What additional laboratory tests and imaging studies are required for a first rib fracture due to trauma?

From the Guidelines

For first rib fractures, a comprehensive imaging workup including a CT scan of the chest with contrast is essential to assess for associated injuries, particularly vascular injuries to the subclavian vessels and aortic arch, as evidenced by studies such as 1.

Initial Assessment

The initial assessment should include a chest X-ray, followed by a CT scan of the chest with contrast to better visualize the fracture and assess for associated injuries to nearby structures.

• A complete trauma workup is necessary due to the significant force required to fracture the first rib, which is protected by the clavicle, scapula, and surrounding musculature.
• Laboratory tests should include a complete blood count to assess for blood loss, basic metabolic panel to evaluate renal function, coagulation studies, and arterial blood gases if respiratory compromise is suspected.

Vascular Injury Evaluation

CT angiography of the thoracic vessels is crucial to evaluate for potential vascular injuries, particularly to the subclavian vessels and aortic arch, as studies have shown an increased likelihood of injury to these vessels with displaced first-rib and second-rib fractures 1.

• Electrocardiogram and cardiac enzymes are recommended to rule out cardiac contusion.
• Neurological assessment with possible cervical spine imaging is warranted as the mechanism of injury often involves significant force that may cause concurrent head or neck trauma.

Pulmonary Evaluation

Pulmonary function tests may be necessary if respiratory symptoms are present, as rib fractures are associated with pulmonary complications, including atelectasis, impaired clearance of secretions, pneumonia, and adult respiratory distress syndrome 1.

• The presence and number of rib fractures, and the degree of displacement of the fractures, may carry prognostic significance, and detection of rib fractures by CT may be indicated under certain circumstances, especially if severe injury is suspected 1.

From the Research

Additional Labs and Imaging for First Rib Fracture Trauma

The following labs and imaging may be required for first rib fracture trauma:

• Chest radiography (CXR) to identify first rib fracture and widened mediastinum 2
• Computed Tomography (CT) scan thorax to diagnose first rib fracture, which can be missed on X-ray chest 3
• Subclavian artery and aortic arch arteriography in patients with traumatic first rib fracture and specific indications such as:
  • Widened mediastinum on chest radiography 2
  • Upper-extremity pulse deficit 2
  • Posteriorly displaced first rib fracture 2
  • Subclavian groove fracture anteriorly 2
  • Brachial plexus injury 2
  • Expanding hematoma 2
• Doppler ultrasound and angiography to diagnose subclavian artery damage 3
• CT scanning to identify associated injuries, such as pelvic fractures 4

Indications for Additional Imaging

Additional imaging may be indicated in the following situations:

• First rib fracture associated with concomitant head, thoracic, abdominal, or long bone trauma 2
• Patients with lateral or posterior rib fractures 5
• Patients with ≥ 3 rib fractures 5
• Patients requiring O2 supplementation 5