Blunt thoracic trauma is a significant cause of morbidity and mortality. Life threats should be identified on the primary survey though some significant injuries (eg: aortic injuries) may not be immediately apparent.
These should be identified and managed as part of the primary survey
Rib fractures are the most common injury from blunt thoracic trauma and can be extremely painful, leading to significant morbidity from hypoventilation and subsequent respiratory compromise.
Flail chest, defined as 3 or more consecutive rib fractures, with more than 1 fracture in each rib, can rapidly lead to respiratory compromise. Bilateral anterior rib fractures can cause central flail segment and lead to similar respiratory compromise.
Upper rib fractures require significant force so may be associated with other significant injuries.
The mainstay of imaging for rib fractures is a CXR, however up to 50% of fractures can be missed on plain radiography Many rib fractures are diagnosed based on clinical findings and further imaging is not required provided there are no concerns for other underlying injuries. Patients that are more severely injured often have a chest CT scan which is more sensitive for detecting rib #s.
Some patients with one or two isolated rib fractures may be suitable for discharge home provided they can mobilise, cough and take a deep breath in. They should be discharged with adequate analgesia and good return advice.
Have a low threshold for admitting patients with rib fractures for analgesia and observation especially if they
Patients that are admitted to hospital with painful rib fractures will require escalating analgesic strategies and early consultation with the acute pain team is recommended.
PO > IV > PCA > thoracic epidural or regional blocks
(note some pain services may have a different approach to rib fracture management in terms of the “analgesia ladder” – contact your local service for advice / follow local guidelines)
Surgical fixation of severe rib fractures (eg: flail segment, severe displacement) with concerns for pain management or respiratory compromise might be a treatment option and may decrease mortality, LOS, duration of mechanical ventilation and the need for a tracheostomy.2,3 Please contact Trauma Services at ACH or 0800 4 TRAUMA to discuss further.
Sternal fractures usually occur from a direct blow to this area, most commonly from motor vehicle accidents (seat belt or steering wheel injuries).
Though chest X-ray (PA and dedicated lateral views) can detect sternal fractures, majority are detected on CT scan. X-rays can miss up to 90% of sternal fractures.
Around 80% of patients have associated thoracic injuries, most common being rib fractures. Other injuries include mediastinal hematoma, pulmonary contusion, pneumothorax, thoracic spine injuries etc. cardiac contusion is rarely the consequence of sternal fracture. Isolated simple sternal fractures are usually benign.1.2
A 12 lead ECG should be performed as a screening test for all patients with suspected chest injury. A CTA of the chest should be requested if there are concerns regarding other underlying mediastinal injuries.
Bicortically displaced sternal fractures may need operative fixation if the pain is not controlled with standard analgesic regimen.
Admission is required if the patient has severe pain or with associated injuries.
Some patients whose pain is well controlled and have no other concerning features of serious injury might be amenable for discharge from the ED with good return advice. 1.2
|2. Michael R Perez et al. Sternal fracture in the age of pan scan. Injury, 2015-07-01, Volume 46, Issue 7, Pages 1324-1327|
Clavicle fractures can occur from a direct blow, or from an impact to the shoulder or fall on outstretched hand.
Most clavicle fractures are managed expectantly with a broad arm sling, however some may require operative fixation (eg: open fractures, skin tenting, severe displacement or angulation, comminution, neurovascular compromise). Discuss with your local orthopaedic service.
A dislocation at the sternoclavicular joint is relatively uncommon and can be difficult to diagnose on plain radiography – check for pain and bogginess over this area. CT is the imaging modality of choice. Anterior dislocations are usually treated conservatively. Posterior fractures can be associated with injury to the great vessels and should always be reduced in theatre
Fractures of the scapula are usually caused by significant force so are often associated with other injures, especially rib fractures. Most scapula fractures are treated conservatively though some will require operative repair (eg: glenohumeral joint instability, severe displacement of scapula neck, open fractures)
Treat with adequate pain relief, to facilitate deep breathing.
Blunt lung injuries can occur with or without rib fractures
Pulmonary contusions are injuries of the lung parenchyma and can occur with or without rib #s.
Pulmonary contusions may not be obvious on initial CXR. CT is the most useful imaging modality.
Treatment is supportive and consists of adequate analgesia, supplemental oxygen if needed and physiotherapy. Severe pulmonary contusions or those associated with other significant injuries can lead to the development of ARDS with respiratory compromise, requiring intubation and ventilation.
Patients with pulmonary contusions should be admitted for observation. Some patient may need HDU review eg: respiratory distress, elderly, significant underling lung disease.Pulm contusions
Injuries to the trachea and main bronchi are relatively rare in blunt trauma (<1% of major blunt trauma patients). Many patient with this injury will die at the scene.
The mechanism of injury is usually from increased luminal pressure (eg: forced expiration against a closed glottis), compression of the trachea against the vertebral column or from shearing forces in patient who are subjected to sudden deceleration.
Delay in diagnosis is not uncommon
Patient with upper tracheal injuries may present with dyspnoea, dysphonia and subcutaneous emphysema.
The hallmark of an intrathoracic tracheobronchial injury is a pneumothorax with a significant airleak.
CXR and CT may show subcutaneous emphysema, pneumothorax or pneumomediastinum but definitive diagnosis is usually made with bronchoscopy.
BCI is a challenging clinical diagnosis due to lack of clear diagnostic criteria and lack of uniform grading system. Incidence varies between 3% and 76%. Minor injuries may be asymptomatic while severe injuries can cause severe morbidity and death.
AAST grading system is as follows:
ECG is the main investigation to be done in all suspected cases of BCI. A normal ECG has a 95% negative predictive value. The value of troponin in less well established. However, some studies indicate that normal troponin values with a normal ECG increases the NPV to 100%.
Management: most of the following recommendations are based on level 2 or 3 evidence.
A normal ECG (and a normal troponin level) rules out BCI with high certainty. Sternal fracture may or may not be associated with BCI. Its presence should not lead to additional investigations if ECG is normal. Conversely, its absence should not rule out BCI.
Most patients with an aortic injury die at the scene. For those that survive to present to hospital, a high index of suspicion and dedicated investigations are required for diagnosis.
Significant deceleration (eg: high speed RTC, fall >1 storey) is usually required to cause blunt aortic injury. The most common area of injury is around the ligamentum arteriosum where the aorta is tethered and therefore prone to shearing forces.
Aortic injuries can result in
Most patient are asymptomatic or will have distracting injuries – hence a high degree of suspicion is needed. Other clinical signs include:
The most common abnormality of aortic injury is a widened mediastinum >8cm (which represents a mediastinal haematoma) – this is present in around 70-75% of patients with aortic injury.9,10
Note that this can be difficult to assess if the patient is supine or rotated
Other signs suggestive of aortic injury (in approximate order of incidence)
Up to 10% of patients with an aortic injury may have a “normal” CXR10
The most sensitive test and the usual modality to diagnose aortic injury
May have a role in the unstable patient but ideally should have a transoesophageal study
Patients with an aortic injury should have early consultation with the vascular surgical team at Auckland Hospital
CALL 0800 4TRAUMA if outside of Auckland Hospital (At Middlemore – discuss with the MMH Vascular Consultant first)
Note that many patients that have survived to hospital presentation and subsequent CT diagnosis of aortic injury do not require urgent aortic repair (unless there is evidence of major haemorrhage from the aorta) and should have other life threats (eg: haemorrhage control from other areas or neurological management) prioritised.
To prevent further aortic injury, blood pressure should be controlled – aim for SBP between 100-120.
Blunt traumatic oesophageal injuries are rare and can be difficult to detect. The mechanism of injury may be due to compression against adjacent vertebral fractures or from increased intraluminal pressure (eg: distal pressure exerted against a closed glottis).
Failure to treat can lead to significant morbidity and mortality from mediastinitis. Symptoms may include: dysphagia, haematemesis, shortness of breath and chest pain. The most commonly observed finding is subcutaneous emphysema.
CXR or CT might show pneumomediastinum, pleural effusion or pneumothorax but is generally non-specific.
The best diagnostic modalities are esophagogram with water soluble contrast, complemented by endoscopy. The negative predictive value of these two tests are nearly 100%.
Treatment ranges from conservative management (Nil oral, NG tube drainage, NG feeding) to operative management.
Most patient with blunt chest trauma will have a CXR obtained early in their management.
The decision to perform a CT chest on patients with blunt trauma is a balance between the risk of radiation exposure and the risk of missing a significant injury.
Some clinical decision rules have been developed (eg: NEXUS CT-ALL) but have very broad inclusion criteria (eg: CT scan all patients with any chest wall tenderness, all patients with clavicle fractures etc… ) so have very high sensitivity (99%), but low specificity (20%) for detecting major injuries.11
Patients will need to be assessed in terms of their injury patterns and mechanism of injury.
The following are some indications for CT chest in patients with blunt trauma.