How to clear a cervical spine (C-spine) collar in a trauma patient?

Clearing Cervical Spine Collar in Trauma Patients

The most effective approach to clearing a cervical spine collar in trauma patients is to divide patients into two groups based on their clinical status: those who can be clinically evaluated within 48-72 hours and those who cannot, with appropriate imaging protocols for each group. 1

Initial Assessment by Senior Clinician

A senior clinician should assess the patient for all four of these preconditions:

1. GCS 15, alert
2. No intoxicants
3. No neck signs (pain, tenderness)
4. No distracting injuries

If the patient meets ALL four preconditions, the cervical spine can be considered stable and cleared immediately. If the patient fails even one precondition, further evaluation is required. 1

Patient Classification Algorithm

Group 1: Patients Expected to be Clinically Evaluable within 48-72 hours

This includes:

• Intoxicated patients who will sober up
• Patients with no significant head injury
• Postoperative patients undergoing brief periods of ventilation

For these patients:

1. Obtain baseline three-view cervical spine radiographs (lateral, anteroposterior, and odontoid)
2. Obtain thoracolumbar AP and lateral plain films
3. When the patient becomes clinically evaluable, perform a complete clinical examination
4. If the examination is negative, the cervical spine can be cleared 1

Group 2: Patients Unlikely to be Evaluable within 48-72 hours

This includes:

• Patients with severe head injuries
• Patients with multiple injuries
• Patients with organ failure

For these patients:

1. Obtain three-view cervical spine radiographs (lateral, anteroposterior, and odontoid)
2. Obtain thoracolumbar AP and lateral plain films
3. Perform high-resolution CT of the entire cervical spine (1.5-2mm slices) with sagittal reconstructions
4. If interpreted as normal by a senior radiologist, the cervical spine may be assumed stable and the collar removed 1

Special Considerations

Thoracolumbar Spine Clearance

• Full evaluation of the entire spine should be considered after identification of a fracture, as there is an estimated 16% incidence of non-contiguous spine fractures 1
• CT is superior to plain imaging for detection of thoracolumbar injuries with 100% sensitivity and 97% specificity compared to 73% sensitivity for plain radiographs 1
• If a CT of chest/abdomen/pelvis has already been performed, use reformats rather than additional plain imaging 1

Role of MRI

There is ongoing controversy regarding the need for MRI in obtunded patients:

• The "conservative" approach argues that plain films and CT can never fully "clear" the cervical spine due to the possibility of isolated ligamentous injury 1
• The "liberal" approach allows removal of immobilization based on normal CT findings alone 1

Recent evidence suggests that CT alone may be sufficient in obtunded patients with gross movement of all extremities. A prospective study of 197 obtunded patients with negative CT scans had collars removed at a mean of 3.3 days with no subsequent neurological deterioration 2

Complications of Prolonged Immobilization

Prolonged cervical collar use (beyond 48-72 hours) is associated with significant complications:

• Cutaneous pressure ulceration
• Elevated intracranial pressure
• Difficult airway management
• Compromised central venous access
• Poor oral care
• Failed enteral nutrition
• Gastric reflux and aspiration
• Restricted physiotherapy
• Increased risk of thromboembolism
• Increased risk of cross-infection 1

Pitfalls to Avoid

1. Relying solely on mechanism of injury: This has limited performance with only 50% accuracy and 20% of injuries missed 1

2. Premature collar removal in high-risk patients: Never clear the cervical spine based on a single lateral plain film alone, which has a false negative rate of approximately 15% 1

3. Excessive caution in low-risk patients: Prolonged immobilization carries significant risks and most trauma patients (90-95%) do not have cervical spine injuries 1

4. Overreliance on MRI findings: Recent evidence suggests MRI signal changes within cervical spine ligaments should be interpreted with caution, as they may appear alarming but not necessarily indicate instability requiring intervention 3

5. Neglecting the thoracolumbar spine: Remember to evaluate the entire spine, as non-contiguous fractures occur in approximately 16% of cases 1

By following this algorithmic approach based on patient evaluability and appropriate imaging, clinicians can effectively clear cervical spine collars in trauma patients while minimizing both the risk of missed injuries and complications from prolonged immobilization.