Thoracic Trauma Dirty Dozen

Trauma to the thoracic cavity/chest can lead to life-threatening injuries both immediately and over the next few days after the event. These injuries sometimes require prompt recognition and treatment in the field. The difficulty is recognizing if the injury is immediately life-threatening because there is a significant overlap between trauma mechanisms, physical exam findings, and vital sign changes that occur. Most of these types of patients will have sustained a high-energy blunt or penetrating mechanism. They may have diminished breath sounds, elevated JVD or distant heart sounds, and they may be tachycardia, tachypneic, or hypotensive. Therefore, assessing for subtle differences in patient presentation, mechanism, physical exam, and vital sign changes will help better diagnose these injuries.  

The 12 most life-threatening thoracic trauma injuries are often referred to as the Thoracic Trauma Dirty Dozen (below). Over the next four weeks, this letter will provide an overview of each of the injuries, three per week, detailing common trauma mechanisms, physical exam findings, vital sign changes, and the immediate and hospital-based treatments. It will follow along with some of the in-person sessions you may have with your local EMS teams. 

Tension Pneumothorax: A tension pneumothorax is immediately life-threatening. Patients with a tension pneumothorax have often sustained high-energy blunt trauma such as a high-speed Motor Vehicle Collision (MVC), or a fall from higher than ground level. With these injuries, either from rib fractures or direct injury to the lung, air fills the pleural space around the lung and is trapped there. As more air accumulates in this space, pressure or tension builds, the lung collapses, and the entire mediastinum shifts to the opposite side of the chest. As a result, patients will present with dyspnea, tachypnea, tracheal deviation, and absent or diminished breath sounds on the affected side.  

As the pressure builds, it becomes higher than the pressure filling the heart with blood. If this occurs, the heart does not have enough blood to pump, and the patient develops obstructive shock manifested by tachycardia and hypotension. If the pressure is not immediately released, then the patient may die. To quickly relieve this pressure and allow the air to evacuate the pleural space, a needle decompression should be performed. With a needle decompression, a large 14-gauge needle is placed in either the 2nd intercostal space at the midclavicular line or in the 4th or 5th intercostal space at the anterior axillary line. If successful, a large gush of air will be heard evacuating the pleural cavity. Blood pressure and heart rate will normalize, oxygenation will improve, and breath sounds should return to the affected side. In the hospital, a chest tube or pigtail catheter will be placed, and the injury usually heals over the next 3-4 days. 

Open Pneumothorax: An open pneumothorax, similar to a tension pneumothorax, is air entering the pleural space. An open pneumothorax more typically occurs in a patient suffering a penetrating injury as the pleural space. In contrast to a tension pneumothorax, because the wound is open and the air in the pleural space can escape, there is no tension effect, and the patient will not be in obstructive shock. For patients with shock and an open pneumothorax, other thoracic traumatic injuries related to bleeding, like massive hemothorax and cardiac tamponade, should be entertained. No immediate treatment in the field is needed except to ensure that the wound remains open. Any dressing that is placed should be non-occlusive, which will allow air to pass into and out of the chest freely. In the hospital, a chest tube or pigtail catheter is placed while the injury heals.  

Hemothorax: A hemothorax is blood within the pleural cavity. A hemothorax can occur after either blunt or penetrating trauma. The blood typically comes from injury to the lung parenchyma or an intercostal blood vessel. A hemothorax is immediately life-threatening if the bleeding continues unabated, as the chest can hold several liters of blood. Smaller hemothoraces are not immediately life-threatening but need to be evacuated from the pleural space. There is no immediate intervention in the field except for overall supportive care. In the hospital, for unstable patients, the bleeding is controlled surgically. For stable patients, chest tube placement, along with blood transfusions, are typically all that is needed. 

Next week, the topics will be cardiac tamponade, blunt cardiac injury, and blunt aortic injuries.

Sincerely,

Joe Posluszny, MD

June 12, 2023 - Thoracic Dirty Dozen

Thoracic Trauma Dirty Dozen

Last week’s letter discussed tension pneumothorax, open pneumothorax, and hemothorax. In review, a tension pneumothorax occurs following a high-energy blunt trauma in which injury to the ribs or lung leads to air within the pleural cavity. As that air builds up, pressure builds in the chest that collapses the lung and can overcome blood return to the heart leading to shock and death. In the field, this can be treated with needle decompression. An open pneumothorax is typically not life-threatening as the open nature of the wound allows air to go into and out of the pleural space, and all that is required in the field is a non-occlusive dressing on the wound. A hemothorax occurs after a blunt or penetrating injury to the chest that leads to bleeding, which accumulates in the thoracic cavity. If massive, this bleeding can lead to shock and death.  

This week’s topics will be cardiac tamponade, blunt cardiac injury, and blunt aortic injury. 

Cardiac Tamponade: The pericardium is a tough tissue layer that surrounds the heart, and there is always a small amount of fluid that bathes the space between the pericardium and heart. Cardiac tamponade can occur following blunt and penetrating chest trauma as the pericardial space fills with blood. If enough blood accumulates in the pericardial space, the heart cannot contract or relax effectively to receive and pump blood, and shock and death can occur. In the field, little can be done to treat cardiac tamponade. In the hospital, cardiac tamponade can be rapidly diagnosed with an ultrasound in the trauma bay that will show fluid around the heart. Once identified, the patient is taken to surgery immediately to evacuate the blood from the pericardium and then repair the injury that led to the bleeding. 

Blunt Cardiac Injury: Like any other part of the body, the heart can be bruised following a direct blow to the chest. And like any bruise, as blood vessels and tissue are damaged, blood products and fluid will accumulate. If this bruise occurs along the tracts that control the electrical conduction system that regulate the heartbeat and rhythm, then arrhythmias can develop. Therefore, patients who present with blunt chest trauma and associated thoracic injuries are screened for blunt cardiac injury in the trauma bay with an EKG and troponin level. If either of these are abnormal, then the patient is monitored with telemetry for 24 hours, as this is the time that arrhythmias will develop. The force to the chest is sometimes so great that the septum between the chambers of the heart or the support structure for a heart valve can tear. This is rare, and patients with these injuries are often extremely unstable. 

Blunt Aortic Injury: Similar to a blunt cardiac injury, a blunt aortic injury occurs after a high-energy blunt mechanism. However, there is often a deceleration component to the trauma that leads to the aortic injury. During the traumatic event, as the entire body stops moving forward, the aorta, which is fixed in position at its origins at the heart, at the ligamentum arteriosum, at the take-off of the left subclavian artery, and at the diaphragm, but otherwise free to move, tears at these fixation points. If the aorta ruptures freely, then the patient will exsanguinate immediately. For patients with a partial tear or contained rupture who make it to the hospital, surgery or close hemodynamic control of heart rate and blood pressure are pursued. If possible, the aortic injury can be stented through endovascular techniques.  

Next week’s topics will be airway obstruction, tracheobronchial injury, and flail chest. 

Joe Posluszny, MD

June 19, 2023

Thoracic Trauma Dirty Dozen

Another week discussing trauma primarily in the chest. Specifically, this week’s topics are airway obstruction, tracheobronchial injury, and flail chest.  



Last week’s letter discussed cardiac tamponade, blunt cardiac injury, and blunt aortic injury. In review, cardiac tamponade occurs when the pericardial space between the heart and pericardium fills with blood and prevents adequate relaxation and contraction of the heart. As a result, the patient develops obstructive shock. Treatment includes surgical evacuation of the blood and repair of the injury that caused the bleeding. Blunt cardiac injury is bruising of the heart which can lead to changes in the electrical conduction pathways that maintain a normal heart rate and rhythm. Occasionally, this can lead to life-threatening arrhythmias. There is no intervention other than supportive care. With a blunt aortic injury, the aorta tears at an anatomic location where it is fixed in place. It typically occurs after a high-energy mechanism with deceleration. If the patient survives the initial injury, then it can be treated either with endovascular surgery or with strict heart rate and blood pressure control.

Airway Obstruction: Following a penetrating or blunt injury to the head and neck, bleeding can lead to hematoma formation, which can distort normal anatomy. Even a small amount of bleeding can lead to airway obstruction. In the field, head tilt, chin lift, and jaw thrust maneuvers can help to maintain airway patency. These maneuvers should be performed while keeping in mind other neck or cervical spine injuries that may also be present. In the trauma bay, if the airway is obstructed or there is a concern for an impending obstruction, then a definitive artificial airway is established with an endotracheal tube, or if unable to be obtained, a surgical airway via a cricothyroidotomy or tracheostomy may be necessary.

Tracheobronchial Injury: In this educational series, airway obstruction refers to obstructions above the level of the trachea. A tracheobronchial injury can occur below this level from both blunt or penetrating injuries and are often deep within the neck or chest. Patients will present with respiratory distress, stridor, and subcutaneous emphysema. In the field, there are limited interventions other than local wound care. In the hospital, the airway is typically secured first to maintain airway patency and ensure ventilation and oxygenation. After this, the injury can be repaired primarily with surgery, covered with a stent, and allowed to heal on its own or to have airflow bypassed with a bronchial blocker.  

Flail Chest: Flail chest occurs after a high-energy blunt trauma when multiple ribs are fractured. If a single rib is fractured in two different locations, that rib segment is independent of the remainder of the chest wall. When multiple ribs in sequence are fractured like this, a large section of the chest wall will have a paradoxical motion in relation to the chest cavity. As the patient inhales, the uninjured chest wall will expand, but this segment will remain still or collapse. The opposite happens as the patient exhales and the chest wall relaxes. It can lead to significant respiratory distress and can impair ventilation. In the hospital, the patient will get pain control, pulmonary support with possible intubation and mechanical ventilation, and rib plating to stabilize the rib fractures. 

Next week’s topics will be diaphragm rupture, esophageal injury, and pulmonary contusion. 

Joe Posluszny, MD

June 26, 2023

Thoracic Trauma Dirty Dozen

In review of last week’s discussion of tracheobronchial injuries, airway obstruction occurs after any injury that leads to bleeding and hematoma formation in the head and neck that distorts normal anatomy. Maintaining airway patency with head tilt, chin lift, and jaw thrust maneuvers is essential in the field.  In the hospital, tracheobronchial injuries can be treated with tracheal stents, surgical repair, or bronchial blockers. Flail chest occurs when multiple sequential ribs are broken in more than one location leading to a free-floating segment of the chest wall that has paradoxical motion during inspiration and expiration.    

This week’s topics are diaphragm rupture, esophageal injury, and pulmonary contusion.    

Diaphragm Rupture:  The diaphragm can rupture following a high-energy blunt mechanism like a fall from a height or MVC with direct pressure of the steering wheel against the abdomen. The massive force against the abdomen can be transmitted to the thin-walled diaphragm, which can tear, allowing for herniation of intraabdominal contents into the chest. On the right side of the abdomen, the liver protects intraabdominal contents from herniating into the chest. On the left side, the stomach and part of the colon can easily traverse the diaphragm defect and enter the chest. In the field, the patient may present with both abdominal pain and tenderness and respiratory distress.  

In the trauma bay, the classic finding is a nasogastric tube that enters the abdomen below the diaphragm and then curls up into the stomach in the chest. This injury is repaired in the operating room either with a suture alone or a piece of mesh.  

Esophageal Injury: A traumatic esophageal injury can occur anywhere along the length of the esophagus from the neck down the chest and into the abdomen. The esophagus courses next to the aorta and spine, as well as the trachea, bronchi, and heart. Given its long course in the neck, chest and abdomen, an injury to the esophagus must be considered any time one of these other structures is injured. In the field, an esophageal injury should be suspected when there is bilious drainage from a neck or chest wound and can be treated with local wound care. In the hospital, an esophageal injury is confirmed with a contrast study like an esophogram.  

Once identified, the injury can be treated with stenting, esophagectomy, or in severe cases with other major chest injuries, diversion of the esophageal flow down the esophagus with a proximal esophagostomy or spit fistula.    

Pulmonary Contusion:  A pulmonary contusion is bruising of the lung typically from a blunt mechanism but may also be from a high-energy penetrating injury like a gunshot wound. As with any bruise, tissue injury leads to edema and inflammatory mediator infiltration. If severe and diffuse enough, pulmonary contusions can lead to significant respiratory distress leading to respiratory failure and the need for intubation and mechanical ventilation. Mechanical ventilation itself can worsen the amount of inflammation and further impair oxygenation and ventilation. In the field, recognition of the injury pattern and potential for pulmonary contusion and communicating those findings will heighten the suspicion of this injury, allowing the appropriate steps to be taken in the trauma bay. In the hospital, there is very little that can be done other than limit IV fluids and protect the lungs from additional or worsened injury.      

I hope this weekly review helped in your knowledge and understanding of the 12 common thoracic traumatic injuries. Please relay any instances in which this may have helped your assessment and treatment of trauma patients and suggestions for topics in the future.

Joe Posluszny, MD