Blunt chest trauma

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.

 

Immediate life threats

These should be identified and managed as part of the primary survey

 

 

Musculoskeletal trauma

 

Rib fractures

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.

They may also cause injury to underlying structures and are a common cause of pneumothorax, haemothorax and pulmonary contusion. Lower rib fractures can be associated with solid organ injuries. Multiple rib fractures in two or more places can lead to a flail chest, which can rapidly lead to respiratory compromise. Upper rib fractures require significant force so may be associated with other significant injuries.

Investigations

The mainstay of imaging for rib fractures is a CXR, however up to 50% of fractures can be missed on plain radiography.1 Ultrasound may have a role in detecting occult fractures, though many of these 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 fractures.

Disposition

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

  • have multiple (>2) rib fracturess
  • have 1st, 2nd or 3rd rib fractures
    • associated with higher force, though studies have shown that in the absence of neurological or vascular signs these are not associated with an increase in mortality when an isolated finding
  • have any rib fracture with inability to mobilise, cough or take a deep breath despite adequate analgesia
  • have evidence of underlying pulmonary contusion
  • are elderly/frail or are in a poor social situation
  • have underlying chronic cardiac or respiratory disease

 

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)

Surgical fixation of severe rib fractures (eg: flail segment, severe displacement) with concerns for respiratory compromise might be a treatment option and may decrease mortality, LOS, duration of mechanical ventilation and the need for a tracheostomy.2,3

Interhospital transfer guidelines
RIB #

 

Sternal fractures

Sternal fractures usually occur from a direct blow to this area, most commonly from motor vehicle accidents (seat belt or steering wheel injuries).

Investigations

PA and lateral CXRs can detect sternal fractures, though a dedicated lateral sternal view is often requested. Like rib fractures, undisplaced fractures can be missed on plain radiography.

Sternal fractures can be associated with underlying cardiac, mediastinal or pulmonary injuries, though the emphasis on this has decreased, with many studies showing that isolated simple sternal fractures are usually benign.4,5

A 12 lead ECG should be performed as a screening test for all patients with suspected sternal fractures as myocardial contusion can occur in up to 6% of patients.

A CTA of the chest should be requested if there are concerns regarding other underlying mediastinal injuries.

Disposition

There is some debate regarding the routine admission of all patients with sternal fractures. Many patients will require admission for observation and analgesia, especially if there is concern for underlying injury.

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. 6,7

Interhospital transfer guidelines
sternal #

 

Clavicle injuries

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

 

Scapula fractures

Fractures of the scapula are usually caused by significant force so are often associated with other injures. Most scapula fractures are treated conservatively though some will require operative repair (eg: glenohumeral joint instability, severe displacement of scapula neck, open fractures)

 

 

Pulmonary injuries

 Blunt lung injuries can occur with or without rib fractures

 

Pneumothorax

 

Haemothorax

 

Pulmonary contusion

Pulmonary contusions are injuries of the lung parenchyma and can occur with or without rib #s.

Investigations

Pulmonary contusions may not be obvious on initial CXR. CT is the most useful imaging modality.

Treatment

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.

Disposition – interhospital transfer guidelines

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

 

Tracheobronchial injury

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.

 

Cardiac and mediastinal injuries

 

Blunt cardiac injury

A range of blunt cardiac injuries (BCI) can occur. Most patients have significant chest wall trauma and/or a history of sudden deceleration 

Injuries

  • cardiac rupture (most die at scene)
    • would present with severe shock and cardiac tamponade
  • septal or valvular rupture
    • are rare injuries, would present with shock and failure
  • myocardial infarction
    • most commonly from left anterior descending artery injury
  • myocardial contusion
    • the most common form of BCI diagnosed however is controversial as there is no universally accepted definition or gold standard test.8
      • Can present with arrhythmias
      • Associated with sternal #s and significant anterior chest wall injury

 

Investigations

ECG

A newly abnormal ECG is probably the most sensitive investigation for blunt cardiac injury and should be used as a screening test for patients with significant anterior chest wall injury

  • Most common changes: persistent tachycardia, new bundle branch block, ST elevation or depression, new AF or arrhythmia
    • Consider the “chicken-egg” scenario with an abnormal ECG – did a medical event (eg: dysrhythmia) cause the patient to become injured?
  • Patients with a newly abnormal ECG should be admitted for cardiac monitoring and considered for further investigations

Cardiac biomarkers

The role of troponin is less clear, but patients with a positive troponin should also monitored (consider only performing troponins in patients with abnormal ECGs)

Echocardiogram

Patients who are haemodynamically unstable or have suspect significant structural cardiac injury should have an urgent echocardiogram

Echo probably contributes little to patients with BCI who are haemodynamically stable with no signs of cardiac failure.

 

A normal ECG and negative troponin can rule out blunt cardiac injury (though the optimal timing of these measurements is unknown)8

 

Management

Patients with structural cardiac damage will require urgent cardiothoracic consultation

CALL 0800 4TRAUMA if outside of Auckland Hospital

Consult cardiology in patients with signs of myocardial infarction, failure or persistent arrhythmias.

Patients who are diagnosed with an uncomplicated myocardial contusion (minor ECG changes or troponin rise) should probably have cardiac monitoring for 24-48 hours

 

Aortic injury

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

  • Rupture (most die immediately)
  • Pseudoaneurysm
  • Intimal tear

 

Clinical signs

  • Dyspnoea
  • Severe transthoracic pain
  • Stridor/hoarse voice
  • Neck haematoma
  • Unilateral diminished pulse, radio-radio or radio-femoral delay, asymmetric BP
  • Hypertension
  • New murmur
  • Limb ischaemia

 

Imaging

CXR

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)

  • loss of normal aortic contour (indistinct arch)
  • loss of aorto-pulmonary window
  • left apical pleural haematoma (apical cap)
  • downward displacement of main stem bronchus (left down, right up)
  • tracheal deviation to the right
  • deviation of NG tube to the right
  • large left sided haemothorax

 

Up to 10% of patients with an aortic injury may have a “normal” CXR10

 

CT aortogram

The most sensitive test and the usual modality to diagnose aortic injury

 

Echocardiography

May have a role in the unstable patient but ideally should have a transoesophageal study

 

 

Disposition and management

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.

 

 

Oesophageal injury

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 CXR/CT performed with contrast swallow or endoscopy

 

Imaging of patients with blunt chest trauma 

CXR

Most patient with blunt chest trauma will have a CXR obtained early in their management.

Ultrasound (e-FAST)

Ultrasound can be a useful adjunct, especially in the unstable patient. It can rapidly detect pneumothorax, haemothorax and cardiac tamponade.

CT chest

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 fracturess 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.

  • Severely injured multitrauma patients as part of a “pan-scan”
  • Suspicion of aortic injury
    • Dangerous mechanism (sudden deceleration from fall from height or RTC)
    • Abnormal CXR (widened mediastinum or other concerns for aortic injury)
  • Suspected thoracic spine or scapula fractures
  • Displaced sternal # (or other concerns for underlying injury)
  • Suspicion of significant lung injury (eg: pulmonary contusion)
    • Multiple rib fractures
    • Haemothorax or concerning pneumothorax

 

References

  1. Bergeron E, Lavoie A, Clas D, et al. Elderly trauma patients with rib fractures are at greater risk of death and pneumonia. J Trauma. 2003;54:478–85
  2. de Moya M, Nirula R, Biffl W. Rib fixation: Who, What, When?. Trauma Surgery & Acute Care Open. 2017 Apr 1;2
  3. Kasotakis G, Hasenboehler EA, Streib EW, Patel N, Patel MB, Alarcon L, Bosarge PL, Love J, Haut ER, Como JJ. Operative fixation of rib fractures after blunt trauma: A practice management guideline from the Eastern Association for the Surgery of Trauma. Journal of Trauma and Acute Care Surgery. 2017 Mar 1;82(3):618-26.
  4. Celik B, Sahin E, Nadir A, Kaptanoglu M. Sternum fractures and effects of associated injuries. The Thoracic and cardiovascular surgeon. 2009 Dec;57(08):468-71.
  5. Roy-Shapira A, Levi I, Khoda J. STERNAL FRACTURES: A RED FLAG OR A RED HERRING?. Journal of Trauma and Acute Care Surgery. 1994 Jul 1;37(1):59-6
  6. Khoriati, A., Rajakulasingam, R., & Shah, R. (2013). Sternal fractures and their management. Journal of Emergencies, Trauma, and Shock, 6(2), 113–116. http://doi.org/10.4103/0974-2700.110763
  7. Bestbets – Admission not needed for uncomplicated sternal fractures (http://bestbets.org/bets/bet.php?id=5)
  8. Clancy K, Velopulos C, Bilaniuk JW, Collier B, Crowley W, Kurek S, Lui F, Nayduch D, Sangosanya A, Tucker B, Haut ER. Screening for blunt cardiac injury: an Eastern Association for the Surgery of Trauma practice management guideline. Journal of Trauma and Acute Care Surgery. 2012 Nov 1;73(5):S301-6.
  9. Ekeh AP, Peterson W, Woods RJ, Walusimbi M, Nwuneli N, Saxe JM, McCarthy MC. Is chest x-ray an adequate screening tool for the diagnosis of blunt thoracic aortic injury?. Journal of Trauma and Acute Care Surgery. 2008 Nov 1;65(5):1088-92.
  10. Stark P, Cook M, Vincent A, Smith DC. Traumatic rupture of the thoracic aorta. A review of 49 cases. Der Radiologe. 1987 Sep;27(9):402-6.
  11. Rodriguez RM, Langdorf MI, Nishijima D, Baumann BM, Hendey GW, Medak AJ, Raja AS, Allen IE, Mower WR. Derivation and validation of two decision instruments for selective chest CT in blunt trauma: a multicenter prospective observational study (NEXUS Chest CT). PLoS medicine. 2015 Oct 6;12(10):e1001883.

 

About this guideline

Published: February 2018

Author: Emma Batistich

Approved by: Northern Region Trauma Network, ADHB, WDHB, CMDHB, NDHB

Review due: 2 years