What is the approach to cervical spine (c-spine) clearance?

Cervical Spine Clearance Protocol

A comprehensive approach to cervical spine clearance should include clinical assessment, appropriate imaging, and follow-up based on the patient's level of consciousness and injury pattern, with CT scanning being the preferred initial imaging modality for suspected cervical spine injury in trauma patients. 1

Clinical Assessment for Alert Patients

For alert patients with normal mental status, cervical spine clearance can be approached as follows:

Initial Clinical Evaluation

• Four key criteria must be met for clinical clearance without imaging:

  1. GCS 15, fully alert
  2. No intoxication (alcohol or drugs)
  3. No neck pain or tenderness
  4. No distracting injuries

• If all four criteria are met, the cervical spine can be considered stable and cleared without imaging 1

• The Canadian C-Spine Rule is commonly used (71% of major trauma centers) for clinical clearance 2

Important Clinical Point

• The concept of "distracting injuries" preventing clinical clearance has been challenged by recent evidence showing clinical examination has 99% sensitivity and >99% negative predictive value even in patients with distracting injuries 3

Imaging Approach

For Patients Not Meeting Clinical Clearance Criteria:

1. First-line imaging: High-resolution CT scan (1.5-2mm slices) with sagittal reconstructions 1

   • 72% of major trauma centers prefer CT as first-line imaging 2
   • CT has superior sensitivity (100%) compared to plain radiographs (63%) for detecting skeletal injuries 4

2. Plain radiographs (if CT unavailable)

   • Three-view series (lateral, anteroposterior, and odontoid)
   • Single lateral view alone is insufficient (misses approximately 15% of injuries) 1

3. For persistent neck pain with negative CT:

   • MRI is recommended to evaluate for ligamentous injury 1, 2
   • 52% of trauma centers perform MRI in this scenario 2

Clearance Algorithm Based on Patient Status

Group 1: Patients Expected to Be Clinically Evaluable Within 48-72 Hours

• Examples: Intoxicated patients or those requiring brief ventilation
• Approach:
  1. Obtain baseline three-view cervical spine radiographs
  2. Maintain immobilization until clinical evaluation is possible
  3. Complete clinical assessment when patient becomes evaluable 1

Group 2: Patients Unlikely to Be Evaluable Within 48-72 Hours

• Examples: Severe head injuries, multiple injuries, organ failure
• Approach:
  1. Obtain three-view cervical spine radiographs
  2. Perform high-resolution CT scan (1.5-2mm slices) with sagittal reconstructions
  3. If both are normal (interpreted by a senior radiologist), the cervical spine may be considered stable 1

Special Considerations for Obtunded Patients

The management of obtunded patients remains controversial:

• Current evidence supports: Cervical spine clearance in obtunded adults with negative results from a well-interpreted, high-quality CT scan is likely safe and efficient 5
• Alternative approach: MRI or continued immobilization until clinical examination is possible 1, 2

Risks of Prolonged Immobilization

Prolonged cervical spine immobilization (>48-72 hours) carries significant risks:

• Pressure sores (may require skin grafting)
• Increased intracranial pressure (problematic in patients with head injuries)
• Airway complications
• Aspiration pneumonia
• Venous thromboembolism
• Increased ICU and hospital length of stay 1

Implementation Considerations

• Only 63% of trauma centers in California have written cervical spine clearance protocols 6
• Only 51% of centers follow current evidence-based guidelines 6
• Standardization of protocols is essential to prevent missed injuries and secondary neurologic damage 6

Key Pitfalls to Avoid

1. Relying solely on a single lateral radiograph - misses approximately 15% of injuries 1
2. Failing to obtain adequate imaging of C7-T1 junction - a common site for missed injuries 1
3. Ignoring the risk of isolated ligamentous injury - though rare (0.1-0.7% of trauma patients), can lead to instability 1
4. Prolonged unnecessary immobilization - increases complications after 48-72 hours 1
5. Removing immobilization in obtunded patients without adequate imaging - can lead to secondary neurologic injury 1

Remember that any patient with a neurological deficit referable to the spine requires urgent MRI and consultation with neurosurgery or orthopedic spine surgery.