Blunt trauma

Blunt trauma is most commonly due to motor vehicle accidents and is a major cause of morbidity and mortality in all age groups. The most common signs of significant abdominal trauma are pain, gastrointestinal hemorrhage, hypovolemia, and peritoneal irritation. The patterns of chest injury are highly dependent on the intensity of the trauma and may vary from harmless contusions to possible life-threatening injuries of the heart and/or the aorta. Management is initially focused on the ABCs (airway, breathing, circulation). FAST and CT imaging are used to detect intraabdominal bleeding and organ damage, while chest x-ray is the most important initial diagnostic tool in the assessment of blunt chest trauma. Treatment depends on the specific injury, as well as the hemodynamic status of the patient. Conservative management with close monitoring is indicated for hemodynamically stable patients. However, emergency surgery is often necessary. This article provides a brief overview of the clinical features and management of blunt trauma to the abdomen and chest.

For information on prehospital care and general principles of trauma management, see “Prehospital trauma care.”
Penetrating trauma is discussed in its own article.

• Etiology
  • Motor vehicle accidents (50–75%)
  • Falls
• Mechanism of injury
  • Rapid deceleration: results in shear forces that cause vascular tears, as well as hollow and solid organ contusions and ruptures
  • External compression and crushing

Possible injuries

• Most common: splenic rupture and liver injury (e.g., hematoma, laceration)
• Severe bleeding
• Pancreatic contusion, laceration, or rupture (through direct epigastric impact, e.g., handlebar injury)
• Traumatic injuries of the kidney and bladder
• Diaphragmatic rupture
• Duodenal damage and hematoma: common injury in children who suffer blunt abdominal trauma
• Pelvic fracture
• Abdominal compartment syndrome

Clinical features

• Pain, tenderness
• Abdominal distention
• Guarding or rigidity
• Signs of abdominal bleeding
  • Hemodynamic instability/shock ;, anxiety, flank discoloration
    • Hypotension
    • Tachycardia
    • Cyanosis
  • Liver hematoma
    • Ecchymoses over the right chest
    • Referred pain in the right shoulder (due to diaphragmatic irritation)
  • Duodenal hematoma
    • Bilious vomiting (due to intestinal obstruction)

Approach to blunt abdominal trauma

• Primary survey
  • See “Prehospital trauma care.”
  • Resuscitation procedures and stabilization (e.g., rapid transfusions, CPR) if indicated
• Imaging to assess the location and extent of abdominal injury
  • FAST exam: to detect hemoperitoneum (collection of blood in the peritoneal cavity)
  • CT
    • If FAST is inconclusive and patient is stabilized
    • Detects free abdominal fluid
    • Solid organ injury
    • Retroperitoneal injury (e.g., upper retroperitoneal hematomas)
  • X-ray: less useful than CT or FAST
    • Detects fracture
    • Free intra-abdominal air
    • Large collections of blood
• Diagnostic peritoneal lavage
  • Has been largely replaced by the rapid, noninvasive FAST exam
  • Useful for assessing hemodynamically unstable patients if FAST is inconclusive
    • Emergency laparotomy is indicated, if fecal matter or significant amounts of blood are detected (positive test)
    • Highly sensitive, but invasive
• Negative FAST/CT: identify extra-abdominal cause of hemodynamic instability
• Laparotomy is indicated for patients with
  • Hemodynamic instability
  • Signs of peritonitis
  • Intra-abdominal bleeding detected on imaging
• Conservative management: depends on the location and extent of injury
  • Close monitoring of vital signs and serial examinations
  • Management of pancreas injury: percutaneous drainage (with culture) and debridement to prevent complications (pseudocysts, abscess)
  • Management of duodenal injury
    • Nasogastric suction and parenteral nutrition to allow healing
    • If patients remain unstable, laparotomy may be indicated.
  • Angiography and embolization (e.g., control bleeds, manage low retroperitoneal hematomas)

The absence of pain does not rule out significant intra-abdominal injury. Imaging must be performed.

If FAST exam is not available, a hemodynamically unstable patient should be taken to the operating room immediately.

Possible injuries

• Aortic injury (highest lethality rate)
• Pneumothorax
• Cardiac contusion
• Pericardial effusion and cardiac tamponade
• Chest wall injuries
  • Flail chest
  • Rib fracture
  • Sternal fracture
• Pulmonary contusion
• Hemothorax
• Tracheobronchial injury
• Diaphragmatic rupture
• Esophageal rupture

Clinical features

• Chest pain
• Signs of bleeding
  • Hypotension
  • Tachycardia
  • Hypoxia
• Diminished breath sounds (pneumothorax)
• Jugular venous distention

Approach to blunt chest trauma

• Primary survey
  • See “Prehospital trauma care.”
  • Resuscitation procedures and stabilization (e.g., rapid transfusions, CPR) if indicated
• Emergency assessment: : of hemodynamically unstable patients to rule out life-threatening conditions
• Rapid diagnostic evaluation
  • Chest x-ray (initial test for all blunt chest trauma patients)
  • Ultrasound (extended FAST)
  • Echocardiography and ECG
  • Others
    • CT
    • Transesophageal echocardiography (TEE)
    • Bronchoscopy
    • Angiography
• Management
  • Close monitoring of vital signs
  • Appropriate surgical repair after stabilization of vitals
  • Unstable patient: immediate surgery/explorative thoracotomy

Rib fracture

• Etiology
  • Blunt trauma
  • Pathologic fractures
  • Nonaccidental trauma (e.g., child abuse)
• Clinical features
  • Pain on inspiration
    • Respiratory distress
    • Tachypnea
    • Shallow breaths
  • Crepitus
  • Flail chest
    • Multiple (≥ 3) rib fractures in 2 or more places
    • Resulting in a floating section of ribs and soft tissue within the chest wall
    • Paradoxical movement: the floating segment moves inward during inspiration and outward during expiration
  • Focal chest wall tenderness
  • Chest wall deformity
• Diagnostics
  • Chest x-ray (AP and lateral view)
    • Fracture lines
    • Displaced fractures
  • CT: if complications are suspected
• Treatment
  • Usually no surgery necessary
  • Analgesia
    • NSAIDs
    • Opiates
    • Local nerve block or epidural catheter
  • Intubation with positive pressure ventilation in severe flail chest (bridge to surgery)
  • In case of pneumothorax or hemothorax: thoracic drainage and thoracic surgical intervention
  • Indications for surgery
    • Significant chest wall deformity
    • Severe flail chest
    • Nonunion
• Complications
  • Pneumothorax
  • Hemothorax
  • Atelectasis/pneumonia: especially in the elderly individuals, caused by splinting and hypoventilation
  • Pulmonary contusion
  • Respiratory failure
  • Fracture of the lower ribs → abdominal organ injury

Phrenic nerve paralysis

• Anatomical course of the nerve
  • Originates as a branch from the cervical plexus of C3–C5
  • Passes ventrally on the anterior scalene muscle before descending into the chest wall
  • Runs between pleura and pericardium accompanied by pericardiacophrenic artery and vein
  • Supplies motor innervation of the diaphragm and sensory innervation of the pericardium, parietal pleura (mediastinal and diaphragmatic part), and peritoneum
• Etiology
  • Unilateral
    • Trauma
    • Iatrogenic
    • Compression (e.g., malignancy)
  • Bilateral
    • Motor neuron diseases (e.g., amyotrophic lateral sclerosis)
    • Neuropathies (e.g., Guillain-Barré syndrome, post-polio syndrome
    • Cervical spine surgery
    • Trauma
    • Tumor
• Clinical features
  • Unilateral paralysis
    • Often asymptomatic
    • Exertional dyspnea possible
  • Bilateral paralysis → severe dyspnea
• Diagnostics
  • Unilateral phrenic nerve paralysis
    • Auscultation
      • ↓ Respiratory movement
      • Dull on percussion
    • Chest x-ray
      • Diaphragmatic elevation
      • Possibly mediastinal shift
      • Compression atelectasis
    • Fluoroscopy: paradoxical elevation of the paralyzed hemidiaphragm on respiration or on asking the patient to sniff (sniff test)
  • Bilateral phrenic nerve paralysis
    • Spirometry: ↓ vital capacity
    • Diaphragmatic electromyography
• Treatment
  • Ventilation may be required.
  • Possible implantation of a diaphragmatic pacemaker

Cardiac injury

• Possible injuries
  • Cardiac contusion: Clinical features depend on the extent of the injury.
    • Cardiac arrhythmia
      • Palpitations
      • Dizziness
      • Syncope
    • Hypotension and tachycardia that do not respond to fluid resuscitation
      • Both are typically due to hemorrhage
      • Cardiac contusion should be suspected if tachycardia persists despite fluid resuscitation
      • It can result in cardiac wall motion abnormalities and cardiac dysfunction with poor cardiac output.
  • Myocardial rupture
    • Hypotension
    • Muffled heart sounds
  • Septal or valvular injury
  • Acute coronary syndrome
• Diagnostics
  • Ultrasound (FAST): best initial test
  • ECG
  • Echocardiography
• Treatment
  • Cardiac monitoring
  • Cardiac rupture: immediate surgery

Aortic injury and traumatic rupture of the aorta (aortic rupture)

• Typical location: aortic isthmus distal to the exit of the left subclavian artery (∼ 70%)
• Clinical features
  • Initially often asymptomatic or unspecific findings (e.g., chest pain, dyspnea)
  • Severity ranges from intimal lesions to aortic rupture.
  • In case of rupture: signs of hemorrhagic shock (tachycardia, hypotension)
• Diagnostics
  • Initial test: chest x-ray
    • Mediastinal widening
    • Tracheal deviation
    • Hemothorax
  • Further tests
    • In hemodynamically stable patients: CT scan and contrast-enhanced CT angiography (high sensitivity and specificity)
    • In hemodynamic unstable patients: transesophageal echocardiography (TEE) in the operating room
• Treatment
  • IV fluids
  • Definitive treatment
    • Endovascular repair
    • Open surgical repair
• Prognosis: ∼ 80% of patients die before reaching the hospital.

Pulmonary contusion

• Clinical features
  • Dyspnea, tachypnea
  • Tachycardia
  • Hypoxia and hypoxemia: may worsen after fluid administration as pulmonary edema worsens
  • Chest pain
• Diagnostics
  • Chest x-ray
    • Patchy alveolar infiltrates
    • White out or diffuse opacity
  • CT: if x-ray is inconclusive
• Differential diagnosis: pneumothorax (ipsilateral reduced or absent breath sounds)
• Treatment
  • Monitor blood gases
  • Intubation: only necessary if respiratory distress with severe hypoxia develops
• Complications
  • ARDS
  • Pneumonia

Tracheobronchial injury (TBI)

• Clinical features
  • Subcutaneous emphysema
  • Treatment-resistant pneumothorax: In contrast to a tension-pneumothorax, TBI usually does not feature midline shift and distended neck veins.
  • Dyspnea
  • Hoarseness
  • Dysphonia
  • Bloody tracheal secretions
• Diagnostics
  • Chest x-ray: air in surrounding soft tissue
  • Bronchoscopy: visualization of the lesion
• Treatment: mostly surgical repair
• Complications
  • Chylothorax
  • Chylopericardium
  • Chylomediastinum

Pneumomediastinum ^[1]

• Definition: presence of gas (usually air) in the mediastinum
• Etiology
  • Primary (spontaneous)
    • Rupture of pulmonary blebs
    • Predisposing factor: smoking
  • Secondary
    • Traumatic: penetrating injuries of chest and/or abdomen
    • Non-traumatic
      • Boerhaave syndrome
      • Bronchiectasis
      • COPD
      • Asthma
      • Interstitial lung disease
      • Lung cancer
    • Iatrogenic
      • Endoscopy
      • Intubation
      • Central line placement
• Pathophysiology: ↑ intra-alveolar pressure → rupture of alveoli → air travel along the peribronchial and perivascular sheaths to enter the mediastinum
• Clinical features
  • Chest pain
    • Sudden in onset
    • Retrosternal
    • Radiates to the neck or back
  • Dyspnea
  • Subcutaneous emphysema
  • Cough
  • Voice change
    • Rhinolalia
      • Nasal quality of voice
      • Occurs due to the presence of air within the soft palate
    • Hoarseness
  • Hamman's sign: precordial crepitation that is audible synchronous to the heartbeat
• Diagnosis
  • Chest X-ray
    • Air outlining the mediastinal structures (e.g. aorta, trachea)
    • Visible mediastinal pleura
  • CT scan: performed if chest x-ray findings are inconclusive

Diaphragmatic rupture

See “Diaphragmatic rupture.”

1. Kouritas VK, Papagiannopoulos K, Lazaridis G, et al. Pneumomediastinum. J Thorac Dis. 2015; 7 (Suppl 1): p.S44-49. doi: 10.3978/j.issn.2072-1439.2015.01.11 . | Open in Read by QxMD