Re-expansion pulmonary edema

　　The pathological changes are similar to adult respiratory distress syndrome or pulmonary edema after lung transplantation. The pathogenesis is not yet fully understood, but it is generally believed that the degree of lung collapse, the duration of time, the speed of lung re-expansion, the speed of chest drainage (air and fluid drainage), the amount in one go being too large, or the use of negative pressure suction are the main causes. The age may also be one of the causes of re-expansion pulmonary edema. The strong permeability of pulmonary capillaries may be the main cause of re-expansion pulmonary edema.

　　19. In addition to general symptoms, it may also cause other diseases. This disease may be complicated with DIC and acid-base imbalance. Since various organs and systems are damaged, it may eventually lead to multiple organ failure. Therefore, once it is found, active treatment should be given, and preventive measures should also be taken in daily life.

　　16. It often occurs suddenly, with severe dyspnea, shallow and rapid breathing, sitting breathing, coughing, expectoration of white or pinkish foam-like sputum, pale complexion, cyanosis of the lips and extremities, profuse sweating, restlessness, palpitations, fatigue, etc. Signs include widespread bubbling sounds and/or wheezing in both lungs, increased heart rate, gallop rhythm and systolic murmur in the apex, expansion of the heart border to the left, and possible arrhythmia and alternating pulse.

　　Re-expansion pulmonary edema should focus on prevention, and early detection, early diagnosis, early treatment should be achieved to reduce the incidence and mortality of re-expansion pulmonary edema. The key lies in the correct understanding of the disease, especially for some elderly and weak patients with malignant tumors, chronic severe empyema, etc., who often have hypoproteinemia and hypoxemia. Once re-expansion pulmonary edema occurs, it is easy to lead to multiple organ failure and death. To prevent re-expansion pulmonary edema, the following points should be paid attention to in clinical work:

　　12. For pleural effusion, pneumothorax, especially for large amounts of effusion and pneumothorax, where the lung has been compressed and collapsed for a long time, the speed of drainage of effusion, pneumothorax, and closed chest drainage should be slow, and the drainage tube should be clamped intermittently or the flow rate regulated by an infusion clamp, with the first day's drainage volume ≤1000ml. Some suggest that if the lung is compressed for 7 days or more, the first drainage volume should be ≤1000ml, the first fluid extraction about 500ml, and the first gas extraction ≤3/4 of the compressed volume. The second day's drainage volume should be ≤2000ml, and the gas extraction can be arbitrary.

　　11. Strictly control the indications for closed chest negative pressure drainage, and if negative pressure drainage is required, the pressure should not exceed 20cmH2O (1.96kPa).

　　10. During double-lumen tube anesthesia for thoracotomy surgery, intermittent ventilation of both lungs should be performed to avoid the lung on the surgical side from being collapsed for a long time. During the recovery process from anesthesia, it is best to manually control the bag to re-expand the lung, at a slow speed and with moderate tidal volume.

　　9. During the process of large gas and fluid exhaust, drainage of gases and fluids, or after surgery, closely observe the patient. For those who experience chest tightness, shortness of breath, palpitations, persistent or frequent coughing in a short period of time, be highly vigilant about the occurrence of re-expansion pulmonary edema, immediately stop the relevant procedures, and can inject about 200ml of gas or fluid into the chest.

　　8. Control the volume and rate of fluid administration, closely observe urine output, and perform central venous pressure monitoring and bed-side X-ray chest films if necessary.

　　1. There is a history of pleural effusion, pneumothorax, or lung collapse due to compression.

　　2. Chest drainage or acute re-expansion of the lung after surgery may induce it.

　　3. After lung re-expansion, symptoms of dyspnea may appear in a short period, such as severe coughing, coughing out or吸出 a large amount of white or pinkish foam-like sputum or fluid, and shallow and rapid breathing.

　　4. The patient may have fine bubbling sounds in one or both lungs and an increased heart rate.

　　5. During the recovery period of anesthesia, there may be shallow and rapid spontaneous breathing, coughing out or吸出 foam-like sputum or pinkish fluid through the tracheal tube.

　　6. SpO2 is unstable early on and then continues to decline.

　　7. Imaging examination shows scattered and patchy hazy shadows throughout the affected lung.

　　8. Special examinations include blood hypercoagulability, intrapulmonary shunting, hypoxemia, metabolic acidosis, and others.

　　Eat high-sugar foods as much as possible, adjust the structure to the first carbohydrate, the second fat, and the third protein. Consume liquid energy as much as possible if conditions allow, such as fruit juice, soup, milk, which can also supplement some water. Milk tea is a good food, and butter tea is also good. They are high-calorie foods with a lot of fat, which can protect and moisten the skin. The theophylline in them also has a diuretic effect.

　　The key to the diagnosis and treatment of re-expansion pulmonary edema lies in maintaining sufficient oxygenation and hemodynamic stability in the patient. The main measures include:

　　1. Keep the respiratory tract unobstructed. Adopt the lateral decubitus position with the affected side up to facilitate expectoration. For patients with different conditions, use various methods such as aspiration with a suction apparatus, fiberoptic bronchoscope aspiration, tracheal intubation, or tracheotomy aspiration.

　　2. Oxygen therapy and respiratory support treatment. For patients with mild hypoxemia, oxygen therapy can correct the condition. When using nasal cannula or face mask for oxygen therapy, the oxygen concentration should be ≥50%, and at the same time, add defoaming agents such as 50% alcohol. If the condition is severe and tracheal intubation or tracheotomy has been performed, use positive pressure mechanical ventilation at the end of expiration, with a pressure of 5.0 cmH2O (0.49 kPa) to maintain alveolar opening, reduce excessive alveolar surface tension caused by insufficient pulmonary surfactant, improve the ventilation/perfusion ratio imbalance, and reduce intrapulmonary shunting, reduce transmural pressure of pulmonary capillaries and leakage of blood components, and increase oxygen partial pressure to a level that can be accepted clinically.

　　3. Maintain blood volume. Insert a central venous catheter, monitor central venous pressure (CVP), and effectively control fluid volume and infusion rate.

　　4. Use adrenal cortical hormones to increase the stability of the pulmonary capillary membrane, and at the same time, use diuretics (furosemide, hydrochlorothiazide), cardiotonics (digoxin), aminophylline, and correct electrolyte and acid-base imbalances.

　　5. Use corticosteroids as appropriate, control fluid intake, and strictly monitor the condition and acid-base balance.