Mediastinal Trauma (Injury to the Chest Organs)

What is Mediastinal Trauma (Injury to the Chest Organs)?

The mediastinum is a space in the chest that houses many very important blood vessels and organs. Any damage to these structures due to an injury can be immediately life-threatening. Most people with chest injuries are treated without surgery, but doctors should always be on the lookout for possible damage to the mediastinum. Treatment for patients with mediastinal injuries should follow the Advanced Trauma Life Support guidelines. Injuries to the mediastinum caused by blunt force are not normally as deadly as those caused by piercing, which often result in surgery and have a high death rate. This writing will break down how to assess and treat a mediastinal injury caused by trauma.

What Causes Mediastinal Trauma (Injury to the Chest Organs)?

The exact causes of isolated injuries in the mediastinal area (the space in the chest between the lungs) aren’t completely understood. However, the leading cause of such blunt chest injuries in the U.S. is car accidents. Certain factors linked with chest injury in car accidents include high-speed driving, not wearing seatbelts, severe car damage, and deformity of the steering wheel.

Another common cause of chest injury is penetrating trauma, which usually happens from gunshots and knife wounds. Less common reasons for such injuries can include being impaled by objects during work accidents, falls, crashes, blasts or military devices.

Risk Factors and Frequency for Mediastinal Trauma (Injury to the Chest Organs)

Chest trauma is the third most common form of injury in the United States, following head and extremity trauma. Surprisingly, one in four traumatic deaths in the country is linked to chest injuries. The occurrence of chest injuries due to penetrating injury fluctuates significantly depending on the region.

In Europe, such incidences could be as low as 4%.
In contrast, in war-affected zones, up to 95% of military deaths could result from penetrating chest injuries.
In the United States, about 10% of serious injuries are caused by gunshot wounds to the chest, while stab wounds to the chest account for approximately 9.5%.

Signs and Symptoms of Mediastinal Trauma (Injury to the Chest Organs)

If a person experiences chest trauma, they may have damaged the area in their body called the mediastinum. The primary people who will be able to tell if an injury may have occured in the mediastinum are the first responders at the scene of the accident. Injuries to the front of the chest may make these healthcare workers think that there may be a mediastinal injury. As is the case with all trauma victims, following systematic checks, known as ATLS principles, allows healthcare workers to rapidly identify life-threatening injuries. If someone has a mediastinal injury, checks should be made for low blood volume shock caused by bleeding or obstructive shock caused by fluid around the heart i.e., cardiac tamponade. Signs of shock due to bleeding include a narrow difference between the systolic and diastolic blood pressure, low blood pressure and a fast heart rate. Cardiac tamponade, on the other hand, can display symptoms such as low blood pressure, muffled heart sounds, and swollen neck veins. Once the primary checks are completed, a top-to-bottom body check should be performed to spot any other injuries.

Testing for Mediastinal Trauma (Injury to the Chest Organs)

When trauma patients are brought in for evaluation, they undergo a series of lab tests. This often includes a full check of the blood chemistry, blood count, clotting parameters, and lactic acid level.

Along with these lab tests, imaging like a chest X-ray and ultrasound exam, known as a FAST (Focused Assessment with Sonography in Trauma) exam, are commonly used. The chest X-ray can show if there’s air in the mediastinum (the area between the lungs), which could indicate injury to the esophagus or windpipe. It can also show if the mediastinum is wider than usual, which could mean there’s blood inside the sac around the heart or bleeding from the major blood vessels.

The FAST exam can detect blood in the sac around the heart. However, if there’s also bleeding in the chest cavity, it might miss the bleeding around the heart.

An echocardiogram, a type of ultrasound of the heart, can help detect blood in the sac around the heart, symptoms of tamponade (a medical emergency when fluid builds up around the heart), or heart injury. Also, to check for blunt heart injury, doctors might do an EKG (electrocardiogram – a test of the heart’s electrical activity) and check a blood test called troponin. A normal EKG and negative troponin test can rule out a blunt heart injury.

For patients who are stable, a CT (computed tomography) scan can detect injuries in the mediastinum. This scan can provide critical information for patients suffering from trauma. In case of a penetrating injury, it can show the path of the penetrating object to check if the mediastinum was touched. Also, it can detect injuries to the esophagus or windpipe, whether due to blunt or penetrating trauma. Using oral contrast with the CT scan can help see the esophagus better, while injecting contrast into the vein can help detect injuries to blood vessels like the aorta.

A double contrast esophagram might be used to rule out an injury to the esophagus. This involves giving a water-soluble contrast orally or through a nasogastric tube (a tube inserted through the nose into the stomach). Then pictures are taken. If no leakage is detected, the process is repeated using a barium contrast.

Finally, for those with a significant mechanism of injury, a bronchoscopic and endoscopic examination might be recommended. These tests can help evaluate if there’s any damage to the esophagus and the bronchial tree, the part of the airway that connects the windpipe with the lungs.

Treatment Options for Mediastinal Trauma (Injury to the Chest Organs)

If a patient has sustained a traumatic chest injury but remains stable after examination, they may be sent home. However, those showing signs of chest injury should be monitored in the hospital for at least 24 hours. If a patient’s condition does not improve with initial treatment and resuscitation in the emergency room, immediate surgery may be necessary to address internal bleeding or a condition known as cardiac tamponade, which is when fluid fills the sac around the heart and restricts its function.

Some injuries, such as rapid deceleration damage to the main blood vessel coming from the heart (the aorta), can be fatal in 80% of cases. In surviving patients, prompt treatment is crucial, as these injuries can worsen rapidly. Blood pressure control medications are typically used to stabilize these patients while other serious injuries are addressed. After stabilization, the aortic injury can be repaired surgically.

Heart injuries can range from minor bruising to serious ruptures. Proper patient stabilization methods, resuscitation and medications can help. In severe cases, the heart lining itself may rupture, which often leads to swift deterioration and necessitates urgent surgical intervention. For these patients, a process known as pericardial window may be used to help identify and assess the injury.

Esophageal repair strategy should be determined based on the injury’s location and severity. Chest or neck incisions are typically made to access and repair the injury. More complicated scenarios may require more extensive procedures, such as esophageal exclusion, followed by thorough resuscitation and delayed reconstruction in the intensive care unit.

Tracheobronchial injuries, which affect the windpipe and the main branches leading into the lungs, are relatively rare but can occur in less than 1% of patients with blunt chest injury. Surgical strategies depend on the location of the injury and typically involve removing unhealthy tissue and using sutures for repair.

In some instances, emergency department thoracotomy, a surgical procedure performed on the chest, may be required. This procedure is usually reserved for patients in or near cardiac arrest and provides immediate access to the heart and aorta for life-saving measures. Survival rates from this procedure vary greatly depending on the nature of the injury and the patient’s status upon arrival at the hospital.

The exact indications for emergency department thoracotomy are still a subject of debate, but established guidelines suggest it is appropriate for specific patient groups. It’s most successful in treating patients with penetrating injuries confined to the chest.

A tear in the main artery (Aortic rupture)
A tear or cut in the heart muscle (Cardiac laceration)
Injury to the clavus, a part of the brain (Claval injury)
Bone break in the collarbone (Clavicular fracture)
Sudden disturbance or shock to the heart due to a blunt force (Commotio Cordis)
Condition where a section of the rib cage breaks and becomes separated (Flail chest)
Accumulation of blood in the chest cavity (Hemothorax)
Injury to the artery that runs between the ribs (Intercostal artery injury)
Damaged oesophagus, the tube that carries food from the mouth to the stomach (Oesophageal injury)
Broken rib (Rib fracture)

Possible Complications When Diagnosed with Mediastinal Trauma (Injury to the Chest Organs)

Calculating the complication rate of traumatic chest injuries, also known as mediastinal injuries, is challenging since they usually occur alongside other injuries. The complications that might arise among these patients are varied. Here are some of them:

Narrowing or blockage of the bronchial tubes or esophagus, known medically as bronchial or esophageal stricture.
Development of abnormal connections between the trachea and esophagus, referred to as tracheoesophageal fistulas, can happen in patients with injuries to these specific areas.
Patients may develop empyema, a condition where pus accumulates in the chest cavity, or ventilator-associated pneumonia if they have mediastinal trauma.
Lastly, damage to the thoracic duct and chylothorax, a type of lung disease where lymphatic fluid leaks into the space between the lung and chest wall, can also occur.

Frequently asked questions

Mediastinal trauma refers to an injury to the organs and blood vessels in the chest, specifically the mediastinum. It can be life-threatening and should be treated according to Advanced Trauma Life Support guidelines. Blunt force injuries to the mediastinum are generally less deadly than piercing injuries, which often require surgery and have a higher death rate.

Chest trauma is the third most common form of injury in the United States.

Signs and symptoms of Mediastinal Trauma (Injury to the Chest Organs) include: - Low blood volume shock caused by bleeding, which can be indicated by a narrow difference between the systolic and diastolic blood pressure, low blood pressure, and a fast heart rate. - Obstructive shock caused by fluid around the heart, known as cardiac tamponade. Symptoms of cardiac tamponade include low blood pressure, muffled heart sounds, and swollen neck veins. - Injuries to the front of the chest may suggest the possibility of a mediastinal injury. - First responders at the scene of the accident are the primary people who can identify if an injury may have occurred in the mediastinum. - Following systematic checks, known as ATLS principles, allows healthcare workers to rapidly identify life-threatening injuries. - Once the primary checks are completed, a top-to-bottom body check should be performed to spot any other injuries.

The exact causes of isolated injuries in the mediastinal area (the space in the chest between the lungs) aren't completely understood. However, the leading cause of such blunt chest injuries in the U.S. is car accidents. Certain factors linked with chest injury in car accidents include high-speed driving, not wearing seatbelts, severe car damage, and deformity of the steering wheel. Another common cause of chest injury is penetrating trauma, which usually happens from gunshots and knife wounds. Less common reasons for such injuries can include being impaled by objects during work accidents, falls, crashes, blasts or military devices.

The doctor needs to rule out the following conditions when diagnosing Mediastinal Trauma (Injury to the Chest Organs): 1. A tear in the main artery (Aortic rupture) 2. A tear or cut in the heart muscle (Cardiac laceration) 3. Injury to the clavus, a part of the brain (Claval injury) 4. Bone break in the collarbone (Clavicular fracture) 5. Sudden disturbance or shock to the heart due to a blunt force (Commotio Cordis) 6. Condition where a section of the rib cage breaks and becomes separated (Flail chest) 7. Accumulation of blood in the chest cavity (Hemothorax) 8. Injury to the artery that runs between the ribs (Intercostal artery injury) 9. Damaged oesophagus, the tube that carries food from the mouth to the stomach (Oesophageal injury) 10. Broken rib (Rib fracture)

To properly diagnose mediastinal trauma (injury to the chest organs), a doctor may order the following tests: 1. Lab tests: - Full blood chemistry - Blood count - Clotting parameters - Lactic acid level 2. Imaging tests: - Chest X-ray to check for air in the mediastinum and widening of the mediastinum - Ultrasound exam (FAST exam) to detect blood in the sac around the heart 3. Additional tests: - Echocardiogram to detect blood in the sac around the heart, symptoms of tamponade, or heart injury - EKG (electrocardiogram) and troponin blood test to check for blunt heart injury - CT scan to detect injuries in the mediastinum, path of penetrating objects, and injuries to the esophagus or windpipe - Double contrast esophagram to rule out esophageal injury - Bronchoscopic and endoscopic examination to evaluate damage to the esophagus and bronchial tree It is important to note that the specific tests ordered may vary depending on the patient's condition and the suspected injuries.

Mediastinal trauma, or injury to the chest organs, is treated based on the specific type and severity of the injury. For stable patients, they may be sent home if there are no signs of chest injury. However, patients showing signs of chest injury should be monitored in the hospital for at least 24 hours. If initial treatment and resuscitation in the emergency room do not improve the patient's condition, immediate surgery may be necessary. The treatment options for different types of chest organ injuries include blood pressure control medications for aortic injuries, surgical repair for heart injuries, esophageal repair strategies based on location and severity of the injury, and surgical strategies for tracheobronchial injuries. In some cases, emergency department thoracotomy may be required for life-saving measures, but its indications are still a subject of debate.

The side effects when treating Mediastinal Trauma (Injury to the Chest Organs) can include: - Narrowing or blockage of the bronchial tubes or esophagus, known as bronchial or esophageal stricture. - Development of abnormal connections between the trachea and esophagus, referred to as tracheoesophageal fistulas. - Accumulation of pus in the chest cavity, known as empyema. - Ventilator-associated pneumonia. - Damage to the thoracic duct and chylothorax, where lymphatic fluid leaks into the space between the lung and chest wall.

Injuries to the mediastinum caused by blunt force are not normally as deadly as those caused by piercing, which often result in surgery and have a high death rate.

A trauma surgeon.