Pathology of closed chest injury

2021-01-30 12:00 AM

In the case of a large amount of pleural haemorrhage, it may pose a problem of blood transfusion to restore the amount of drained blood. Be sure to ensure sterile and proper dialysis unit.

Understanding the pathophysiology and trauma mechanism of the breast helps to detect lesions and provide timely, proper diagnosis and treatment.

There are two causes of acute compression that should be considered: pericardial effusion or pneumothorax under pressure.

Causes of closed-chest injuries: Traffic accidents account for 70% of cases and 25% of cases die on the spot. The mortality is secondary to 2 disorders: respiratory failure and circulatory failure.

Pathophysiology of closed chest injury

Due to direct injury

This mechanism is common.

It is divided into 2 cases:

Injury when the chest is fixed.

Injury when the chest moves.

In the first case, the traumatic agent hits the chest directly. The severity of trauma depends on the volume, speed and shape of the trauma agent. Injury to the chest when the chest moves and hits the obstruction directly. The severity of injury depends on the degree of change in speed, position and direction of impact. The change in the position of the organs in the thorax causes the lesions to spit at the fixed position of the organs.

Injury caused by compression

This mechanism causes damage in the chest wall and collapses the cardiopulmonary muscle.

Lesions are common in direct trauma and compression

Includes lesions in the chest wall and chest organs. The chest wall is composed of the ribs and diaphragm. Fracture of ribs is common from 3rd to 10th rib. The injuries causing 1-2 rib fractures are usually very severe and need to study the damage of the aorta and the aorta on loops. Fracture of the end ribs should look for coordinated intra-abdominal lesions. A rupture of the diaphragm is caused by increased intra-abdominal pressure. 80% is a rupture of the left diaphragm.

Among thoracic factors, first of all attention is paid to vascular factors (heart, aorta, the aortic trunks on the loops of the aorta). The heart muscle stroke is the main damage to the heart, usually caused by pinching or pressing the heart against the sternum. The abrupt deceleration mechanism damages the aortic waist rupture between the mobile part (loops of the aorta) and the fixed part (descending aorta). The bronchi can be damaged by a compression or deceleration mechanism. The lung parenchyma can collide, causing hematoma and gas in the affected area.

Pathophysiology of respiratory failure

Ventilation mechanism disturbances

Participation in this mechanism includes central nervous system, chest wall and lung parenchyma. The dysfunction of one of these factors can cause respiratory distress.

Neurological respiratory failure: Due to traumatic brain injury, but also from cervical spinal cord injury.

Respiratory failure due to chest wall causes: Mobile ribs. This is the main cause of respiratory failure in chest trauma. Cell amplitude depends on the size, location and area of ​​the rib array. Hypoxemia is caused by decreased alveolar ventilation, due to a decrease in movement of the chest wall (the reverse respiratory view is incorrect: Indeed, the thoracic wall and the movable rib plate move in the same direction but the cell amplitude causes decreased chest wall movement).

The anterior and lateral movable ribs are often unstable, whereas the posterior rib array is covered by the shoulder blade and dorsal muscle mass so it is less mobile.

Another cause is a rupture of the diaphragm. Indeed, the difference in pressure between the abdominal cavity (positive pressure) and thoracic (negative pressure) causes the abdominal organs to be drawn up in the thorax causing a condition such as pleural effusion that depresses the body. product of the lung.

Respiratory failure due to bronchial obstruction: Bronchiectasis is suggested by obstruction of the upper airways in the presence of a combined facial injury or bronchial rupture. Bronchiectasis can also cause obstruction.

This is more likely to occur after stress or due to secondary hypoventilation following a chest wall injury.

Impairment of alveolar-capillary gas metabolism

The first cause of damage to the alveolar-capillary membrane is collapsing lungs. In such circumstances, hypoxemia is explained by three phenomena: Shunt's effect due to the presence of an unvented perfusion area, the actual shunt due to vascular damage and lung parenchyma damage.

Pathophysiology of circulatory failure

There are two possible shock conditions in a closed chest trauma. Heart shock is more common. Understand that myocardial shock is the primary cause. But it could also be secondary to damage to the heart valves or a compression of the heart. Decreased shock due to bleeding or failure. Among the causes of intrathoracic bleeding can be rupture of the aorta (90% rupture of the aorta) or rupture of the aortic loops.

Diagnose

Assessing the severity of injury depends on the severity of the injury and the patient's profile.

Injury to the chest wall

Diagnosis of rib fracture is mainly based on clinical practice. Chest pain is increased with respiratory movements, clinical examination determines sharp pain when touching fracture. X-rays help make a more accurate diagnosis. In addition, chest X-ray also helps detect complications caused by fracture of the ribs such as bleeding, pneumothorax. When there is a fracture of the last two ribs, it is necessary to find the combined abdominal lesions and do an abdominal ultrasound.

Fracture of the sternum is suggestive of palpation pain and has a "hierarchical image" due to displacement of the two fractured bones. Diagnosis is confirmed by X-ray of the tilted sternum. When diagnosing a sternum fracture, it is necessary to immediately look for cardiomyopathy.

Suspect diaphragm rupture when abdominal fracture and chest pain are present. Hear the sound of the lungs. Chest radiograph shows continuous loss of the diaphragm and the level of water vapor in the chest or contrast peptic scan. Abdominal ultrasound can reveal a discontinuity of the diaphragm.

Bleeding or pleural gas, may be mixed

The pneumothorax syndrome includes patients with chest pain valve, difficulty breathing, ringing, alveolar whispering (RRPN) decreased. Chest radiograph shows overly bright images of the damaged lung. Pneumothorax under pressure is a surgical emergency. Need to find and detect early when there is dyspnea associated with vascular collapse. Chest radiograph shows pneumothorax and mediastinal gas being pushed to the opposite side.

Pleural hemorrhage: Clinical percussion, decreased RRFN, X-ray conspicuous in the damaged lung. Echo determined pleural hemorrhage.

Sometimes there are cases of air spill - combined effusion.

Lungs pounding

Clinical signs of pulmonary collapse are less specific. Clinically found tachycardia and decreased RRFN. X-rays have unevenly limited fuzzy contrast circular images with uniform contrast blurring or spots. These X-ray images often appear slowly: It is immediately visible on the scanner image.

Trauma to the bronchial air

Complete rupture of the trachea, damage can occur from the larynx to the lobe bronchus. Clinical and radiology allow for diagnostic direction and be confirmed by bronchoscopy. The clinical picture is very diverse, with clinical manifestations such as respiratory failure, neck mediastinal airflow, hemoptysis, and pneumothorax. There may be a more discreet clinical presentation and a diagnosis considered when the air exits the persistent drainage, the lungs are not enlarged or collapsed.

Tracheal rupture can be detected by acute difficulty breathing. In intubation, chest radiographs suggest pneumothorax and combined mediastinal airflow and subcutaneous airflow. Mediastinal gas spillage, on radiograph there are rows of light next to the mediastinum. Bronchoscopy is a means of helping to determine the morphology and nature of the lesion. Lesions can range from simple to complex, such as the rupture or rupture of the entire tracheal circumference. Bronchoscopy is performed only when the patient has had bronchoscopy.

Aortic rupture due to injury

This injury has been suggested in chest trauma due to a deceleration mechanism. There is no specific clinical manifestation. One in two cases has a hemodynamic instability. Asymmetric peripheral circuits in 1/10 cases.

Chest radiograph is abnormal in 85% of cases, diagnosis is suggested to have indirect signs. Chest x-ray, if possible; photograph the patient in a sitting position. Changes in the position of the thoracic organs were observed: trachea pushed to the right, left main bronchus pushed down, patient had gastric catheterization saw gastric catheter pushed to the left. Compared with the aortic loops, mediastinum dilated, aortic loop contour is not clear. When there are images that suspect additional tests are required, such as an aortic scan, a contrast-injected spiral scanner is a highly sensitive and specific test. is a useful test.

Injuries hit the heart

The clinical manifestations are very diverse, the common conditions are acute pericardial effusion with acute compression, combined with dizziness, right heart failure with prominent neck veins, inversion veins, and distant faint heart sound. Diagnosing a heart attack is often difficult. The clinical presentation may be normal or in severe heart failure. ECG presents with arrhythmia or conduction disturbances. Cardiac enzymes have little diagnostic value. Diagnosis is based on a special echocardiography of the esophagus. Echocardiography helps to see ventricular movement disorders, evaluate valve damage.

Emergency management attitude

Evaluate the severity of the breast injury

Look for signs of respiratory distress such as tachypnea rate over 35 times / min, bluish-purple, sometimes blue-purple signs obscure symptoms of severe anemia, signs of difficulty breathing: ribs, inverse respiration.

 Look for signs of circulatory failure such as low blood pressure combined with tachycardia. Examination of the neck veins is extremely important because it helps guide the diagnosis either due to hypovolemic shock or acute compression of the heart. In the case of a prominent cervical vein combined with dizziness is a sign of acute heart compression.

The mechanism of trauma, combined lesions, sites, and patient history are among the criteria that contribute to the assessment of patient severity.

Purpose of treatment

Ensure a stable blood oxygen exchange and hemodynamic condition.

In order for oxygen exchange to be guaranteed, release of the upper respiratory tract and therapeutic oxygen is required. Supportive ventilation is initiated only when no pulmonary compression is warranted or after chest drainage is placed. Assign supportive respiration when Glasgow <8 points, hemodynamic and respiratory conditions (frequency> 35 beats / min, SaO2 <90% with O2)

Pleural drainage in case of pleural hemorrhage, aspiration or pneumothorax draining in case of pneumothorax.

To ensure a stable hemodynamic condition, it is necessary to apply hemostatic pressure bandage to peripheral wounds, and place 2 large intravenous lines.

In the case of a large amount of pleural hemorrhage, it may pose a problem of blood transfusion to restore the amount of drained blood. Be sure to ensure sterile and proper dialysis unit.

Refrained blood transfusion is contraindicated when there is a perforation of the abdomen or an empty organ perforation. When there is a lot of coughing up blood need to raise the problem of selective intubation.

Follow

What to do: Blood formula, blood type, Rhésus, blood gases, heart enzymes, ECG, echocardiography of the heart and abdomen, CT Scanner for timely surgical indications.

In the first hour: Clinical follow-up. Ultrasound of the abdomen, chest, and heart. Indication of thoracotomy is indicated when the amount of blood in the pleural space is worth more than 1200 ml or the chest drain is> 200 ml / 1 hour.

In the first 24 hours: Chest X-ray to check for lesions that is coordinated is the cervical spine. If there are signs of focal nerve, perceptual disorders need cranial ST Scanner.

 Depending on the clinical signs and conditions to suggest other additional tests such as: Chest CT Scanner with combined angiogram, CT scanner of abdomen.

The principles of treatment

Damage to the chest wall

Broken ribs:

For a simple rib fracture, there is no problem of specific treatment.

For multi-rib fractures with movable rib array, it is necessary to specifically treat the rib plate immobilization. Aim to improve respiratory condition and relieve pain.

There are many means of relieving pain in chest injuries including local pain relief, regional pain relief, and general relief. Epidural anesthesia is an extremely effective method for relieving pain on both sides of the chest, but care should be taken in the case of a combined abdominal injury as it can be difficult to detect coordinated lesions. Intercostal anesthesia has also been shown to be effective, but there is a risk of over-dosage of anesthetic due to the need for multiple intercostal anesthesia, and complications of pneumothorax. Systemic pain relief should be cautious in case of other combined lesions, caution should be exercised in small patients with prior chronic respiratory failure.

Means to treat mobile ribs such as: Supportive ventilation.

This method is effective in situations where a movable rib array is present at the front, or where a movable rib array is suspended over the orthopedic frame. Or means of fusion of bones with nails, with agrafage are indicated in the presence of surgical thoracic intervention or in the case of severe thoracic deformation.

For diaphragm rupture as an indication for surgical treatment, the problem is the choice of the operating route. Treatment with classic surgical methods is opening the abdomen and stitching the diaphragm or with laparoscopic surgery when the size of the rupture is small.

Hemorrhage and pleural gas:

Chest drainage is a fundamental procedure in breast trauma. All thoracic drainage should be performed under guaranteed sterility. Chest X-ray is required before and after pleural drainage. The thoracic drainage location is the II intercostal space on the median line or the IV rib space on the anterior axillary line. Conduct local anesthesia, each layer, cut the skin about 2cm dissect each layer from the skin to the pleura. Insert the drainage duct through the trocat into the pleural cavity. Connect the drain hose to a closed, continuous suction system with negative pressure.

The main complication of chest drainage is damage to the lung parenchyma or organs in the abdomen.

For pneumothorax, the location of the drainage duct is elevated and in front of the pleural cavity. Monitoring drainage, if the gas is excreted much, the suction is ineffective, it is necessary to specify chest endoscopy for diagnosis and treatment.

For pulmonary hemorrhage drains set back and low. If the amount of blood through the drainage duct is less than 100ml / h, the patient should be closely monitored. If the amount of blood in the pleural space is initially assessed at about 1000 ml or the amount of blood flowing through the drainage tube is between 100 and 200 ml, chest endoscopy is required to collect blood clots and assess the lesion. If the initial blood count is assessed above 1200ml or the bleeding through the drainage tube is more than 200ml / hour, emergency chest opening is indicated.

Treatment of lung collapse

The first is oxygen masque therapy. If ineffective then supportive respiration under constant positive pressure is required.

Treatment of bronchial rupture

Diagnosed by bronchoscopy. Emergency treatment includes pleural drainage, intubation beyond the damaged segment. Treatment methods include: tracheostomy for lateral tear, complete suture for complete rupture or removal of the lobe or segment of the lung below the lesion. Surgical treatment is no later than 3-4 days after the injury. Because after this time the risk of infection is high.