Pulmonary Embolism in the Elderly
Introduction
Introduction to pulmonary embolism in the elderly Pulmonary embolism (PE) refers to the pathological and clinical syndrome caused by the insertion of the embedding substance into the pulmonary artery and its branches, blocking the blood supply of the lung tissue. Common emboli are thrombus, and rare new cell clusters and fats. Drops, bubbles, etc. Since the lung tissue has a dual blood supply to the pulmonary artery-bronchial artery, and direct gas exchange between the lung tissue and the alveolar gas is possible, most of the pulmonary embolism does not necessarily form an infarction, and there is no obvious clinical manifestation. In the elderly, pulmonary embolism is a common and frequently-occurring disease. basic knowledge The proportion of illness: 0.051% Susceptible people: the elderly Mode of infection: non-infectious Complications: shock, sudden death
Cause
Causes of pulmonary embolism in the elderly
Thrombosis (20%):
The important basis of modern diagnosis and treatment of pulmonary embolism is to recognize the close relationship between deep vein thrombosis and pulmonary embolism. The vast majority of pulmonary embolism can be considered as a complication of deep vein thrombosis or its clinical manifestations. It shows that more than 90% of the patients have clinical manifestations of pulmonary embolism, and the emboli are from the proximal deep vein of the lower extremity (the iliac vein, femoral vein). After the thrombus falls off, the embolism is caused by circulation to the pulmonary artery. The data also indicate that the proximal deep vein of the lower extremity Thrombosis complicated with pulmonary embolism rate of more than 50%, but most of them have no obvious clinical symptoms; there are no obvious clinical symptoms from the iliac or distal venous thrombosis, which may be that the smaller thrombus does not cause obvious lung blood. - The change of respiratory dynamics, thrombosis in the early stage of deep vein thrombosis, the fibrinolysis process is active and the risk of pulmonary embolism is the highest, blood stasis, hypercoagulable state, high viscosity state and venous endothelial injury is thrombosis Promoting factors. Therefore, trauma, surgery, prolonged bed rest, varicose veins, diabetes, obesity, etc. may be risk factors for pulmonary embolism. Residual blood clots in the proximal deep vein thrombosis of the lower extremities may also lead to recurrence of pulmonary embolism.
Heart disease (20%):
It is believed to be the most common cause of pulmonary embolism in China, accounting for 40%, which can be seen in various types of heart disease. It occurs mostly in patients with atrial fibrillation, heart failure, and subacute bacterial endocarditis. Cardiac thrombosis can also be a bacterial embolus.
Malignant tumors (20%):
It is also considered to be a common cause of pulmonary embolism in China, accounting for 35%, common in lung cancer, digestive system tumors, choriocarcinoma, leukemia, etc., one third of the embedding is tumor thrombus, and 2/3 is thrombus.
Other (10%):
Rare embedding can also be seen in fat droplets in long bone fractures, amniotic fluid during childbirth, air emboli during accidental or decompression sickness.
Mechanical obstruction of the embolus during pulmonary embolism will lead to hemodynamic disturbance of the pulmonary circulation. It is generally believed that the mean pulmonary artery pressure begins to increase when the pulmonary vascular bed obstruction is 30%; the right atrial pressure increases when 35%; the pulmonary artery is 50% The mean pressure and pulmonary vascular resistance are significantly increased, causing acute pulmonary heart disease. In addition to mechanical obstruction of embolism, there are complex humoral factors and nerve reflexes involved in pulmonary embolism. Serotonin, thromboxane, leukotrienes during pulmonary embolism The release of cytokines such as platelet activating factor and neuro-humoral reflex will aggravate pulmonary hemodynamic disorders, and even cause local bronchoconstriction, atelectasis, pulmonary edema, alveolar hemorrhage, alveolar wall necrosis, clinical manifestations of dyspnea , hairpins, lungs, etc.
Pathogenesis
The etiology of PE is complicated. The above causes can form an embolus or induce the formation of an embolus. After shedding, the blood flows to the pulmonary artery, causing obstruction of the pulmonary artery and its branches.
Prevention
Elderly pulmonary embolism prevention
In view of the fact that most of the pulmonary embolism comes from the thrombosis of the deep veins of the lower extremities or the right heart chamber, it prevents vascular endothelial damage, corrects hypercoagulable hyperviscosity, and prevents hemodynamic disorders (such as blood stasis and atrial fibrillation, etc.) It is the key to prevent pulmonary embolism. Specific preventive measures: 1 Avoid entering drugs that are irritating to the vein wall, remove the venous cannula early, and actively treat varicose veins.
2 long-term bedridden should avoid the underarms under the armpits, encourage the bed to do active activities and coughing movements of the lower limbs, wear long tube elastic stockings or use inflatable long boots to intermittently press the lower limbs to encourage early getting out of bed.
3 active treatment of hypercoagulable, hyperviscosity.
4 active treatment of deep vein thrombosis of the lower extremities, including thrombolysis, anticoagulation and even surgical treatment.
5 patients with peripheral thrombosis should maintain a smooth bowel movement.
6 correct atrial fibrillation and so on.
Complication
Elderly pulmonary embolism complications Complications
Mainly bleeding, right heart failure or shock, and even sudden death.
Symptom
Pulmonary embolism symptoms in the elderly Common symptoms Difficulty breathing Chest pain Pulmonary embolism Pleural effusion Wheezing Myocardial infarction Mindset Thoracic pain Painful dyspnea Sudden death
The clinical manifestations of pulmonary embolism are non-specific, but may be free of any symptoms or only slight discomfort. In the case of acute right heart failure or shock, or even sudden death, the severity of the disease depends on the size of the embolus and the extent of occlusion of blood flow. , the location and speed of occurrence, as well as the patient's original cardiopulmonary function, some scholars have summarized the clinical manifestations of pulmonary embolism into four types:
Pulmonary embolism
Difficulty breathing (especially unexplained labor dyspnea) and chest pain, a small number also see a small amount of hemoptysis, chest pain can be radiated to the shoulder or abdomen, the main signs are breathing and heart rate, lung wet voice or wheezing, Pleural friction sounds can also be heard with fibrinous pleurisy.
2. Pulmonary infarction
Sudden dyspnea and chest pain, sometimes manifested as post-sternal pain like myocardial infarction, and even syncope or shock, in addition to the above, there may be skin cold, pale or cyanosis, blood pressure and so on.
3. Acute pulmonary heart disease type
Sudden and severe dyspnea, chest pain, suffocation, irritability, mental disorder, shock, syncope, etc., and even sudden death, in addition to the above, there may be P2 hyperthyroidism, tricuspid systolic reflux murmur, Jugular vein engorgement, positive for jugular vein regurgitation.
4. Chronic embolic pulmonary hypertension
In addition to the performance of pulmonary hypertension, a small amount of hemoptysis is common.
About 40% of patients have low, moderate fever, a small number of patients with high fever in the early stage, double lower extremity examination, often have one or both sides of the swelling, more asymmetry, often accompanied by tenderness, superficial varicose veins and so on.
20% to 30% of patients with pulmonary embolism die due to lack of timely diagnosis and active treatment, timely diagnosis and anticoagulation, thrombolytic therapy can reduce the mortality rate to 8%, so early diagnosis is very important, the current rate of misdiagnosis of pulmonary embolism and The rate of missed diagnosis is extremely high. The reason is that the diagnosis is not strong, and it is wrong to think that pulmonary embolism is rare in China. Second, it is not enough to understand its clinical manifestations. It is often only in sudden severe chest pain, hemoptysis, and difficulty breathing. The disease is considered only when the hair is in the shadow of the chest. In fact, there are less than one-third of the so-called "typical" syndromes. Most of them have only one or two symptoms, such as "pneumotitis", especially in elderly patients.
Older people (especially those who have been in bed for a long time, or after surgery, or who have had heart disease) have difficulty breathing due to unexplained reasons. Patients with palpitations or chest pain should be advised to exclude pulmonary embolism. If the lower extremities are swollen, tender, varicose veins or atrial fibrils More vigilance should be used when vibrating, you can use lower extremity Doppler vascular examination, or radionuclide venography, or volume impedance map, or real-time (B type) ultrasound, deep vein thrombosis, and chest see "Hump "Shadows, or blood D-dimer test positive can be initially diagnosed; radionuclide lung ventilation / perfusion scan showed a mismatch, the perfusion defect in the distribution of the lung segment is highly suggestive of pulmonary embolism, if necessary, pulmonary angiography can be further Confirmed diagnosis.
Elderly people with unexplained sudden dyspnea, palpitations, chest pain, fever and bloody pleural effusion should be alert to the possibility of pulmonary infarction; sudden breathing difficulties, palpitations, severe chest pain, suffocation or sudden death, cyanosis, fainting, shock, etc. Should be alert to the possibility of acute pulmonary heart disease caused by extensive embolization of the pulmonary artery, should be further examined and confirmed in time.
Studies have shown that 2/3 of suspected cases of pulmonary embolism can not rely solely on radionuclide lung scan + clinical evaluation to make or exclude the diagnosis of pulmonary embolism, and the examination of deep venous thrombosis of the lower extremities will greatly improve the correct diagnosis rate.
Examine
Examination of pulmonary embolism in the elderly
1. Blood gas analysis: PaO2 decreased and PaCO2 increased.
2. White blood cell count: normal or elevated, erythrocyte sedimentation rate, serum lactate dehydrogenase and muscle phosphokinase increased.
3. X-ray chest X-ray: the lung texture in the obstructed area is reduced, the local transillumination is increased, and the patch infiltrates, the atelectasis, the diaphragmatic levator, the pleural effusion, and the pleural basal bulge to the hilum. Shadow, acute pulmonary heart disease type can also be seen right heart enlargement; chronic embolic pulmonary hypertension type can be seen in the right lower pulmonary artery widening and residual root sign.
4. Electrocardiogram: no abnormalities in mild cases; severe cases can be similar to acute pulmonary heart disease-like SIQIII TIII sign, pulmonary P wave, right bundle branch block.
5. Pulmonary angiography: It is the "gold standard" for the diagnosis of pulmonary embolism. It can accurately understand the location and extent of embolism, but it has certain risks to the elderly. Only when other methods are difficult to diagnose clearly, weigh the pros and cons. use.
6. Pulmonary Nuclide Scan: Perfusion of radiolabeled human serum albumin for lung scan, radioactive rare or absent, but must be excluded from other lung lesions, radionuclide perfusion lung scan combined with radionuclide aerosol lung Ventilation scan can significantly improve the positive rate and accuracy of the diagnosis.
7.D-dimer detection: D-dimer is a good marker of fibrin degradation in vivo, highly sensitive to pulmonary embolism (95% to 98%), but poor specificity (30% to 40%) ), D-dimer detection negative as a diagnostic diagnosis of pulmonary embolism is of great value.
8. Spiral CT and MRI: There is also a certain value in the diagnosis of pulmonary embolism.
9. Lower extremity venography: is the "gold standard" for the diagnosis of deep venous thrombosis of the lower extremities, but may cause the embolus to fall off, which is currently used less.
10. Lower extremity Doppler vascular examination: radionuclide venography, volume impedance map, real-time (B-type) ultrasound examination, are common methods for the diagnosis of deep vein thrombosis of lower extremities, both have high sensitivity and specificity.
Diagnosis
Diagnosis and diagnosis of pulmonary embolism in the elderly
Need to be differentiated from acute myocardial infarction, pneumonia, pleurisy.
