Pulmonary Embolism
Introduction
Pulmonary embolism (PE) is the presence of a thrombus in the pulmonary arterial circulation. Typically, emboli arise from the lower limb deep venous system but can arise from venous thrombosis in more proximal vessels.
VTE (Venous Thromboembolism) is a term that incorporates both deep venous thrombosis (DVT) and PE (Pulmonary Embolism). It is estimated that VTE are responsible for over 500,000 deaths in Europe each year and is the leading direct cause of maternal death in the UK and Ireland (1).
Risk Factors
Risk factors for thromboembolic disease include;
Previous DVT/PE
Active Malignancy
Obesity
Exogenous Oestrogen (e.g. COCP/HRT)
Pregnancy
Recent surgery (<4 weeks) or immobilisation for >3 days
Recent prolonged travel/long haul flight
Lower Limb Trauma
Thrombophilia (e.g. Factor V Leiden, Protein S/C Deficiency)
Clinical Features
Signs and symptoms of PE may be vague or non-specific requiring alternative diagnoses to be ruled out concurrently.
Patients with PE may present with;
Signs
Clinical examination may be normal but commonly present signs include
Tachycardia
Tachypnoea
Hypoxia
It is very important to also assess for signs of lower limb DVT
Unilateral leg swelling
Pitting oedema greater on the affected limb
Tenderness along the deep venous system
Symptoms
Chest pain, often described as pleuritic
Shortness of breath (dyspnoea)
Palpitations
Haemoptysis
Collapse
Differential Diagnosis
Respiratory
Pneumothorax
Respiratory tract infection / pneumonia
Exacerbation of COPD / asthma
Cardiovascular
Acute coronary syndrome
Acute aortic dissection
Clinical Decision Rules
Clinical Investigions
ECG from Life in the Fast Lane (2)
Management & Disposition
Initial Assessment & Resuscitation
Assess airway, work of breathing and circulation
Iv access
Continuous cardiac monitoring if vitals abnormal
Symptomatic Treatment
Oxygen if required
Target sats to >94%, unless hx of COPD, in which case target 88-92%
Analgegsia
Paracetamol or ibuprofen
Morphine for severe pain
Specific Treatment
Therapeutic anticoagulation
Low molecular weight heparin
Clexane 1.5mg/kg or
Tinzaparin 175units/kg
In patients with massive PE who are stable iv unfractionated heparin should be used in case of deterioration and the need for thrombolysis
Haemodynamically unstable patients
These patients require input and decision making around their management from senior decision makers in emergency medicine, ICU, coagulation, radiology and medical admitting team
They may require thrombolysis
Systemic or
Catheter directed
Disposition
Patients with suspected PE should be referred to the medical on call team for work-up and investigation
References
1. Thrombosis Ireland – Irish Statistics- http://thrombosisireland.ie/wp-content/uploads/2017/10/irish-stats.pdf
2. ECG Changes in Pulmonary Embolism – Life in the Fast Lane - https://litfl.com/ecg-changes-in-pulmonary-embolism/
3. Dunn K.L. et al Normal D-Dimer levels in emergency department patients suspected of acute pulmonary embolism. J. Am. Coll. Cardiol. 2002. 8(16); 1475-1478
4. Radiopedia.org - Pulmonary Embolism https://radiopaedia.org/articles/pulmonary-embolism
5. Thromboembolic Disease in Pregnancy and the Perperium: Acute Management. Royal College of Obstetricians and Gynaecologists https://www.rcog.org.uk/globalassets/documents/guidelines/gtg-37b.pdf
6. Wells P.S. et al. Excluding pulmonary embolism at the bedside without diagnostic imaging: management of patients with suspected pulmonary embolism presenting to the emergency department by using a simple clinical model and d-dimer. Ann. Intern. Med. 2001. 135(2);98-107
This blog was written by Dr. James Condren and was last updated in October 2020