Pulmonary embolism is the occlusion of one or more branches of the pulmonary artery, usually by blood clots in the lower extremities that break off and migrate to the pulmonary vessels.

Pulmonary embolism is the 3rd most common cardiovascular disease and is particularly common in hospitalized patients. Given the severity and potential consequences of the condition, early diagnosis and treatment are crucial.

What are the symptoms of pulmonary embolism?

Most of the time it can manifest with mild or no symptoms such as shortness of breath, tachypnea, tachycardia, pleurodynia, cough and rarely hemoptysis, while sometimes the first manifestation can be cardiorespiratory shock.

Diagnosis of pulmonary embolism: Laboratory tests

Its diagnosis is confirmed by laboratory tests and risk assessment algorithms.

1. Electrocardiogram. Findings are tachycardia 110 to 130 beats per minute and T wave inversion
2. Blood gases Hypoxemia occurs with Po2 <95
3. D-dimers. They appear elevated as end products of the fibrinous coagulation cascade
4. Chest x-ray The radiological findings are not specific and atelectasis, lateral effusion, megalocardia appear
5. Axial pulmonary angiography (spiral CT). It is the test of choice for the early diagnosis of thrombus in the pulmonary vessels.
6. Triplex Veins of lower extremities. In this examination, the existence of clots in the venous system of the lower extremities is recognized, from where parts of them detach and migrate to the pulmonary vessels.

Causes and risk factors of pulmonary embolism

Risk factors for the occurrence of pulmonary embolism are symptoms of deep vein thrombosis, tachycardia>100/min, surgery, major trauma, hemoptysis, immobilization for more than 3 days, previous history of pulmonary embolism, thrombosis of the veins of lower extremities, contraceptives and thrombophilia. Pregnancy is a risk factor for pulmonary embolism and according to statistics from Great Britain it is the number one cause of death for pregnant women.

Cancer is also an important predisposing risk factor.

The risk factors are divided into:

1. Transient/induced: long-term operations, contraceptives, pregnancy and immobilization in bed for > three days are included.
2. Persistent/unprovoked: includes active cancer, paralysis of lower limbs and thrombophilia.

Wells criteria (risk assessment algorithm): The sum of the individual scores of each symptom based on the Wells criteria is the probability indicator of pulmonary embolism. If the index is >4 then the diagnosis of pulmonary embolism is likely.

What is the treatment for pulmonary embolism?

Treatment is determined by the severity of the patient’s symptoms. In the case of severe cardiorespiratory instability, treatment must be immediate as the risk of death is high.

In this particular case, immediate cardiopulmonary resuscitation must be performed, which includes:

1. Thrombolytic therapy (intravenous medicinal solution of the clot).
2. Surgical removal of the pulmonary embolus.
3. Treatment of the thrombus by guided catheterization.
4. Inferior vena cava filter. The goal is to contain lower extremity blood clots so they don’t migrate to the lungs.

In cases where the patient does not show cardiorespiratory instability, the therapeutic option is anticoagulant therapy, namely:

1. Low molecular weight heparin or Fondaparinux (injectable subcutaneously)
2. Newer oral anticoagulant pills eg. Rivaroxaban, Dabigatran Apixaban.
3. Acenocoumarol (Syndrome).
4. Classic heparin (mainly in the first days).

The duration of treatment is 3 months. However, there are cases where an extension is recommended, such as in cases with persistent/unprovoked risk factors. The purpose of the extension is to avoid recurrence of the disease and occurrence of new episodes. In cases with certain risk factors the treatment can be continued for life.

in conclusion

Pulmonary embolism remains a strong factor in patient morbidity and mortality, particularly in hospitals. Algorithms for diagnosis, assessment of risk factors and treatment options help to avoid complications. Newer oral anticoagulants are, according to the latest guidelines, the best option for treating patients (without cardiorespiratory instability) at home.