Rigid collars are routinely used to immobilise the cervical spine during ea
rly management of trauma victims until spinal injury is excluded. Spinal in
juries commonly coexist in patients with severe head injury, and there is s
till uncertainty as to whether application of a rigid collar may adversely
affect intracranial pressure. The aim of this study was to examine this eff
ect by applying rigid collars to patients with traumatic head injury. The r
esults showed a significant rise from the baseline intracranial pressure wh
en the collars were applied (mean rise = 4.6 mmHg, p < 0.0001). The mean ri
se in intracranial pressure was greater in those patients with a baseline i
ntracranial pressure > 15 mmHg compared to those with a baseline intracrani
al pressure < 15 mmHg (p < 0.05). Since there was no significant change in
cardiorespiratory parameters during this time, venous compression in the ne
ck seems a likely explanation for the effect observed. These findings sugge
st that in head-injured patients, rigid collars should be removed as soon a
s cervical spine injury has been excluded or, if this is delayed, an altern
ative method of spinal stabilisation considered.