Pulmonary Embolus

Presentation

  • Dyspnoea
  • Pleuritic chest pain
  • Tachypnoea

Other features:

  • Haemoptysis
  • Syncope
  • Cough or fever
  • Crepitations


History

Onset of symptoms- acute or gradual
Recent long-haul travel
Recent immobilisation (>5 days bed rest)
Recent surgery, especially orthopaedic
Active cancer, including treatment for cancer
A personal or family history of DVT or PE
Pregnancy- in particular 6 weeks postpartum
Known bleeding disorders


Vital signs / observations

Hypoxaemia
Tachycardia
Pyrexia
Hypotension(systolic<90 mmHg) is a severe sign, and may be an indication for thrombolysis


Examination

Are there any features of DVT
Examination is usually non-specific in regards to signs and symptoms


Bedside tests

ECG

Sinus tachycardia is the most common finding
S1Q3T3 is the classical description, though clinically seldom seen

ABG

Hypoxaemia
Hypocapnia


Laboratory investigations

D-dimer

This the most important laboratory investigation. For patients with low-risk Well's scores (see below), D-dimer should be used to exclude PE.
Many other conditions, such as infections and malignancy may cause false positives

Assessment

Well's score

Previous VTE (1.5)
HR >100 (1.5)
Recent surgery / immobilisation (1.5)
Clinical signs of DVT (3)
Alternative diagnosis less likely than PE (3)
Haemoptysis (1)
Cancer treated in last 6 months (1)
Low-risk score (0-4) should have D-dimer, and those with positive D-dimers should have radiological investigations
High-risk scores (5 or more) should be treated as PE until excluded by radiological investigation.

Modified Geneva Score

This is less commonly used


Radiological investigations

Chest Radiograph

Not specific or sensitive to PE
Can rule out other potential causes of symptoms e.g. penumonia, pneumothorax

Computed tomography pulmonary angiography (CTPA)

Gold-standard investigation
Contraindications: Pregnancy, renal function, radiological contrast allergies

Ventilation-perfusion scan

Investigation of choice in pregnant patients, or those with other contraindications to CTPA.


Management

ARRANGE IMMEDIATE ADMISSION FOR ANYONE SEVERELY ILL WITH A SUSPECTED PULMONARY EMBOLISM

First line

Haemodynamically stable
Confirmed PE and normal blood pressure

  • LMWH
  • e.g. Fondaparinux- body-weight <50 kg= 5 mg every 24 hours; body-weight 50–100 kg= 7.5 mg every 24 hours. NOT RECOMMENDED FOR CHILDREN <17yrs.
  • Dalteparin

Continue for at least 5 days or until the INR is >2 for at least 24 hours- whichever is longer

Haemodynamically Unstable
Consider thrombolytic therapy

Second line

Patients with severe renal impairment or renal failure (creatinine clearance less than 20 ml/minute)
High risk of bleeding
Give Unfractionated Heparin
IV bolus loading dose 10,000units
Continuous IV infusion- 18units/kg/hour using actual body weight

Dose adjustments based on the APTT:

  • <50- Repeat loading bolus dose and increase infusion rate by 0.1ml/hour
  • 50-59- Increase infusion rate by 0.1ml/hour
  • 60-85- No change
  • 86-95- Decrease infusion rate by 0.1ml/hour
  • 96-120- STOP infusion for 30 mins then restart and decrease infusion rate by 0.1ml/hour
  • >120- STOP infusion for 1 hour then restart and decrease infusion rate by 0.2ml/hour

Prior to discharge

Give patients having anticoagulation treatment verbal and written information about:

  • how to use anticoagulants
  • planned duration of treatment
  • possible side effects and what to do if these occur
  • the effects of other medications, foods and alcohol on oral anticoagulation treatment
  • monitoring their anticoagulant treatment
  • how anticoagulants may affect their dental treatment
  • taking anticoagulants if they are planning pregnancy or become pregnant
  • how anticoagulants may affect activities such as sports and travel
  • when and how to seek medical help.

Provide patients with an 'anticoagulant alert card' and advise them to carry it at all times

Follow up

Start all patients on Warfarin within 24 hours of diagnosis

  • Continue Warfarin therapy for 3 months
  • Offer Warfarin beyond 3 months in patients with unprovoked (no major clinical risk factors) PE

Pregnant women- continue LMWH until end of pregnancy
Cancer patients- continue LMWH until cancer considered cured for at least 6 months
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Prognosis

  • Treatment with heparin and anticoagulants results in a low mortality rate
  • If untreated, the risk of death in people from pulmonary embolism is high
  • In people with clinically massive pulmonary embolism (hypotension) the risk of death within 90 days is about 50%
  • PE is the leading cause of maternal death in the UK
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