Pulmonary Embolism
- Fysiobasen
- Sep 9
- 4 min read
Pulmonary embolism (PE) is an acute, life-threatening condition in which one or more blood clots block blood flow in the pulmonary arteries. The condition most often occurs when a deep vein thrombosis (DVT) from the leg detaches, travels through the bloodstream, and lodges in the pulmonary vessels. Rapid diagnosis and initiation of treatment are crucial for the prognosis of PE.
Pathological Process
Thrombus formation usually occurs with venous stasis in deep veins, especially in the calf. The severity of the PE course depends on the patient’s cardiopulmonary status as well as the size and number of emboli. Small emboli may be asymptomatic, while larger clots can be fatal. In larger PE, increased alveolar dead space and ventilation-perfusion mismatch¹ are caused. This raises pressure in the pulmonary arteries and the load on the right ventricle², which can lead to right-sided heart failure and subsequently left-sided heart failure, with circulatory collapse and cardiac arrest.
In rare cases, the pulmonary artery may also be occluded by non-thrombotic materials, such as air, fat, amniotic fluid, bone fragments, or tumor cells³.
Prevalence and Incidence
PE is the third most common cardiovascular cause of death after myocardial infarction and stroke⁴. Many PE cases are asymptomatic and are only discovered as a complication of deep vein thrombosis⁵ ⁶. European guidelines report an annual incidence of venous thromboembolism and PE of 0.5–1.0 per 1000 inhabitants, with variation between different countries⁷.
Risk Factors
Thrombi develop on the basis of increased coagulation tendency. Important risk factors include severe injuries, surgery, immobilization, prolonged bed rest or sitting position over six hours, trauma, spinal cord injury, smoking, use of contraceptive pills or hormone therapy, cancer, chemotherapy, pregnancy and postpartum period, advanced age (>40 years), cast or orthosis, central venous catheters, overweight, and hypercholesterolemia⁸ ⁹.
Clinical Presentation
Pulmonary embolism is a medical emergency. Typical symptoms may include sudden shortness of breath, increased respiratory rate, sharp pleuritic chest pain, cough (often blood-streaked), rapid and weak pulse, sweating, fever, pronounced S2 heart sound, hypotension, dizziness, syncope, and cyanosis¹. Some patients only have mild symptoms or are completely asymptomatic. When PE is suspected, clinical scoring tools such as the Wells Score, Geneva Score, and Revised Geneva Score are often used¹⁰.
Preliminary Laboratory Diagnostics
Suspicion of PE should always be based on thorough medical history, assessment of risk factors, and clinical examination⁹. D-dimer and ultrasound of the leg are useful for detecting DVT and increased coagulation activity¹¹ ⁶. ECG may detect cardiac stress in larger emboli, and elevated troponins may strengthen suspicion of massive PE. Chest X-ray is important to rule out other diagnoses such as pleural effusion¹² ¹³.
Imaging Diagnostics
Several imaging methods can be used to diagnose PE⁹. CT pulmonary angiography (CTA) is considered the gold standard, with the highest specificity and sensitivity for detecting emboli in the pulmonary arteries. Ventilation/perfusion scintigraphy has high diagnostic value when the patient has no other significant cardiac or pulmonary disease. MRI may be considered in special cases.
Medical Treatment
When the diagnosis of PE is confirmed, anticoagulation is initiated to prevent growth of the clot and new emboli² ⁹. Heparin or fondaparinux is often used initially. In patients where anticoagulation is contraindicated or has caused severe side effects, insertion of a filter in the inferior vena cava may be considered to prevent further emboli. In massive PE with circulatory collapse, thrombolytic therapy may be indicated, and in special cases emboli can be surgically removed (embolectomy).
Differential Diagnosis
Pulmonary embolism can present with symptoms that overlap with several other acute and chronic diseases of the heart and lung systems. Therefore, it is important to consider other possible causes of the patient’s symptoms, especially in the emergency department. Conditions most often confused with PE include acute heart failure, pneumonia, COPD exacerbation, atrial fibrillation, and acute myocardial infarction¹⁴. All of these may cause dyspnea, chest pain, low oxygen saturation, and impaired general condition.
Physiotherapeutic Implications
Mobilization and physical activity play a central role in rehabilitation after pulmonary embolism. After initiation of anticoagulant therapy and possible thrombolysis, initial rest is usually recommended, followed by gradual progression to mobilization on the ward. The goal of physiotherapy is to optimize lung function and oxygen uptake, as well as to prevent complications related to immobilization¹.
Physiotherapy measures include pulmonary physiotherapy, focusing on improving ventilation and promoting effective coughing. Endurance training is later introduced, typically in the form of walking or cycling, adjusted according to the patient’s function and medical status. Good follow-up helps reduce the risk of further complications, loss of function, and recurrence.
References
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