PECARN rules: Findings associated with very low risk of significant traumatic brain injury in children*^[1]

TBI: traumatic brain injury; GCS: Glasgow Coma Scale; LOC: loss of consciousness; CSF: cerebrospinal fluid.
* Significant TBI such as death or injury that requires neurosurgical intervention, endotracheal intubation for longer than 24 hours, or hospitalization for 2 or more nights is very unlikely if all of the clinical criteria are present. Thus, computed tomography of the head is usually not necessary in such patients. When individual criteria are not met, observation or neuroimaging may be indicated. Refer to topics on minor head trauma in infants and children for further discussion.
¶ For the purposes of this criterion, LOC does not include very brief (<5 seconds) LOC associated with low-risk mechanisms for head trauma.
Δ Severe mechanism of injury: fall >0.9 m (3 feet); head struck by high-impact object; motor vehicle collision with patient ejection, death of another passenger, or rollover; pedestrian or bicyclist without helmet struck by a motorized vehicle.
◊ Signs of altered mental status: agitation, somnolence, repetitive questioning, or slow response to verbal questioning.
§ As for children under 2 years of age except fall >1.5 m (5 feet) considered severe.
¥ Early signs of basilar skull fracture at presentation include hemotympanum, CSF rhinorrhea, and CSF otorrhea; late signs of basilar skull fracture, occurring up to 24 hours after injury, include raccoon eyes and post-auricular hematoma (Battle sign).