Where does a blood clot come from?
In the vast majority of cases, the source is deep vein thrombosis of the legs or pelvis. A fragment of the blood clot breaks off, passes through the right side of the heart and gets stuck in the pulmonary artery. Part of the blood flow in the lungs stops, the load on the right ventricle increases, and the oxygen saturation of the blood decreases.
Hence an important conclusion: prevention of pulmonary embolism means prevention and timely treatment of venous thrombosis.
Who's at risk
- Previous history of deep vein thrombosis or pulmonary embolism
- Major surgeries, especially orthopedic, and trauma
- Prolonged immobility: bed rest, plaster cast, flights over 4 hours
- Oncological diseases and chemotherapy
- Pregnancy and postpartum period
- Hormonal contraceptives and replacement therapy, especially for smokers
- Obesity, age, hereditary thrombophilias
Symptoms
Manifestations depend on how large a branch is blocked. When small branches are affected, the symptoms are erased, while with massive embolism they are catastrophic.
- Sudden shortness of breath is the most common symptom and occurs at rest or with minimal exertion
- Chest pain, often stabbing, worsens with inspiration
- Increased heart rate and breathing
- Cough, sometimes streaked with blood
- Dizziness, fainting, severe weakness
- With massive pulmonary embolism - drop in pressure, cyanosis, circulatory arrest
Отличие от инфаркта: при ТЭЛА боль чаще колющая и связана с дыханием, на первый план выходит одышка, а в анамнезе есть фактор риска — перелёт, операция, отёк ноги. Но надёжно различить их без обследования нельзя, поэтому в обоих случаях вызывают скорую.
Diagnosis and treatment
- Anticoagulant therapy is the basis of treatment, begins immediately if there is a high probability
- Thrombolysis - for massive pulmonary embolism with unstable hemodynamics
- Surgical or catheter removal of a blood clot - in selected cases
- Vava filter - if anticoagulation is impossible or relapses against its background
- Oxygen support and intensive care
- Long-term anticoagulation after discharge; the period depends on the reason
- Оценка клинической вероятности по шкалам, ЭКГ и рентген для исключения других причин.
- D-димер — при низкой вероятности отрицательный результат позволяет исключить ТЭЛА.
- КТ-ангиография лёгочных артерий — main подтверждающий метод.
- Эхокардиография — оценка перегрузки правых отделов сердца, особенно при нестабильном состоянии.
- УЗИ вен ног — поиск источника тромба.
Prevention
- Early activation after operations and injuries is the most important measure
- Prophylactic anticoagulants in high-risk patients as prescribed by a physician
- Compression hosiery for operations, pregnancy, flights
- On long flights: get up every hour, exercise your feet, drink enough fluids
- Timely treatment of deep vein thrombosis and varicose veins
- Quitting smoking while taking hormonal contraceptives
