Pulmonary embolism: an unsuspected killer

Efficacy of pulse oximetry for early diagnosis of pulmonary embolism after total knee arthroplasty

INTRODUCTION

Early diagnosis and aggressive treatment of pulmonary embolism (PE) are crucial for preventing severe complications after total knee arthroplasty (TKA). This study aimed to examine the efficacy of measuring oxygen saturation (SpO2) using a pulse oximeter for early diagnosis of PE after total knee arthroplasty (TKA).

MATERIALS AND METHODS

We consecutively examined 1645 patients who underwent TKA between January 2015 and November 2019. Postoperative SpO2 was measured with a pulse oximeter, which was stopped if SpO2 was maintained at ≥ 95% until postoperative day 2 (POD2). To diagnose PE, computed tomographic pulmonary angiography (CTPA) was performed for specific indications, including persistently low SpO2 < 95% (group 1), sudden decrease in SpO2 (group 2), and decrease in SpO2 after POD3 with presenting symptoms (group 3). Also, we divided the patients into unilateral, simultaneous and sequential TKA groups and compared the results with specific statistical techniques.

RESULTS

Of the 1645 patients who underwent TKA, there were 20 patients with PE (1.2%), and symptomatic PE was observed in only 4 patients (0.24%). CTPA was performed in 58 (3.5%) patients, of whom 20 were diagnosed with PE. In groups 1 (n = 34), 2 (n = 21), and 3 (n = 3), CTPA was performed 2.4, 2.6, and 8.3 days after TKA, respectively, and 12, 8, and 0 patients were diagnosed with PE, respectively. Of the 782, 416, and 447 unilateral, simultaneous, and sequential (done in same admission with interval 1 or 2 weeks) patients with TKA, 38, 18, and 2 received CTPA, and 13, 6, and 1 were diagnosed with PE, respectively. All patients diagnosed with PE have persistently low SpO2 < 95% (group 1), or sudden decrease in SpO2 (group 2) until POD2. Of the patients diagnosed with PE, SpO2 decreased without the presentation of symptoms in 16 patients (11 and 5 from groups 1 and 2, respectively) and with the presentation of symptoms, such as mild dyspnea and chest discomfort, in 4 patients (1 and 3 from groups 1 and 2, respectively).

CONCLUSIONS

Measuring SpO2 using a pulse oximeter until POD2 was an effective method for early diagnosis of PE after TKA. No case of morbidity or mortality was observed after early diagnosis with early stage CTPA and management of PE. We recommend measuring SpO2 with a pulse oximeter for early diagnosing of PE in TKA.

Comparison of international guideline recommendations for the diagnosis of pulmonary embolism

Pulmonary embolism is one of the leading causes of death due to cardiovascular disease. Timely diagnosis is crucial, but challenging, as the clinical presentation of pulmonary embolism is unspecific and easily mistaken for other common medical emergencies. Clinical prediction rules and D-dimer measurement allow stratification of patients into groups of expected prevalence and are key elements in adequate selection of patients for diagnostic imaging; however, the strengths and weaknesses of the multiple proposed prediction rules, when to measure D-dimer, and which cutoff to apply might be elusive to a significant proportion of physicians. 13 international guidelines authored by medical societies or expert author groups provide recommendations on facets of the diagnostic investigations in suspected pulmonary embolism, some of which are hallmarked by pronounced heterogeneity. This Review summarises key recommendations of each guideline, considers the most recent evidence on the topic, compares guideline recommendations on each facet of the diagnosis of pulmonary embolism, and provides a synthesis on the most common recommendations.

Multiorgan ultrasonographic findings in patients with pulmonary embolism at diagnosis and clinical follow-up: a proof of concept study

PURPOSE

The purpose of this descriptive feasibility study was to assess the clinical impact and feasibility of conducting a multiorgan ultrasound examination of patients with pulmonary embolism at both time of diagnosis and at clinical follow-up.

METHODS

Hemodynamically stable patients with pulmonary embolism verified by CT pulmonary angiography or ventilation perfusion scintigraphy were eligible for inclusion. Enrolled patients underwent multiorgan ultrasound investigation encompassing echocardiography supplemented with focused lung and deep venous ultrasound emphasizing right ventricular strain, subpleural consolidations and presence of deep venous thrombi. Identical investigations were conducted at 3 months follow-up. The presence of ultrasonographic findings at diagnosis and follow-up was compared and the clinical impact of any remaining pathology or strain was described.

RESULTS

Twenty-one patients were enrolled in the study of whom 20 survived to attend follow-up. Mean age was 62 ± 15 years and 48% were female. At diagnosis, the most prevalent ultrasonographic findings were subpleural consolidations in 11 patients and right ventricular dilation in eight. At follow-up, signs of right ventricular strain had resolved in all patients. However, in one patient, no resolution was seen in a subpleural consolidation observed at the time of pulmonary embolism diagnosis, resulting in referral to a chest CT. Additionally, one patient exhibited residual deep venous thrombotic material, leading to prolongation of anticoagulative treatment.

CONCLUSION

In patients with pulmonary embolism, multiorgan ultrasound is feasible in follow-up and adequately powered studies should determine the clinical utility of such an approach.

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

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

Pulmonary embolism presenting as delirium: an acute confusional state in an elderly patient-a case report

Background

Large numbers of elderly patients are admitted to hospitals in acute confusional states. In many, the underlying causes are easily found; in some, correct diagnosis is difficult. Pulmonary embolism (PE), the most serious clinical presentation of venous thromboembolism, is often misdiagnosed because of its non-specific features including delirium.

Case presentation

A 73-year-old woman was admitted to our hospital in a confused state with no obvious risk factors of PE. D-dimer levels were elevated and contrast-enhanced high-resolution computed tomography (HRCT) of the chest confirmed the diagnosis of PE. She was treated with enoxaparin and discharged on dabigatran. Her symptoms had resolved at the time of discharge, and she has been stable for over three month's follow-up visit.

Conclusion

PE should be regarded as a differential in elderly patients with an acute confusional state despite the absence of obvious risk factors. Investigating for and treating when confirmed may save a life.

Diagnostic accuracy of focused deep venous, lung, cardiac and multiorgan ultrasound in suspected pulmonary embolism: a systematic review and meta-analysis

OBJECTIVE

To determine the diagnostic accuracy of point-of-care ultrasound in suspected pulmonary embolism.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

MEDLINE, Embase, CINAHL and Cochrane library were searched on 2 July 2020 with no restrictions on the date of publication. Subject headings or subheadings combined with text words for the concepts of pulmonary embolism, ultrasound and diagnosis were used.

ELIGIBILITY CRITERIA AND DATA ANALYSIS

Eligible studies reported sensitivity and specificity of deep venous, lung, cardiac or multiorgan ultrasound in patients with suspected pulmonary embolism, using an adequate reference-test. Prospective, cross-sectional and retrospective studies were considered for eligibility. No restrictions were made on language. Studies were excluded if a control group consisted of healthy volunteers or if transesophageal or endobronchial ultrasound was used. Risk of bias was assessed using quality assessment of diagnostic accuracy studies-2. Meta-analysis of sensitivity and specificity was performed by construction of hierarchical summary receiver operator curves. I² was used to assess the study heterogeneity.

MAIN OUTCOME MEASURES

The primary outcome was overall sensitivity and specificity of reported ultrasound signs, stratified by organ approach (deep venous, lung, cardiac and multiorgan). Secondary outcomes were stratum-specific sensitivity and specificity within subgroups defined by pretest probability of pulmonary embolism.

RESULTS

6378 references were identified, and 70 studies included. The study population comprised 9664 patients with a prevalence of pulmonary embolism of 39.9% (3852/9664). Risk of bias in at least one domain was found in 98.6% (69/70) of included studies. Most frequently, 72.8% (51/70) of studies reported >24 hours between ultrasound examination and reference test or did not disclose time interval at all. Level of heterogeneity ranged from 0% to 100%. Most notable ultrasound signs were bilateral compression of femoral and popliteal veins (22 studies; 4708 patients; sensitivity 43.7% (36.3% to 51.4%); specificity 96.7% (95.4% to 97.6%)), presence of at least one hypoechoic pleural-based lesion (19 studies; 2134 patients; sensitivity 81.4% (73.2% to 87.5%); specificity 87.4% (80.9% to 91.9%)), D-sign (13 studies; 1579 patients; sensitivity 29.7% (24.6% to 35.4%); specificity 96.2% (93.1% to 98.0%)), visible right ventricular thrombus (5 studies; 995 patients; sensitivity 4.7% (2.7% to 8.1%); specificity 100% (99.0% to 100%)) and McConnell's sign (11 studies; 1480 patients; sensitivity 29.1% (20.0% to 40.1%); specificity 98.6% (96.7% to 99.4%)).

CONCLUSION

Several ultrasound signs exhibit a high specificity for pulmonary embolism, suggesting that implementation of ultrasound in the initial assessment of patients with suspected pulmonary embolism may improve the selection of patients for radiation imaging.

PROSPERO REGISTRATION NUMBER

CRD42020184313.

Sudden Death in Adults: A Practical Flow Chart for Pathologist Guidance

The medico-legal term "sudden death (SD)" refers to those deaths that are not preceded by significant symptoms. SD in apparently healthy individuals (newborn through to adults) represents a challenge for medical examiners, law enforcement officers, and society as a whole. This review aims to introduce a useful flowchart that should be applied in all cases of SD. Particularly, this flowchart mixes the data obtained through an up-to-date literature review and a revision of the latest version of guidelines for autopsy investigation of sudden cardiac death (SCD) in order to support medico-legal investigation. In light of this review, following the suggested flowchart step-by-step, the forensic pathologist will be able to apply all the indications of the scientific community to real cases. Moreover, it will be possible to answer all questions relative to SD, such as: death may be attributable to cardiac disease or to other causes, the nature of the cardiac disease (defining whether the mechanism was arrhythmic or mechanical), whether the condition causing SD may be inherited (with subsequent genetic counseling), the assumption of toxic or illicit drugs, traumas, and other unnatural causes.

Safety of exercise therapy after acute pulmonary embolism

OBJECTIVE

The role of exercise therapy after acute pulmonary embolism (PE) is unknown. Exercise therapy is safely used after myocardial infarction and chronic obstructive pulmonary disease. The aim of this study was to investigate the safety of exercise therapy after acute PE.

METHODS

We implemented a 3-month exercise program after acute PE. Outcomes were death, bleeding, readmissions, recurrent events, changes in peak VO2 and quality of life (QoL).

RESULTS

A total of 23 patients were enrolled and received anticoagulation; no adverse events were reported during the exercise period. One death, 1 DVT and 5 readmissions were reported due to non-exercise related reasons. Functional capacity improved as evidenced by an increased peak VO2 at 3 months (+3.9 ± 5.6 mL/kg/min; p = 0.05). Improvement in QoL was observed at 6-months on the functional (+17.0 ± 22.6, p = 0.03) and physical health factor scales (+0.9 ± 4.6, p = 0.03).

CONCLUSION

Exercise therapy is feasible and safe in appropriately anticoagulated patients after PE.

Ambulatory management of pulmonary embolism

The diagnosis of pulmonary embolism can be very difficult and elusive. It depends greatly on the use of diagnostic tests, which are in turn interpreted according to a pre-test clinical probability. These include non-specific tests such as the chest X-ray and electrocardiograph, which help exclude other conditions such as pneumonia or myocardial infarction. On the other hand, more specific tests such as computed tomography or ventilation/perfusion scanning are used to confirm or exclude the diagnosis of pulmonary embolism. The condition is potentially fatal, and in the past patients with suspected pulmonary embolism constituted a significant number of hospital admissions. Despite this, the majority were found not to have pulmonary embolism. More recently, studies have suggested that most patients with suspected pulmonary embolism who are haemodynamically stable can be safely managed on an ambulatory pathway. Therefore, there is a paradigm shift towards investigating and treating pulmonary embolism in the outpatient setting. This article discusses the ambulatory pathway of the diagnosis and treatment of pulmonary embolism.

Incidental pulmonary emboli in stage IV melanoma patients: Prevalence in CT staging examinations and improved detection with vessel reconstructions based on dual energy CT

OBJECTIVES

Malignancy is the strongest predictor for venous thromboembolism. Dual energy CT (DECT) can support assessment of pulmonary emboli (PE) by providing vessel reconstructions (DECT-VR) and highlighting thrombi. Purpose was to determine prevalence and risk factors of PE in staging examinations of stage IV-melanoma patients and to evaluate the potential of DECT-VR to improve PE diagnosis.

MATERIAL AND METHODS

This retrospective study was approved by IRB. Contrast-enhanced, conventional grey scale CT (cCT) and DECT-VR of 200 stage IV-melanoma patients were reviewed by three radiologists in consensus. Overall prevalence was determined. One-sided Wilcoxon-test was performed to compare the number of detected emboli between cCT and cCT with supplementary DECT-VR. Frequencies of risk factors were compared with χ2 test.

RESULTS

On cCT, 9 PE were detected (6 patients, correlating to 3% of the study population with 0.05 emboli per patient). With the supplementary DECT-VR, number of diagnosed emboli increased from 9 to 17 (p < 0.05) (in total 9 patients, correlating to 0.09 emboli per patient). Emboli on DECT-VR were mainly subsegmentally (7 of 8). There was no significant difference in the frequency of risk factors.

CONCLUSIONS

The prevalence of pulmonary emboli in our cohort of 200 stage IV melanoma patients was 5%. DECT-VR improved significantly diagnosis of PE, especially when located subsegmentally.

Pulmonary thromboembolism: new diagnostic imaging techniques

The accurate diagnosis of pulmonary thromboembolism is essential to reducing the morbidity and mortality associated with the disease. The diagnosis of pulmonary thromboembolism is challenging because of the nonspecific nature of the clinical profile and the risk factors. Imaging methods provide the definitive diagnosis. Currently, the imaging method most commonly used in the evaluation of pulmonary thromboembolism is computed tomography. The recent development of dual-energy computed tomography has provided a promising tool for the evaluation of pulmonary perfusion through iodine mapping. In this article, we will review the importance of diagnosing pulmonary thromboembolism, as well as the imaging methods employed, primarily dual-energy computed tomography.

Acute Pulmonary Embolism: Focus on the Clinical Picture

Acute pulmonary embolism (APE) is characterized by numerous clinical manifestations which are the result of a complex interplay between different organs; the symptoms are therefore various and part of a complex clinical picture. For this reason, it may not be easy to make an immediate diagnosis. This is a comprehensive review of the literature on all the various clinical pictures in order to help physicians to promptly recognize this clinical condition, remembering that our leading role as cardiologists depends on and is influenced by our knowledge and working methods.

Autopsy findings in an atypical case of occult massive fatal pulmonary embolism in a backdrop of hyperhomocysteinemia

A 43-year-old apparently healthy male presented with fever and presyncope. He was suspected to have massive pulmonary thromboembolism based on the clinico-biochemical profile. Despite aggressive thrombolytic therapy, he succumbed to his illness within 12 h of admission. Postmortem examination showed massive pulmonary thromboembolism and hyperhomocysteinemia with low high-density lipoproteins (HDL) cholesterol with antemortem blood sample. Herein, we report autopsy findings in a rare case of a young male with occult massive pulmonary thromboembolism without deep vein thrombosis, who had an atypical clinical presentation and was found to have underlying hyperhomocysteinemia and decreased HDLc. An acute, massive PE can present a diagnostic challenge due to the rate and severity of decompensation seen in afflicted patients. A high index of suspicion is required for early detection of pulmonary embolism in a young patient with atypical presentation and without obvious risk factors.

Clinical Significance of Late Phase of Lung Perfusion Blood Volume (Lung Perfusion Blood Volume) Quantified by Dual-Energy Computed Tomography in Patients With Pulmonary Thromboembolism

PURPOSE

Using dual-energy computed tomography (DECT), we quantified the lung perfusion blood volume (PBV) in the late phase, which may reflect both the pulmonary artery and systemic collateral flow. We then investigated the clinical significance of late-phase lung PBV values.

MATERIALS AND METHODS

We retrospectively studied 206 patients (266 scans) who underwent early-phase and late-phase DECT. The patients were divided into 2 groups depending on whether or not they had pulmonary thromboembolism (PTE) (n=94 and 112). Patients with PTE were further divided into 2 subgroups, depending on whether they had acute PTE or chronic PTE (n=66 and 28). Pulmonary artery enhancement (PAenh) was measured on DECT. We then calculated the [lung PBV/PAenh] ratio in all patients during both the early and late phases for adjustment of timing.

RESULTS

The [late-phase lung PBV/PAenh] ratio was 0.092±0.029 in the group with PTE and 0.108±0.030 in the group without PTE, showing a significant difference between the 2 groups (P<0.0001). The [early-phase lung PBV values/PAenh]/[late-phase lung PBV values/PAenh] ratio was 0.68±0.19 and 0.84±0.20, respectively, also showing a significant difference between the 2 groups (P<0.0001). Finally, the [early-phase lung PBV/PAenh]/[late-phase lung PBV/PAenh] ratio was 0.71±0.19 in patients with acute PTE and 0.56±0.16 in patients with chronic PTE, and there was a significant difference between these 2 subgroups (P=0.0004).

CONCLUSIONS

It may be useful to determine late-phase lung PBV values in patients with PTE, because this parameter may reflect the systemic collateral flow, which is increased in chronic PTE.

Usefulness of a Low Tube Voltage: Knowledge-Based Iterative Model Reconstruction Algorithm for Computed Tomography Venography

OBJECTIVES

The objective of this study was to evaluate the use of 80-kVp scans with knowledge-based iterative model reconstruction (IMR) for computed tomography venography (CTV).

METHODS

This prospective study received institutional review board approval; a previous informed consent was obtained from all participants. We enrolled 30 patients with suspected deep venous thrombosis or pulmonary embolism who were to undergo 80-kVp CTV studies. The images were reconstructed with filtered back projection (FBP), hybrid iterative reconstruction (HIR), and IMR. The venous attenuation, image noise, and contrast-to-noise ratio at the iliac, femoral, and popliteal veins were compared on FBP, HIR, and IMR images. We performed qualitative image analysis (image noise, image contrast, image sharpness, streak artifacts, and overall image quality) of the 3 reconstruction methods and measured their reconstruction times.

RESULTS

There was no significant difference in venous attenuation among the 3 reconstruction methods (P > 0.05). On IMR images, the image noise was lowest at all 3 venous locations, and the contrast-to-noise ratio was highest. Qualitative evaluation scores were also highest for IMR images. The reconstruction time for FBP, HIR, and IMR imaging was 25.4 ± 1.9 seconds, 43.3 ± 3.3 seconds, and 78.7 ± 6.0 seconds, respectively.

CONCLUSIONS

At clinically acceptable reconstruction times, 80-kVp CTV using the IMR technique yielded better qualitative and quantitative image quality than HIR and FBP.

The prevalence and radiological findings of pulmonary embolism in HIV-positive patients referred for computed tomography pulmonary angiography in the Western Cape of South Africa

Aim:

To provide imaging data and report associations between human immunodeficiency virus (HIV), tuberculosis (TB) and pulmonary embolism (PE) in a South African population that underwent computed tomography pulmonary angiography (CTPA) for suspected PE.

Methods:

A validated Qanadli severity scoring system for PE was used for 164 CTPA scans, and parenchymal, pleural and cardiovascular complications were reported. Serological confirmation of HIV testing and microbiological confirmation of TB were recorded.

Results:

Prevalence of PE in the CTPA population was 26% (95% CI: 19.67–33.65%). HIV-positive prevalence in patients with PE was 67% (95% CI: 48.17–82.04%), however it was not statistically significantly different when compared with the patients without PE (p = 1). HIV-positive patients had more extensive partial thrombus in the right middle lobe (p = 0.045), but no other differences when compared with HIV-negative patients. TB prevalence in patients with PE was 57% (95% CI: 34.49–76.81%). This was statistically significantly different when compared with the patients without PE (p = 0.073 at the 10% level). Prevalence of TB co-morbidity in the HIV-positive group with proven PE was 71% (95% CI: 41.90– 91.61%), however there was no statistically significant difference in comparison with the HIV-negative patients with TB and PE (p= 0.305).

Conclusion:

The high number of patients presenting for CTPA who were HIV infected (and also infected with TB) highlights that PE evaluation should include severity/extent of the disease, as these patients may have more severe disease in specific lung lobes. The use of a validated scoring system, such as the Qanadli score, when reporting PE may have a profound effect on patient risk stratification, management and prognosis and would also provide a system for collecting larger volumes of data for analysis.

Occult Lung Cancer Occluding a Pulmonary Vein with Suspected Venous Infarction, Mimicking Pneumonia and a Pulmonary Embolus

BACKGROUND

Patients with lung cancer present to the emergency department (ED) in a variety of ways. Symptoms are often nonspecific and can lead to a delay in diagnosis. Here, a lung cancer mimicked two illnesses, adding to the diagnostic complexity. This case highlights diagnostic pitfalls as well as advantages and limitations of imaging utilized in the emergency setting.

CASE REPORT

We report a case of an occult lung cancer occluding a pulmonary vein, which at first mimicked pneumonia and later a pulmonary embolism (PE) and arterial lung infarction. The patient presented to the ED with cough and a lung opacity on chest radiograph that was treated with antibiotics. However, recurrent visits to the ED with similar complaints were further investigated with computed tomography angiogram (CTA). At first the scan was considered positive for PE. Further inspection revealed that the CTA findings were not typical for PE, but rather a slow flow state likely caused by an occult mass occluding a pulmonary vein with venous infarction. Biopsy revealed a lung adenocarcinoma. In addition to the case presentation, the typical signs of PE on CTA with correlating images and diagnostic pitfalls are discussed. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: This case report raises two themes that can be of interest to emergency physicians. The first is that lung cancer has many guises. Here it mimicked two distinctly different diseases, pneumonia and PE. The second is that, although CTA is highly sensitive and specific for diagnosing PE, it has limitations that may lead to false positive readings. When clinical signs and symptoms fail to correlate with the imaging diagnosis, alternative explanations should be sought.

Genetic association of PROC variants with pulmonary embolism in Northern Chinese Han population

To evaluate SNPs (single nucleotide polymorphism) in PROC (protein C gene) associated with pulmonary embolism (PE) susceptibility in North Chinese Han population. A case-control study design was used, and patients with PE and healthy participants were enrolled from the Emerging Department of the several hospitals in Weifang, Shandong, China. SNPs in PROC were genotyped using Mass ARRAY system. The allele frequency of rs199469469 was significantly different between PE patients and the control [OR (95 % CI) = 5.00 (1.66-15.12), P = 0.004], and the difference remained significantly after controlling for age and gender [OR (95 % CI) = 5.34 (1.47-19.39), P = 0.011). The G(del)G in the haplotype includes rs1799809|rs199469469|rs2069928 was of a significantly difference (P = 0.016) among PE patients and the controls, and remained significant (P = 0.015) after adjustment for age and sex. Our study reports that PROC SNPs (rs199469469) might be associated with PE susceptibility, with the G allele of rs199469469 serving as the protective factors for incidence of PE. These findings may contribute to the understanding and primary prevention of PE.

Venous thromboembolism after surgical treatment of non-spinal skeletal metastases - An underdiagnosed complication

INTRODUCTION AND AIM

Venous thromboembolism (VTE) is a severe complication associated both with major orthopaedic surgery and cancer. However, survival and postoperative complications of skeletal metastases despite their thrombogenic potential, have received little attention in both the clinical management and research setting. This single-centre observational cohort study aimed to evaluate the incidence and impact of VTE in association with cancer surgery targeted to the management of fractures secondary to skeletal metastases.

METHODS

Data were collected retrospectively from the medical database. We included consecutive 306 patients operated for 343 non-spinal skeletal metastases during a 15-year period (1999-2014). The incidence of VTE and its risk factors were assessed using binary logistic regression analysis. Kaplan-Meier and Cox regression analyses were used to evaluate variables affecting survival.

RESULTS

The rate of symptomatic VTE was 10% (30/306) during the 3-month postoperative period, while 79% received thromboprophylaxis. Fatal pulmonary embolism (PE) rate was high, 3.3% (10/306) after surgery. Intraoperative oxygen saturation drop, pulmonary metastases and intramedullary nailing were independent risk factors for VTE. Indicators of decreased survival were lung cancer, intramedullary nailing, multiple skeletal and pulmonary metastases, anaemia, leukocytosis, and PE.

CONCLUSION

Relationship between fractures secondary to skeletal metastases and VTE needs further clinical attention. Whether the survival of patients with fractures secondary to skeletal metastases can be improved by targeted thromboprophylactic means should be studied further.

Prognostic value of Tpeak-Tend interval in patients with acute pulmonary embolism

Background

The aim of this study was to examine the Tpeak-Tend (Tpe/corrected Tpe) interval, which is an indicator of transmural myocardial repolarization, measured non-invasively via electrocardiogram in patients with acute pulmonary embolism (PE), and to investigate the relationship with 30-day mortality and morbidity.

Methods

The study included 272 patients diagnosed with acute PE, comprising 154 females and 118 males, with a mean age of 63.1 ± 16.8 years. Tpe/cTpe intervals were calculated from the electrocardiograms with a computer program after using a ruler or vernier caliper manual measuring tool to obtain highly sensitive measurements. The relationship between the electrocardiogram values and 30-days mortality and morbidity were measured.

Results

The study group was divided into three groups according to cTpe intervals: Group 1, < 113 ms; Group 2, 113–133 ms; and Group 3, > 133 ms. White blood cell count and troponin T levels, corrected QT intervals with QRS complex durations, percentage of right ventricle dilatation with right/left-ventricular ratio, 30-day death, and combinations of these values were seen at a higher rate in Group 3 patients compared to the other groups. Kaplan–Meier analysis showed that the cTpe interval measured at > 126 ms could be used as a cut-off value in the prediction of mortality and morbidity. The cTpe cut-off values of 126 ms had sensivity, specificity, negative predictive value, and positive predictive value of 80.56 %, 59.32 %, 95.2 %, and 23.2 %, respectively.

Conclusions

cTpe interval could be a useful method in early risk stratification in patients with acute PE.

Caution for acute submassive pulmonary embolism with syncope as initial symptom: a case report

Pulmonary embolism (PE) may escape prompt diagnosis since clinical symptoms and signs are nonspecific. The occurrence of syncope as the sole initial symptom in a previously healthy patient with no predisposing factors to embolism and no hemodynamic instability is extremely rare, which may have been a factor in the delayed diagnosis. We describe a case of acute submassive PE with syncope as the initial symptom. A 62-year-old previously healthy female was admitted to our hospital for transitory episode of syncope. Following admission, chest computed tomography demonstrated embolism in the right main pulmonary and left inferior pulmonary arteries. Following the final diagnosis, the patient was successfully treated with thrombolytic therapy with systemic urokinase. We consider that raised awareness and early diagnosis and treatment were key factors in ensuring a satisfactory prognosis.

The use of oral anticoagulants for the treatment of venous thromboembolic events in an ED

Venous thromboembolism (VTE) is a disease spectrum that ranges from deep vein thrombosis (DVT) to pulmonary embolism (PE). Rapid diagnosis and treatment of VTE by emergency care providers are critical for decreasing patient mortality, morbidity, and the incidence of recurrent events. Recent American College of Chest Physicians guidelines recommend initial treatment with unfractionated heparin, low-molecular weight heparin, or fondaparinux overlapped with warfarin for a minimum of 5 days for the treatment of VTE in most cases. Warfarin monotherapy is thereafter continued for 3, 6, or 12 months. These guidelines were published before the approval of target-specific oral anticoagulants (TSOACs), and they have yet to be updated to reflect these new treatment options. For some patients, TSOACs, which act by directly inhibiting factor IIa or factor Xa, may provide safer, more convenient alternatives to warfarin. Their advantages include ease of use, reduced monitoring requirements, and lower bleeding risk than traditional therapy. Additionally, clinical trials have established noninferiority of TSOACs to warfarin for the prevention of recurrent VTE. These trials have demonstrated that TSOACs exhibit similar or lower bleeding rates, particularly intracranial bleeding rates compared with warfarin. Anticoagulation therapy with TSOACs may allow early discharge or outpatient management options for low-risk patients with DVT and PE. This review addresses the importance of early diagnosis and treatment of VTE, outcomes of VTE risk assessment, key efficacy and safety data from phase 3 clinical trials for the various TSOACs for the treatment of DVT and PE, and the corresponding considerations for clinical practice.

Effective diagnosis and treatment of pulmonary embolism: Improving patient outcomes

Pulmonary embolism can be life threatening and difficult to diagnose as signs and symptoms are not specific. European guidelines recommend stratification of pulmonary embolism by risk of early mortality. Patients with suspected pulmonary embolism should be assessed for clinical probability of pulmonary embolism using a validated risk score. A low or intermediate clinical probability plus a negative high-sensitivity D-dimer test excludes pulmonary embolism. Anticoagulation is indicated in patients with a positive multidetector computed tomography or high-probability lung scan. An important part of the management of patients with pulmonary embolism has traditionally been anticoagulant treatment with parenteral heparins and oral vitamin K antagonists. Although effective, this dual-drug approach is associated with limitations. Direct oral anticoagulants that may overcome some of these problems have been tested in phase III clinical trials for the treatment of venous thromboembolism. Of these, rivaroxaban and apixaban have demonstrated non-inferiority to standard therapy when given as single-drug approaches for venous thromboembolism treatment, and provided significant reductions in major bleeding rates. Dabigatran and edoxaban were non-inferior to standard therapy when given as part of a dual-drug approach after initial parenteral anticoagulation, and reduced clinically relevant bleeding rates. There may be a benefit to extended anticoagulation with direct oral anticoagulants for the prevention of recurrent venous thromboembolism. Registry studies will provide more information on the use of these agents in real-world populations. Accurate diagnosis and risk stratification of patients with pulmonary embolism, together with simplified anticoagulation therapy, is likely to improve outcomes.

Pulmonary embolism in elderly patients: prognostic impact of the Cumulative Illness Rating Scale (CIRS) on short-term mortality

BACKGROUND

Pulmonary embolism (PE) is associated with high short-term mortality in elderly patients, even when hemodynamically stable.

METHODS

One hundred and seventy hemodynamically stable patients with confirmed PE (41<65years and 129≥65years) were prospectively followed for one month in order to assess whether comorbidities can predict short-term mortality in elderly patients. Upon admission, patients' clinical characteristics (including instrumental and laboratory parameters) were evaluated, and two clinical scores were calculated: the Cumulative Illness Rating Scale (CIRS), commonly used to evaluate comorbidities in elderly patients, and the Pulmonary Embolism Severity Index (PESI).

RESULTS

Fifteen patients (all elderly) died within one month from their PE diagnosis (mortality rate=8.8%; 95%CI:4.6-13.1%). In these non survivors, arterial partial oxygen pressure (p<0.0001) and saturation (p<0.0001), pH (p=0.001) and systolic blood pressure (p=0.017) at admission were significantly lower than in survivors, whereas their respiratory rate (p<0.0001), white blood cells (p<0.0001), lactate dehydrogenase (p<0.0001), troponin T (p=0.001) and D-dimer (p=0.023) were significantly higher. CIRS correlated with PESI (rho=0.54, p<0.0001), and was higher in non-survivors (p=0.002). The age- and sex-adjusted odds ratio of 1-month mortality was 1.91 (95%CI:1.24-2.95) for every 1-point increase in CIRS. The AUC was 0.78 (95%CI:0.67-0.89) for the logistic model containing CIRS, and 0.88 (95%CI:0.79-0.96) for that containing PESI (p=0.059).

CONCLUSIONS

In elderly patients with PE, CIRS demonstrated a fairly good performance in predicting short-term mortality. Its easiness and suitability for use in common clinical practice make CIRS a potentially useful prognostic score for short-term mortality in these patients.

Lung ischaemia-reperfusion injury in a canine model: dual-energy CT findings with pathophysiological correlation

OBJECTIVE

To evaluate dual-energy CT (DECT) findings of pulmonary ischaemic-reperfusion injury (PIRI) and its pathophysiological correlation in the canine model.

METHODS

A PIRI model was established in 11 canines, utilizing closed pectoral balloon occlusion. Two control canines were also included. For the PIRI model, the left pulmonary artery was occluded with a balloon, which was deflated and removed after 2 h. DECT was performed before, during occlusion and at 2, 3 and 4 h thereafter and was utilized to construct pulmonary perfusion maps. Immediately after the CT scan at the fourth hour post reperfusion, the canines were sacrificed, and lung specimens were harvested for pathological analysis. CT findings, pulmonary artery pressure and blood gas results were then analysed.

RESULTS

Data at every time point were available for 10 animals (experimental group, n = 8; control group, n = 2). Quantitative measurements from DECT pulmonary perfusion maps found iodine attenuation values of the left lung to be the lowest at 2 h post embolization and the highest at 1 h post reperfusion. In the contralateral lung, perfusion values also peaked at 1 h post reperfusion. Continuous hypoxia and acid-based disorders were observed during PIRI, and comprehensive analysis showed physiological changes to be worst at 3 h post reperfusion.

CONCLUSION

DECT pulmonary perfusion mapping demonstrated pulmonary perfusion of the bilateral lungs to be the greatest at 1 h post reperfusion. These CT findings corresponded with pathophysiological changes.

ADVANCES IN KNOWLEDGE

DECT pulmonary perfusion mapping can be used to evaluate lung ischaemia-reperfusion injury.

Thromboprophylaxis use and concordance with guidelines among medical and surgical patients in Morocco

INTRODUCTION

No data are available on thromboprophylaxis use in Morocco. Our aim was to characterize patients at risk of venous thromboembolism and assess the rate of appropriate thromboprophylaxis.

MATERIALS AND METHODS

This was a national, observational, multicentre survey of venous thromboembolism risk and thromboprophylaxis use in hospitalized patients. Data were collected on a predefined date in three university hospitals in Morocco using a standardized pre-printed form. Thromboembolic risk was assessed according to the American College of Chest Physicians (ACCP) 2008 guidelines. Patients were classified as "thromboprophylaxis indicated" or "thromboprophylaxis not indicated".

RESULTS

784 patients were analysed: 307 (39.2%) medical and 477 (60.8%) surgical. 421 (53.7%) were female. Medical patients were older than surgical patients (57.6 ± 11.5 vs. 46.2 ± 16.9 years, p<0.0001) and were more likely to have risk factors for thromboembolism (50.5% vs. 45.7% of patients, p=NS). 57% of patients without contraindications or bleeding risk were at risk of thromboembolism according to ACCP guidelines and thromboprophylaxis was prescribed to 42.8% of these patients. In contrast, 7.4% of patients with no thromboembolic risk also received thromboprophylaxis (proportion agreement: 61.0%; Kappa=0.296). Over half (54.5%) of medical patients at risk of thromboembolism did not receive thromboprophylaxis whereas 6.3% of those with no risk did receive it (proportion agreement: 76.4%; Kappa=0.433). These figures were 57.9% and 9.2%, respectively, for surgical patients (proportion agreement: 52.7%; Kappa=0.191). Thromboprophylaxis was given to 19.2% of patients with contraindications or a bleeding risk.

CONCLUSIONS

Educational initiatives are imperative to inform doctors about appropriate thromboprophylaxis.

Dual-energy CT based vascular iodine analysis improves sensitivity for peripheral pulmonary artery thrombus detection: an experimental study in canines

PURPOSE

To evaluate the performance of dual-energy CT (DECT) based vascular iodine analysis for the detection of acute peripheral pulmonary thrombus (PE) in a canine model with histopathological findings as the reference standard.

MATERIALS AND METHODS

The study protocol was approved by our institutional animal committee. Thrombi (n = 12) or saline (n = 4) were intravenously injected via right femoral vein in sixteen dogs, respectively. CT pulmonary angiography (CTPA) in DECT mode was performed and conventional CTPA images and DECT based vascular iodine studies using Lung Vessels application were reconstructed. Two radiologists visually evaluated the number and location of PEs using conventional CTPA and DECT series on a per-animal and a per-clot basis. Detailed histopathological examination of lung specimens and catheter angiography served as reference standard. Sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) of DECT and CTPA were calculated on a segmental and subsegmental or more distal pulmonary artery basis. Weighted κ values were computed to evaluate inter-modality and inter-reader agreement.

RESULTS

Thirteen dogs were enrolled for final image analysis (experimental group = 9, control group = 4). Histopathological results revealed 237 emboli in 45 lung lobes in 9 experimental dogs, 11 emboli in segmental pulmonary arteries, 49 in subsegmental pulmonary arteries, 177 in fifth-order or more distal pulmonary arteries. Overall sensitivity, specificity, accuracy, PPV, and NPV for CTPA plus DECT were 93.1%, 76.9%, 87.8%, 89.4%, and 84.2% for the detection of pulmonary emboli. With CTPA versus DECT, sensitivities, specificities, accuracies, PPVs, and NPVs are all 100% for the detection of pulmonary emboli on a segmental pulmonary artery basis, 88.9%, 100%, 96.0%, 100%, and 94.1% for CTPA and 90.4%, 93.0%, 92.0%, 88.7%, and 94.1% for DECT on a subsegmental pulmonary artery basis; 23.8%, 96.4%, 50.4%, 93.5%, and 36.7% for CTPA and 95.9%, 75.5%, 88.2%, 86.5%, and 91.9% on a sub-subsegmental and more distal pulmonary artery basis, respectively. Good inter-modality (κ = 0.65, P<0.001) and inter-reader (κ = 0.70, P<0.001) agreement were observed.

CONCLUSION

With histopathological findings as the reference standard, DECT based vascular iodine analysis improves the sensitivity for detecting peripheral PE compared with CTPA, albeit at the price of decreased specificity and PPV.

Thromboembolic complications in nephrotic syndrome: imaging spectrum

Thromboembolism is a well-known complication of nephrotic syndrome. Pulmonary embolism, renal vein thrombosis, and deep vein thrombosis are the most common venous thromboembolic diseases in patients with nephrotic syndrome, while arterial thromboembolic complications are observed less frequently. Imaging plays an important role in the detection and follow-up of thromboembolism in these patients. The purpose of this essay is to describe the epidemiology, pathophysiological mechanisms, the imaging diagnosis, and treatment of thromboembolism in patients with nephrotic syndrome.

Pulmonary thromboembolism presenting with abdominal symptoms

Background:

Abdominal pain is rarely reported as the presenting complaint of pulmonary thromboembolism.

Case Report:

We report a case of a 42 year old white male with no known past medical problems except a left humeral fracture two weeks prior who presented to the emergency department with acute onset of right flank and lower abdominal pain. Initial evaluation including abdominal CT suggested cholecystitis. Lack of improvement with empiric antibiotics and symptomatic therapy prompted further evaluation revealing the patient to have a pulmonary thromboembolism (PTE).

Conclusions:

Pulmonary thromboembolism (PTE) can be effectively treated once diagnosed. Abdominal pain as a presenting complaint in PTE is rarely reported as a cause of PTE. We believe that clinicians should consider PTE in their differential of abdominal pain in patients with risk factors for VTE.

MR imaging of pulmonary embolism: diagnostic accuracy of contrast-enhanced 3D MR pulmonary angiography, contrast-enhanced low-flip angle 3D GRE, and nonenhanced free-induction FISP sequences

PURPOSE

To evaluate relative detection of pulmonary embolism (PE) with standard bolus-triggered contrast-enhanced breath-hold magnetic resonance (MR) pulmonary angiography, contrast-enhanced recirculation-phase breath-hold low-flip angle three-dimensional (3D) gradient-echo (GRE), and nonenhanced free-induction cardiac- and respiratory-triggered true fast imaging with steady-state precession (FISP) MR sequences.

MATERIALS AND METHODS

The study was HIPAA compliant and institutional review board approved. Twenty-two patients with a computed tomographic (CT) angiography diagnosis of PE underwent MR imaging within 48 hours of CT. MR included three complementary techniques: MR pulmonary angiography, 3D GRE, and triggered true FISP. Each sequence was analyzed separately by two independent reviewers who recorded presence of emboli in categorized pulmonary artery anatomic territories. CT angiography results were analyzed by a third independent reviewer, who retrospectively recorded presence of emboli using the same format; these results served as the reference standard. Sensitivity, specificity, and positive and negative predictive values for PE detection were calculated for each MR technique on a per-embolus basis, and 95% confidence intervals were calculated according to the efficient-score method. A two-sample t test was used to compare values among MR techniques.

RESULTS

Sensitivities for PE detection were 55% for MR pulmonary angiography, 67% for triggered true FISP, and 73% for 3D GRE MR imaging. Combining all three MR sequences improved overall sensitivity to 84%. Specificity was 100% for all detection methods except for MR pulmonary angiography (one false-positive). Agreement between readers was high (κ = 0.87). Embolus detection rates were lowest in the lingula branch for all MR sequences compared with remainder of the vascular territories (P = .07).

CONCLUSION

There are complementary benefits to combining standard MR pulmonary angiography, 3D GRE, and triggered true FISP MR examinations for evaluation of PE.

Pulmonary embolism

Pulmonary embolism (PE) remains one of the most challenging medical diseases in the emergency department. PE is a potentially life threatening diagnosis that is seen in patients with chest pain and/or dyspnea but can span the clinical spectrum of medical presentations. In addition, it does not have any particular clinical feature, laboratory test, or diagnostic modality that can independently and confidently exclude its possibility. This article offers a review of PE in the emergency department. It emphasizes the appropriate determination of pretest probability, the approach to diagnosis and management, and special considerations related to pregnancy and radiation exposure.

Acute and subacute dual energy CT findings of pulmonary embolism in rabbits: correlation with histopathology

OBJECTIVE

The purpose of this study was to describe quantitative dual energy CT (DECT) findings and their accuracy in the detection of acute and subacute pulmonary embolism (PE) in rabbits.

METHODS

Pulmonary emboli were created in 24 rabbits by gelatin sponge femoral vein injection. Conventional CT pulmonary angiography (CTPA) and DECT were obtained at either 2 h, 1 day, 3 days or 7 days after embolisation (n=6 rabbits for each time point). The location and number of PEs in the different stages were recorded at CTPA and iodine maps from DECT on a per-lobe basis. With histopathology as the reference standard, sensitivity and specificity of CTPA and DECT were calculated. CT and iodine map overlay values of the embolic and non-embolic areas were measured for each scan.

RESULTS

With histopathology as the reference standard, the overall sensitivity and specificity of CTPA were 98% and 100% and those of iodine maps were 100% and 95%, respectively. Conventional CT and iodine map values of the embolised and non-embolised areas were significantly different between 2 h and 1 day (p<0.001), but not between 3 days and 7 days (p>0.05). A statistical difference was found for overlay values measured in the embolic and non-embolic regions for four groups.

CONCLUSION

Iodine maps derived from DECT show alterations in lung perfusion for acute and subacute PE in an experimental rabbit model and show comparable sensitivity for PE detection and conventional CTPA.

Dual-energy computed tomography in pulmonary embolism

The introduction of modern dual-energy CT (DECT) scanners has enabled contrast material to be distinguished at imaging without the need for a separate unenhanced scan. Images of pulmonary parenchymal contrast enhancement obtained using DECT improve the detection of defects, augmenting our ability to detect pulmonary emboli; however, with these advances new pitfalls are also introduced. In this pictorial review, we present the technique, clinical applications and causes and remedies of false results of dual-energy pulmonary parenchymal enhancement defects in pulmonary embolism.

Pitfalls in the evaluation of shortness of breath

This article illustrates the challenges practitioners face evaluating shortness of breath, a common emergency department complaint. Through a series of patient encounters, pitfalls in the evaluation of shortness of breath are reviewed and discussed.

Venous thrombotic emergencies

Thrombosis is a common complication of cancer, occurring in up to 15% of patients. This article reviews the diagnosis and management of the most common cancer-related thrombotic problem; deep venous thrombosis, pulmonary embolism, and catheterrelated thrombosis. Rarer entities, such as cerebral vein thrombosis and Budd-Chiari syndrome, are also reviewed.

Pulmonary embolism detection with dual-energy CT: experimental study of dual-source CT in rabbits

PURPOSE

To evaluate feasibility and added value of dual-energy computed tomography (CT) in diagnosis of pulmonary embolism (PE).

MATERIALS AND METHODS

This institutional animal experimental committee-approved study was performed in accordance with animal care guidelines. Eight New Zealand rabbits underwent standard unenhanced and contrast material-enhanced dual-source CT. Gelatin sponge particles were injected into the pulmonary artery, and rabbits underwent contrast-enhanced dual-source CT pulmonary angiography, from which blood-flow (BF) and fusion images were created. Immediately after dual-source CT, rabbits were sacrificed, their lungs were removed and fixed in 10% formalin, and detailed pathologic determination of location and number of lung lobes with PE was performed. Two rabbits were excluded: One died during the procedure. In the other, the catheter tip was retained in the left inferior pulmonary artery. This caused marked postembolization CT image artifacts in adjacent regions. Six rabbits were included in final analysis. Two radiologists without knowledge of pathologic results evaluated five pulmonary lobes in each rabbit and recorded whether PE was present. Pathologic results served as the reference standard. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the techniques were calculated. Weighted kappa values were calculated to evaluate agreement between modalities.

RESULTS

Pathologic analysis revealed PE in 18 of 30 pulmonary lobes. Conventional CT angiography was used to correctly identify PE in 12 lobes and absence of emboli in 18 lobes, which corresponded to sensitivity, specificity, PPV, and NPV of 67%, 100%, 100%, and 67%, respectively. A kappa value of 0.65 indicated good correlation with pathologic findings. On BF images, segments with an embolic region showed low perfusion compared with segments with a normal pulmonary region. BF images and fused images correctly showed PE in 16 of 18 pulmonary lobes and absence of emboli in 11 of 12 lobes, which corresponded to sensitivity, specificity, PPV, and NPV of 89%, 92%, 94%, and 85%, respectively, in detection of PE. A kappa value of 0.80 indicated good correlation with pathologic findings.

CONCLUSION

Dual-source CT can depict normal and abnormal blood perfusion distribution in a rabbit's lung. Abnormal pulmonary blood distribution, as shown at dual-source CT, improves detection of acute PE in rabbits.

Radiology resident interpretation of on-call CT pulmonary angiograms

RATIONALE AND OBJECTIVES

To evaluate the interpretation of computed tomographic pulmonary angiograms performed outside of regular reporting hours, comparing the initial interpretation by the radiology resident to the attending radiologist.

MATERIALS AND METHODS

Records for 840 consecutive computed tomographic pulmonary angiograms (CTPA) performed outside of regular reporting hours at two tertiary referral centers from January 1, 2004-December 31, 2005 were reviewed. The preliminary interpretation by the on-call radiology resident was compared to the subsequent final report issued by a subspecialty trained chest radiologist. Studies were stratified as positive, negative, or equivocal for pulmonary embolus. Cases with discordant interpretations or negative CTPA were reviewed to determine impact on clinical outcome. Patients were followed up to 12 months after CTPA to document any subsequent thromboembolic event.

RESULTS

Sixteen percent (131/840) of CTPAs were reported positive by the staff radiologist. There was agreement in 90% (752/840) of studies (P = .76, 95% confidence interval, 0.71-0.81) with 86% (114/133) agreement for studies interpreted as positive by residents, 95% (582/612) for studies interpreted as negative by residents, and 63% (60/95) for studies interpreted as equivocal by residents. Studies of optimal quality had higher interobserver agreement than studies of suboptimal quality (P < .0001). In-patient studies were more likely to be positive than emergency room patients (20% vs. 13%) (P = .004). No adverse clinical outcomes were attributed to discordant interpretations.

CONCLUSIONS

Radiology residents provide a high level interpretation of on-call CTPA studies, achieving good concordance with the attending radiologists' assessment.