NOTE: Some of the criteria are similar to those used in the Canadian CT rule (see above).
Criteria for head CT scan:
(1) A Glasgow coma score (GCS) < 13 at any time since the trauma.
(2) A GCS 13 or 14 at 2 hours after the trauma.
(3) A suspected depressed or open skull fracture.
(4) Any sign of a basal skull fracture.
(5) A seizure episode after the trauma.
(6) A focal neurological deficit, including:
(6a) problems understanding, speaking, reading or writing.
(6b) loss of feeling in any part of the body.
(6c) problems with balance or walking
(6d) general weakness
(6e) any change in eyesight
(7) 2 or more episodes of vomiting since the trauma, unless the patient is < 12 years of age and the physician feels that the vomiting is unrelated to head injury.
(8) Interval of amnesia for events before the trauma > 30 minutes.
(9) age >= 65 years of age AND if loss of consciousness or amnesia occurred after the trauma
(10) coagulopathy AND if loss of consciousness or amnesia occurred after the trauma
(11) anticoagulation therapy AND if loss of consciousness or amnesia occurred after the trauma
(12) dangerous mechanism of injury AND if loss of consciousness or amnesia occurred after the trauma
Signs of basal skull fracture includes:
(1) hemotympanum
(2) "racoon" eyes (periorbital ecchymosis)
(3) CSF otorrhea or rhinorrhea
(4) Battle's sign (discoloration in the line of the posterior auricular artery, with ecchymosis first appearing near the tip of the mastoid process)
Dangerous mechanism of injury:
(1) pedestrian struck by motor vehicle
(2) person ejected from motor vehicle
(3) fall in adult > 1 meter or > 5 stairs
(4) fall from any height in child < 5 years of age
(5) any high energy injury
Ideally the CT scan should be performed immediately (within 1 hour of physician order) for most of these conditions. For some criteria (8 and 12) the CT scan may not need to be done immediately but should be done within 8 hours of the head trauma.
