Most pulmonary embolisms are caused by the formation of a deep vein thrombosis in the lower extremities, which dislodges the thrombus and returns through the veins into the pulmonary arteries.
Lower extremity deep vein thrombosis (DVT) and pulmonary embolism (PE) are collectively referred to as venous thromboembolism. Nearly 50% of patients with proximal DVT of the leg have asymptomatic PE; about 80% of patients with PE are found to have DVT (mainly asymptomatic); some DVT can be asymptomatic, with the first symptom being PE; more than 50% of proximal DVT progresses to PE.
Causes of thrombosis.
(1) Slow or stagnant venous blood flow in the lower extremities.
Perioperative bed braking; intraoperative distortion of body position; history of varicose veins, etc.
(2) Blood hypercoagulation.
Perioperative “dehydration” state; release of tissue factor after anesthesia and trauma, activation of exogenous coagulation system.
(3) Venous wall injury: intraoperative use of tourniquets, surgical mechanical manipulation, central venous cannulation, etc.
Factors that predispose to deep vein thrombosis.
(4) Smoking.
(5) Obesity, advanced age.
(6) Long-term bed rest or lower limb paralysis.
(7) Malignant tumor: 3-5 times higher incidence.
(8) Previous history of varicose veins, venous thrombosis.
(9) Major compound trauma: pelvic fracture and acute spinal cord injury.
(10) Severe medical disease: hypertension, diabetes mellitus, acute heart attack, etc.
Clinical manifestations of venous thromboembolism.
(1) Clinical manifestations of lower limb deep vein thrombosis (3-6% of deep vein thrombosis have obvious clinical symptoms since childhood, related to the size of the embolus and clinical symptoms)
A. Swelling, pain and pressure pain of the affected limb.
B. Change of skin temperature and color: the skin is warm and red, or may be pale.
(2) Main clinical manifestations of pulmonary embolism (PTE).
A. Pleural-like chest pain: the most common.
B, dyspnea and shortness of breath.
C, syncope and shock are the characteristics of patients with combined severe central PTE.
Prevention is more important than cure, and the cost of prevention is less than the cost of treatment.
In Asia, the incidence of venous thromboembolism in patients after major orthopedic surgery is high, and this disease has become a “roadblock” to the development of surgery. Therefore, the response at this stage is to actively prevent it in all patients undergoing major orthopedic surgery.
1. Basic preventive measures
(1) Operate gently and delicately around the extremities or adjacent pelvic veins to avoid damage to the venous lining.
(2) When elevating the affected limb after surgery, do not put a separate pillow in the N fossa or under the calf to avoid affecting the deep vein reflux in the calf.
(3) Encourage the patient to perform active foot and toe activities as early as possible and make more deep breathing and coughing movements.
(4) Get out of bed as early as possible, and wear gradual compression compression stockings (GCS) for the lower limbs.
2.Mechanical preventive measures
Lower limb blood circulation promoter or graded compression stocking, they both use mechanical principle to accelerate the venous blood flow of lower limb, which can reduce the incidence of deep vein thrombosis of lower limb after surgery.
3.Drug preventive measures
4.The coagulation process continues to be activated for up to 4 weeks after major orthopedic surgery, and the risk of venous thromboembolism can last up to 3 months, and the duration of deep vein thrombosis prevention is generally not less than 7-10 days, which can be extended to 28-35 days.
Health tips to prevent deep vein thrombosis and pulmonary embolism.
It is important to actively prevent deep vein thrombosis in your life. Drink more water to dilute the blood viscosity on the one hand, on the other hand, you can also take the opportunity to go to the toilet to move your lower limbs more, and do travel leisure exercises when possible.
For people at risk, it is important to resolve to change their lifestyles, such as quitting smoking, exercising properly, controlling weight, maintaining a relaxed mood, and keeping a healthy lifestyle.
Diet should pay attention to reduce cholesterol intake, eat more vegetables and fruits, and drink tea in moderation. For women who have been taking oral contraceptives for a long time, they should pay attention to the fact that they should not take the pill for more than 5 years, and they can also use the intermittent pill method.
Senior patients who have medium and major surgery are among those who are at high risk of deep vein thrombosis, so please make sure you are alert to the occurrence of deep vein thrombosis and pulmonary embolism.
Cooperate with the health education given to you by the nurse lady before the operation.
When suspicious symptoms such as chest tightness, chest pain and elevated body temperature occur, patients should promptly notify the nurse and doctor and promptly ask the specialist to start standardized treatment in order to save the patient’s life.
If you can’t go down to the ground immediately after the operation, you should wear step-by-step compression elastic stockings and active active activities mainly knee extension and flexion exercises and foot and ankle active and passive exercises.
In embolism-prone patients with congenital deficiencies of certain anticoagulant factors, lifelong oral anticoagulants may be required.