A new decision tool can help reduce the number of children getting a head CT scan
after blunt head trauma, researchers found.
These traumas send about 2 million children to U.S. emergency departments each year,
and clinicians may turn to head CTs to determine if the injuries are serious. However,
such imaging exposes children to radiation often without finding serious brain injuries.
Researchers set out to determine whether the NEXUS II Head Computed Tomography Decision
Instrument could prevent unnecessary imaging. The tool lays out seven criteria: no
evidence of skull fracture, no scalp hematoma, no neurologic deficit, normal level
of alertness, normal behavior, no persistent vomiting and no coagulopathy. Patients
who do not have all seven characteristics need imaging.
The team tested the instrument on 1,018 blunt head injury pediatric patients who underwent
CT. After the test was ordered, clinicians assessed patients based on the NEXUS criteria
and compared the data to CT outcomes.
Researchers found the tool correctly deemed all 27 needing neurosurgical intervention
as being high risk. Of the remaining 991 who did not need surgery, the tool correctly
assigned low-risk status to 330.
In addition, the tool correctly assigned high-risk status to all but one of the 49
patients with significant intracranial injuries. It deemed 329 of the remaining 969
as being low-risk, misclassifying one with significant injuries. The finding “implies
that the rule could have reduced unnecessary imaging by approximately one-third, had
it been implemented in our study,” authors wrote.
Unlike other tools, the NEXUS instrument is not intended for use on all patients with
blunt head trauma. Instead, clinicians should use their clinical judgment to first
rule out those who do not need imaging, then use the tool for those they believe are
at high risk.
Authors noted their study was limited by low numbers of injuries requiring surgery
and acknowledged NEXUS criteria still are subject to the clinician’s judgment.