When can a cervical (c) collar be removed?

Requirements for Cervical Collar Removal

A cervical collar should be removed when a high-quality CT scan is negative for cervical spine injury in obtunded adult blunt trauma patients, while patients with neurological deficits require additional MRI imaging before collar removal. 1

Diagnostic Evaluation Before C-Collar Removal

Imaging Requirements

• High-quality CT scan: Multi-detector CT with axial thickness less than 3mm, including sagittal and coronal reconstructions 2
• Additional MRI: Required only in specific circumstances:
  • Patients with neurological deficits attributable to spinal cord 1
  • Patients with persistent neck pain after negative CT 1
  • When CT shows concerning subtle findings (e.g., widening between spinous processes) 3

Clinical Assessment

• Neurologically intact patients: Can have collar removed after negative CT scan 1
• Obtunded patients: Can have collar removed after negative high-quality CT scan alone 2
• Patients with neurological deficits: Require MRI before collar removal 1

Procedural Considerations for C-Collar Removal

During Airway Management

• When tracheal intubation is needed, the anterior part of a rigid collar should be removed to improve glottic exposure while maintaining manual in-line stabilization 1
• Videolaryngoscopy is preferred over direct laryngoscopy for patients with suspected cervical spine injury 1

Timing of Removal

• Early collar removal is beneficial to avoid complications of prolonged immobilization 1
• Como et al. reported collar removal on hospital day 3 compared to day 7.5 in previous protocols 1

Risks of Prolonged C-Collar Use

Prolonged cervical collar immobilization can lead to:

• Cutaneous pressure ulceration (documented in up to 0.5% of patients) 1
• Elevated intracranial pressure
• Airway management difficulties
• Difficulty with central venous access
• Poor oral care
• Feeding complications
• Restricted physiotherapy
• Increased risk of thromboembolism
• Higher risk of cross-infection 1

Risks of Premature C-Collar Removal

• Standard cervical collars provide insufficient immobilization for unstable cervical spine injuries 4
• Missed ligamentous injuries can lead to devastating neurological consequences 3
• CT has limitations in detecting purely ligamentous injuries (approximately 9% cumulative literature incidence of stable injuries missed on CT) 2

Evidence Quality and Controversies

• The evidence for collar removal based on CT alone in obtunded patients is conditional (Grade 2+ recommendation) 1
• Studies show 0% incidence of unstable injuries missed by high-quality CT scans 2
• MRI identifies soft tissue injuries in 5-24% of blunt trauma patients with negative CT, but most do not require surgical intervention 1
• Recent multicenter trials suggest a small but clinically significant risk of missed injuries with CT alone, with MRI identifying actionable findings in some cases 1

Algorithm for C-Collar Removal Decision-Making

1. Perform high-quality CT scan of cervical spine
2. If CT negative and patient neurologically intact: Remove collar
3. If CT negative but patient has neurological deficits: Perform MRI before collar removal
4. If CT positive: Continue immobilization and consult spine specialist
5. If CT negative but patient obtunded:
   • Modern practice supports collar removal based on negative CT alone
   • Consider MRI if there is high clinical suspicion or subtle CT findings

This approach balances the risks of missed injuries against the complications of prolonged immobilization, with mortality and morbidity outcomes as the priority.