24.1 Thoracic Trauma: Flail Chest, Pulmonary Contusion, Great Vessel & Tracheobronchial Injury

Immediately Life-Threatening Thoracic Injuries

Resuscitative thoracotomy is considered for penetrating thoracic trauma with witnessed loss of vital signs and a short down time; outcomes are poor in blunt arrest. Resuscitative endovascular balloon occlusion of the aorta (REBOA) may temporize subdiaphragmatic hemorrhage but is not a substitute for definitive control.

Rib Fractures and Flail Chest

• Significance: rib fractures mark the energy of injury and cause morbidity through pain, splinting, atelectasis, and pneumonia, particularly in older adults (3 or more fractures, or any fracture in a patient over 65, predicts complications).
• Flail chest: at least 3 consecutive ribs fractured in 2 places, creating a segment that moves paradoxically. The main physiologic insult is often the underlying pulmonary contusion, not the mechanics alone.
• Analgesia is the core therapy, in a stepwise fashion:
  • Scheduled acetaminophen and, where safe, NSAIDs.
  • Opioids, titrated and minimized.
  • Regional techniques: thoracic epidural, paravertebral block, erector spinae plane or serratus anterior plane blocks, or intercostal nerve blocks. Regional analgesia improves ventilation and reduces pneumonia.
  • Avoid sedating doses of opioids that suppress cough.
• Pulmonary toilet: incentive spirometry, early mobilization, chest physiotherapy, and secretion clearance.
• Surgical stabilization of rib fractures reduces ventilator days, ICU stay, and pneumonia in selected patients (flail chest, severe displacement, failure to wean, or persistent pain), ideally within about 72 hours.
• Noninvasive support: high-flow nasal oxygen or noninvasive ventilation can avert intubation when pain is controlled and secretions are manageable.

Pulmonary Contusion

• Alveolar hemorrhage and edema from direct energy transfer, often beneath rib fractures.
• It worsens over 24 to 48 hours, so initial imaging underestimates it; CT is more sensitive than chest radiography.
• Management: lung-protective ventilation, judicious fluids (avoid overload but do not under-resuscitate a bleeding patient), analgesia, and selective bronchodilators. Steroids and prophylactic antibiotics are not indicated.
• Complications include ARDS, pneumonia, and persistent air leak.

Blunt Aortic and Great Vessel Injury

• Mechanism: rapid deceleration, with the tear typically just distal to the left subclavian artery at the ligamentum arteriosum.
• Clues: a widened mediastinum, an indistinct aortic knob, left apical cap, tracheal or nasogastric tube deviation, first or second rib or scapular fracture, and a pseudocoarctation pattern with upper extremity hypertension.
• Diagnosis: CT angiography of the chest.
• Management:
  1. Impulse control: a heart rate below about 80 bpm and a systolic pressure of about 100 to 120 mmHg, usually with esmolol, balanced against brain and other injuries.
  2. Thoracic endovascular aortic repair (TEVAR) has lower mortality and paraplegia rates than open repair and is now standard, typically delayed until other life-threatening injuries are addressed, except for free rupture or an expanding hematoma.
  3. Grade I (intimal tear) lesions are often managed medically with repeat imaging.
• Great vessel and subclavian injuries present with pulse deficits, expanding hematoma, or brachial plexus signs; most are now treated endovascularly.

Tracheobronchial Injury

• Mechanism: blunt deceleration with shearing near the carina, penetrating injury, or iatrogenic from intubation.
• Presentation: massive subcutaneous emphysema, pneumomediastinum, hemoptysis, and a large persistent air leak with a pneumothorax that does not resolve despite a well-placed functioning chest tube. The "fallen lung sign" on imaging is characteristic.
• Diagnosis and management: bronchoscopy confirms and localizes the tear. Secure the airway distal to the injury (sometimes with a double-lumen tube or single-lung ventilation), minimize positive pressure, and arrange surgical repair for large or symptomatic injuries; small iatrogenic tears can be managed conservatively or with stenting.

Blunt Cardiac Injury

• Spectrum: from asymptomatic troponin elevation to arrhythmia, free wall rupture, septal rupture, valve injury, and coronary dissection.
• Screening: ECG and troponin. A normal ECG with a normal troponin effectively excludes clinically significant injury; abnormal results warrant monitoring and echocardiography.
• Management: telemetry for 24 to 48 hours, treat arrhythmias, echocardiography for structural injury or hemodynamic instability, and surgery for rupture or significant valve injury. Commotio cordis causes arrest from a precordial blow during a vulnerable repolarization window and is treated with immediate defibrillation.

Other Thoracic Problems After Trauma

• Retained hemothorax: drain early; video-assisted thoracoscopic evacuation within about 3 to 7 days prevents empyema and fibrothorax. Intrapleural fibrinolytics are an alternative in selected patients.
• Diaphragmatic rupture: more often left-sided, with bowel in the chest on imaging; requires surgical repair.
• Esophageal injury: see the esophageal emergencies section.
• Foreign body aspiration: sudden choking with unilateral wheeze; rigid bronchoscopy for central objects, flexible for peripheral.
• Air embolism after penetrating lung injury or positive-pressure ventilation: place the patient head down and left side down, give 100% oxygen, and consider thoracotomy with hilar clamping.
• Subcutaneous emphysema itself is rarely dangerous but signals an airway or pleural leak; it is managed by treating the source rather than by incisions.