Overview
Definition:
Tracheobronchial injuries encompass traumatic disruptions of the trachea and major bronchi, ranging from mucosal tears to complete transection
These injuries are rare but life-threatening, often associated with significant morbidity and mortality.
Epidemiology:
Tracheobronchial injuries occur in approximately 1-2% of severe blunt chest trauma patients and 0.5-1.5% of penetrating chest trauma cases
The most common location is within 2-3 cm of the carina
Mortality rates can exceed 50% without prompt diagnosis and management.
Clinical Significance:
Inadequate repair or delayed diagnosis can lead to airway obstruction, severe sepsis, mediastinitis, bronchopleural fistula, pneumothorax, and death
Expertise in rapid assessment and timely surgical intervention is critical for patient survival and optimal functional recovery.
Clinical Presentation
Symptoms:
Massive subcutaneous emphysema extending to the face and neck
Hemoptysis
Severe dyspnea and respiratory distress
Stridor or hoarseness
Chest pain
Cough
Sputum production
Symptoms of associated injuries (e.g., pneumothorax, hemothorax).
Signs:
Audible air leak from chest tube
Cricothyroid or suprasternal crepitus
Rapidly expanding cervical or mediastinal emphysema
Paradoxical chest wall movement
Hypoxia and signs of shock
Mediastinal widening on chest X-ray
Persistent air leak despite chest tube drainage.
Diagnostic Criteria:
Diagnosis is primarily based on clinical suspicion in the context of trauma, supported by imaging and bronchoscopy
No formal diagnostic criteria, but a high index of suspicion in severe thoracic trauma with characteristic signs and symptoms is key.
Diagnostic Approach
History Taking:
Mechanism of injury: blunt trauma (e.g., steering wheel impact, fall from height, rapid deceleration) or penetrating trauma (e.g., stab wound, gunshot wound)
Circumstances of the event
Prior thoracic surgeries or conditions
Allergies and comorbidities.
Physical Examination:
Rapid assessment of airway, breathing, and circulation
Palpation for subcutaneous emphysema
Auscultation for breath sounds (diminished or absent)
Examination of the entire chest wall and abdomen for associated injuries
Neurological assessment.
Investigations:
Chest X-ray: may reveal pneumothorax, mediastinal widening, pleural effusion, or subcutaneous emphysema
CT scan of the chest with intravenous contrast: gold standard for visualizing tracheal and bronchial injuries, assessing extent, and identifying associated injuries
Bronchoscopy: essential for direct visualization of the injury, assessment of severity, and determining the need for surgical repair
can be performed bedside in unstable patients
Arterial blood gases (ABGs): to assess oxygenation and ventilation status
Complete blood count (CBC), coagulation profile, and electrolytes.
Differential Diagnosis:
Esophageal rupture
Severe pulmonary contusion
Laryngeal injury
Tracheal transection secondary to endotracheal intubation
Mediastinitis from other causes
Aortic injury.
Management
Initial Management:
Secure the airway: establish definitive airway control, preferably with a tracheostomy distal to the injury if feasible, or endotracheal intubation carefully placed to avoid further injury
Provide ventilatory support: adequate oxygenation and mechanical ventilation
Chest tube insertion: for pneumothorax or hemothorax, to evacuate air and fluid and re-expand the lung
Hemodynamic stabilization: intravenous fluids and blood products as needed
Analgesia for pain control
Rapid transport to a specialized trauma center.
Medical Management:
Prophylactic antibiotics: to prevent infection, especially in penetrating injuries or when contamination is suspected
Anticoagulation is generally avoided unless indicated for other reasons due to risk of bleeding.
Surgical Management:
Indications for surgery: Complete transection of the trachea or bronchus
Injuries >50% of the luminal circumference
Significant air leak
Penetrating injuries with major vascular involvement
Associated injuries requiring operative intervention
Procedures: Tracheal resection and primary anastomosis (for injuries up to 4-5 cm)
Tracheal reconstruction with flaps (e.g., pericardial, pleural) or grafts for larger defects
Bronchial repair typically involves primary repair with absorbable sutures
Management of associated injuries: repair of great vessel injuries, lung resection if necessary
Surgical approach: anterior median sternotomy, posterolateral thoracotomy, or cervical approach depending on the level and extent of the injury.
Supportive Care:
Postoperative ventilation management: meticulous control of ventilator settings to minimize airway pressure and shear forces
Nutritional support: often requires enteral feeding via nasojejunal tube
Aggressive pulmonary toilet: suctioning, chest physiotherapy, and early mobilization to prevent pneumonia and atelectasis
Pain management: effective multimodal analgesia
Monitoring: continuous pulse oximetry, capnography, and chest X-rays
Drain management: vigilant monitoring of chest tube output for air leak and bleeding.
Complications
Early Complications:
Worsening subcutaneous emphysema
Mediastinitis
Sepsis
Pneumonia
Acute respiratory failure
Airway obstruction
Hemorrhage
Anesthesia complications.
Late Complications:
Tracheal stenosis
Tracheoesophageal fistula
Granulation tissue formation
Vocal cord paralysis
Chronic cough and dyspnea
Recurrent pneumonia
Malunion or non-union of tracheal repair
Stricture formation at the anastomosis site.
Prevention Strategies:
Early and accurate diagnosis
Prompt surgical intervention
Meticulous surgical technique with adequate tissue coverage
Careful airway management postoperatively
Aggressive pulmonary toilet
Judicious use of antibiotics
Close monitoring for signs of infection or airway compromise.
Prognosis
Factors Affecting Prognosis:
Severity and location of the injury
Time to diagnosis and definitive treatment
Presence of associated injuries
Patient's comorbidities
Promptness and quality of surgical repair
Presence and management of complications like infection and dehiscence.
Outcomes:
With prompt and appropriate management, outcomes can be favorable, with successful airway reconstruction and return to normal function
However, severe injuries or delayed treatment significantly increase morbidity and mortality
Long-term complications like stenosis can impair quality of life.
Follow Up:
Regular follow-up appointments are crucial
Bronchoscopy at 3-6 months post-operatively to assess healing and rule out stenosis or granulation tissue
Pulmonary function tests may be indicated
Long-term monitoring for respiratory symptoms.
Key Points
Exam Focus:
High index of suspicion in blunt and penetrating chest trauma
CT chest with contrast and bronchoscopy are key diagnostic modalities
Early airway control and prompt surgical repair are paramount
Bronchopleural fistula and tracheal stenosis are major late complications.
Clinical Pearls:
Remember that significant subcutaneous emphysema can mask other thoracic injuries
Be cautious during endotracheal intubation in patients with suspected airway injury to avoid exacerbating the tear
Tracheostomy should be considered if the injury is within the thoracic inlet or if prolonged mechanical ventilation is anticipated.
Common Mistakes:
Delaying diagnosis due to perceived rarity of injury
Inadequate airway management leading to further compromise
Overlooking associated injuries
Insufficient operative time for complete repair
Inadequate postoperative respiratory care leading to complications.