Bronchial Injury Should Be Considered
In a trauma patient with persistent pneumothorax despite appropriate chest tube function, bronchial injury is the most critical additional injury to consider. This represents a major airway disruption that prevents lung re-expansion despite adequate pleural drainage.
Clinical Reasoning
Key Diagnostic Features Present
The clinical presentation strongly suggests tracheobronchial injury:
- Persistent pneumothorax despite functioning chest tube - This is the hallmark finding that distinguishes major airway injury from simple pneumothorax 1
- Moderate subcutaneous thoracic crepitus - Indicates ongoing air leak into soft tissues, consistent with large airway disruption 1
- Hemodynamic instability (BP 82/66, HR 120) with tachypnea (RR 36) - Suggests significant injury beyond simple pneumothorax 1
Why Bronchial Injury (Answer A)
Bronchial injury creates a persistent bronchopleural fistula with continuous air leak that exceeds the drainage capacity of standard chest tubes. When a major bronchus is disrupted, air flows directly from the airway into the pleural space faster than any chest tube can evacuate it 1. The guidelines specifically note that a 24-28F chest tube may be needed "if the patient is anticipated to have a bronchopleural fistula with a large air leak" 1.
The presence of moderate subcutaneous emphysema in this context is particularly concerning, as it suggests "a malpositioned, kinked, blocked, or clamped tube" OR "a small tube in the presence of a very large leak" 1. Given that the question states the chest tube is functioning appropriately, the latter scenario—a massive air leak from bronchial injury—is most likely.
Why Not the Other Options
Cardiac contusion (B) - Would present with arrhythmias, elevated cardiac enzymes, or wall motion abnormalities, but would not cause persistent pneumothorax 2, 3
Esophageal rupture (C) - Typically presents with mediastinal air, pleural effusion (often left-sided), and signs of mediastinitis, not isolated persistent pneumothorax 2
Pulmonary contusion (D) - Causes parenchymal injury with consolidation and hemorrhage on imaging, but does not create persistent air leaks or prevent pneumothorax resolution 2, 4
Management Implications
Immediate Actions
- Refer to thoracic surgery urgently - Persistent air leak exceeding 48 hours requires surgical consultation, but in trauma with immediate persistence, referral should be immediate 1
- Consider larger chest tube - A 24-28F tube may be needed for the large air leak 1
- Apply high-volume, low-pressure suction (-10 to -20 cm H₂O) if not already done 1
Diagnostic Confirmation
Bronchoscopy is the definitive diagnostic test to visualize the bronchial injury and determine its location and extent. CT chest with careful attention to the airways may show the disruption.
Common Pitfalls
Do not assume chest tube malfunction without verification - The question states appropriate function, directing attention to the underlying injury rather than technical issues 1, 5.
Do not delay surgical consultation - While guidelines suggest referral at 48 hours for persistent air leak in spontaneous pneumothorax 1, traumatic bronchial injury requires immediate surgical evaluation given the mechanism and clinical instability 1.
Recognize that standard management fails in major airway injury - The usual approach of observation, aspiration, or standard chest tube drainage is inadequate when the air source (disrupted bronchus) continuously overwhelms drainage capacity 1.