When should an X-ray (X-radiation) be performed in trauma patients?

When to Perform X-ray in Trauma Patients

In hemodynamically unstable trauma patients, obtain chest and pelvic X-rays immediately alongside E-FAST during resuscitation; in hemodynamically stable patients, skip plain films and proceed directly to CT scan with contrast. 1

Hemodynamically Unstable Patients

Immediate X-ray imaging is essential when patients cannot undergo CT scanning due to ongoing resuscitation needs. 1

Required X-rays During Resuscitation:

• Chest X-ray - to identify pneumothorax, hemothorax, or need for tube thoracostomy 1
• Pelvic X-ray - to detect unstable pelvic fractures requiring urgent intervention 1
• These are the only imaging modalities compatible with ongoing resuscitation efforts 1

Clinical Decision Algorithm:

• Perform chest X-ray + pelvic X-ray + E-FAST simultaneously at bedside 1, 2
• This combination enables 98% appropriate urgent intervention decisions (tube thoracostomy, emergency thoracotomy, pelvic angiography/embolization, emergency laparotomy) 1, 2
• When chest X-ray and E-FAST rule out extra-pelvic bleeding sources, proceed directly to pelvic angiography 1
• In rare cases of uncontrollable hemorrhagic shock, angiography can be performed immediately after chest X-ray and E-FAST 1

Hemodynamically Stable Patients

Do not obtain pelvic X-rays in stable patients - proceed directly to CT scan with intravenous contrast. 1

Rationale for Skipping Plain Films:

• CT identifies 35.6% more pelvic fractures than pelvic X-ray 3
• In 22% of cases, pelvic fractures are completely missed on X-ray but detected on CT 3
• Pelvic X-ray findings do not change emergency department management when CT is planned 3, 4
• CT has 93.9% positive predictive value and 87.5% negative predictive value for detecting active bleeding compared to angiography 1

Imaging Pathway for Stable Patients:

• Perform E-FAST first to rapidly detect free fluid 1, 5
• Proceed directly to thoraco-abdomino-pelvic CT scan with IV contrast 1
• CT provides complete injury inventory including hepatic, splenic, renal, and pelvic injuries 1

Special Considerations

Chest X-ray in Stable Patients:

• Not routinely indicated in stable patients with normal chest physical examination 6
• In stable patients with normal chest exam, only 0.6% required intervention based on chest imaging 6
• Reserve chest X-ray for clear clinical indications: respiratory distress, abnormal breath sounds, chest wall tenderness, or penetrating trauma 6

Common Pitfalls to Avoid:

• Do not delay CT scanning to obtain pelvic X-rays in stable patients - this adds no clinical value 3, 4
• Do not skip E-FAST - it has 97% positive predictive value for intra-abdominal bleeding and 97% negative predictive value in shock patients 1, 5
• Watch for E-FAST false positives including hemoretroperitoneum suffusion and intraperitoneal bladder rupture 1, 5
• Most commonly missed fractures on pelvic X-ray are sacral and iliac injuries 3

High-Risk Mechanisms Requiring Imaging:

• Motor vehicle crashes (60% of pelvic fractures) 1
• Falls from height (23% of pelvic fractures) 1
• Motorcycle collisions and pedestrian accidents 1
• Unstable pelvic fractures correlate with massive hemorrhage and associated thoracic, abdominal, and head injuries 1

When Pelvic X-ray IS Indicated in Stable Patients:

• Only when CT is inaccessible or unavailable 1
• Patient has pelvic instability or hip dislocation on physical examination 3
• Otherwise, pelvic X-ray should be eliminated from the routine trauma evaluation 3, 4