Talking about “pulmonary embolism” now seems to be a bit “cliché”, because it is an old topic, not a new thing. Acute pulmonary embolism seriously affects life and health, and the disease is characterized by high misdiagnosis rate, high underdiagnosis rate and high mortality rate. Previous statistics show that the mortality rate of pulmonary embolism is as high as 20%-30%. In recent years, clinicians pay great attention to it, and with the improvement of medical imaging technology, a good platform for diagnosing the disease has been established, and the diagnosis rate has increased significantly.
In clinical work, there are often tumor patients with sudden onset of unexplained respiratory distress and even sudden death, so we should be alert to whether “pulmonary embolism” has occurred? Common clinical manifestations: patients suddenly have unexplained deficiency, pale face, cold sweat, dyspnea, chest pain, coughing, coughing blood, etc., and have symptoms of cerebral hypoxia such as extreme anxiety, lethargy, nausea, convulsions and coma.
I. Pulmonary embolism is also a common complication of malignant tumors, and it has been reported in the literature that malignant tumors increase the incidence of pulmonary embolism by 4 times. In China, tumor is the second cause of pulmonary embolism (accounting for 35%), which is much higher than foreign 6%, and the reasons are related to the following factors.
1, tumor cells act on the coagulation system, making the body in a state of hypercoagulation and abnormal function of the fibrinolytic system;
2, malignant tumor secondary to abnormal platelet activity and thrombocytosis, aggravating the hypercoagulable state of blood;
3. Various interventions, including surgical anesthesia, long-term bed rest, tumor compression and inadequate fluid replacement, slow blood flow and stagnation;
4, direct tumor invasion, radiotherapy and central venous placement, which directly damage the blood vessel wall and promote thrombosis.
Doctors suggest that patients with initial unprovoked pulmonary embolism should be routinely screened for cancer in order to detect malignant tumors under the cover of pulmonary embolism at an early stage.
Pulmonary arteriography is the current “gold standard” for the diagnosis of PE, but it is not yet widely available due to various limitations. Non-interventional methods, such as fibrin degradation products (e.g., D-dimer), spiral CT, electrocardiography, and vascular ultrasound, tend to increase after pulmonary embolism, are commonly used for diagnosis. Combining examination with clinical manifestations, most PE can be diagnosed, and the morbidity and mortality rate of PE can be reduced to 2%-8% with treatment.
For patients with confirmed cancer combined with pulmonary embolism, the following treatment should be taken.
1.General treatment
Most patients with massive pulmonary embolism are hemodynamically unstable, blood pressure, heart rate, respiration and oxygen saturation should be monitored; patients should be absolutely bedridden to avoid thrombus dislodgement again; analgesic drugs such as morphine, dulcolax and codeine should be given to those with severe chest pain; for those with hypotension or shock, dobutamine and alamine can be given intravenously to maintain normal body circulation; when PaO2<60~65mmhg, oxygen should be given by face mask and assisted breathing in time. and timely assisted breathing. < span="">
2. Thrombolytic therapy
This is the most popular and effective treatment option in clinical practice. Thrombolytic therapy can dissolve the thrombus in the pulmonary artery, improve blood perfusion in the pulmonary tissue, reduce pulmonary circulatory resistance and pulmonary artery pressure, and improve right heart function; dissolve the thrombus in the deep venous system, and also reduce the source of emboli and recurrence of pulmonary embolism; improve the quality of life and long-term prognosis. According to the recommendations of thrombolytic therapy of the Chinese Medical Association’s Respiratory Medicine Branch: PE patients with a diagnosis of massive PE with shock or right heart insufficiency within 2 weeks after the onset of symptoms of pulmonary embolism should undergo thrombolytic therapy. However, it has also been proposed that thrombolytic therapy should be taken if a diagnosis of massive or submassive pulmonary embolism is made, even in the absence of hemodynamic changes.
The commonly used thrombolytic agents are urokinase (UK), streptokinase (SK), and heavy tissue fibrinogen activator (rt-PA).
It should be noted that active gastrointestinal bleeding; intracranial hemorrhage within 2 months; and post-cranial and spinal surgery are absolute contraindications to thrombolysis for pulmonary embolism. The relative contraindications to thrombolytic therapy are mainly.
① major external or gynecological surgery within 10 days, childbirth;
②Recent gastrointestinal bleeding, liver and kidney failure;
③Severe trauma and hypertensive patients with systolic blood pressure ≥180mmHg and diastolic blood pressure ≥110mmHg.
3.Anticoagulation therapy
The anticoagulants commonly used in clinical practice are common heparin, low molecular weight heparin (LMWH) and warfarin, with LMWH as the first choice.
Anticoagulation therapy for PE is mainly applicable to: those who are treated with pure anticoagulation after PE thrombolysis and those who do not have the indication of PE thrombolysis. The clinical dose of anticoagulant drugs should be adjusted according to the partial prothrombin time (APTT) and the international standard ratio (INR).
Generally, heparin is effectively anticoagulated for 3-5 days, and the clinical situation is stabilized before switching to oral warfarin. The oral starting dose of warfarin is often 3 mg, and the dose is adjusted according to the INR. In patients with a first episode without risk factors, the course of treatment should be at least 6 months; if risk factors can be removed, anticoagulation for 3 months; if risk factors are not modifiable, those with combined pulmonary heart disease, especially those prone to embolism, the course of treatment needs to be extended, or even lifelong anticoagulation is required.