic tools and risk stratifying patients with PE to receive the correct treatment.

Brain-Derived Neurotrophic Factor Expression in Patients with Acute Pulmonary Embolism Compared to the General Population: Diagnostic and Prognostic Implications.

(1) Background: Pulmonary embolism (PE) is a severe condition, representing the third most important cardiovascular cause of death after myocardial infarction and stroke. Despite the use of clinical pre-test probability scores, D-dimer measuring, and computer tomography pulmonary angiography (CTPA), PE diagnosis remains a challenge. Brain-derived neurotrophic factor (BDNF) is the most important member of the neurotrophin family, which has also been shown to be involved in the physiopathology of cardiovascular conditions such as heart failure and myocardial infarction. In this study, we aimed to assess the BDNF expression in patients with acute PE compared to the general population, and to also investigate its diagnostic and prognostic role. (2) Methods: We conducted a single center prospective study, which included 90 patients with PE and 55 healthy volunteers. Clinical and paraclinical parameters, together with plasma levels of BDNF, were evaluated in all patients after admission. (3) Results: The plasma levels of BDNF were significantly lower in the PE patients compared with the control group (403 vs. 644 pg/mL, p < 0.001). ROC analysis revealed an AUC of 0.806 (95% CI 0.738–0.876, p < 0.001) and a cut-off value of 564 pg/mL, which associated a sensitivity of 74.4% and a specificity of 78.2% for PE. Low BDNF levels also correlated with prognostic markers of PE, such as PESI score (p = 0.023), NT-proBNP (p < 0.01), right ventricular diameter (p = 0.029), and tricuspid annular plane systolic elevation (p = 0.016). Moreover, we identified a decreased BDNF expression in patients with high-risk PE (p < 0.01), thrombolytic treatment (p = 0.01), and patients who died within 30 days (p = 0.05). (4) Conclusions: Our study revealed that plasma BNDF is significantly lower in patients with PE when compared with the general population, and may be considered as a promising biomarker in complementing the current diagnostic tools for PE. Furthermore, low levels of BDNF might also be used to predict a poor outcome of this condition.

The Prognostic Significance of Pulmonary CT Angiography in Predicting the Outcomes of Acute Pulmonary Thromboembolism

Background: Pulmonary embolism (PE) is a potentially fatal condition. Knowledge of the prognostic factors for PE may facilitate the management of these patients. Pulmonary computed tomography (CT) angiography (PCTA) can play an effective role in their management. Objectives: To evaluate the prognostic value of certain PCTA-derived indicators of right ventricular dysfunction in patients with acute PE. Patients and Methods: A total of 61 hemodynamically stable patients with acute PE underwent PCTA and were followed-up for 60 days. The Qanadli index and 60-day mortality represented the PE severity and prognostic endpoints, respectively. The clinical significance of the following variables in predicting PE severity and mortality was examined: An abnormally positioned interventricular septum, right ventricular to left ventricular diameter ratio (RVD/LVD) on the axial plane, contrast medium reflux into the inferior vena cava (IVC), transverse diameter of the pulmonary trunk, and bolus-time curve indicators. Results: The 60-day mortality was estimated at 14.8% in this study. An abnormal interventricular septum morphology, RVD/LVD ratio, and contrast medium reflux into the IVC were significantly correlated with the Qanadli index. The pulmonary trunk diameter was the only predictor of 60-day mortality (optimal cutoff value, 33.5 mm; sensitivity, 66.7%; and specificity, 65.4%). The bolus-time curve indicators did not have any significant predictive value. Conclusion: Some PCTA-derived indicators of right ventricular dysfunction may serve as severity/prognostic predictors in hemodynamically stable patients with acute PE.

Early-stage COVID-19 pandemic observations on pulmonary embolism using nationwide multi-institutional data harvesting

We introduce a multi-institutional data harvesting (MIDH) method for longitudinal observation of medical imaging utilization and reporting. By tracking both large-scale utilization and clinical imaging results data, the MIDH approach is targeted at measuring surrogates for important disease-related observational quantities over time. To quantitatively investigate its clinical applicability, we performed a retrospective multi-institutional study encompassing 13 healthcare systems throughout the United States before and after the 2020 COVID-19 pandemic. Using repurposed software infrastructure of a commercial AI-based image analysis service, we harvested data on medical imaging service requests and radiology reports for 40,037 computed tomography pulmonary angiograms (CTPA) to evaluate for pulmonary embolism (PE). Specifically, we compared two 70-day observational periods, namely (i) a pre-pandemic control period from 11/25/2019 through 2/2/2020, and (ii) a period during the early COVID-19 pandemic from 3/8/2020 through 5/16/2020. Natural language processing (NLP) on final radiology reports served as the ground truth for identifying positive PE cases, where we found an NLP accuracy of 98% for classifying radiology reports as positive or negative for PE based on a manual review of 2,400 radiology reports. Fewer CTPA exams were performed during the early COVID-19 pandemic than during the pre-pandemic period (9806 vs. 12,106). However, the PE positivity rate was significantly higher (11.6 vs. 9.9%, p < 10−4) with an excess of 92 PE cases during the early COVID-19 outbreak, i.e., ~1.3 daily PE cases more than statistically expected. Our results suggest that MIDH can contribute value as an exploratory tool, aiming at a better understanding of pandemic-related effects on healthcare.

988 A Case of Cocaine Associated Pneumomediastinum: An Unusual Diagnosis

Abstract Cocaine inhalation is an extremely rare but previously described association of spontaneous pneumomediastinum. We describe an unusual case of a previously well 20-year-old female who presented with a five-day history of central, pleuritic chest pain beginning one week after last cocaine inhalation. Blood tests were within the normal limits except for a positive d-dimer. Clinical examination was unremarkable, and a chest X-ray appeared grossly normal. A CT pulmonary angiogram revealed an extensive pneumomediastinum extending into the soft tissues of the neck and down to the peri-oesophageal region at the hiatus, without evidence of pneumothorax. The lungs and oesophagus appeared intact. The patient was admitted for observation and discharged within 48 hours. There is limited literature on this phenomenon, but almost all previous case reports suggest a benign, self-limiting course and resolution of radiological findings within 30 days. Invasive procedures are only considered if there is suspicion of oesophageal rupture or bronchial tree laceration. Spontaneous pneumomediastinum associated with cocaine inhalation is a relatively benign but uncommon condition with a predictable clinical course.

727 Pulmonary Embolism Following Posterior Shoulder Dislocation and Traumatic Brachial Plexus Injury - a Case Report

Abstract Traumatic brachial plexus injuries are considered to be among the rarest but most debilitating complications of shoulder dislocation. In addition, posterior shoulder dislocations are also rare, accounting for only 2–4% of all shoulder dislocations. A 40-year-old female patient presented to the emergency department (ED) with a dislocated right shoulder secondary to a mechanical fall. Plain film X-rays demonstrated a posterior dislocation of the humeral head. The shoulder was reduced under procedural sedation. Clinical examination after relocation demonstrated dense flaccid paralysis affecting all dermatomes and myotomes throughout the right upper limb. Urgent magnetic resonance imaging (MRI) of the shoulder showed oedematous thickening and haematoma along the brachial plexus, a large ‘reverse’ Hill-Sachs lesion, greater tuberosity avulsion fracture and glenohumeral capsular tear. The patient was referred to the specialist peripheral nerve injury unit, who advised nerve conduction studies and a magnetic resonance angiogram (MRA) to rule out expanding haematoma. The MRA scan revealed brachial plexus findings consistent with the MRI scan, no active bleeding, however a thrombus in the brachial vein. Two days after the MRA scan, the patient presented to ED with ongoing flaccid paralysis, severe neuropathic pain, and right-sided chest pain. Blood tests revealed a d-dimer &amp;gt;1000. CT pulmonary angiography confirmed extensive bilateral pulmonary emboli and she was commenced on appropriate anticoagulation. Association between brachial plexus injury, flaccid paralysis and venous thromboembolism are rare sequelae resulting from posterior shoulder dislocation. Further studies are required to investigate its incidence and establish whether all patients should receive VTE prophylaxis as standard.

PrEdictive value of coMbined pre-test proBability and blOod gas anaLysis In pulmonary emboliSM—the EMBOLISM study

In patients with suspected pulmonary embolism (PE), the number of unnecessary computed tomography pulmonary angiography (CTPA) scans remains high, especially in patients with low pre-test probability (PTP). So far, no study showed any additional benefit of capillary blood gas analysis (BGA) in diagnostic algorithms for PE. In this retrospective analysis of patients with suspected PE and subsequent CTPA, clinical data, D-dimer levels and BGA parameters (including standardized PaO2) were analyzed. Logistic regression analyses were performed to identify independent predictors for PE and reduce unnecessary CTPA examinations in patients with low PTP according to Wells score. Of 1538 patients, PE was diagnosed in 433 patients (28.2%). The original Wells score (odds ratio: 1.381 [95% CI 1.300–1.467], p < 0.001) and standardized PaO2 (odds ratio: 0.987 [95% CI 0.978–0.996], p = 0.005) were independent predictors for PE. After cohort adjustment for low PTP a D-dimer cut-off < 1.5 mg/L (278 patients (18.1%) with 18 PE (6.5%)) was identified in which a standardized PaO2 > 65 mmHg reduced the number of unnecessary CTPA by 31.9% with a 100% sensitivity. This approach was further validated in additional 53 patients with low PTP. In this validation group CTPA examinations were reduced by 32.7%. No patient with PE was missed. With our novel algorithm combining BGA testing with low PTP according to Wells score, we were able to increase the D-Dimer threshold to 1.5 mg/L and reduce CTPA examinations by approximately 32%.

The prevalence of pulmonary embolism among COVID-19 patients underwent CT pulmonary angiography

BackgroundPulmonary embolism (PE) is a common and fatal complication of COVID-19 infection. COVID-19's main clinical manifestations are not only pneumonia but also coagulation disorders. This study evaluates the prevalence of pulmonary embolism at CT pulmonary angiography (CTA) for positive coronavirus patients as well as the factors associated with PE severity. Materials and methodsThis is a retrospective cross-sectional study that was conducted at King Faisal Medical Complex (KFMC) in Taif city of Saudi Arabia from June 2020 to June 2021. Data was collected from the picture archiving and communication system (PACs) for a total of 445 positive patients who underwent CT pulmonary angiography and analyzed using SPSS. ResultsThe mean age and gender of the male were 57.3 ± 15.8 years and 64.5%, respectively. The prevalence of pulmonary embolism at CTA among patients with COVID-19 was found to be 8.1%. Bilateral segmental and bilateral subsegmental pulmonary embolism were found to be the most common sites for PE (16.7% for each). Furthermore, shortness of breath (SOB) was found to be the most common reported symptom among the respondents. Lastly, shortness of breath, chest pain, loss of taste or smell, D-dimer, and cardiac troponin were found to be significantly associated with PE (P-value = < 0.001, <0.001, 0.001, <0.001 and 0.037 respectively). ConclusionPresent results show that the prevalence of pulmonary embolism among COVID19 patients with CT Pulmonary Angiography at KFMC is relatively low (8.1%) and most of the patients were from the ICU department. Early detection and treatment of COVID-19 patients with PE and APE complications are critical for lowering the mortality rate.

Editorial

Editorial

Assessment of right ventricular function by 2D transthoracic echocardiography in COVID-19 hospitalized patient in correlation with CT pulmonary angiographic findings

Background:. The Egyptian protocol in COVID-19 patients includes doing a non- contrast CT chest for patients with suspicious respiratory symptoms. However, many patients with worsened symptoms especially during the second week of disease showed symptoms of thrombotic events of pulmonary arteries, and that is why CT pulmonary angiography (CTPA) became recommended by multiple reports. Aim of the Work: Evaluation of RV Function by Echocardiography in COVID-19 hospitalized patients in correlation with CT pulmonary angiographic findings. Patients and Methods: This study is a prospective study which included 100 consecutive adult patients (≥18 years of age). Results: Our study showed that there was non statistically significant difference found between two groups regarding Basal right ventricular diameter , FAC , PASP ,TAPSE (except for sever pulmonary embolism ) Conclusion: Our study revealed the variable presentation of COVID-19 as a cause of pulmonary embolism. And no statistically significant difference found between pulmonary embolism group and no pulmonary embolism group regarding right ventricular dysfunction .