EMS Chest Injury

Etiology

Mechanisms of traumatic chest injuries can be classified as penetrating (eg, gunshots, lacerations, and punctures) or blunt (eg, motor vehicle accidents, falls, crush injuries, blasts, and burns). The majority of chest trauma cases are associated with blunt injuries. Both types of trauma can result in various sequelae, including tension pneumothorax, open pneumothorax, hemothorax, flail chest, pericardial effusion, cardiac tamponade, aortic rupture, esophageal rupture, tracheal or bronchial tree rupture, myocardial or pulmonary contusion, and diaphragmatic rupture.[4]

Epidemiology

Chest injuries are associated with 14% of all blunt trauma cases and 12% of all penetrating trauma cases, accounting for approximately 25% of all trauma-related mortality.[4] Thoracic aortic injuries, while uncommon, are particularly associated with poor outcomes.

Pathophysiology

Most pathological effects result from disrupted respiratory and hemodynamic functions. A flail chest occurs when 3 or more contiguous ribs are each broken in at least 2 places, creating a "free-floating" segment of the chest wall. Pneumomediastinum and pneumopericardium may also occur during chest trauma.

Examples of complex chest trauma occur via the following mechanisms: 

• Tracheobronchial esophageal injury 
• Pneumothorax with concomitant pericardial disruption 
• The Macklin effect—a pathophysiological process initiated by blunt traumatic alveolar ruptures or basement membrane destruction, interstitial emphysema, and dissecting air along the pulmonary vasculature into the mediastinum.

History and Physical

EMS providers may receive inaccurate or incomplete information from dispatch before the patient arrives at the emergency department. Many factors, including the patient's condition and scene safety, determine how much time can be spent gathering information in the field. Ideally, EMS personnel should obtain an abbreviated summary of the inciting event, the overall timeline, and the patient's medical history while performing a brief physical examination.

If a patient is incapacitated, family members or other witnesses may be able to provide relevant information. Details such as the amount of blood loss (eg, from gunshots, stabbings, and amputations), extraction times (eg, from motor vehicle accidents and structural collapses), and any changes in mental status or vital signs during transport should be communicated to hospital providers upon arrival.

A detailed history and physical examination performed by in-hospital providers are essential for determining appropriate treatment or the need for further transport. The physical examination is arguably more important than the history, especially in cases where the patient cannot communicate with the providers. 

Evaluation

When caring for a trauma patient, EMS providers have 3 critical tasks—physical examination and recognition of injuries, stabilization, and transportation to a nearby trauma center or hospital. The primary survey follows the "ABC" assessment—airway, breathing, and circulation. These critical categories must be resolved before progressing to the secondary survey, even if the patient has an apparent or distracting traumatic injury. The patient's vital signs and level of consciousness must also be assessed regularly. Prehospital care providers should focus on severe hemorrhage control, airway maintenance, and recognition of life-threatening conditions. 

Airway

Assessment and stabilization of the airway is the initial step of providing care to trauma patients. A preliminary impression can be ascertained from the patient's appearance and verbalization. An altered mental status or injury to the head or neck can complicate this step. Cervical spine precautions are vital, and there should be a low threshold for immobilization and cervical collar placement. Necessary airway interventions include jaw thrust maneuvers, oropharyngeal or nasopharyngeal airways, suctioning, and supplemental oxygen via nasal cannula or non-rebreather facemasks. Further airway control may be temporizing (eg, supraglottic airway) or definitive (eg, endotracheal intubation).

Breathing

The patient's respiratory status is assessed immediately after, and often simultaneously with, the airway. Evaluation of the respiratory rate, chest wall movements, breath sounds, and oxygenation status aids in determining the need for immediate intervention. Providers should look for signs or symptoms of tension pneumothorax, open pneumothorax, and flail chest in particular.

Circulation

Assessment of circulatory status is particularly important for patients with chest trauma, as hemodynamic compromise can be rapid and severe. The "C" of circulation includes evaluating distal pulses in all extremities.

Cardiac monitoring, examination for signs of internal or external bleeding, and applying direct pressure or a tourniquet are critical actions that may be indicated. Intravenous (IV) or intraosseous (IO) access may be obtained en route for fluid bolus administration but should not delay transport. Similarly, cardiac monitoring and a 12-lead ECG may be helpful but should not delay timely delivery to the hospital.[5]

Other Considerations

Several EMS considerations are associated with the prehospital setting. The first is assessing and establishing scene safety. EMS providers practice in diverse environments, ranging from cramped personal living quarters to widespread disaster areas. Each setting poses unique threats to both patient and EMS personnel safety. Although there is an innate inclination to help the victim, providers must recognize that their well-being is imperative to be able to help others. Precautions must be taken early to minimize the risk to providers during patient treatment. Additionally, environmental conditions can change rapidly, and periodic reassessment of scene safety is recommended when possible.[3] 

In prehospital settings, the SAFE approach is recommended: [6]

• Shout/call for help.
• Assess the scene.
• Free from danger?
• Evaluate the casualty.

EMS providers also encounter scenarios involving multiple injured individuals. In these situations, EMS personnel must rely on clinical assessment and established system-specific triage criteria to distribute resources appropriately and determine each patient's proper setting and order. Triage protocols vary between systems and are continually being reviewed and revised. 

The typical clinical signs of severe chest injury may not be apparent in the field. For example, paradoxical motion may not be observed in a patient with shallow breathing due to pain. Auscultation during the prehospital interval may be challenging due to surrounding noise and other distractions. Therefore, prehospital providers should maintain a high index of suspicion for underlying severe injuries.

Ultrasound Use in Prehospital Settings

The use of ultrasound devices for trauma patients in prehospital settings has been explored in Europe and parts of the United States, although it is not yet universal. The benefits of ultrasound include increased diagnostic accuracy and improved decision-making regarding triage, choice of transport modality, and receiving facility. For chest trauma specifically, ultrasound can facilitate quicker, more reliable diagnoses of pneumothorax, pericardial effusion, and other conditions. However, additional research is needed to determine whether prehospital use of ultrasound is associated with reduced morbidity and mortality in trauma patients.[7]

Treatment / Management

Several potential complications can arise from chest trauma, some requiring immediate intervention. Any critical issues identified during the primary survey demand an immediate response before further assessment. Some pathologies are indications of a "load-and-go" approach, focusing on rapid, noninvasive intervention and timely transport to a definitive healthcare facility. After stabilization, the primary objective of EMS is to transport the right patient to the right place at the right time. EMS personnel are a key component of trauma management due to the time-dependent nature of the injuries incurred.

Tension Pneumothorax

Tension pneumothorax is characterized by the progressive accumulation of air within the thoracic cavity, creating a volume of air and positive pressure within the pleural space. This volume exerts a progressively worsening mass effect on the mediastinal and intrathoracic structures. Creating a one-way valve allows air to enter the thoracic cavity but restricts its exit. As air volume increases, local thoracic pressure rises, leading to the collapse of the ipsilateral lung and compression of the contralateral lung. The mediastinum shifts away from the trapped air volume, reducing venous return to the heart. If left untreated, even a small pneumothorax can advance to obstructive shock and, potentially, fatal outcomes.

Signs and symptoms of tension pneumothorax include hypoxia, tachycardia, tachypnea, hypotension, tracheal deviation away from the injured side, and diminished breath sounds, hyperresonance, hyperexpansion, and reduced chest wall movements on the injured side.

EMS providers may perform needle decompression by inserting a 14-gauge needle, typically in the second intercostal space in the mid-clavicular line on the affected side, which allows the buildup of air and pressure to escape the thorax safely. The success rate for this procedure varies; the cannula can become obstructed by tissue or become lodged within the muscle. This approach can temporarily stabilize a deteriorating patient by providing a stop-gap measure while preparing for definitive management, such as placement of a pigtail catheter or chest tube thoracostomy, typically conducted in a hospital setting.[8][9](A1)

Open Pneumothorax

Open pneumothorax is an open, "sucking" chest wound that communicates with the pleural space and allows free air entry during inspiration but significantly limits the air that can escape during expiration. An open pneumothorax presents similar to (and often precludes) a tension pneumothorax. Immediate intervention is necessary to prevent rapid progression and severe complications. Applying an occlusive dressing and a non-permeable cover sealed tightly on 3 out of 4 sides reduces air entry during inspiration and allows more air to escape during expiration. This temporary measure buys time until definitive hospital management can be performed.[10] 

Flail Chest

A flail chest occurs when adjacent ribs have 2 or more fractures each, creating a detached section of the rib cage. This segment depresses inward during inspiration (due to negative intrathoracic pressure) and is pushed outward during expiration (due to positive intrathoracic pressure). This phenomenon is termed "paradoxical breathing," as it is the opposite of normal chest wall motion. Blunt forces with the magnitude capable of causing multiple rib fractures often also cause pulmonary contusion. However, a bruised lung is typically not clinically apparent and may only be detected incidentally during imaging. EMS providers can stabilize flail segments in the field by applying manual pressure during transport to prevent hypoventilation.[11](A1)

Other Diagnoses

Other diagnoses associated with chest trauma span from benign to life-threatening emergencies. EMS protocols have not yet been developed to address severe conditions such as pericardial tamponade, massive hemothorax, aortic rupture, diaphragmatic tear, and esophageal injury. Therefore, EMS providers focus on stabilizing the "ABCs" and adopting a "load-and-go" approach.[12][13] 

Differential Diagnosis

Differential diagnoses to consider when evaluating a chest injury include the following:

• Tension pneumothorax
• Open pneumothorax
• Hemothorax
• Flail chest
• Pericardial effusion
• Cardiac tamponade
• Aortic rupture
• Tracheal or bronchial tree injury
• Myocardial contusion
• Pulmonary contusion
• Diaphragmatic rupture
• Esophageal rupture

Prognosis

Chest injuries are associated with high morbidity and mortality rates, with prognosis significantly influenced by the severity of the chest injury, the extent of extrathoracic injuries, and preexisting medical conditions. The majority of patients with blunt traumatic aortic injuries die before reaching a hospital or stand-alone emergency facility. However, early assessment, stabilization, and effective technical intervention are associated with improved patient survival rates. Advanced age in patients correlates with worse outcomes.

Complications

Chest injuries can lead to various complications involving multiple thoracic organs, often requiring radiographic imaging or operative exploration to diagnose and repair. Tension pneumothorax is a common life-threatening complication of both blunt and penetrating chest injuries. Pulmonary complications following traumatic chest injury pose a significant burden. Paradoxical rib movement in patients with flail chest injuries makes breathing difficult and can contribute to respiratory failure.