Lung Trauma Flashcards
What is a pneumothorax, and what are its causes?
A pneumothorax is air accumulation in the pleural space leading to lung collapse. Causes include:
- Trauma (rib fracture, penetrating injury, barotrauma)
- Spontaneous (primary in young, tall, thin males; secondary in COPD, cystic fibrosis, lung infections)
- Iatrogenic (central line placement, mechanical ventilation, thoracentesis).
What are the key clinical features of pneumothorax?
Presentation includes:
- Acute pleuritic chest pain and dyspnea
- Absent breath sounds and hyperresonance on percussion
- Tracheal deviation away from the affected side (in tension pneumothorax)
- Subcutaneous emphysema (air trapped under skin, felt as crepitus).
- Ipsilateral diaphragm flattening
How is pneumothorax diagnosed?
- Chest X-ray: Shows visceral pleural line with absent lung markings peripherally.
- Ultrasound (E-FAST): Absence of lung sliding (‘barcode sign’).
- CT scan: Most sensitive, used if X-ray is equivocal or to detect small pneumothoraces.
How do you manage different types of pneumothorax?
- Small, stable (<20%): Observe with high-flow O₂ (speeds air resorption).
- Large or symptomatic: Chest tube placement.
- Tension pneumothorax: Immediate needle decompression (2nd ICS, MCL), followed by chest tube (5th ICS, MAL).
What are the key differences between pneumothorax and hemothorax?
- Pneumothorax: Air in pleural space, hyperresonance to percussion.
- Hemothorax: Blood in pleural space, dullness to percussion. Often follows trauma with lung parenchymal or vascular injury.
What is a hemothorax, and how does it present?
A hemothorax is blood accumulation in the pleural space, typically from lung or vessel injury. Clinical features:
- Chest pain and dyspnea
- Diminished breath sounds on affected side
- Dullness to percussion
- Signs of hemorrhagic shock (hypotension, tachycardia) if severe (>1500 mL blood loss).
How do you diagnose a hemothorax?
- Chest X-ray: Shows pleural effusion (blunting of costophrenic angle, fluid level in upright film).
- Ultrasound (E-FAST): Detects free fluid in pleural cavity.
- CT scan: Best for detecting small or complex hemothorax.
How do you manage a hemothorax?
- Chest tube placement (5th ICS, MAL).
- If initial output >1500 mL or continued bleeding (>200 mL/hr x 3 hrs), thoracotomy is required to control hemorrhage.
- Blood transfusion if signs of shock.
What is flail chest, and why is it dangerous?
Flail chest occurs when ≥3 adjacent ribs are fractured in ≥2 places, creating a floating chest wall segment. This results in:
- Paradoxical chest wall movement (inward on inspiration, outward on expiration)
- Severe respiratory distress and hypoxia
- Underlying pulmonary contusion (high mortality risk).
- Fractured ribs can also cause pneumothorax, atelectasis, or pneumonia development.
How do you manage flail chest?
- Pain control (opioids, nerve blocks) to improve ventilation.
- Oxygen and pulmonary hygiene to prevent pneumonia.
- Positive pressure ventilation (mechanical ventilation if severe hypoxia or respiratory failure).
- Surgical rib fixation if severe.
What is a pulmonary contusion, and how does it present?
A pulmonary contusion is a lung bruise causing alveolar hemorrhage and edema, leading to hypoxia. Presentation:
- Dyspnea and hemoptysis
- Crackles and wheezing on auscultation
- Patchy infiltrates on CXR (non-lobar distribution)
- Symptoms worsen over 24-48 hours post-trauma (delayed onset hypoxia).
Why should chest trauma be carefully monitored during the course of hospitalization?
Pulmonary contusions are a common injury resulting from blunt chest trauma. Patients typically have chest pain and may develop respiratory distress and hypoxemia that is delayed up to 24 hours from the time of injury. Chest x-ray characteristically shows an irregular, localized lung pacification. Blunt trauma to the lungs results in accumulation of edema and blood in a localized area of the lung parenchyma. Patients typically have chest pain and may develop accompanying shortness of breath and hemoptysis, and chest x-ray characteristically shows an irregular, localized pacification at the site of injury. The onset of respiratory symptoms may be delayed for approximately 24 hours from the time of injury, and initial chest x-ray sometimes demonstrates no airspace disease. CT scan is more diagnostically sensitive; however, contusions that are apparent on CT scan but not on chest x-ray are often minor and may be of low clinical significance. Depending on the size of the contusion, respiratory distress and significant hypoxemia can develop.
How do you manage pulmonary contusion?
- Oxygen therapy and pulmonary hygiene (incentive spirometry, chest physiotherapy).
- Conservative IV fluids (prevent worsening edema).
- Mechanical ventilation if ARDS develops.
- No prophylactic antibiotics unless pneumonia develops.
Patients in whom there is suspicion of significant pulmonary contusion should be admitted to the hospital and monitored for 24-48 hours. In those who develop respiratory symptoms, treatment involves adequate pain control to avoid hypoventilation, as well as supportive care to include pulmonary hygiene (eg, chest physiotherapy, suctioning) and supplemental oxygen and ventilatory support as needed. With adequate support and monitoring, most patients experience resolution of symptoms within 3-5 days.
What is diaphragmatic rupture, and how does it present?
Diaphragmatic rupture is a tear in the diaphragm from blunt or penetrating trauma, often left-sided. Presentation:
- Dyspnea and bowel sounds in chest
- Scaphoid abdomen (abdominal organs herniated into chest)
- CXR: Elevated hemidiaphragm, bowel loops in thorax
- Can be acute or delayed (months later with bowel obstruction).
How is diaphragmatic rupture diagnosed and treated?
- CXR: Shows elevated diaphragm, bowel in chest.
- CT chest/abdomen: Confirms diagnosis.
- Surgical repair (laparotomy or thoracotomy).
What is tracheobronchial rupture, and how does it present?
Tracheobronchial rupture is a tear in the trachea or main bronchi from blunt deceleration injury or penetrating trauma. Presentation:
- Persistent pneumothorax despite chest tube placement
- Subcutaneous emphysema (air tracking into skin)
- Dyspnea, cough, hemoptysis
- CXR: Pneumomediastinum, collapsed lung
How do you diagnose and manage tracheobronchial rupture?
- CT scan: Shows airway discontinuity.
- Bronchoscopy: Gold standard for direct visualization.
- Airway management (intubation past the tear if possible).
- Surgical repair via thoracotomy.
