Vascular
Pulmonary Embolism
A blockage in one of the pulmonary arteries in your lungs, usually caused by blood clots that travel from the legs.
Pulmonary embolism (PE) occurs when a blood clot — most often from the deep leg veins — travels to the lungs and blocks blood flow. It is a medical emergency requiring urgent diagnosis and treatment.
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A pulmonary embolism is a life-threatening medical emergency where a blood clot obstructs blood flow in the lungs, requiring immediate treatment.
Pulmonary Embolism: A Clot That Has Reached the Lungs
A pulmonary embolism (PE) is a blood clot — almost always one that started as a deep vein thrombosis in the leg or pelvis — that has broken loose, travelled through the heart, and lodged in an artery in the lungs.
The blocked artery cannot deliver blood to part of the lung, oxygen levels fall, and the right side of the heart has to strain against the obstruction. The effect ranges from a small clot that causes only mild breathlessness to a large one that causes collapse. Any suspected PE is a medical emergency and is assessed in hospital, not the clinic.
The blocked artery cannot deliver blood to part of the lung, oxygen levels fall, and the right side of the heart has to strain against the obstruction. The effect ranges from a small clot that causes only mild breathlessness to a large one that causes collapse. Any suspected PE is a medical emergency and is assessed in hospital, not the clinic.
The Symptoms: Call 995
PE often comes on suddenly. The common features are unexplained breathlessness, a sharp chest pain that is worse when you breathe in, a fast heartbeat, and a cough that may bring up a little blood. A larger clot can cause light-headedness, a faint, or a collapse.
Sometimes the only clue is new breathlessness on exertion, or a leg that quietly swelled a few days earlier. If you have any of these symptoms together with a risk factor for clots — recent surgery, a long flight, cancer, pregnancy, immobility — call 995.
Sometimes the only clue is new breathlessness on exertion, or a leg that quietly swelled a few days earlier. If you have any of these symptoms together with a risk factor for clots — recent surgery, a long flight, cancer, pregnancy, immobility — call 995.
Diagnosis in Singapore
In the emergency department, the team scores how likely a PE is and checks a D-dimer blood test; a normal result in a low-risk patient rules it out.
The confirming test is a CT pulmonary angiogram (CTPA), a rapid contrast scan of the lung arteries available around the clock at the restructured hospitals. A V/Q scan is used instead when contrast must be avoided, as in pregnancy or kidney impairment. An ECG and an echocardiogram assess how much strain the clot is placing on the right heart, which determines how urgently and where you are treated.
The confirming test is a CT pulmonary angiogram (CTPA), a rapid contrast scan of the lung arteries available around the clock at the restructured hospitals. A V/Q scan is used instead when contrast must be avoided, as in pregnancy or kidney impairment. An ECG and an echocardiogram assess how much strain the clot is placing on the right heart, which determines how urgently and where you are treated.
Treatment: From Tablets at Home to Clot-Busters in Intensive Care
Treatment is matched to how sick the clot has made you.
- Stable patients — a direct oral anticoagulant (rivaroxaban or apixaban), and selected low-risk patients are now safely discharged the same or next day
- Intermediate-risk patients — anticoagulation with close monitoring in hospital, and clot removal if they deteriorate
- High-risk patients (low blood pressure, shock) — an urgent clot-dissolving drug given into a vein, or catheter-based clot removal at a specialist centre
- Duration — at least three months for everyone, and longer or indefinitely for an unprovoked or recurrent PE or ongoing cancer
After a PE: Recovery and the Long View
Many people feel breathless and tire easily for weeks to months after a PE, even once the clot has been treated — this ‘post-PE’ deconditioning improves with a gradual return to activity and, where available, pulmonary rehabilitation.
A small proportion develop chronic thromboembolic pulmonary hypertension (CTEPH), where scar tissue narrows the lung arteries; persistent breathlessness three to six months after a PE should prompt a follow-up echocardiogram, because CTEPH is treatable. Whether your PE was provoked or unprovoked sets the length of anticoagulation and your future travel precautions. We follow patients through this first year from Paragon Medical Centre on Orchard Road.
A small proportion develop chronic thromboembolic pulmonary hypertension (CTEPH), where scar tissue narrows the lung arteries; persistent breathlessness three to six months after a PE should prompt a follow-up echocardiogram, because CTEPH is treatable. Whether your PE was provoked or unprovoked sets the length of anticoagulation and your future travel precautions. We follow patients through this first year from Paragon Medical Centre on Orchard Road.
Pulmonary Embolism: Common Questions
Concerned About Pulmonary Embolism?
Dr. Peter Chang offers specialist assessment and personalised management at Paragon Medical Centre, Singapore.