When is it safe to forego a CT in kids with head trauma?
New clinical prediction rules make it easier to identify children at low risk of serious brain injury—and reduce the reliance on CT scanning.
Based on their clinical assessment, emergency physicians obtained CT scans for a total of 14,969 children and found ciTBIs in 376—35% and 0.9% of the 42,412 study participants, respectively. Sixty patients required neurosurgery. Investigators ascertained outcomes for the 65% of participants who did not undergo CT imaging via telephone, medical record, and morgue record follow-up; 96 patients returned to a participating health care facility for subsequent care and CT scanning as a result. Of those 96, 5 patients were found to have a TBI. One child had a ciTBI and was hospitalized for 2 nights for a cerebral contusion.
The investigators used established prediction rule methods and Standards for the Reporting of Diagnostic Accuracy Studies (STARD) guidelines to derive the rules. They assigned a relative cost of 500 to 1 for failure to identify a patient with ciTBI vs incorrect classification of a patient who did not have a ciTBI.
Negative finding=0 of 6 predictors
The rules that were derived and validated on the basis of this study are more detailed than previous pediatric prediction rules. For children <2 years, the new standard features 6 factors: altered mental status, palpable skull fracture, loss of consciousness (LOC) for ≥5 seconds, nonfrontal scalp hematoma, severe injury mechanism, and acting abnormally (according to the parents).
The prediction rule for children ≥2 years has 6 criteria, as well, with some key differences. While it, too, includes altered mental status and severe injury mechanism, it also includes clinical signs of basilar skull fracture, any LOC, a history of vomiting, and severe headache. The criteria are further defined, as follows:
Altered mental status: GCS <15, agitation, somnolence, repetitive questions, or slow response to verbal communication.
Severe injury mechanism: Motor vehicle crash with patient ejection, death of another passenger, or vehicle rollover; pedestrian or bicyclist without a helmet struck by a motor vehicle; falls of >3 feet for children <2 years and >5 feet for children ≥2; or head struck by a high-impact object.
Clinical signs of basilar skull fracture: Retroauricular bruising—Battle’s sign (peri-orbital bruising)—raccoon eyes, hemotympanum, or cerebrospinal fluid otorrhea or rhinorrhea.
In both prediction rules, a child is considered negative and, therefore, not in need of a CT scan, only if he or she has none of the 6 clinical predictors of ciTBI.
New rules are highly predictive
In the validation cohorts, the rule for children <2 years had a 100% negative predictive value for ciTBI (95% confidence interval [CI], 99.7-100) and a sensitivity of 100% (95% CI, 86.3-100). The rule for the older children had a negative predictive value of 99.95% (95% CI, 99.81-99.99) and a sensitivity of 96.8% (95% CI, 89-99.6).
In a child who has no clinical predictors, the risk of ciTBI is negligible—and, considering the risk of malignancy from CT scanning, imaging is not recommended. Recommendations for how to proceed if a child has any predictive factors depend on the clinical scenario and age of the patient. In children with a GCS score of 14 or with other signs of altered mental status or palpable skull fracture in those <2 years, or signs of basilar skull fracture in kids ≥2, the risk of ciTBI is slightly greater than 4%. CT is definitely recommended.
In children with a GCS score of 15 and a severe mechanism of injury or any other isolated prediction factor (LOC >5 seconds, non-frontal hematoma, or not acting normally according to a parent in kids <2; any history of LOC, severe headache, or history of vomiting in patients ≥2), the risk of ciTBI is less than 1%. For these children, either CT or observation may be appropriate, as determined by other factors, including clinician experience and patient/parent preference. CT scanning should be given greater consideration in patients who have multiple findings, worsening symptoms, or are <3 months old.
WHAT’S NEW: Rules shed light on hazy areas
These new PECARN rules perform much better than previous pediatric clinical predictors and differ in several ways from the 8 older pediatric head CT imaging rules. The key provisions are the same—if a child has a change in mental status with palpable or visible signs of skull fracture, proceed to imaging. However, this study clarifies which of the other predictors are most important. A severe mechanism of injury is important for all ages. For younger, preverbal children, a nonfrontal hematoma and a parental report of abnormal behavior are important predictors; vomiting or a LOC for <5 seconds is not. For children ≥2 years, vomiting, headache, and any LOC are important; a hematoma is not.
