The effects of rigid collar placement on intracranial and cerebral perfusion pressures.

Rigid collars are routinely used to immobilise the cervical spine during early management of trauma victims until spinal injury is excluded. Spinal injuries commonly coexist in patients with severe head injury, and there is still uncertainty as to whether application of a rigid collar may adversely affect intracranial pressure. The aim of this study was to examine this effect by applying rigid collars to patients with traumatic head injury. The results showed a significant rise from the baseline intracranial pressure when the collars were applied (mean rise = 4.6 mmHg, p < 0.0001). The mean rise in intracranial pressure was greater in those patients with a baseline intracranial pressure > 15 mmHg compared to those with a baseline intracranial pressure < 15 mmHg (p < 0.05). Since there was no significant change in cardiorespiratory parameters during this time, venous compression in the neck seems a likely explanation for the effect observed. These findings suggest that in head-injured patients, rigid collars should be removed as soon as cervical spine injury has been excluded or, if this is delayed, an alternative method of spinal stabilisation considered.