Pediatric Head Injury in the ED: Is Imaging Necessary?

Dr Jacqueline MacKay, PGY2, FMEM, Dalhousie University

Traumatic brain injury is the leading cause of disability and death in children worldwide. Head injuries are one of the most common reasons for ED visits in pediatric populations, where approximately 50% of children undergo CT. However, some brain injuries are not seen on CT, and many TBIs identified on CT do not require acute intervention. Furthermore, it is well documented that radiation from CT can cause lethal malignancies.

A clinical decision making tool was developed and validated in 2009 by the Pediatric Emergency Care Applied Research Network (PECARN) to assist physicians in determining if a pediatric patient presenting wit h minor head injury requires CT. The study excluded children with trivial mechanisms such as ground level falls or walking into stationary objects, and no signs or symptoms of head trauma other than scalp lacerations/abrasions. The outcome was a set of rules that identify children at very low risk for clinically important traumatic brain injury in whom CT can be routinely avoided.

*Severe mechanism defined as MVA with ejection/fatality/rollover, pedestrian or unhelmeted cyclist vs. vehicle, fall greater than 3ft for children under age 2 and greater than 5ft for children 2 and over, or head struck by high impact object

In the intermediate risk group where there is a 0.9% risk of clinically important TBI, the decision rule is assistive rather than directive. In children with isolated findings, the risk of TBI is significantly less than 1%, and observation without CT may be appropriate. In children with multiple findings or worsening symptoms, CT may be more strongly considered. Clinician experience and parental preference should also be taken into account when making a decision about CT imaging in this group.

The prediction rule for children under 2 was 100% sensitive with a negative predictive value of 100% for clinically important TBI. For children aged 2 and over, the prediction rule was 96.8% sensitive with a negative predictive value of 99.95% for clinically important TBI. A subsequent study comparing the PECARN rules to other clinical prediction tools (CATCH, CHALICE) as well as physician judgement confirmed the sensitivity of the PECARN rules, as well as determining that only the PECARN rules and physician judgement identify all clinically significant traumatic brain injuries.

Bottom line: in children presenting to the ED with minor head injuries, use a clinical decision making tool in addition to clinical judgment when deciding if CT is warranted

References:

Easter J. et al. Comparison of PECARN, CATCH, and CHALICE Rules for Children With Minor Head Injury: A Prospective Cohort Study. Ann Emerg Med. 2014 Mar 10. PMID: 24635987
Kuppermann N. et al. “Identification of children at very low risk of clinically-important brain injuries after head trauma: a prospective cohort study.”. The Lancet. 2009. 374(9696):1160-1170.