Pulmonary Embolism — Blood Clot in the Lung
Pulmonary embolism (PE) is a potentially life-threatening condition occurring when a blood clot — usually originating from a deep vein thrombosis in the leg or pelvis — travels through the bloodstream and blocks one or more pulmonary arteries in the lungs. The resulting obstruction reduces oxygenation, strains the right side of the heart, and in massive cases causes cardiovascular collapse and cardiac arrest.
Symptoms
- Sudden breathlessness — the most common and often the only symptom
- Pleuritic chest pain — sharp pain worse on breathing, from irritation of the pleura
- Haemoptysis — coughing up blood, from pulmonary infarction
- Rapid heart rate (tachycardia) and low blood pressure in severe cases
- Collapse or syncope — in massive PE with haemodynamic compromise
- Leg swelling or pain — suggesting the DVT source
Pulmonary embolism is a medical emergency
Sudden breathlessness, chest pain on breathing, rapid heart rate, or collapse — particularly in a patient with known DVT risk factors — requires immediate emergency assessment. Call +91-9000352998 or present to AIG Hospitals emergency department immediately.
Risk stratification
| Low-risk PE | Normal blood pressure, no right heart strain on echo or CT. Outpatient anticoagulation is safe. |
| Intermediate-risk PE | Normal blood pressure but elevated troponin and BNP, or right heart dysfunction on imaging. Hospitalisation required. Close monitoring for deterioration. |
| High-risk (massive) PE | Sustained hypotension, cardiac arrest, or haemodynamic collapse. Requires immediate reperfusion — systemic thrombolysis, catheter-directed thrombolysis, or surgical embolectomy. ICU admission essential. |
Diagnosis
- CT pulmonary angiography (CTPA) — the gold standard. Directly visualises clot in pulmonary arteries. Performed rapidly in emergency settings.
- V/Q scan — nuclear medicine alternative when CTPA is contraindicated (pregnancy, contrast allergy, renal failure)
- Echocardiogram — bedside assessment of right ventricular strain and function. D-shaped septum and elevated PASP confirm significant haemodynamic impact.
- D-dimer — useful to rule out PE in low-probability patients. Not diagnostic if elevated.
Treatment
- Anticoagulation — DOACs (rivaroxaban, apixaban) are first-line for most PE cases. Started immediately upon diagnosis.
- Systemic thrombolysis (tPA) — for massive PE with haemodynamic instability. Rapidly dissolves the clot but carries significant bleeding risk including intracranial haemorrhage.
- Catheter-directed thrombolysis — delivers thrombolytic drug directly into the pulmonary artery clot at lower dose than systemic therapy, reducing bleeding risk while effectively dissolving the clot. Available at :contentReference[oaicite:0]{index=0}.
- Surgical pulmonary embolectomy — for massive PE when thrombolysis is contraindicated or fails.
- ECMO (Extracorporeal Membrane Oxygenation) — in cardiac arrest from massive PE, ECMO provides temporary cardiopulmonary support while definitive treatment is performed.