Pulmonary embolism (PE): prevention
Last reviewed: 19.10.2021
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Prevention of PE is the timely expansion of bed rest in the postoperative period, diagnosis and treatment of thrombophlebitis of the veins of the lower extremities.
Patients with heart failure, obese, with malignant neoplasms operated on pelvic organs and retroperitoneal space, after alloprosthetics of the hip joint for the prevention of phlebothrombosis of the lower extremities and PE it is recommended to inject 5,000 units of heparin SC 2 times / sug from the evening preceding operative intervention, until the end of the period of greatest risk of phlebotrombosis (7-10 days).
In recent years, it is proposed to use low molecular weight heparins for phlebothrombosis prophylaxis.
Low molecular weight heparin preparations contain a fraction with a molecular weight of 3000-9000 Dalton and have relatively high inhibitory activity with respect to factor Xa. This leads to a more pronounced antithrombotic effect. At the same time, low-molecular-weight heparin preparations very slightly inactivate thrombin, less influence on vascular permeability and less thrombocytopenia than conventional unfractionated heparin, which causes a significantly lower risk of bleeding.
Recommended doses of low molecular weight heparins for the prevention of deep vein thrombosis:
- enoxaparin (clexane, lovenox) - 40 mg (or 4000 IU) once a day or 30 mg (3000 IU) 2 times a day;
- Fraxiparin (supraparin) - 0.3 ml (or 3075 IU) for 3 days, and from 4 days 0.4 ml (or 4100 ME) once a day;
- Dalteparin (Fragmin) 5000 IU once a day or 2500 IU twice a day;
- reviparin (cleavage) - 0.25-0.5 ml (or 1750-3500 ME) once a day.
The use of heparin reduces the risk of non-lethal PE by 40%, lethal - by 60%, deep vein thrombosis - by 30%.
In recent years, the method of surgical prevention of pulmonary embolism has been spread by implanting an umbrella filter into the infrarenal section of the inferior vena cava. This operation is shown:
- with embologenic thromboses of the ileoccava segment, when it is not possible to perform embolectomy;
- with repeated embolism in the pulmonary artery in patients with an unknown source of embolism;
- with massive PE.
Umbilical filters ("emboos") are installed in the infrarenal vena cava by percutaneous puncture of the jugular or femoral vein.
All patients who undergone PE are to be monitored for at least 6 months to timely detect chronic pulmonary hypertension, which develops in 1-2% of cases due to a mechanical obstruction to blood flow in the small circulation.