How To Treat Pulmonary Embolism

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1 Pulmonary embolism Essence of this ArticlePulmonary embolism (PE) occurs when a part of a thrombus, usually dislodged from a deep vein thrombosis (DVT), passes into the pulmonary circulation, occluding the pulmonary arteries. PE is a potentially life-threatening condition and is the most common reason for preventable hospital death. Rapid diagnosis is crucial, but a diagnosis of PE can often be missed because of its non-specific clinical symptoms. Long-term complications of PE include chronic thromboembolic pulmonary hypertension (CTEPH). The Wells score is one scoring system that is commonly used to predict the clinical probability of PE. Computed tomography (CT) pulmonary angiography has become the method of choice for diagnostic imaging in patients with suspected PE, although other diagnostic methods are now available. The 2014 update of the European Society of Cardiology (ESC) guidelines for the management of PE brings about new recommendations for prognosis and treatment. Pulmonary embolismbookmark this page Pulmonary embolism. The pathway of a pulmonary embolus from the lower part of the body: inferior vena cava, to right atrium, to right ventricle, to the pulmonary artery. This might eventually obstruct blood flow to the lung. Patients with deep vein thrombosis are at risk of PE, a life-threatening event. PE, pulmonary embolism. PE is a potential cardiovascular emergency that occurs when a part of a thrombus, usually dislodged from a DVT (and then called an embolus), passes into the pulmonary circulation, occluding the pulmonary arteries. Nearly four-fifths of patients with PE have evidence of DVT, [144] and approximately half of those with proven proximal DVT have an associated PE and, like DVT, PE is often asymptomatic. [145] However, approximately 20 30% of cases are unprovoked (idiopathic). [146] Epidemiological data indicate that, of the more than 1.1 million cases of VTE that occur in the European Union (EU) each year, approximately one-third are PE cases. [124] PE is the most common reason for preventable hospital death. [119] Long-term complications of PE include CTEPH, which can have serious consequences. [147, 148]

2 Pulmonary embolus with haemorrhage. Section of pulmonary parenchyma with middle right (round) blood vessel containing embolus. The surrounding lung parenchyma has undergone haemorrhagic infarction. Diagnosis of PE Signs and symptomspe is a potentially life-threatening condition and in severe cases the occurrence of circulatory collapse and cardiac arrest may result in sudden death. Early fatality occurs in up to 15% of patients, [146] and thus rapid diagnosis is crucial. However, the diagnosis of PE may be missed because of its non-specific clinical symptoms. [146] Common signs and symptoms of PE are: [149] Dyspnoea Pleuritic chest pain Cough Substernal chest pain Fever Haemoptysis Syncope Unilateral leg pain Signs of DVT (unilateral extremity swelling) These symptoms are not specifically diagnostic of PE. For this reason, the diagnostic process, and decisions regarding the need for imaging tests specifically designed to detect PE, should be based on a careful assessment of clinical probability. [149] A clinician should maintain a high index of suspicion for this condition, because prompt treatment of PE can dramatically reduce the levels of morbidity and mortality associated with PE. The ESC guidelines recommends the use of a stepwise diagnostic algorithm that combines several evidence-based diagnostic strategies. [149]

3 European Society of Cardiology algorithm for patients with suspected high-risk PE. Adapted from Konstantinides et al.149 aincludes cases in which the patient s condition is so critical that it only allows bedside diagnostic tests. bapart from the diagnosis of RV dysfunction, a bedside transthoracic echocardiogram may, in some cases, directly confirm PE by visualizing mobile thrombi in the right heart chambers. cthrombolysis; alternatively, surgical embolectomy or catheter-directed treatment.ct, computed tomography; PE, pulmonary embolism; RV, right ventricular. Algorithms for the diagnosis of PE The 2014 ESC guidelines include algorithms for the diagnosis of PE that stratify patients according to their risk of early death based on clinical symptoms. [149] High-risk PE in this context is usually suspected if shock and/or hypotension are present. Once stabilized, suspected high-risk PE patients can undergo CT pulmonary angiography to confirm or dismiss the diagnosis of PE. If PE is not found to be the cause of haemodynamic instability, other causes (such as acute coronary syndrome) should be investigated. [149] In the absence of shock and/or hypotension, patients are categorized to have suspected low-to-intermediate risk PE. CT pulmonary angiography is not recommended as a first-line test in these patients, because most patients will be found not have the disease. Instead, the ESC guidelines recommend further risk stratification using clinical judgement or a clinical prediction rule such as the Wells score. Patients deemed to have a high clinical probability of PE after this assessment are recommended to undergo CT pulmonary angiography for confirmation of the diagnosis. Patients with a low/intermediate clinical probability of PE should first undergo a plasma D-dimer test before imaging of the pulmonary vasculature. [149] These algorithms have been validated in both the emergency ward and primary care settings. [149]

4 European Society of Cardiology algorithm for patients with suspected non-high-risk PE.Adapted from Konstantinides et al.32 atwo alternative classification schemes may be used for clinical probability assessment, i.e. a three-level scheme (clinical probability defined as low, intermediate or high) or a two-level scheme (PE unlikely or PE likely). btreatment refers to anticoagulation treatment for PE. cct pulmonary angiogram is considered to be diagnostic of PE if it shows PE at the segmental or more proximal level. din case of a negative CT pulmonary angiogram in patients with a high clinical probability, further investigation may be considered before withholding PE-specific treatment.ct, computed tomography; PE, pulmonary embolism. Clinical probability scores Scoring systems used in clinical practice include several key risk factors and markers for PE based on patient history and presentation. The Wells score is one scoring system that is commonly used method to predict clinical probability of PE. [149] This prediction rule has been revised several times since its development to make it simpler and more accurate. [150] Risk factors for recurrence As with DVT, the risk of recurrent PE appears to be higher in patients with an initial unprovoked PE and/or persistent risk factors than in those with transient risk factors. [152] Persistent risk factors include: [152] Active cancer Elevated levels of antiphospholipid antibodies Elevated D-dimer concentration after discontinuation of therapy

5 Several studies have indicated that patients with an initial PE are at high risk of recurrent PE, and one meta-analysis suggested that the risk for recurrent PE is 3.1-fold greater in patients who have had an initial symptomatic PE than in those with initial proximal DVT. [153] 119 Geerts WH, Bergqvist D, Pineo GF et al. Prevention of venous thromboembolism: American College of Chest Physicians evidence-based clinical practice guidelines (8th Edition). Chest 2008;133:381S 453S. 124 Cohen AT, Agnelli G, Anderson FA et al. Venous thromboembolism (VTE) in Europe. The number of VTE events and associated morbidity and mortality. Thromb Haemost 2007;98: Tapson VF. Acute pulmonary embolism. N Engl J Med 2008;358: Girard P, Musset D, Parent F et al. High prevalence of detectable deep venous thrombosis in patients with acute pulmonary embolism. Chest 1999;116: Torbicki A, Perrier A, Konstantinides S et al. Guidelines on the diagnosis and management of acute pulmonary embolism: the Task Force for the Diagnosis and Management of Acute Pulmonary Embolism of the European Society of Cardiology (ESC). Eur Heart J 2008;29: Pengo V, Lensing AW, Prins MH et al. Incidence of chronic thromboembolic pulmonary hypertension after pulmonary embolism. N Engl J Med 2004;350: Lang I. Advances in understanding the pathogenesis of chronic thromboembolic pulmonary hypertension. Br J Haematol 2010;149: Konstantinides SV, Torbicki A, Agnelli G et al ESC Guidelines on the diagnosis and management of acute pulmonary embolism. Eur Heart J 2014;35: Wells PS, Anderson DR, Rodger M et al. Derivation of a simple clinical model to categorize patients probability of pulmonary embolism: increasing the models utility with the SimpliRED D-dimer. Thromb Haemost 2000;83: Fermann GJ, Erkens PM, Prins MH et al. Treatment of pulmonary embolism with rivaroxaban: outcomes by simplified Pulmonary Embolism Severity Index score from a post hoc analysis of the EINSTEIN PE study. Acad Emerg Med 2015;22: Ramzi DW, Leeper KV. DVT and pulmonary embolism: Part I. Diagnosis. Am Fam Physician 2004;69: Baglin T, Douketis J, Tosetto A et al. Does the clinical presentation and extent of venous thrombosis predict likelihood and type of recurrence? A patient level meta-analysis. J Thromb Haemost 2010;8: