Major pulmonary embolism: review of a pathophysiologic approach to the golden hour of hemodynamically significant pulmonary embolism

Predictive Value of Computed Tomography in Acute Pulmonary Embolism: Systematic Review and Meta-analysis

BACKGROUND

Many computed tomography (CT) parameters have been proposed as potential predictors of outcome in acute pulmonary embolism. We sought to summarize available evidence on the predictive value of CT severity parameters for short-term clinical outcome in pulmonary embolism.

METHODS

We searched PubMed and EMBASE through February 2014 for studies that reported on the association between CT parameters of acute pulmonary embolism severity and short-term (≤6 months) clinical outcome. Risk estimates for quantitative parameters of right ventricular (RV) dysfunction (abnormally increased RV/left ventricular [LV] diameter ratio on transverse sections and 4-chamber views), qualitative parameters of RV dysfunction (abnormal septal morphology and contrast reflux), thrombus load, and central thrombus location were derived using random effect regression analysis. Meta-regression analysis was performed to quantify and explain study heterogeneity.

RESULTS

A total of 49 studies with 13,162 patients with acute pulmonary embolism (median age of 61 years, 55.1% were women) who underwent diagnostic CT imaging were included in the analysis. An abnormally increased RV/LV diameter ratio measured on transverse sections was associated with an approximately 2.5-fold risk for all-cause mortality (pooled odds ratio [OR], 2.5; 95% confidence interval [CI], 1.8-3.5) and adverse outcome (OR, 2.3; 95% CI, 1.6-3.4) and a 5-fold risk for pulmonary embolism-related mortality (OR, 5.0; 95% CI, 2.7-9.2). Thrombus load (OR, 1.6, 95% CI, 0.7-3.9; P = .2896) and central location (OR, 1.7; 95% CI, 0.7-4.2; P = .2609) were not predictive for all-cause mortality, although both were associated with adverse clinical outcome.

CONCLUSIONS

Across all end points, the RV/LV diameter ratio on transverse CT sections has the strongest predictive value and most robust evidence base for adverse clinical outcomes in patients with acute pulmonary embolism.

Postmortem-computed tomography and postmortem-computed tomography-angiography: a focused update

The use of multidetector CT (MDCT) represents a reality routinely used in several forensic institutes, for the numerous advantages that this diagnostic tool can provide; costs are becoming increasingly lower; data acquisition is always faster and once acquired may be revalued at any time. However, there are also some diagnostic limitations, for example, the visualization of the vascular system or a limited soft tissue contrast. In order to overcome these limitations, in recent years, contrast medium has been introduced in postmortem cases, with the development of several techniques of PMCT angiography (PMCTA) and standardized protocols to make them easily reproducible. The aim of this review is to highlight the advantages and pitfalls of PMCT and PMCTA in forensic investigation, taking into consideration the broad spectrum of applications both for natural and unnatural deaths and the numerous methods currently used. Secondly, in the light of the considerable progress in this field and the attempt to develop standardized protocols of PMCTA, the authors aim to evaluate the diagnostic value of PMCTA in comparison both to PMCT and conventional autopsy.

Diuretic versus placebo in normotensive acute pulmonary embolism with right ventricular enlargement and injury: a double-blind randomised placebo controlled study. Protocol of the DiPER study

INTRODUCTION

In acute pulmonary embolism (PE), poor outcome is usually related to right ventricular (RV) failure due to the increase in RV afterload. Treatment of PE with RV failure without shock is controversial and usually relies on fluid expansion to increase RV preload. However, several studies suggest that fluid expansion may worsen acute RV failure by increasing RV dilation and ischaemia, and increase left ventricular compression by RV dilation. By reducing RV enlargement, diuretic treatment may break this vicious circle and provide early improvement in normotensive patients referred for acute PE with RV failure.

METHODS AND ANALYSIS

The Diuretic versus placebo in Pulmonary Embolism with Right ventricular enlargement trial (DiPER) is a prospective, multicentre, randomised (1:1), double-blind, placebo controlled study assessing the superiority of furosemide as compared with placebo in normotensive patients with confirmed acute PE and RV dilation (diagnosed on echocardiography or CT of the chest) and positive brain natriuretic peptide result. The primary end point will be a combined clinical criterion derived from simplified Pulmonary Embolism Severity Index (PESI) score and evaluated at 24 h. It will include: (1) urine output >0.5 mL/kg/min for the past 24 h; (2) heart rate <110 bpm; (3) systolic blood pressure >100 mm Hg and (4) arterial oxyhaemoglobin level >90%. Thirty-day major cardiac events defined as death, cardiac arrest, mechanical ventilation, need for catecholamine and thrombolysis, will be evaluated as a secondary end point. Assuming an increase of 30% in the primary end point with furosemide and a β risk of 10%, 270 patients will be required.

ETHICS AND DISSEMINATION

Ethical approval was received from the ethical committee of Ile de France (2014-001090-14). The findings of the trial will be disseminated through peer-reviewed journals, and national and international conference presentations.

TRIAL REGISTRATION NUMBER

NCT02268903.

Neurologically normal survival after fibrinolysis during prolonged cardiac arrest: case report and discussion

Cardiac arrest secondary to pulmonary embolism is a devastating condition with a high mortality rate. It is currently unclear whether fibrinolysis (thrombolysis) is beneficial in this setting. We report the case of a 28-year-old woman with a pulmonary embolism who developed return of pulses following the administration of tissue plasminogen activator after 38 minutes of pulseless electrical activity cardiac arrest. She went on to make a full neurologic and cardiopulmonary recovery. This case is discussed with reference to the current literature on the subject.

Comparison of multidetector computed tomography findings with clinical and laboratory data in pulmonary thromboembolism

BACKGROUND

Pulmonary thromboembolism (PTE) is a common disease with a high mortality rate that is difficult to diagnose and treat. Because of the variety of clinical symptoms and signs, it is difficult to diagnose. Therefore, the diagnosis of PTE is mainly confirmed by imaging techniques. The aim of this study was to evaluate whether there is any corelation of the Wells rule, D-dimer and LDH values with computerized tomography pulmonary angiography (CTPA) findings in PTE diagnosis.

MATERIAL/METHODS

A consecutive series of 62 patients, which included 31 males and 31 females, with high/moderate/low risk of embolism according to Wells pulmonary embolism score, selected from the emergency service and/or outpatient clinic, enrolled in this prospective study. The patients with clinical or laboratory findings of elevated D-dimer level or elevated lactate dehydrogenase (LDH) level were suspected of embolism and underwent tomography.

RESULTS

PTE was detected in 26 patients (42%). A significant difference was not detected between tomography finding positive and negative embolisms in the patient group in terms of age or gender distribution (P=0.221 and P=0.416, respectively). No significant difference was detected between tomography finding positive and negative embolisms in the patient group in terms of elevated LDH or/and D-dimer levels (P=0.263 and P=1.000, respectively). The distribution of low-risk-factor patients in the non-embolism group, and the distribution of high-risk-factor patients in the embolism-positive group was statistically significantly high (P<0.001). There was no statistically significant difference between the groups (P=0.053). Correlation test showed no correlation between LDH and D-dimer levels. (r=0.214, P=0.180).

CONCLUSIONS

In conclusion, when a patient presents with chest pain, our carrying out LDH and D-Dimer tests will not exclude PTE without CTPA. However, we suggest that LDH isoenzymes should be studied in further research.

Association between electrocardiographic findings, right heart strain, and short-term adverse clinical events in patients with acute pulmonary embolism

BACKGROUND

Electrocardiographic (ECG) changes may be seen with pulmonary emboli (PE). Whether ECG is associated with short-term adverse clinical events after PE is less well established.

HYPOTHESIS

ECG findings are associated with short-term clinical deterioration after PE.

METHODS

Consecutive adult PE patients were enrolled in an academic emergency department from 2008 to 2011. The primary outcome was right heart strain (RHS) on echocardiogram or CT pulmonary angiography, or TnT ≥0.1 ng/mL. We derived an ECG (TwiST) score that is associated with RHS and short-term adverse clinical events.

RESULTS

We enrolled 298 patients with PE. On multivariate analysis, T-wave inversion in leads V(1) through V(3) (OR: 4.7, 95% confidence interval [CI]: 1.7-13.2), S wave in lead I (OR: 2.0, 95% CI: 1.1-3.5), and tachycardia (OR: 2.5, 95% CI: 1.3-4.8) were associated with RHS. A TwiST score ≤2 (n = 210, 72%) was 84% (95% CI: 77%-90%) sensitive for the absence of RHS, whereas a TwiST score ≥5 (n = 47, 16%) was 93% (95% CI: 88%-97%) specific for the presence of RHS.

CONCLUSIONS

A simple ECG (TwiST) score can identify patients likely or not likely to have RHS with >80% specificity and sensitivity and may assist in identifying patients with acute PE at risk for adverse clinical events before pursuing other advanced imaging tests.

Evaluation of cardiac biomarkers and right ventricular dysfunction in patients with acute pulmonary embolism

OBJECTIVE

Right ventricular dysfunction (RVD) with myocardial damage may lead to fatal complications in patients with acute pulmonary embolism (PE). Cytoplasmic heart-type fatty acid-binding protein (HFABP) and the N-terminal fragment of its prohormone (NT-proBNP) are sensitive and specific biomarkers of myocardial damage. We evaluated RVD and cardiac biomarkers for myocardial damage and short-term mortality in patients with acute PE.

METHODS

We analyzed 41 patients (24 females, 17 males) with confirmed acute PE prospective. Three groups (massive, submassive, and non-massive) of patients were defined, based on systemic systolic blood pressure measured on admission and RVD by transthoracic echocardiography (TTE). Also, systolic (s) and mean (m) pulmonary artery pressures (PAPs) were recorded by TTE, and plasma concentrations of cardiac troponin T (cTn-T), NT-proBNP, and HFABP were evaluated 6 month follow-up.

RESULTS

Seventeen (41.5%) patients experienced a complicated clinical course in the 6-month follow-up for the combined end-point, including at least one of the following: death (n=12, 29.3%; 3 PE-related), chronic PE (n=4, 9.8%), pulmonary hypertension (n=2, 4.9%), and recurrent PE (n=1, 2.4%). Multivariate hazard ratio analysis revealed HFABP, NT-proBNP, and PAPs as the 6-month mortality predictors (HR 1.02, 95% CI 1.01-1.05; HR 1.01, 95% CI 1.01-1.04; and HR 1.02, 95% CI 1.02-1.05, respectively).

CONCLUSION

HFABP, NT-proBNP, and PAPs measured on admission may be useful for short-term risk stratification and in the prediction of 6-month PE-related mortality in patients with acute PE.

A single imaging modality in the diagnosis, severity, and prognosis of pulmonary embolism

Introduction. This study aimed to investigate the currency of computerized tomography pulmonary angiography-based parameters as pulmonary artery obstruction index (PAOI), as well as right ventricular diameters for pulmonary embolism (PE) risk evaluation and prediction of mortality and intensive care unit (ICU) requirement. Materials and Methods. The study retrospectively enrolled 203 patients hospitalized with acute PE. PAOI was calculated according to Qanadli score. Results. Forty-three patients (23.9%) were hospitalized in the ICU. Nineteen patients (10.6%) died during the 30-day follow-up period. The optimal cutoff value of PAOI for PE 30th day mortality and ICU requirement were found as 36.5% in ROC curve analysis. The pulmonary artery systolic pressure had a significant positive correlation with right/left ventricular diameter ratio (r = 0.531, P < 0.001), PAOI (r = 0.296, P < 0.001), and pulmonary artery diameter (r = 0.659, P < 0.001). The patients with PAOI values higher than 36.5% have a 5.7-times increased risk of death. Conclusion. PAOI is a fast and promising parameter for risk assessment in patients with acute PE. With greater education of clinicians in this radiological scoring, a rapid assessment for diagnosis, clinical risk evaluation, and prognosis may be possible in emergency services without the need for echocardiography.

Peri-operative massive pulmonary embolism management: is veno-arterial ECMO a therapeutic option?

Pulmonary embolism remains an important clinical problem with a high mortality rate. The potential for sudden and fatal hemodynamic deterioration highlights the need for a prompt diagnosis and appropriate intervention. The purpose of the present case report is to describe a successful peri-operative veno-arterial extra corporeal membrane oxygenation (VA-ECMO) implantation for assumed massive pulmonary embolism associated with high hemodynamic instability and severe hypoxemia. A 52-year-old female victim of a motorcycle accident had been operated on for unstable fractures that required optimal repair. Despite subcutaneous administration of 40 mg enoxaparin on day 0 and day 1, the patient developed a massive pulmonary embolism leading to peri-operative pulseless activity. As intravenous thrombolysis was strictly contraindicated, a VA-ECMO was successfully implanted and permitted to stabilize the patient's hemodynamics. The hemodynamic and respiratory status improved by day 3, and the ECMO was removed. A vena cava filter was implanted before successful and definitive stabilization of the femoral fracture and the L2 fracture on days 4 and 5. The patient was able to be mobilized 2 days after the surgery and was transferred to a rehabilitation ward on day 15. At that time, her cognitive functions had fully recovered. ECMO can provide lifesaving hemodynamic and respiratory support in patients with massive pulmonary embolism who are too unstable to tolerate other interventions, who have failed other therapies or for whom other therapies are contraindicated.

In silico modeling of magnetic resonance flow imaging in complex vascular networks

The paper presents a computational model of magnetic resonance (MR) flow imaging. The model consists of three components. The first component is used to generate complex vascular structures, while the second one provides blood flow characteristics in the generated vascular structures by the lattice Boltzmann method. The third component makes use of the generated vascular structures and flow characteristics to simulate MR flow imaging. To meet computational demands, parallel algorithms are applied in all the components. The proposed approach is verified in three stages. In the first stage, experimental validation is performed by an in vitro phantom. Then, the simulation possibilities of the model are shown. Flow and MR flow imaging in complex vascular structures are presented and evaluated. Finally, the computational performance is tested. Results show that the model is able to reproduce flow behavior in large vascular networks in a relatively short time. Moreover, simulated MR flow images are in accordance with the theoretical considerations and experimental images. The proposed approach is the first such an integrative solution in literature. Moreover, compared to previous works on flow and MR flow imaging, this approach distinguishes itself by its computational efficiency. Such a connection of anatomy, physiology and image formation in a single computer tool could provide an in silico solution to improving our understanding of the processes involved, either considered together or separately.

Successful catheter-directed thrombolysis of a massive pulmonary embolism in a patient after recent pneumonectomy

Massive pulmonary embolism (PE) after major thoracic surgery is an uncommon but life-threatening event that is challenging to manage. At present, the treatment of acute PE is either anticoagulation with or without systemic thrombolytic therapy. We report a case of a 65-year-old female with recent left pneumonectomy who developed a massive PE. The patient was successfully and safely treated with catheter-directed thrombolysis. To our knowledge, this is the first patient treated in this fashion.

Randomised trial of no hydration vs. sodium bicarbonate hydration in patients with chronic kidney disease undergoing acute computed tomography-pulmonary angiography

BACKGROUND

Hydration to prevent contrast-induced acute kidney injury (CI-AKI) induces a diagnostic delay when performing computed tomography-pulmonary angiography (CTPA) in patients suspected of having acute pulmonary embolism.

AIM

To analyze whether withholding hydration is non-inferior to sodium bicarbonate hydration before CTPA in patients with chronic kidney disease (CKD).

METHODS

We performed an open-label multicenter randomized trial between 2009 and 2013. One hundred thirty-nine CKD patients were randomized, of whom 138 were included in the intention-to-treat population: 67 were randomized to withholding hydration and 71 were randomized to 1-h 250 mL 1.4% sodium bicarbonate hydration before CTPA. Primary outcome was the increase in serum creatinine 48-96 h after CTPA. Secondary outcomes were the incidence of CI-AKI (creatinine increase > 25%/> 0.5 mg dL(-1) ), recovery of renal function, and the need for dialysis within 2 months after CTPA. Withholding hydration was considered non-inferior if the mean relative creatinine increase was ≤ 15% compared with sodium bicarbonate.

RESULTS

Mean relative creatinine increase was -0.14% (interquartile range -15.1% to 12.0%) for withholding hydration and -0.32% (interquartile range -9.7% to 10.1%) for sodium bicarbonate (mean difference 0.19%, 95% confidence interval -5.88% to 6.25%, P-value non-inferiority < 0.001). CI-AKI occurred in 11 patients (8.1%): 6 (9.2%) were randomized to withholding hydration and 5 (7.1%) to sodium bicarbonate (relative risk 1.29, 95% confidence interval 0.41-4.03). Renal function recovered in 80.0% of CI-AKI patients within each group (relative risk 1.00, 95% confidence interval 0.54-1.86). None of the CI-AKI patients developed a need for dialysis.

CONCLUSION

Our results suggest that preventive hydration could be safely withheld in CKD patients undergoing CTPA for suspected acute pulmonary embolism. This will facilitate management of these patients and prevents delay in diagnosis as well as unnecessary start of anticoagulant treatment while receiving volume expansion.

The CORE scan: concentrated overview of resuscitative efforts

Critically ill patients require rapid, accurate assessments and appropriate therapeutic interventions to maximize their chances of recovery. Often the cause of a patient's decompensation is not readily apparent based solely on history and physical examination findings. The Concentrated Overview of Resuscitative Efforts (CORE scan) is a compilation of targeted bedside ultrasound exams that should be performed during the assessment and management of critically ill patients. The CORE scan can be used to help make critical diagnoses and guide resuscitation efforts in patients with undifferentiated deterioration.

Acute pulmonary embolus: the next frontier in venous thromboembolic interventions

OPINION STATEMENT

Submassive pulmonary embolism (PE) represents a patient population that is under-recognized and under-treated. Recent clinical trials demonstrated the hemodynamic benefit of IV thrombolytic therapy among these patients; however, it came at the cost of a significantly increased risk of major, particularly intracranial, hemorrhage. Catheter-based treatment modalities have garnered considerable clinical interest in recent years. In particular, ultrasound accelerated thrombolysis, a catheter-based technology that enhances the process of thrombolytic delivery into the thrombus, has emerged as a treatment modality with an increasing number of single-center studies, as well as randomized, controlled clinical trials. Results from these experiences are consistent in achieving outcomes of thrombus resolution and hemodynamic recovery with a low dose thrombolytic infusion protocol, but without the high risk of bleeding complications associated with IV thrombolysis. The clinical data will hopefully be impactful to the development of the next edition of the treatment guidelines, in support of overall recommendations for catheter-based interventions. When available and with appropriate expertise, this modality should be considered as the preferred treatment of both massive and submassive PE.

Acute Surgical Abdomen: An Unusual Presentation of Pulmonary Embolus

Background. Pulmonary embolism is a common and potentially lethal condition. Most patients who die from massive pulmonary embolism do so within the first few hours of the event. The clinical manifestations of pulmonary embolism are nonspecific, which makes the diagnosis difficult. Case Report. We present a case of massive pulmonary embolism presenting as an acute surgical abdomen that underwent exploratory laparotomy and made a complete recovery. Why should an emergency physician be aware of this? Emergency department physicians should be aware that massive pulmonary embolism could present as an acute surgical abdomen in young healthy individuals.

Management of massive and submassive pulmonary embolism

Massive pulmonary embolism has a high mortality rate despite advances in diagnosis and therapy. This article attempts to review the evidence-based risk stratification, diagnosis, initial stabilization, and management of massive and submassive pulmonary embolism.

Efficacy and safety of flow-directed pulmonary artery catheter thrombolysis for treatment of submassive pulmonary embolism

OBJECTIVE

The purpose of this study was to assess the efficacy and safety of flow-directed catheter thrombolysis for treatment of submassive pulmonary embolism (PE).

MATERIALS AND METHODS

In this single-institution retrospective study, 19 patients (nine men and 10 women; mean age [± SD], 54 ± 13 years) with submassive PE underwent catheter-directed thrombolysis between 2009 and 2013. Presenting symptoms included dyspnea in 18 of 19 (95%) cases. Submassive PE was diagnosed by pulmonary CT arteriography and right ventricular strain. PE was bilateral in 17 of 19 (89%) and unilateral in two of 19 (11%) cases. Thrombolysis was performed via a pulmonary artery (PA) catheter infusing 0.5- 1.0 mg alteplase per hour and was continued to complete or near complete clot dissolution with reduction in PA pressure. IV systemic heparin was administered. Measured outcomes included procedural success, PA pressure reduction, clinical success, survival, and adverse events.

RESULTS

Procedural success, defined as successful PA catheter placement, fibrinolytic agent delivery, PA pressure reduction, and achievement of complete or near complete clot dissolution, was achieved in 18 of 19 (95%) cases. Thrombolysis required 57 ± 31 mg of alteplase administered over 89 ± 32 hours. Initial and final PA pressures were 30 ± 10 mm Hg and 20 ± 8 mm Hg (p < 0.001). All 18 (100%) technically successful cases achieved clinical success because all patients experienced symptomatic improvement. Eighteen of 19 (95%) patients survived to hospital discharge; 18 of 19 (95%) and 15 of 16 (94%) patients had documented 1-month and 3-month survival. One fatal case of intracranial hemorrhage was attributed to supratherapeutic anticoagulation because normal fibrinogen levels did not suggest remote fibrinolysis; procedural success was not achieved in this case because of early thrombolysis termination. No other complications were encountered.

CONCLUSION

Among a small patient cohort, flow-directed catheter thrombolysis with alteplase effectively dissolved submassive PE and reduced PA pressure. Postprocedure short-term survival was high, and patients undergoing thrombolysis required close observation for bleeding events.

Gas exchange and pulmonary hypertension following acute pulmonary thromboembolism: has the emperor got some new clothes yet?

Patients present with a wide range of hypoxemia after acute pulmonary thromboembolism (APTE). Recent studies using fluorescent microspheres demonstrated that the scattering of regional blood flows after APTE, created by the embolic obstruction unique in each patient, significantly worsened regional ventilation/perfusion (V/Q) heterogeneity and explained the variability in gas exchange. Furthermore, earlier investigators suggested the roles of released vasoactive mediators in affecting pulmonary hypertension after APTE, but their quantification remained challenging. The latest study reported that mechanical obstruction by clots accounted for most of the increase in pulmonary vascular resistance, but that endothelin-mediated vasoconstriction also persisted at significant level during the early phase.

Prognostic significance of tricuspid annular displacement in normotensive patients with acute symptomatic pulmonary embolism

BACKGROUND

Tricuspid annular plane systolic excursion (TAPSE) is an emerging prognostic indicator in patients with acute symptomatic pulmonary embolism (PE).

METHODS AND RESULTS

We prospectively examined 782 normotensive patients with PE who underwent echocardiography in a multicenter study. As compared with patients with a TAPSE of > 1.6 cm, those with a TAPSE of ≤ 1.6 cm had increased systolic pulmonary artery pressure (53.7 ± 16.7 mmHg vs. 40.0 ± 15.5 mmHg, P < 0.001), right ventricle (RV) end-diastolic diameter (3.5 ± 0.8 cm vs. 3.0 ± 0.6 cm, P < 0.001), and RV to left ventricle end-diastolic diameter ratio (1.0 ± 0.3 vs. 0.8 ± 0.2, P < 0.001), and a higher prevalence of RV free wall hypokinesis (68% vs. 11%, P < 0.001). Patients with a TAPSE of ≤ 1.6 cm at the time of PE diagnosis were significantly more likely to die from any cause (hazard ratio [HR] 2.3; 95% confidence interval [CI] 1.2-4.7; P = 0.02) and from PE (HR 4.4; 95% CI 1.3-15.3; P = 0.02) during follow-up. In an external validation cohort of 1326 patients with acute PE enrolled in the international multicenter Registro Informatizado de la Enfermedad TromboEmbólica, a TAPSE of ≤ 1.6 cm remained a significant predictor of all-cause mortality (HR 2.1; 95% CI 1.3-3.2; P = 0.001) and PE-specific mortality (HR 2.5; 95% CI 1.2-5.2; P = 0.01).

CONCLUSIONS

In normotensive patients with PE, TAPSE reflects right ventricular function. For these patients, TAPSE is independently predictive of survival.

A comparison of different techniques of two-dimensional speckle-tracking strain measurements of right ventricular systolic function in patients with acute pulmonary embolism

BACKGROUND

Speckle-tracking echocardiography has been applied to measure right ventricular (RV) systolic function in various diseases. However, variations in strain measurement by different vendors have limited the application of these techniques for assessment of RV function. We sought to compare two methods for the assessment of RV systolic function in patients with acute pulmonary embolism (PE).

METHODS

From August 2007 to May 2011, all consecutive PE patients were prospectively included in this cohort study. Global longitudinal strains of RV measured with EchoPAC PC software (GLSRV-EchoPAC; GE Medical Systems) and velocity vector imaging (GLSRV-VVI; Siemens Medical Systems) were recorded on the same set of echocardiographic images.

RESULTS

We analyzed a total of 50 patients (12 males, 68 ± 14 years) with acute PE in this study. GLSRV-EchoPAC and GLSRV-VVI were correlated (r = 0.793, p < 0.001) and they showed significant correlations with conventional echocardiographic parameters of RV systolic function and Log B-type natriuretic peptide (BNP) level. However, GLSRV-VVI only showed significant correlations with cardiac biomarkers as serum creatinine kinase-MB (r = 0.367, p = 0.010) and tropoinin-I concentrations (r = 0.294, p = 0.040).

CONCLUSION

GLSRV-VVI and GLSRV-EchoPAC showed significant correlations with conventional echocardiographic parameters of RV systolic function and LogBNP value in patients with PE.

Hemodynamic indexes derived from computed tomography angiography to predict pulmonary embolism related mortality

Pulmonary embolism (PE) induces an acute increase in the right ventricle afterload that can lead to right-ventricular dysfunction (RVD) and eventually to circulatory collapse. Hemodynamic status and presence of RVD are important determinants of adverse outcomes in acute PE. Technologic progress allows computed tomography angiography (CTA) to give more information than accurate diagnosis of PE. It may also provide an insight into hemodynamics and right-ventricular function. Proximal localization of emboli, reflux of contrast medium to the hepatic veins, and right-to-left short-axis ventricular diameter ratio seem to be the most relevant CTA predictors of 30-day mortality. These elements require little postprocessing time, an advantage in the emergency room. We herein review the prognostic value of RVD and other CTA mortality predictors for patients with acute PE.

Treatment of acute pulmonary embolism: update on newer pharmacologic and interventional strategies

Acute pulmonary embolism (PE) is a common complication in hospitalized patients, spanning multiple patient populations and crossing various therapeutic disciplines. Current treatment paradigm in patients with massive PE mandates prompt risk stratification with aggressive therapeutic strategies. With the advent of endovascular technologies, various catheter-based thrombectomy and thrombolytic devices are available to treat patients with massive or submassive PE. In this paper, a variety of newer treatment strategies for PE are analyzed, with special emphasis on various interventional treatment strategies. Clinical evidence for utilizing endovascular treatment modalities, based on our institutional experience as well as a literature review, is provided.

Massive pulmonary embolism and cardiac arrest; thrombolytic therapy in a patient with recent intracranial surgery and glioblastoma multiforme

Treatment options for pulmonary embolism are increasing, but the scale of the treatments and their availability in the emergency department (ED) are limited. Thrombolytic therapy remains the most commonly used treatment in patients who present a massive pulmonary embolism in the ED. However, systemic thrombolysis is contraindicated in certain cases, such as a known intracranial tumor or a history of cranial surgery.In this case report, we report a 63-year-old man with a history of intracranial surgery due to glioblastoma multiforme 20 days prior to being admitted to the ED. Multidetector-row computed tomography angiography revealed embolisms in both main pulmonary arteries.There was a progression of cardiac arrest while preparing for catheterization; thus, cardiopulmonary resuscitation was initiated.After administering 10 minutes of cardiopulmonary resuscitation, a50-mg alteplase bolus was given. Within minutes, a pulse has returned. No complications associated with the thrombolytic therapy were observed.Our aim was to discuss the management of massive pulmonary embolism with a contraindication to systemic thrombolytic therapy.

Impact of catheter fragmentation followed by local intrapulmonary thrombolysis in acute high risk pulmonary embolism as primary therapy

BACKGROUND

Pulmonary embolism (PE) with more than 50% compromise of pulmonary circulation results significant right ventricular (RV) afterload leading to progressive RV failure, systemic hypotension and shock. Prompt restoration of thrombolysis, surgical embolectomy, or percutaneous mechanical thrombectomy (PMT) prevents progressive hemodynamic decline. We report our single center experience in high risk PE patients treated with standard pigtail catheter mechanical fragmentation followed by intrapulmonary thrombolysis as a primary therapy.

METHODS

50 consecutive patients with diagnosis of high risk PE defined as having shock index >1 with angiographic evidence of >50% pulmonary arterial occlusion are included in the present study. All patients underwent emergent cardiac catheterization. After ensuring flow across pulmonary artery with mechanical breakdown of embolus by rotating 5F pigtail catheter; bolus dose of urokinase (4400 IU/kg) followed by infusion for 24 h was given in the thrombus. Hemodynamic parameters were recorded and follow up pulmonary angiogram was done. Clinical and echo follow up was done for one year.

RESULTS

Pigtail rotational mechanical thrombectomy restored antegrade flow in all patients. The mean pulmonary artery pressure, Miller score, Shock index decreased significantly from 41 ± 8 mmHg, 20 ± 5, 1.32 ± 0.3 to 24.52 ± 6.89, 5.35 ± 2.16, 0.79 ± 0.21 respectively (p < 0.0001). In-hospital major complications were seen in 4 patients. There was a statistically significant reduction of PA pressures from 62 ± 11 mmHg to 23±6 mmHg on follow up.

CONCLUSIONS

Rapid reperfusion of pulmonary arteries with mechanical fragmentation by pigtail catheter followed by intrapulmonary thrombolysis results in excellent immediate and intermediate term outcomes in patients presenting with high risk pulmonary embolism.

Timing of vasopressor initiation and mortality in septic shock: a cohort study

Introduction

Despite recent advances in the management of septic shock, mortality remains unacceptably high. Earlier initiation of key therapies including appropriate antimicrobials and fluid resuscitation appears to reduce the mortality in this condition. This study examined whether early initiation of vasopressor therapy is associated with improved survival in fluid therapy-refractory septic shock.

Methods

Utilizing a well-established database, relevant information including duration of time to vasopressor administration following the initial documentation of recurrent/persistent hypotension associated with septic shock was assessed in 8,670 adult patients from 28 ICUs in Canada, the United States of America, and Saudi Arabia. The primary endpoint was survival to hospital discharge. Secondary endpoints were length of ICU and hospital stay as well as duration of ventilator support and vasopressor dependence. Analysis involved multivariate linear and logistic regression analysis.

Results

In total, 8,640 patients met the definition of septic shock with time of vasopressor/inotropic initiation documented. Of these, 6,514 were suitable for analysis. The overall unadjusted hospital mortality rate was 53%. Independent mortality correlates included liver failure (odds ratio (OR) 3.46, 95% confidence interval (CI), 2.67 to 4.48), metastatic cancer (OR 1.63, CI, 1.32 to 2.01), AIDS (OR 1.91, CI, 1.29 to 2.49), hematologic malignancy (OR 1.88, CI, 1.46 to 2.41), neutropenia (OR 1.78, CI, 1.27 to 2.49) and chronic hypertension (OR 0.62 CI, 0.52 to 0.73). Delay of initiation of appropriate antimicrobial therapy (OR 1.07/hr, CI, 1.06 to 1.08), age (OR 1.03/yr, CI, 1.02 to 1.03), and Acute Physiology and Chronic Health Evaluation (APACHE) II Score (OR 1.11/point, CI, 1.10 to 1.12) were also found to be significant independent correlates of mortality. After adjustment, only a weak correlation between vasopressor delay and hospital mortality was found (adjusted OR 1.02/hr, 95% CI 1.01 to 1.03, P <0.001). This weak effect was entirely driven by the group of patients with the longest delays (>14.1 hours). There was no significant relationship of vasopressor initiation delay to duration of vasopressor therapy (P = 0.313) and only a trend to longer duration of ventilator support (P = 0.055) among survivors.

Conclusion

Marked delays in initiation of vasopressor/inotropic therapy are associated with a small increase in mortality risk in patients with septic shock.

Hypoxic pulmonary vasoconstriction as a contributor to response in acute pulmonary embolism

Hypoxic pulmonary vasoconstriction (HPV) is an adaptive response unique to the lung whereby blood flow is diverted away from areas of low alveolar oxygen to improve ventilation-perfusion matching and resultant gas exchange. Some previous experimental studies have suggested that the HPV response to hypoxia is blunted in acute pulmonary embolism (APE), while others have concluded that HPV contributes to elevated pulmonary blood pressures in APE. To understand these contradictory observations, we have used a structure-based computational model of integrated lung function in 10 subjects to study the impact of HPV on pulmonary hemodynamics and gas exchange in the presence of regional arterial occlusion. The integrated model includes an experimentally-derived model for HPV. Its function is validated against measurements of pulmonary vascular resistance in normal subjects at four levels of inspired oxygen. Our results show that the apparently disparate observations of previous studies can be explained within a single model: the model predicts that HPV increases mean pulmonary artery pressure in APE (by 8.2 ± 7.0% in these subjects), and concurrently shows a reduction in response to hypoxia in the subjects who have high levels of occlusion and therefore maximal HPV in normoxia.

Timing of troponin T measurements in triage of pulmonary embolism patients

Aim

To determine the appropriate timing of cardiac troponin T (cTnT) measurement for the early triage of pulmonary embolism (PE) patients.

Methods

In this single-center prospective study, PE was confirmed in all patients using computed tomography. 104 consecutive patients were divided into three groups (high-risk, intermediate, and low-risk) based on their hemodynamic status and echocardiographic signs of right ventricular dysfunction. cTnT levels were measured on admission and then after 6, 24, 48, and 72 hours with threshold values greater than 0.1 ng/mL.

Results

Intermediate-risk PE patients had higher cTnT levels than low-risk patients already in the first measurement (P = 0.037). Elevated cTnT levels significantly correlated with disease severity after 6 hours (intermediate vs low risk patients, P = 0.016, all three groups, P = 0.009).

Conclusion

In hemodynamically stable patients, increased cTnT level on admission differentiated intermediate from low-risk patients and could be used as an important element for the appropriate triage of patients.

Right ventricular function and thrombus load in patients with pulmonary embolism and diagnostic delay

INTRODUCTION

It has been reported that the time between symptom onset and objective diagnosis of pulmonary embolism (PE) does not affect patients' prognosis with regard to re-thrombosis and mortality risk. However, this observation is contra-intuitive and poorly understood. We further elaborated on this paradox by evaluating thrombus load and right ventricular function in patients with and without diagnostic delay.

MATERIALS AND METHODS

We performed a post hoc analysis of a previously published observational prospective outcome study in 113 consecutive PE patients. Qanadli-score and RV/LV ratio were scored in all patients, as was the duration from symptom onset to clinical presentation and diagnosis. Diagnostic delay was defined as a period of more than 7 days between symptom onset and clinical presentation. Further endpoints were mortality and hospital readmission in a 6-week follow-up period.

RESULTS

Twenty patients with and 93 patients without delay were studied, who had comparable baseline characteristics and co-morbidities. In linear analyses, Qanadli-score (R² of 0.021; P = 0.130) and RV/LV ratio (R² < 0.001; P = 0.991) were not associated with diagnostic delay. Likewise, longer delay was not predictive of 6-week mortality (odds ratio, 0.65; 95% CI, 0.08-5.57) or hospital readmission (odds ratio, 0.75; 95% CI, 0.15-3.65).

CONCLUSION

In our patient cohort, diagnostic delay was not associated with higher thrombus load or right ventricular dysfunction. This provides a possible explanation for the lack of prognostic relevance of diagnostic delay.

The impact of saddle embolism on the major adverse event rate of patients with non-high-risk pulmonary embolism

OBJECTIVE

Wider application of CT angiography (CTA) improves the diagnosis of acute pulmonary embolism (PE). It also permits the visualisation of saddle embolism (SE), namely thrombi, which are located at the bifurcation of the main pulmonary artery. The aim of this study was to assess the prevalence of SE and whether SE predicts a complicated clinical course in patients with non-high-risk PE.

METHODS

In total, 297 consecutive patients with non-high-risk PE confirmed using CTA in the emergency department were studied. The presence of SE and its ability to predict the occurrence of major adverse events (MAEs) within 1 month were determined.

RESULTS

Of the 297 patients, 27 (9.1%) had an SE. The overall mortality at 1 month was 12.5%; no significant difference was observed between the SE and non-SE groups (18.5% vs 11.9%, p=0.32). However, patients with SE were more likely to receive thrombolytic therapy (29.6% vs 8.1%, p<0.01) and had significantly more MAEs (59.3% vs 25.6%, p<0.01).

CONCLUSION

At the time of diagnosis, SE, as determined using CTA, is associated with the development of MAE within 1 month. It may be a simple method for risk stratification of patients with non-high-risk PE.

ADVANCES IN KNOWLEDGE

The prognosis of patients with SE, especially those who are haemodynamically stable, is unclear. This study shows that patients with SE, determined with CTA, is associated with the development of MAE.

Assessment of the severity of acute pulmonary embolism using CT pulmonary angiography parameters

AIM

To evaluate the association between computed tomography parameters and clinical signs in patients with acute pulmonary embolism.

METHODS

109 patients retrospectivelly selected from hospital database with acute pulmonary embolism verified by CT pulmonary angiography. The following parameters were assessed: pulmonary artery diameter to aorta diameter ratio (PA/Ao), normalized pulmonary artery diameter (nPA), right ventricular to left ventricular diameter ratio from CT (RV CT/LV CT), normalized end-diastolic right ventricular diameter (nRVD echo) and right to left ventricular end diastolic diameter ratio (RV echo/LV echo) from echocardiography.

RESULTS

Multivariate regression analysis showed a significant association between PA/Ao and thrombolysed (0.99) to non-thrombolysed (0.90) patients, OR=1.56 P=0.012, and also RV CT/LV CT and thrombolysed 1.5 to non-thrombolysed (0.94) patients OR=1.24 P=0.002. The significant difference was also found in intensive care unit hospitalization necessity (ICU-Y/N) and RV CT/LV CT ratio (ICU-Y 1.42, ICU-N 0.91) OR=1.26 P=0.003, and RV echo/LV echo (ICU-Y 0.82, ICU-N 0.65) OR=1.83 P=0.033.

CONCLUSION

From the CT pulmonary angiography parameters, the RV CT/LV CT showed a significant association with both thrombolysis administration and ICU hospitalization. The PA/Ao had relation only to thrombolytic therapy as well as RV echo/LV echo only to ICU hospitalization.

Clinical features of patients inappropriately undiagnosed of pulmonary embolism

PURPOSES

The objective of this study was to identify clinical factors associated with delayed diagnosis of acute pulmonary embolism (PE) in the emergency department (ED).

BASIC PROCEDURES

A retrospective observational study was performed at three University affiliated Hospitals; 436 consecutive patients who presented to the ED with an acute PE confirmed by chest computed tomography from 2008 to 2011 were included. Patients were divided into 3 groups: group 1, PE was diagnosed while the patient was still in the ED; group 2, PE was diagnosed during hospitalization; group 3, patients who were sent home with a wrong alternative diagnosis and returned to the ED and were diagnosed of PE.

MAIN FINDINGS

One hundred forty-six patients (33.5%) had a delayed diagnosis of PE--21.5% belong to group 2 and 11.9% to Group 3. Chronic coexisting medical conditions like asthma or chronic obstructive pulmonary disease were independent predictors of a delayed diagnosis in patients who were admitted to hospital whereas non-specific and less severe symptoms like the presence of pleuro-mechanic thoracic pain, fever, hemoptysis, or the presence of a pulmonary infiltrate in chest x-ray were independent predictors of a delayed diagnosis in patients who were sent home.

PRINCIPAL CONCLUSIONS

Delay in diagnosis of acute PE is frequent despite current diagnostic strategies. Patients are sent home or admitted to hospital with a wrong diagnosis depending on clinical presentation or coexisting medical conditions.

Massive pulmonary embolism

Massive pulmonary embolism (PE) is a potentially lethal condition, with death usually caused by right ventricular (RV) failure and cardiogenic shock. Systemic thrombolysis (unless contraindicated) is recommended as the first-line treatment of massive PE to decrease the thromboembolic burden on the RV and increase pulmonary perfusion. Surgical pulmonary embolectomy or catheter-directed thrombectomy should be considered in patients with contraindications to fibrinolysis, or those with persistent hemodynamic compromise or RV dysfunction despite fibrinolytic therapy. Critical care management predominantly involves supporting the RV, by optimizing preload, RV contractility, and coronary perfusion pressure and minimizing afterload. Despite these interventions, mortality remains high.

Impact of delay in clinical presentation on the diagnostic management and prognosis of patients with suspected pulmonary embolism

RATIONALE

The nonspecific clinical presentation of pulmonary embolism (PE) frequently leads to delay in its diagnosis.

OBJECTIVES

This study aimed to assess the impact of delay in presentation on the diagnostic management and clinical outcome of patients with suspected PE.

METHODS

In 4,044 consecutive patients with suspected PE, patients presenting more than 7 days from the onset of symptoms were contrasted with those presenting within 7 days as regards the safety of excluding PE on the basis of a clinical decision rule combined with D-dimer testing. Patients were followed for 3 months to assess the rates of recurrent venous thromboembolism and mortality.

MEASUREMENTS AND MAIN RESULTS

A delayed presentation (presentation >7 d) was present in 754 (18.6%) of the patients. The failure rate of an unlikely clinical probability and normal D-dimer test was 0.5% (95% confidence interval [CI], 0.01-2.7) for patients with and 0.5% (95% CI, 0.2-1.2) for those without diagnostic delay. D-dimer testing yielded a sensitivity of 99% (95% CI, 96-99%) and 98% (95% CI, 97-99%) in these groups, respectively. Patients with PE with diagnostic delay more frequently had centrally located PE (41% vs. 26%; P < 0.001). The cumulative rates of recurrent venous thromboembolism (4.6% vs. 2.7%; P = 0.14) and mortality (7.6% vs. 6.6%; P = 0.31) were not different for patients with and without delayed presentation.

CONCLUSIONS

PE can be safely excluded based on a clinical decision rule and D-dimer testing in patients with a delayed clinical presentation. A delayed presentation for patients who survived acute PE was associated with a more central PE location, although this did not affect the clinical outcome at 3 months.

Mechanical ventilation and acute lung injury in emergency department patients with severe sepsis and septic shock: an observational study

OBJECTIVES

The objectives were to characterize the use of mechanical ventilation in the emergency department (ED), with respect to ventilator settings, monitoring, and titration and to determine the incidence of progression to acute lung injury (ALI) after admission, examining the influence of factors present in the ED on ALI progression.

METHODS

This was a retrospective, observational cohort study of mechanically ventilated patients with severe sepsis and septic shock (June 2005 to May 2010), presenting to an academic ED with an annual census of >95,000 patients. All patients in the study (n = 251) were analyzed for characterization of mechanical ventilation use in the ED. The primary outcome variable of interest was the incidence of ALI progression after intensive care unit (ICU) admission from the ED and risk factors present in the ED associated with this outcome. Secondary analyses included ALI present in the ED and clinical outcomes comparing all patients progressing to ALI versus no ALI. To assess predictors of progression to ALI, significant variables in univariable analyses at a p ≤ 0.10 level were candidates for inclusion in a bidirectional, stepwise, multivariable logistic regression analysis.

RESULTS

Lung-protective ventilation was used in 68 patients (27.1%) and did not differ based on ALI status. Delivered tidal volume was highly variable, with a median tidal volume delivered of 8.8 mL/kg ideal body weight (IBW; interquartile range [IQR] = 7.8 to 10.0) and a range of 5.2 to 14.6 mL/kg IBW. Sixty-nine patients (27.5%) in the entire cohort progressed to ALI after admission to the hospital, with a mean (±SD) onset of 2.1 (±1) days. Multivariable logistic regression analysis demonstrated that a higher body mass index (BMI), higher Sequential Organ Failure Assessment (SOFA) score, and ED vasopressor use were associated with progression to ALI. There was no association between ED ventilator settings and progression to ALI. Compared to patients who did not progress to ALI, patients progressing to ALI after admission from the ED had an increase in mechanical ventilator duration, vasopressor dependence, and hospital length of stay (LOS).

CONCLUSIONS

Lung-protective ventilation is uncommon in the ED, regardless of ALI status. Given the frequency of ALI in the ED, the progression shortly after ICU admission, and the clinical consequences of this syndrome, the effect of ED-based interventions aimed at reducing the sequelae of ALI should be investigated further.