From the Guidelines
Cervical collars can increase intracranial pressure, and their routine application by first aid providers is not recommended due to the potential harm and lack of clear benefit. The application of a cervical collar can compress the jugular veins in the neck, impairing venous drainage from the brain and leading to increased blood volume within the cranial vault, subsequently raising intracranial pressure 1. This effect is particularly concerning in patients with traumatic brain injury or other conditions where elevated ICP is already a risk.
The mechanism involves compression of the jugular veins by the collar, especially when fitted too tightly. Studies have shown that ICP can increase following cervical collar application, and the task force suggests against the routine application of cervical collars by first aid providers due to the growing body of evidence demonstrating harmful effects, such as increased intracranial pressure and potential airway compromise 1.
Some key points to consider include:
- The potential benefits of applying a cervical collar do not outweigh harms such as increased intracranial pressure and the consequences of unnecessary neck movement 1
- The process for application of a cervical collar by a first aid provider to an individual with cervical spinal trauma could result in further injury 1
- Application of a cervical collar requires training and regular practice to be performed properly, and such training may not be a component of every first aid course curriculum 1
- Alternative methods that cause less jugular compression, such as manual in-line stabilization for short periods or devices specifically designed to minimize venous compression while maintaining cervical spine immobilization, should be considered when cervical immobilization is necessary.
From the Research
Cervical Collars and Intracranial Pressure
- The application of cervical collars in patients with head injuries or acute cervical spine injury has been studied to determine its effect on intracranial pressure (ICP) 2, 3, 4, 5.
- A study published in the ANZ journal of surgery in 2002 found that the application of a hard collar was associated with an increase in ICP in 9 out of 10 head-injured patients 3.
- In contrast, a study published in Aktuelle Traumatologie in 1993 found no significant changes in ICP after placement of a rigid collar in 18 patients with severe head injury 4.
- Another study published in Anaesthesia in 1994 found a significant elevation of cerebrospinal fluid pressure in 7 out of 9 patients when a 'Stifneck' cervical collar was applied 5.
- A more recent study published in 2022 investigated the use of soft collars for acute cervical spine injury immobilization and found no adverse events resulting from collar use, suggesting that soft collars may be a suitable alternative to hard collars 6.
Key Findings
- The use of hard collars may be associated with an increase in ICP in some patients 3, 5.
- Soft collars may be a suitable alternative to hard collars, with no adverse events reported in one study 6.
- The effect of cervical collars on ICP may vary depending on the type of collar used and the individual patient's condition 2, 4.