Pulmonary Embolism

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Key points

  • Diagnostic work up of pulmonary embolism (PE) should be based on well-described clinical prediction scores (Wells score, Geneva score, and so forth). Every patient with a high likelihood of having PE should be started on prompt anticoagulation if there is no absolute contraindication for it.

  • Newer oral anticoagulants are the preferred agent of choice over vitamin K antagonists, except in cancer patients and patients with antiphospholipid antibody syndrome.

  • Patients with submassive or massive PE

Classification of pulmonary embolism

PE can be classified based on clot location or hemodynamic compromise. Saddle PE refers to a clot located in the main PA or bifurcation. Saddle PE does not necessarily translate into a massive PE (defined later). Mortality rate related to saddle PE is close to 5%.31 Likewise, lobar, segmental, and subsegmental PE describe clot location in the pulmonary arterial branches corresponding to the anatomic lung lobe, segment, or subsegment respectively. Terms, such as nonmassive PE and major PE, are

Diagnosis and evaluation

Diagnosis of PE can be challenging because symptoms are nonspecific. Nonetheless, the classic presenting symptoms are pleuritic chest pain (39%) and dyspnea at rest (50%).29 Hemoptysis also is a common presenting complaint due to pulmonary infarction. Hemoptysis can be seen in up to 20% of patients with PE. Hemoptysis in setting of PE is not an absolute indication to stop anticoagulation. Syncope can be an initial presentation of hemodynamically significant PE. It is also important to elicit

D-Dimer

D-dimer is a fibrin degradation product. It is used as a surrogate marker of fibrinolysis and is expected to be elevated during a thrombotic event. Measured using ELISA, a normal level is less than 500 ng/mL in most laboratories. D-dimer can be elevated in various conditions, such as pregnancy, postoperative state, and malignancy, which lowers its specificity. It is also known to have levels that increase with age and thus the levels are adjusted for this parameter.36 In combination with a low

Venous Ultrasound Duplexes

Ultrasound of the lower extremity is useful when evaluating a patient for PE. It is relatively quick and does not require radiation. The goal is to find noncompressible veins, suggesting vessel occlusion. Ultrasonography is not used alone, however; rather, it supplements the diagnosis of PE by identifying a source. A negative venous ultrasound does not rule out the possibility of PE.

Management of pulmonary embolism

All patients with high pretest probability or confirmed PE should be initiated on anticoagulation. Empiric early anticoagulation has been associated with decreased mortality for patients with acute PE.49, 50 Mainstay therapy for patients being admitted is unfractionated heparin that is administered as an 80 U/kg bolus followed by an infusion at 18 U/kg/h bolus or a weight-based dosing for low-molecular-weight heparin (LMWH), such as enoxaparin. Studies have shown there is no difference between

Post–pulmomary embolism discharge

Every patient with VTE should have close outpatient follow-up.71 An attempt should be made to determine the etiology of PE, which sometimes can be difficult in the inpatient setting. Hypercoagulable work-up should be considered on individualized basis and after discussing with patients. Age-appropriate cancer screening should be performed. Modifiable risk factors for VTE like smoking cessation and weight reduction can be addressed on outpatient follow-up visits.72 It is also of paramount

Summary

The authors conclude this review with the following salient points for readers:

  • 1.

    The authors recommend using predictive score (Wells, Geneva, or PERC) for VTE before ordering CTPA.

  • 2.

    CTPA remains the gold standard for diagnosis of PE.

  • 3.

    High pretest probabilities for PE and low bleeding risk should prompt empiric anticoagulation while waiting for confirmative testing.

  • 4.

    Treatment decisions for PE should be based on hemodynamic impact, not merely a clot location and risk stratification.

  • 5.

    Echocardiography,

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References (73)

  • S. Hitchen et al.

    Ventilation perfusion scan or computed tomography pulmonary angiography for the detection of pulmonary embolism?

    Eur J Intern Med

    (2016)
  • S.B. Smith et al.

    Early anticoagulation is associated with reduced mortality for acute pulmonary embolism

    Chest

    (2010)
  • L. Willoughby et al.

    Preemptive anticoagulation in patients with a high pretest probability of pulmonary embolism

    Chest

    (2018)
  • C. Kabrhel et al.

    A multidisciplinary pulmonary embolism response team

    Chest

    (2016)
  • G. Palareti et al.

    D-dimer to guide the duration of anticoagulation in patients with venous thromboembolism: a management study

    Blood

    (2014)
  • S.V. Konstantinides et al.

    Impact of thrombolytic therapy on the long-term outcome of intermediate-risk pulmonary embolism

    J Am Coll Cardiol

    (2017)
  • P.D. Stein et al.

    Pulmonary embolectomy in elderly patients

    Am J Med

    (2014)
  • R. Rosovsky et al.

    Pulmonary embolism response team: inpatient structure, outpatient follow-up, and is it the current standard of care?

    Clin Chest Med

    (2018)
  • M.G. Beckman et al.

    Venous thromboembolism. A public health concern

    Am J Prev Med

    (2010)
  • M. Meignan et al.

    Systematic lung scans reveal a high frequency of silent pulmonary embolism in patients with proximal deep venous thrombosis

    Arch Intern Med

    (2000)
  • A.T. Cohen et al.

    Venous thromboembolism (VTE) in Europe - The number of VTE events and associated morbidity and mortality

    Thromb Haemost

    (2007)
  • R. Alikhan et al.

    Fatal pulmonary embolism in hospitalised patients: a necropsy review

    J Clin Pathol

    (2004)
  • J.A. Heit et al.

    Predictors of survival after deep vein thrombosis and pulmonary embolism: a population-based, cohort study

    Arch Intern Med

    (1999)
  • J.A. Heit et al.

    Effect of a near-universal hospitalization-based prophylaxis regimen on annual number of venous thromboembolism events in the US

    Blood

    (2017)
  • S.B. Deitelzweig et al.

    Venous thromboembolism in the US: does race matter?

    J Thromb Thrombolysis

    (2011)
  • B. Park et al.

    Recent trends in clinical outcomes and resource utilization for pulmonary embolism in the United States findings from the nationwide inpatient sample

    Chest

    (2009)
  • P.M. Rali et al.

    Submassive pulmonary embolism

    Am J Respir Crit Care Med

    (2018)
  • A.T. Cohen et al.

    Extended thromboprophylaxis with betrixaban in acutely ill medical patients

    N Engl J Med

    (2016)
  • C.N. Bagot et al.

    Virchow and his triad: a question of attribution

    Br J Haematol

    (2008)
  • K.S. Burrowes et al.

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

    Ann Biomed Eng

    (2014)
  • R. Mizera

    Pathophysiology of development of pulmonary hypertension after acute pulmonary embolism

    Cesk Fysiol

    (2012)
  • M. Delcroix et al.

    Hypoxic pulmonary vasoconstriction and gas exchange in acute canine pulmonary embolism

    J Appl Physiol

    (1996)
  • H.P. Wiedemann et al.

    Heart disease : a textbook of cardiovascular medicine

  • M.R. Jaff et al.

    Management of massive and submassive pulmonary embolism, iliofemoral deep vein thrombosis, and chronic thromboembolic pulmonary hypertension: a scientific statement from the american heart association

    Circulation

    (2011)
  • J.W. Blom et al.

    Malignancies, prothrombotic mutations, and the risk of venous thrombosis

    J Am Med Assoc

    (2005)
  • U. Seligsohn et al.

    Genetic susceptibility to venous thrombosis

    N Engl J Med

    (2001)
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    Disclosure Statement: None of the listed authors have any commercial or financial conflicts of interest and any funding sources pertaining to topic in discussion.

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