Overview

Definition

Blunt chest trauma is injury and consequential pathology arising from application of significant kinetic forces to the chest that do not cause penetration of the thoracic cavity.

Epidemiology

• United States incidence: 12:1,000,000 each day
  • 33% require hospital admission.
  • Responsible for 20%–25% of all deaths (from motor vehicle collisions)
• Risk factors associated with a poor outcome:
  • Older age
  • Higher injury severity scores (ISS)

Etiology

• Motor vehicle accidents are the most common cause (80%).
• Other common causes:
  • Falls
  • Vehicles striking pedestrians
  • Acts of violence
  • Blast injuries

Classification

• Direct blunt force: object striking the chest wall Chest wall The chest wall consists of skin, fat, muscles, bones, and cartilage. The bony structure of the chest wall is composed of the ribs, sternum, and thoracic vertebrae. The chest wall serves as armor for the vital intrathoracic organs and provides the stability necessary for the movement of the shoulders and arms. Chest Wall (e.g., fist or bat in assault)
• Acceleration or deceleration: rapid changes in kinetic energy (e.g., car stopping rapidly)
• Shear force: forces pushing different parts of the body in opposing directions, often a combination of acceleration and deceleration (e.g., a head-on collision of 2 moving cars)
• Compression: crush injury (e.g., heavy object falling on a person)
• Blasts: transfer of energy into chest tissue from concussive wave (e.g., close explosion)

Pathophysiology

The chest wall Chest wall The chest wall consists of skin, fat, muscles, bones, and cartilage. The bony structure of the chest wall is composed of the ribs, sternum, and thoracic vertebrae. The chest wall serves as armor for the vital intrathoracic organs and provides the stability necessary for the movement of the shoulders and arms. Chest Wall is composed of:

• Bone Bone Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Structure of Bones: ribs and intercostal cartilage Cartilage Cartilage is a type of connective tissue derived from embryonic mesenchyme that is responsible for structural support, resilience, and the smoothness of physical actions. Perichondrium (connective tissue membrane surrounding cartilage) compensates for the absence of vasculature in cartilage by providing nutrition and support. Cartilage
• Musculature: intercostal and pectoral muscle groups
• Neurovasculature: intercostal nerves, arteries Arteries Arteries are tubular collections of cells that transport oxygenated blood and nutrients from the heart to the tissues of the body. The blood passes through the arteries in order of decreasing luminal diameter, starting in the largest artery (the aorta) and ending in the small arterioles. Arteries are classified into 3 types: large elastic arteries, medium muscular arteries, and small arteries and arterioles. Arteries, and veins Veins Veins are tubular collections of cells, which transport deoxygenated blood and waste from the capillary beds back to the heart. Veins are classified into 3 types: small veins/venules, medium veins, and large veins. Each type contains 3 primary layers: tunica intima, tunica media, and tunica adventitia. Veins 
• Connective tissues: visceral and parietal pleura Pleura The pleura is a serous membrane that lines the walls of the thoracic cavity and the surface of the lungs. This structure of mesodermal origin covers both lungs, the mediastinum, the thoracic surface of the diaphragm, and the inner part of the thoracic cage. The pleura is divided into a visceral pleura and parietal pleura. Pleura

The chest wall Chest wall The chest wall consists of skin, fat, muscles, bones, and cartilage. The bony structure of the chest wall is composed of the ribs, sternum, and thoracic vertebrae. The chest wall serves as armor for the vital intrathoracic organs and provides the stability necessary for the movement of the shoulders and arms. Chest Wall’s function is to absorb trauma and protect underlying vulnerable structures from damage:

• Chest wall structures: 
  • Fractures of ribs, clavicles, or cartilage Cartilage Cartilage is a type of connective tissue derived from embryonic mesenchyme that is responsible for structural support, resilience, and the smoothness of physical actions. Perichondrium (connective tissue membrane surrounding cartilage) compensates for the absence of vasculature in cartilage by providing nutrition and support. Cartilage
  • Ecchymosis, laceration, or crush injury of musculature and skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Structure and Function of the Skin
  • Accumulation of blood or air in the potential pleural space
• Underlying structures: 
  • Injury to the aorta and other major blood vessels
  • Bruising of the lungs Lungs Lungs are the main organs of the respiratory system. Lungs are paired viscera located in the thoracic cavity and are composed of spongy tissue. The primary function of the lungs is to oxygenate blood and eliminate CO2. Lungs
  • Bruising/laceration of the heart

Initial Approach to the Trauma Patient

Physical exam

The suspected mechanism of injury should prompt suspicion for blunt chest trauma. Treatment algorithms and guidelines direct evaluation:

• Primary survey—airway, breathing, and circulation (ABC):
  • Airway:
    • Look for foreign objects blocking airway (loose teeth Teeth Normally, an adult has 32 teeth: 16 maxillary and 16 mandibular. These teeth are divided into 4 quadrants with 8 teeth each. Each quadrant consists of 2 incisors (dentes incisivi), 1 canine (dens caninus), 2 premolars (dentes premolares), and 3 molars (dentes molares). Teeth are composed of enamel, dentin, and dental cement. Teeth are common foreign bodies in high-force trauma).
    • Assess for injury to the trachea Trachea The trachea is a tubular structure that forms part of the lower respiratory tract. The trachea is continuous superiorly with the larynx and inferiorly becomes the bronchial tree within the lungs. The trachea consists of a support frame of semicircular, or C-shaped, rings made out of hyaline cartilage and reinforced by collagenous connective tissue. Trachea (tracheal injury means intubation will be complex).
    • Listen for unusual breathing sounds (stridor suggests narrowing by a foreign body or edema Edema Edema is a condition in which excess serous fluid accumulates in the body cavity or interstitial space of connective tissues. Edema is a symptom observed in several medical conditions. It can be categorized into 2 types, namely, peripheral (in the extremities) and internal (in an organ or body cavity). Edema).
  • Breathing:
    • Look at chest wall Chest wall The chest wall consists of skin, fat, muscles, bones, and cartilage. The bony structure of the chest wall is composed of the ribs, sternum, and thoracic vertebrae. The chest wall serves as armor for the vital intrathoracic organs and provides the stability necessary for the movement of the shoulders and arms. Chest Wall movement for even and spontaneous breathing (uneven chest movement suggests “ flail chest Flail chest Flail chest is a life-threatening traumatic injury that occurs when 3 or more contiguous ribs are fractured in 2 or more different locations. Patients present with chest pain, tachypnea, hypoxia, and paradoxical chest wall movement. Flail Chest”).
    • Listen to breath sounds (muffled or uneven may suggest pneumothorax Pneumothorax A pneumothorax is a life-threatening condition in which air collects in the pleural space, causing partial or full collapse of the lung. A pneumothorax can be traumatic or spontaneous. Patients present with a sudden onset of sharp chest pain, dyspnea, and diminished breath sounds on exam. Pneumothorax or hemothorax Hemothorax A hemothorax is a collection of blood in the pleural cavity. Hemothorax most commonly occurs due to damage to the intercostal arteries or from a lung laceration following chest trauma. Hemothorax can also occur as a complication of disease, or hemothorax may be spontaneous or iatrogenic. Hemothorax).
  • Circulation:
    • Palpate pulses on all 4 extremities (tachycardia suggests hemodynamic instability or pneumothorax Pneumothorax A pneumothorax is a life-threatening condition in which air collects in the pleural space, causing partial or full collapse of the lung. A pneumothorax can be traumatic or spontaneous. Patients present with a sudden onset of sharp chest pain, dyspnea, and diminished breath sounds on exam. Pneumothorax).
    • Assess capillary refill on extremities.
• Secondary survey:
  • Mechanism of injury:
    • Helps determine severity of injury
    • May indicate what chest structures are injured
  • Close inspection of the chest wall Chest wall The chest wall consists of skin, fat, muscles, bones, and cartilage. The bony structure of the chest wall is composed of the ribs, sternum, and thoracic vertebrae. The chest wall serves as armor for the vital intrathoracic organs and provides the stability necessary for the movement of the shoulders and arms. Chest Wall: Seatbelt or steering wheel imprint suggests severe injury.

Imaging

While the initial approach to stabilizing a patient with chest trauma is standardized, further imaging and testing is dependent on the injury discovered during the initial assessment.

Choosing the best imaging studies depends on the patient’s hemodynamic stability:

• Chest X-ray and focused assessment with sonography in trauma (FAST) → initial diagnostic studies
• Only stable patients can undergo a computed tomography (CT) scan.
• Unstable patients → emergent surgery must be considered

Injury to the Chest Wall

Rib fracture Fracture A fracture is a disruption of the cortex of any bone and periosteum and is commonly due to mechanical stress after an injury or accident. Open fractures due to trauma can be a medical emergency. Fractures are frequently associated with automobile accidents, workplace injuries, and trauma. Overview of Bone Fractures

• Clinical features:
  • Pain is localized and reproducible by taking a deep breath.
  • Location of pain Pain Pain has accompanied humans since they first existed, first lamented as the curse of existence and later understood as an adaptive mechanism that ensures survival. Pain is the most common symptomatic complaint and the main reason why people seek medical care. Physiology of Pain points to possible further underlying injury:
    • 1st rib: possible trauma of lung apices, subclavian vessels
    • 2nd rib: possible ascending aorta, superior vena cava Superior vena cava The venous trunk which returns blood from the head, neck, upper extremities and chest. Mediastinum and Great Vessels trauma
    • 10th rib: possible diaphragmatic, liver Liver The liver is the largest gland in the human body. The liver is found in the superior right quadrant of the abdomen and weighs approximately 1.5 kilograms. Its main functions are detoxification, metabolism, nutrient storage (e.g., iron and vitamins), synthesis of coagulation factors, formation of bile, filtration, and storage of blood. Liver, splenic injury
    • 11th rib: possible diaphragmatic, liver Liver The liver is the largest gland in the human body. The liver is found in the superior right quadrant of the abdomen and weighs approximately 1.5 kilograms. Its main functions are detoxification, metabolism, nutrient storage (e.g., iron and vitamins), synthesis of coagulation factors, formation of bile, filtration, and storage of blood. Liver, splenic injury
    • 12th rib: possible renal injury
• Physical exam findings:
  • Point tenderness to palpation
  • Possible visible bruising or deformity
  • Crepitus may be audible.
• Imaging:
  • X-ray (appropriate for stable patients):
    • Posteroanterior (PA) chest X-ray 
    • Poor sensitivity, but useful to identify associated pneumothorax Pneumothorax A pneumothorax is a life-threatening condition in which air collects in the pleural space, causing partial or full collapse of the lung. A pneumothorax can be traumatic or spontaneous. Patients present with a sudden onset of sharp chest pain, dyspnea, and diminished breath sounds on exam. Pneumothorax, hemothorax Hemothorax A hemothorax is a collection of blood in the pleural cavity. Hemothorax most commonly occurs due to damage to the intercostal arteries or from a lung laceration following chest trauma. Hemothorax can also occur as a complication of disease, or hemothorax may be spontaneous or iatrogenic. Hemothorax, pulmonary contusion
  • CT scan (suggested for more severe injury):
    • Usually not performed if only rib fracture Fracture A fracture is a disruption of the cortex of any bone and periosteum and is commonly due to mechanical stress after an injury or accident. Open fractures due to trauma can be a medical emergency. Fractures are frequently associated with automobile accidents, workplace injuries, and trauma. Overview of Bone Fractures is suspected
    • Higher sensitivity
    • Useful for more detailed anatomy
  • Ultrasound:
    • Less commonly used
    • Useful in detailing extent of associated pneumothorax Pneumothorax A pneumothorax is a life-threatening condition in which air collects in the pleural space, causing partial or full collapse of the lung. A pneumothorax can be traumatic or spontaneous. Patients present with a sudden onset of sharp chest pain, dyspnea, and diminished breath sounds on exam. Pneumothorax, hemothorax Hemothorax A hemothorax is a collection of blood in the pleural cavity. Hemothorax most commonly occurs due to damage to the intercostal arteries or from a lung laceration following chest trauma. Hemothorax can also occur as a complication of disease, or hemothorax may be spontaneous or iatrogenic. Hemothorax, pulmonary contusion
• Management:
  • Pain control: 
    • Allows patients to take deep breaths, decreases associated pneumonia Pneumonia Pneumonia or pulmonary inflammation is an acute or chronic inflammation of lung tissue. Causes include infection with bacteria, viruses, or fungi. In more rare cases, pneumonia can also be caused through toxic triggers through inhalation of toxic substances, immunological processes, or in the course of radiotherapy. Pneumonia
    • Nerve blocks, opioids Opioids Opiates are drugs that are derived from the sap of the opium poppy. Opiates have been used since antiquity for the relief of acute severe pain. Opioids are synthetic opiates with properties that are substantially similar to those of opiates. Opioid Analgesics, or non-steroidal anti-inflammatory drug ( NSAID NSAID Nonsteroidal antiinflammatory drugs (NSAIDs) are a class of medications consisting of aspirin, reversible NSAIDs, and selective NSAIDs. NSAIDs are used as antiplatelet, analgesic, antipyretic, and antiinflammatory agents. Nonsteroidal Antiinflammatory Drugs) choice based on severity of pain Pain Pain has accompanied humans since they first existed, first lamented as the curse of existence and later understood as an adaptive mechanism that ensures survival. Pain is the most common symptomatic complaint and the main reason why people seek medical care. Physiology of Pain
  • Respiratory therapy: incentive spirometry
  • Surgical fixation:
    • Rarely necessary with a simple fracture Fracture A fracture is a disruption of the cortex of any bone and periosteum and is commonly due to mechanical stress after an injury or accident. Open fractures due to trauma can be a medical emergency. Fractures are frequently associated with automobile accidents, workplace injuries, and trauma. Overview of Bone Fractures
    • Performed when there is associated chest wall Chest wall The chest wall consists of skin, fat, muscles, bones, and cartilage. The bony structure of the chest wall is composed of the ribs, sternum, and thoracic vertebrae. The chest wall serves as armor for the vital intrathoracic organs and provides the stability necessary for the movement of the shoulders and arms. Chest Wall deformity, flail chest Flail chest Flail chest is a life-threatening traumatic injury that occurs when 3 or more contiguous ribs are fractured in 2 or more different locations. Patients present with chest pain, tachypnea, hypoxia, and paradoxical chest wall movement. Flail Chest, or symptomatic non-union

Flail chest

• Clinical features:
  • Tachypnea
  • Tachycardia
  • Hypoxia
• Physical exam findings:
  • Similar finding to simple rib fractures
  • 3 or more adjacent ribs are each fractured in 2 places.
  • Segment of thoracic wall moves opposite to the rest during breathing (paradoxic movement).
• Imaging: 
  • X-ray may show multiple rib fractures.
  • CT is usually employed for better anatomic detail.
• Management:
  • Supplemental oxygen
  • Pain control
  • Positive pressure ventilation (PPV) for respiratory failure Respiratory failure Respiratory failure is a syndrome that develops when the respiratory system is unable to maintain oxygenation and/or ventilation. Respiratory failure may be acute or chronic and is classified as hypoxemic, hypercapnic, or a combination of the two. Respiratory Failure

Clavicle fracture Clavicle fracture A clavicular fracture is a common fracture usually occurring because of trauma. The trauma may be direct or indirect and is generally of high energy, but it may occur secondary to low-energy trauma in the elderly. Clinical presentation includes pain localized to the clavicle, a palpable deformity over the fracture site, and crepitus. Clavicle Fracture

• Clinical features:
  • Localized pain Pain Pain has accompanied humans since they first existed, first lamented as the curse of existence and later understood as an adaptive mechanism that ensures survival. Pain is the most common symptomatic complaint and the main reason why people seek medical care. Physiology of Pain to palpation
  • Pain on rotation of shoulder
  • Sensation of cracking/popping with movement 
• Physical exam findings:
  • Visible localized deformity or swelling 
  • Palpable crepitus
  • Localized pain Pain Pain has accompanied humans since they first existed, first lamented as the curse of existence and later understood as an adaptive mechanism that ensures survival. Pain is the most common symptomatic complaint and the main reason why people seek medical care. Physiology of Pain to palpation
• Imaging: X-ray is sufficient to define the location and severity of injury.
• Management:
  • Pain management Pain Management Pain is defined as an unpleasant sensory and emotional experience associated with actual or potential tissue damage. Pain is a subjective experience. Acute pain lasts < 3 months and typically has a specific, identifiable cause. Pain Management/icing
  • Immobilization with brace restricting shoulder motion to < 30° of abduction, forward flexion, or extension
  • Indications for surgery include:
    • Open fracture Fracture A fracture is a disruption of the cortex of any bone and periosteum and is commonly due to mechanical stress after an injury or accident. Open fractures due to trauma can be a medical emergency. Fractures are frequently associated with automobile accidents, workplace injuries, and trauma. Overview of Bone Fractures
    • Bone Bone Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Structure of Bones displacement
    • Neurovascular injury
    • Skin tenting

Sternal fractures

• Clinical features:
  • Localized pain Pain Pain has accompanied humans since they first existed, first lamented as the curse of existence and later understood as an adaptive mechanism that ensures survival. Pain is the most common symptomatic complaint and the main reason why people seek medical care. Physiology of Pain to sternum
  • Very strong forces necessary, so usually associated with other internal injuries
• Physical exam findings:
  • Pain and tenderness to palpation of sternal area
  • Bony crepitus or deformity
• Imaging:
  • Ultrasound is used to screen.
  • Chest X-ray has poor sensitivity.
  • CT chest and electrocardiogram Electrocardiogram An electrocardiogram (ECG) is a graphic representation of the electrical activity of the heart plotted against time. Adhesive electrodes are affixed to the skin surface allowing measurement of cardiac impulses from many angles. The ECG provides 3-dimensional information about the conduction system of the heart, the myocardium, and other cardiac structures. Normal Electrocardiogram (ECG) ( ECG ECG An electrocardiogram (ECG) is a graphic representation of the electrical activity of the heart plotted against time. Adhesive electrodes are affixed to the skin surface allowing measurement of cardiac impulses from many angles. The ECG provides 3-dimensional information about the conduction system of the heart, the myocardium, and other cardiac structures. Normal Electrocardiogram (ECG)) should be performed for possible associated injuries.
• Management:
  • Stable patients with isolated sternal fractures: Outpatient management is reasonable.
  • More complex fractures with associated pathology: require surgical consultation for management

Injury to the Airway

Tracheobronchial tear

• Clinical features:
  • Airway obstruction Airway obstruction Airway obstruction is a partial or complete blockage of the airways that impedes airflow. An airway obstruction can be classified as upper, central, or lower depending on location. Lower airway obstruction (LAO) is usually a manifestation of chronic disease, such as asthma or chronic obstructive pulmonary disease (COPD). Airway Obstruction causing stridor, marked dyspnea Dyspnea Dyspnea is the subjective sensation of breathing discomfort. Dyspnea is a normal manifestation of heavy physical or psychological exertion, but also may be caused by underlying conditions (both pulmonary and extrapulmonary). Dyspnea, and respiratory failure Respiratory failure Respiratory failure is a syndrome that develops when the respiratory system is unable to maintain oxygenation and/or ventilation. Respiratory failure may be acute or chronic and is classified as hypoxemic, hypercapnic, or a combination of the two. Respiratory Failure
  • Hemoptysis Hemoptysis Hemoptysis is defined as the expectoration of blood originating in the lower respiratory tract. Hemoptysis is a consequence of another disease process and can be classified as either life threatening or non-life threatening. Hemoptysis can result in significant morbidity and mortality due to both drowning (reduced gas exchange as the lungs fill with blood) and hemorrhagic shock. Hemoptysis
  • Failure of pneumothorax Pneumothorax A pneumothorax is a life-threatening condition in which air collects in the pleural space, causing partial or full collapse of the lung. A pneumothorax can be traumatic or spontaneous. Patients present with a sudden onset of sharp chest pain, dyspnea, and diminished breath sounds on exam. Pneumothorax to resolve even when chest tube is placed (due to continuous air leak)
• Physical exam findings:
  • Sternal tenderness
  • Subcutaneous emphysema
  • Hamman sign: audible crepitus on cardiac auscultation 
• Imaging: 
  • Chest X-ray or CT depending on availability 
  • Pneumomediastinum (air trapping in center of chest cavity)
  • Hyoid bone elevation above the 3rd cervical vertebrae
• Management:
  • Bronchoscopy to evaluate extent of injury
  • Surgical repair even with stable patients given risk for developing airway stenosis

Injury to the Heart

Cardiac tamponade Cardiac tamponade Pericardial effusion is the accumulation of excess fluid in the pericardial space around the heart. The pericardium does not easily expand; thus, rapid fluid accumulation leads to increased pressure around the heart. The increase in pressure restricts cardiac filling, resulting in decreased cardiac output and cardiac tamponade. Pericardial Effusion and Cardiac Tamponade

• Clinical features:
  • Symptoms of cardiogenic shock Shock Shock is a life-threatening condition associated with impaired circulation that results in tissue hypoxia. The different types of shock are based on the underlying cause: distributive (↑ cardiac output (CO), ↓ systemic vascular resistance (SVR)), cardiogenic (↓ CO, ↑ SVR), hypovolemic (↓ CO, ↑ SVR), obstructive (↓ CO), and mixed. Types of Shock
  • Dyspnea and tachypnea
  • Chest discomfort or pressure
• Physical exam findings:
  • Beck’s triad: 
    • Hypotension Hypotension Hypotension is defined as low blood pressure, specifically < 90/60 mm Hg, and is most commonly a physiologic response. Hypotension may be mild, serious, or life threatening, depending on the cause. Hypotension
    • ↑ JVP
    • Muffled heart sounds Heart sounds Heart sounds are brief, transient sounds produced by valve opening and closure and by movement of blood in the heart. They are divided into systolic and diastolic sounds. In most cases, only the first (S1) and second (S2) heart sounds are heard. These are high-frequency sounds and arise from aortic and pulmonary valve closure (S1), as well as mitral and tricuspid valve closure (S2). Heart Sounds
  • Pulsus paradoxus: disproportionately large drop in systolic blood pressure on inspiration
  • Pericardial rub: audible crescendo-decrescendo extra heart sound, often described as grating noise 
• Imaging: 
  • Chest X-ray: 
    • Enlarged and globular cardiac silhouette (“water bottle” heart shape)
    • Clear lung fields
  • Echocardiogram: fluid around heart
• Management: Echocardiography-guided pericardiocentesis is both diagnostic and therapeutic.

Myocardial contusion

• Clinical features:
  • Associated sternal fracture Fracture A fracture is a disruption of the cortex of any bone and periosteum and is commonly due to mechanical stress after an injury or accident. Open fractures due to trauma can be a medical emergency. Fractures are frequently associated with automobile accidents, workplace injuries, and trauma. Overview of Bone Fractures
  • Symptoms of cardiac failure:
    • Dyspnea
    • Chest pain Pain Pain has accompanied humans since they first existed, first lamented as the curse of existence and later understood as an adaptive mechanism that ensures survival. Pain is the most common symptomatic complaint and the main reason why people seek medical care. Physiology of Pain
• Physical exam findings: may have signs of congestive heart failure Congestive heart failure Congestive heart failure refers to the inability of the heart to supply the body with normal cardiac output to meet metabolic needs. Echocardiography can confirm the diagnosis and give information about the ejection fraction. Congestive Heart Failure
• Imaging: FAST 
• Management:
  • Sustain cerebral perfusion with fluid resuscitation or medication as needed.
  • Needle pericardiocentesis may be helpful when associated with pericardial effusion Pericardial effusion Pericardial effusion is the accumulation of excess fluid in the pericardial space around the heart. The pericardium does not easily expand; thus, rapid fluid accumulation leads to increased pressure around the heart. The increase in pressure restricts cardiac filling, resulting in decreased cardiac output and cardiac tamponade. Pericardial Effusion and Cardiac Tamponade.

Traumatic cardiac arrest Cardiac arrest Cardiac arrest is the sudden, complete cessation of cardiac output with hemodynamic collapse. Patients present as pulseless, unresponsive, and apneic. Rhythms associated with cardiac arrest are ventricular fibrillation/tachycardia, asystole, or pulseless electrical activity. Cardiac Arrest (commotio cordis)

• Clinical features:
  • Cardiac arrest that occurs in a subsection of predisposed patients when the chest over the heart is struck during a specific portion of the cardiac cycle Cardiac cycle The cardiac cycle describes a complete contraction and relaxation of all 4 chambers of the heart during a standard heartbeat. The cardiac cycle includes 7 phases, which together describe the cycle of ventricular filling, isovolumetric contraction, ventricular ejection, and isovolumetric relaxation. Cardiac Cycle
  • Clinical history of collapse after chest trauma
  • Absence of history of other cardiac disease
• ECG ECG An electrocardiogram (ECG) is a graphic representation of the electrical activity of the heart plotted against time. Adhesive electrodes are affixed to the skin surface allowing measurement of cardiac impulses from many angles. The ECG provides 3-dimensional information about the conduction system of the heart, the myocardium, and other cardiac structures. Normal Electrocardiogram (ECG):
  • Asystole
  • Ventricular fibrillation Ventricular fibrillation Ventricular fibrillation (VF or V-fib) is a type of ventricular tachyarrhythmia (> 300/min) often preceded by ventricular tachycardia. In this arrhythmia, the ventricle beats rapidly and sporadically. The ventricular contraction is uncoordinated, leading to a decrease in cardiac output and immediate hemodynamic collapse. Ventricular Fibrillation
• Management: Cardiopulmonary resuscitation (CPR) and defibrillation following basic life support (BLS) recommendations

Injury to a Blood Vessel

Traumatic aortic rupture

• Clinical features:
  • Interscapular pain Pain Pain has accompanied humans since they first existed, first lamented as the curse of existence and later understood as an adaptive mechanism that ensures survival. Pain is the most common symptomatic complaint and the main reason why people seek medical care. Physiology of Pain
  • Difficulty breathing
  • Altered mental status
  • Often seen in the setting of a rapid deceleration
• Physical exam findings:
  • Sign of significant high-force trauma to the chest (e.g., steering wheel imprint)
  • Left-sided subclavicular hematoma
  • New cardiac murmur
• Imaging:
  • Chest X-ray often obtained per trauma protocol, can show:
    • Mediastinal widening and deviation
    • Distorted aortic arch outline
    • Hemothorax, especially above left lung apex 
  • Chest CT and transesophageal echocardiogram (TEE) are definitive diagnostic modalities.
• Management:
  • Antihypertensive therapy 
  • Emergent operative repair

Injury to the Esophagus or Diaphragm

Diaphragmatic rupture

• Clinical features:
  • Respiratory distress 
  • Nausea/vomiting
• Physical exam findings:
  • Should be suspected based on location of injury → diaphragm Diaphragm The diaphragm is a large, dome-shaped muscle that separates the thoracic cavity from the abdominal cavity. The diaphragm consists of muscle fibers and a large central tendon, which is divided into right and left parts. As the primary muscle of inspiration, the diaphragm contributes 75% of the total inspiratory muscle force. Diaphragm reaches up to the 4th intercostal space during exhalation
  • Bowel sounds in chest due to bowel herniation through the diaphragm Diaphragm The diaphragm is a large, dome-shaped muscle that separates the thoracic cavity from the abdominal cavity. The diaphragm consists of muscle fibers and a large central tendon, which is divided into right and left parts. As the primary muscle of inspiration, the diaphragm contributes 75% of the total inspiratory muscle force. Diaphragm
  • Decreased lung sounds
  • Dullness on percussion
  • Findings more common on left side (right side is protected by liver Liver The liver is the largest gland in the human body. The liver is found in the superior right quadrant of the abdomen and weighs approximately 1.5 kilograms. Its main functions are detoxification, metabolism, nutrient storage (e.g., iron and vitamins), synthesis of coagulation factors, formation of bile, filtration, and storage of blood. Liver)
• Imaging—found incidentally on X-ray, CT, and ultrasound performed for trauma evaluation:
  • Elevation of hemidiaphragm
  • Small bowel in lungs Lungs Lungs are the main organs of the respiratory system. Lungs are paired viscera located in the thoracic cavity and are composed of spongy tissue. The primary function of the lungs is to oxygenate blood and eliminate CO2. Lungs
• Management: surgical closure

Esophageal rupture

• Clinical features—no specific findings, but the following have been seen:
  • Chest pain Pain Pain has accompanied humans since they first existed, first lamented as the curse of existence and later understood as an adaptive mechanism that ensures survival. Pain is the most common symptomatic complaint and the main reason why people seek medical care. Physiology of Pain
  • Difficulty swallowing
• Physical exam findings:
  • Subcutaneous crepitus
  • Neck hematoma
• Imaging: 
  • Chest X-ray or CT:
    • Pneumomediastinum
    • Pleural effusion Pleural Effusion Pleural effusion refers to the accumulation of fluid between the layers of the parietal and visceral pleura. Common causes of this condition include infection, malignancy, autoimmune disorders, or volume overload. Clinical manifestations include chest pain, cough, and dyspnea. Pleural Effusion
  • Water-soluble contrast esophagography is diagnostic.
• Management:
  • Antibiotics and supportive care
  • Surgical repair to reduce the risk of significant leakage that can cause a systemic inflammatory response

Clinical Relevance

• Flail chest: a condition that occurs when 3 or more contiguous ribs are fractured in 2 or more different locations. Marked by chest pain Chest Pain Chest pain is one of the most common and challenging complaints that may present in an inpatient and outpatient setting. The differential diagnosis of chest pain is large and includes cardiac, gastrointestinal, pulmonary, musculoskeletal, and psychiatric etiologies. Chest Pain, tachypnea, hypoxemia, and paradoxic thoracic wall movement. Management includes oxygen supplementation, pain Pain Pain has accompanied humans since they first existed, first lamented as the curse of existence and later understood as an adaptive mechanism that ensures survival. Pain is the most common symptomatic complaint and the main reason why people seek medical care. Physiology of Pain control, and PPV if respiratory failure Respiratory failure Respiratory failure is a syndrome that develops when the respiratory system is unable to maintain oxygenation and/or ventilation. Respiratory failure may be acute or chronic and is classified as hypoxemic, hypercapnic, or a combination of the two. Respiratory Failure presents.
• Hemothorax: a collection of blood in the pleural cavity. Usually occurs following chest trauma, which leads to lung laceration or damage to intercostal arteries Arteries Arteries are tubular collections of cells that transport oxygenated blood and nutrients from the heart to the tissues of the body. The blood passes through the arteries in order of decreasing luminal diameter, starting in the largest artery (the aorta) and ending in the small arterioles. Arteries are classified into 3 types: large elastic arteries, medium muscular arteries, and small arteries and arterioles. Arteries. Symptoms include shortness of breath and chest pain Chest Pain Chest pain is one of the most common and challenging complaints that may present in an inpatient and outpatient setting. The differential diagnosis of chest pain is large and includes cardiac, gastrointestinal, pulmonary, musculoskeletal, and psychiatric etiologies. Chest Pain. Signs include hypotension, tachycardia, decreased air entry, tracheal deviation, and dullness on percussion. Management is chest tube insertion. Thoracotomy may be indicated.
• Pulmonary contusion: a traumatic parenchymal lung injury. Patients present with tachypnea, tachycardia, and hypoxemia. Imaging studies show patchy alveolar infiltrates not restricted by anatomic borders (non-lobar opacification). Management involves oxygen administration, pain Pain Pain has accompanied humans since they first existed, first lamented as the curse of existence and later understood as an adaptive mechanism that ensures survival. Pain is the most common symptomatic complaint and the main reason why people seek medical care. Physiology of Pain control, chest physiotherapy, and mechanical ventilation in severe cases.
• Pneumothorax: an abnormal collection of air in the pleural space. Types of pneumothoraces include simple and tension pneumothorax Pneumothorax A pneumothorax is a life-threatening condition in which air collects in the pleural space, causing partial or full collapse of the lung. A pneumothorax can be traumatic or spontaneous. Patients present with a sudden onset of sharp chest pain, dyspnea, and diminished breath sounds on exam. Pneumothorax. Pneumothoraces can be spontaneous, iatrogenic, or traumatic. Exam shows decreased breath sounds, hyper-resonance on percussion, tracheal deviation, mediastinal shift (away from tension pneumothorax Pneumothorax A pneumothorax is a life-threatening condition in which air collects in the pleural space, causing partial or full collapse of the lung. A pneumothorax can be traumatic or spontaneous. Patients present with a sudden onset of sharp chest pain, dyspnea, and diminished breath sounds on exam. Pneumothorax), decreased tactile vocal fremitus, and distended jugular veins Veins Veins are tubular collections of cells, which transport deoxygenated blood and waste from the capillary beds back to the heart. Veins are classified into 3 types: small veins/venules, medium veins, and large veins. Each type contains 3 primary layers: tunica intima, tunica media, and tunica adventitia. Veins. Treatment includes needle decompression and thoracotomy.
• Cardiac tamponade Cardiac tamponade Pericardial effusion is the accumulation of excess fluid in the pericardial space around the heart. The pericardium does not easily expand; thus, rapid fluid accumulation leads to increased pressure around the heart. The increase in pressure restricts cardiac filling, resulting in decreased cardiac output and cardiac tamponade. Pericardial Effusion and Cardiac Tamponade: an accumulation of fluid in the pericardial space, resulting in reduced ventricular filling and subsequent hemodynamic compromise. Cardiac tamponade Cardiac tamponade Pericardial effusion is the accumulation of excess fluid in the pericardial space around the heart. The pericardium does not easily expand; thus, rapid fluid accumulation leads to increased pressure around the heart. The increase in pressure restricts cardiac filling, resulting in decreased cardiac output and cardiac tamponade. Pericardial Effusion and Cardiac Tamponade is a severe form of a pericardial effusion Pericardial effusion Pericardial effusion is the accumulation of excess fluid in the pericardial space around the heart. The pericardium does not easily expand; thus, rapid fluid accumulation leads to increased pressure around the heart. The increase in pressure restricts cardiac filling, resulting in decreased cardiac output and cardiac tamponade. Pericardial Effusion and Cardiac Tamponade. In a trauma setting, the fluid is blood. Physical examination findings include Beck’s triad (hypotension, jugular venous distention, and muffled heart sounds Heart sounds Heart sounds are brief, transient sounds produced by valve opening and closure and by movement of blood in the heart. They are divided into systolic and diastolic sounds. In most cases, only the first (S1) and second (S2) heart sounds are heard. These are high-frequency sounds and arise from aortic and pulmonary valve closure (S1), as well as mitral and tricuspid valve closure (S2). Heart Sounds). Treatment is pericardiocentesis.
• Aortic dissection Aortic dissection Aortic dissection occurs due to shearing stress from pulsatile pressure causing a tear in the tunica intima of the aortic wall. This tear allows blood to flow into the media, creating a "false lumen." Aortic dissection is most commonly caused by uncontrolled hypertension. Aortic Dissection: occurs when a fissure develops in the inner coat (tunica intima) of the aortic wall, which causes blood to enter the media layer. Marked by severe pain Pain Pain has accompanied humans since they first existed, first lamented as the curse of existence and later understood as an adaptive mechanism that ensures survival. Pain is the most common symptomatic complaint and the main reason why people seek medical care. Physiology of Pain, characteristically known as a “tearing pain Pain Pain has accompanied humans since they first existed, first lamented as the curse of existence and later understood as an adaptive mechanism that ensures survival. Pain is the most common symptomatic complaint and the main reason why people seek medical care. Physiology of Pain.” Aortic dissection Aortic dissection Aortic dissection occurs due to shearing stress from pulsatile pressure causing a tear in the tunica intima of the aortic wall. This tear allows blood to flow into the media, creating a "false lumen." Aortic dissection is most commonly caused by uncontrolled hypertension. Aortic Dissection is a serious medical emergency that needs urgent diagnosis and management. Risk factors include hypertension Hypertension Hypertension, or high blood pressure, is a common disease that manifests as elevated systemic arterial pressures. Hypertension is most often asymptomatic and is found incidentally as part of a routine physical examination or during triage for an unrelated medical encounter. Hypertension, genetic diseases, and trauma. Treatment starts with blood pressure control and often requires cardiovascular surgery for stenting of the aorta.