Thoracic trauma is responsible for 25% of all trauma deaths and contributes to a further 25%. In Australasia and the UK, 90-95% of all chest trauma is secondary to blunt injury2. Motor vehicle crashes account for 70-80% of blunt chest trauma cases3. It is important to be aware of the mechanism of injury in chest trauma as blunt and penetrating injuries have different pathophysiology as well as clinical courses. The initial assessment and management of patients presenting with chest trauma consists of the primary survey with appropriate interventions as per ATLS/EMST guidelines. Of particular note, oxygenation should be optimised early, with consideration of ventilatory support for those patients in respiratory failure. In addition, the treating team must consider tension pneumothorax in all patients with signs of shock.4
Pulmonary contusions, pneumothorax and haemothorax occur in 30-50% of patients with severe blunt chest trauma. Flail chest injury represents a particularly severe form of chest trauma2, and is considered an immediate threat to life. Not only is it associated with contusions and haemopneumothorax, many patients also experience a degree of mechanical ventilatory failure. Delayed or inadequate ventilatory resuscitation, inadequate management of shock, insufficient monitoring of arterial blood gases and delay or failure to perform decompression or drainage as well as inadequate imaging remain identifiable problems that contribute to morbidity and mortality in all patients with chest injury.1
Penetrating thoracic injuries represent 10% of cases and are more likely than blunt injury to require operative intervention. The majority of the remainder will require supportive care which may include pleural decompression and drainage.
Resuscitative Thoracotomy (RT) in penetrating trauma may be considered for patients who arrive pulseless but with electrical activity. Similarly, patients who have sustained blunt chest trauma and display evidence of cardiac tamponade both clinically and on ultrasound examination, who remain severely hypotensive after chest decompression and volume resuscitation may also be candidates for RT.
Delayed life threatening complications are detected in the Secondary Survey where further in depth examination can take place. Adjuncts to the primary survey include CXR, ABG’s, pulse oximetry and ECG monitoring. Hypoxia may be absent early in the presentation however may develop as the injuries evolve. Hypoventilation commonly develops due to pain, fatigue from increased work of breathing as well as side effects of opiate analgesia. Ventilatory support in patients with pulmonary contusions and poor lung compliance requires ventilation at lower tidal volumes and low inspiratory pressure in order to reduce barotrauma and secondary lung injury.
Adequate analgesia is essential and many departments have a chest trauma pain management pathway that is followed to ensure analgesia is appropriately titrated. Any patient who is unable to deep breath and cough without pain should be referred to the hospital acute pain service for consideration for Patient Controlled Analgesia or loco-regional analgesia.
Significant chest injury is rare in paediatric trauma. Death usually occurs soon after the injury in a child, whereas an adult with similar injuries tends to survive longer. This is primarily due to the compliance of the chest wall which allows for greater deformation of the chest wall before the ribs fracture. Major internal injuries may occur without any external chest wall injury.5
Rib fractures are some of the most common injuries in the elderly and those >65 years are twice as likely to develop pneumonia. Patients with co-morbidities including prior poor chest wall compliance as well as the elderly are particularly at risk of hypoventilation in the setting of chest trauma and may deteriorate rapidly.
All patients with thoracic trauma must receive a rapid and systematic primary and secondary survey with appropriate interventions as required. The main goals are to recognise and treat life threatening injuries in the emergency setting, stabilise the patient and detect potentially life threatening injuries in the secondary survey. Patients with significant chest injury, including 3 or more rib fractures, flail chest injury, a need for ventilator support, patients > 65 years of age and with any significant co-morbidities should be transferred to a major trauma service for definitive care.