Pulmonary embolism

When to suspect PE

Suspect pulmonary embolism (PE) in a person with dyspnoea, tachypnoea, pleuritic chest pain, or features of deep vein thrombosis. These features are present in 97% of people with PE.
Other features that may be present include:

Tachycardia (heart rate greater than 100 beats per minute).
Haemoptysis.
Syncope.
Hypotension (systolic blood pressure less than 90 mmHg).
Crepitations.
Cough or fever.

If PE is suspected:
Exclude other conditions that could explain symptoms including:
Respiratory conditions such as pneumothorax, pneumonia, acute exacerbation of chronic lung disease.
Cardiac causes such as acute coronary syndrome, acute congestive heart failure, dissecting or rupturing aortic aneurysm, pericarditis.
Musculoskeletal chest pain. Note that chest pain with chest wall palpation occurs in up to 20% of people with confirmed PE.
Gastro-oesophageal reflux disease.Pregnancy.Any cause for collapse such as vasovagal syncope, orthostatic (postural) hypotension, cardiac arrhythmias, seizures, cerebrovascular disorders.

Do not delay management of suspected PE for results of an ECG or chest X-ray. They have limited value in diagnosis because they are usually normal in someone with a PE. They may be done as part of investigations for breathlessness or chest pain when another diagnosis seems more likely.

ECG signs that may be present include:
sinus tachycardia, non-specific ST-segment and T-wave abnormalities, right axis deviation, incomplete or complete right bundle-branch block, and, less commonly, T-wave inversion in leads V1–V3, P pulmonale, or the classical S1, Q3, T3 (S wave in lead 1, Q wave in lead 3, and T-wave inversion in lead 3).

Chest X-ray features that may be present include: atelectasis, pleural effusion, or elevation of a hemidiaphragm.
If PE is suspected, assess for risk factors for PE.

Major risk factors include:
Deep vein thrombosis (DVT). Suspect if there is unilateral leg pain, swelling, redness, increased temperature, or venous distension. However, only 15% of people with pulmonary embolism have signs of DVT.
Previous DVT or pulmonary embolism.
Active cancer.
Recent surgery, hospitalization, lower limb trauma, or other immobilization (including long-distance travel).
Pregnancy and, in particular, for 6 weeks’ postpartum.

Other risk factors include:

Increasing age (older than 60 years of age).
Combined oral contraception and hormone replacement therapy.
Obesity (body mass index greater than 30 kg/m2).
One or more significant medical comorbidities (for example: heart disease; metabolic, endocrine, neurological disability, or respiratory pathologies; acute infectious disease; or inflammatory conditions).
Varicose veins.
Superficial venous thrombosis.
Known thrombophilias (thrombotic disorders).

Other: indwelling central vein catheter, nephrotic syndrome, chronic dialysis, myeloproliferative disorders, paroxysmal nocturnal haemoglobinuria, or Behçet’s disease.

FOR MANAGEMENT SEE -‘ PE’ 2 -BACK TO BASICS.

G Mohan.