OVERVIEW
Lung injury is a thoracic surgical disease; the lungs are relatively resistant to penetrating injuries (except for high-velocity projectiles), and the lung parenchyma has a very good capacity for repair; unless the hilar structures are damaged, air leakage and hemorrhage from the lung tissues usually stops quickly, and parenchymal injuries to the peripheral portion seldom need to be resected; on the other hand, blunt lung injury, although it results in a relatively small degree of localized damage, due to the increase in the total surface area of the multiple injuries and the secondary reactive changes, it can lead to more serious, even life-threatening, complications.
Questions you may have
What do you mean by inflammatory mediators of lung injury?
Inflammatory mediators of lung injury are inflammatory response chemical factors, such as vasoactive amines and leukotrienes, that are produced and released in body fluids and cells during the inflammatory response in the lungs.
Most of the inflammatory responses caused by these inflammatory factors are caused by the combined action of 2 or more inflammatory mediators. Common inflammatory mediators are listed below:
1. Inflammatory mediators produced by body fluids: such as histamine, cytokines (e.g., IL-1, IL-6, etc.), oxygen free radicals, lysosomal enzymes, etc.
2. inflammatory mediators produced by cells: including complement fragments, prostaglandins, leukotrienes, elastin fibers, and so on.
Inflammatory mediators of lung injury include lysosomal components such as slow-reacting substances, oxygen free radicals, growth factors, etc., in addition to the above.
In case of lung injury, it is recommended to consult a doctor in time for targeted treatment with the help of a doctor.
Etiology
Chest trauma, either blunt or sharp force trauma, can lead to lung injury. However, most of them are caused by blunt violence leading to injury to the lungs and vascular tissues. In addition, lung injuries can also be caused by severe lung infections, pulmonary embolism, and lung surgery.
Symptoms
There are various manifestations of lung injuries and the clinical typology is artificial as they are often combined. In addition, lung parenchymal injuries caused by non-penetrating injuries are frequently combined with injuries to intrathoracic organs, with the exception of lung blast injuries.
1. Localized lung contusion
This is the most common type of lung injury and presents clinically as hemoptysis as blood from the ruptured vessel fills the alveoli and their surrounding interstitium. It is an isolated injury of no clinical importance. Even if the blood flows into the bronchioles resulting in solid lesions in the distal lung tissue, in the absence of significant lung parenchymal rupture, the clot is quickly absorbed and the lung reopens.
2. Lung parenchymal laceration
Rupture of blood vessels and bronchial tubes can cause hemothorax, pneumothorax, or hemopneumothorax if it connects with the pleural cavity. Hemopneumothorax is most common in penetrating injuries, while lung parenchymal tears caused by blunt injuries are mostly located in the deep part of the lung, and the resulting bruises and gases accumulate in a certain place, either forming hematoma or pneumothorax, respectively.
3. Pulmonary hematoma
Unlike pulmonary contusion, which occurs when the bronchial tubes are blocked by blood, pulmonary hematoma is formed by the accumulation of blood from the torn lung parenchyma. Clinical manifestations are chest pain, moderate hemoptysis, low-grade fever and dyspnea, which usually lasts for 1 week and then gradually relieves. pulmonary hematoma in the initial X-ray chest film, the outline of its shadow is blurred, and due to the absorption of the blood accumulated around it, the outline is gradually clear, with a diameter of 2-5 cm. the special status of pulmonary hematoma makes people think that the pulmonary hematoma caused by blunt injuries is due to the mechanism of the counteraction force to produce a shear force in the deep part of the lung parenchyma. Without pre-injury chest X-ray comparison, a small pulmonary hematoma is difficult to distinguish from an existing spherical lesion in the lungs, pending the rapid disappearance of the shadow of the lesion. If the shadow is not absorbed within 3 weeks, an excisional biopsy should be considered to clarify the diagnosis.
4. Traumatic pulmonary cavities
Traumatic pulmonary cavities are rare. Chest injury, such as only tearing a small bronchus, without fine blood vessel injury, the air accumulates in the deep parenchyma, forming an air cavity, usually without secondary infection, and subside within 1 week. Occasionally, if there is a rupture of a thicker bronchus, forming 1 large air cavity, it is difficult to subside and requires surgical suturing of the stump of the bronchus to control the source of the gas, cause the air cavity to atrophy, and relieve the compression of the surrounding lung tissue.
Examination
X-ray chest radiography.
Diagnosis
Based on the history and clinical manifestations, combined with X-ray chest radiography may help in the diagnosis.
Treatment
1. Limited pulmonary contusion
In patients with pulmonary hematoma and traumatic air cavity, if there is dyspnea, nasal cannula or mask oxygen inhalation should be applied during emergency examination of the patient, and analgesics should be given to reduce chest pain and facilitate breathing. After the diagnosis is confirmed by X-ray chest radiographs, the patient is admitted to the hospital for further diagnosis and treatment. In order to prevent inflammation complicating the lung contusion, antibiotic treatment should be given for about 1 week. Closely observe the change of condition, repeat the X-ray chest film, observe the change of lung shadow, whether the hematoma and air cavity shadow is absorbed or whether diffuse fluffy shadow appears, which foretells the possibility of developing respiratory distress syndrome.
Complications of lung parenchymal lacerations (hemothorax, pneumothorax, or hemopneumothorax) are managed accordingly. In cases with severe air leakage or massive bleeding, no response to various measures, unstable vital signs and gradual deterioration of the condition, the chest should be opened and explored immediately, the leaking bronchial tubes and bleeding blood vessels should be sutured, and then the lacerated lung tissues should be sutured, preserving as much as possible the lung tissues, and only partial resection should be done for the extensively lacerated and fragmented lung tissues. After the operation, put closed chest drainage and continue observation.
2.Respiratory therapy
Lung tissue reacts to all kinds of injuries in the same way, and the result is recovery from absorption, complication of infection or solid change, and ultimately cause interstitial fibrous change of the lung. Lung injury, if not treated properly, causes respiratory failure, leading to hypoxemia and respiratory alkalosis, which then develops into tissue hypoxia and metabolic acidosis, and in severe cases, death.
To prevent hypoxemia and improve blood oxygenation, respiratory therapy is an effective method. Information provided by a series of arterial oxygen analyses and daily chest X-rays, combined with changes in clinical signs and symptoms, can determine the initiation and discontinuation of respiratory therapy.