Study: New CATCH rule standardizes CT use for pediatric head injuries
A new clinical decision rule identifying children at two levels of risk has been developed by researchers to facilitate a physicians’ decision for administering CT scans to children presenting with minor head injuries, according to a study published online Feb. 8 in the Canadian Medical Association Journal.

During the study, Martin Osmond, MD, from the department of pediatrics at the Children's Hospital of Eastern Ontario, Canada, and colleagues developed the new CATCH rule (Canadian Assessment of Tomography for Childhood Head Injury).

The current debate regarding the need for CT scanning in the treatment of  this group of children was the basis for their study, as well as the growing concern that early exposure to ionizing radiation may result in a significant rise in lifetime fatal cancer risk, according to the authors. "Without the support of widely accepted, evidence-based guidelines, physicians are likely to follow the conservative approach of ordering CT scans for most children seen in emergency departments with minor head injury," they wrote.

The multicenter study included 3,866 consecutive children, with a mean age 9.2 years, who entered emergency departments with blunt head trauma and presented with loss of consciousness, amnesia, disorientation and/or vomiting and a score of 13–15 on the Glasgow Coma Scale. Emergency department staff completed a standardized assessment form for each child prior to any CT scan.

On the Glasgow Coma Scale, 2.5 percent of patients presented with an initial score of 13, 7.3 percent of patients had a score of 14 and 90.2 percent of patients had a score of 15. The researchers found that CT revealed brain injury in 4.1 percent of patients, and 0.6 percent of patients underwent neurologic intervention.

Osmond and colleagues developed a decision rule for the administration of CT in this cohort by using recursive partitioning to combine variables, including high-risk factors such as failure to reach score of 15 on the Glasgow coma scale within two hours, suspicion of open skull fracture and worsening headache and irritability. Three additional medium-risk factors, including large, boggy hematoma of the scalp, signs of basal skull fracture and dangerous mechanism of injury were also considered for the decision rule.

The high-risk factors were found to have a 100 percent sensitivity rate for predicting the need for neurologic intervention and would require that 30.2 percent of child patients undergo CT. The medium-risk factors resulted in 98.1 percent sensitivity for the prediction of brain injury by CT and would call for 52 percent of patients to undergo CT, wrote Osmond and colleagues.

"We believe an accurate clinical decision rule, like the CATCH Rule, can stabilize or reduce the number of children receiving a CT scan, thereby minimizing both health care costs and exposure to the potentially harmful effects of ionizing radiation,” concluded the authors, who noted the need for further studies in the application of this rule to other pediatric age groups.