A substantial percentage of children who receive a CT scan after apparently minor head trauma do not need it and are consequently exposed to unnecessary radiation, according to a recent study. After analyzing more than 42,000 children with head trauma, a national research team including John Hoyle, MD, a pediatric emergency medicine physician at Helen DeVos Children’s Hospital , has developed guidelines for doctors who care for children with head trauma aimed at reducing those risks. The team’s findings appear in the current issue of The Lancet.
The collaborative study, led by investigators at University of California, Davis, includes data collected at 25 hospitals from children who were evaluated for the possibility of brain injury following head trauma. Researchers found that one in five children older than 2 and nearly one-quarter of those younger than 2 who received CT scans following head trauma did not need them because they were at very low risk of having serious brain injuries. In these low risk children, the risk of developing cancer due to radiation exposure outweighed the risk of serious brain injury.
“No significant data was previously available to tell us when it was safe not to perform a scan,” said Dr. Hoyle. “We have tended to err on the side of caution and perform a CT scan more liberally on children with head trauma. This large scale study allows us to practice evidence-based medicine and safely reduce the number of CT scans for children who are at very low risk of serious brain injury.”
The Centers for Disease Control estimates that 435,000 children younger than 14 visit emergency rooms annually to be evaluated for traumatic brain injury (TBI). Not all head trauma results in a TBI. The severity of a brain injury may range from mild, causing a brief change in mental status or consciousness, to severe, causing permanent symptoms and irreversible damage.
As part of the study, Hoyle and his colleagues developed a set of rules for identifying low risk patients who would not need a CT. The “prediction rules” for children younger than 2 and for those 2 and older depend on the presence or absence of various symptoms and circumstances, including the way the injury was sustained, a history of loss of consciousness, neurological status at the time of evaluation and clinical evidence of skull fracture for both age groups. The use of CT in patients who do not fall into the very low risk group identified by the prediction rules will depend on other factors, such as the physician’s experience, and the severity and number of symptoms, whether the symptoms are improving or worsening, as well as family input. Until now, emergency department physicians have relied mostly on instinct when deciding whether or not the symptoms of a child with minor head trauma warrant the use of CT.
The research was made possible by the Pediatric Emergency Care Applied Research Network (PECARN), which enabled the massive collection of data. Supported by the U.S. Department of Health and Human Services’ Emergency Medical Services for Children Program, PECARN is the first federally funded, multi-institutional network for research in pediatric emergency medicine in the nation. The network conducts research into the prevention and management of acute illnesses and injuries in children and youth across the continuum of emergency medicine and health care. Helen DeVos Children’s Hospital has been part of PECARN since 2001.
History of CT Scan Use
For years, studies have suggested that CT scans were being overused to rule out traumatic brain injuries. However, those studies were considered too small to be sufficiently accurate and not precise enough to be widely applicable to a general population. The size of the current study, and the fact that the investigators created the accurate prediction rules with one large group of children with head trauma and then tested the rules on another large but separate group to demonstrate their validity, allows physicians to have confidence in the results. The researchers emphasized, however, that the rules are not intended to replace clinical judgment.
Previous studies have shown that exposure to radiation increases the risk of cancer. Radiation exposure to the brain of developing children is of particular concern and must be weighed carefully against the risk of traumatic brain injury that could cause permanent damage or death if not identified early. If the new guidelines are applied appropriately, the use of CT scans nationwide could be significantly reduced.
“The sheer number of children involved in this study is part of what makes the data so powerful,” added Hoyle. “We studied large numbers of children, in a variety of settings and from diverse populations, which make the results more applicable to the general population. Our partnership with hospitals across the country made this research and, ultimately, a change in patient care possible.”
About the Study
In order to create the prediction rules, the PECARN investigators studied outcomes in more than 42,000 children with minor initial symptoms and signs of head trauma. CT scans were performed in nearly 15,000 of those patients. Serious brain injuries were diagnosed in 376 children, and 60 children underwent neurosurgery.
Using these data, the researchers developed two prediction rules for identifying mild cases that do not require CT scans. One rule was developed for children younger than 2 and another for those 2 and older. It was important to study children younger than 2 separately because they cannot communicate their symptoms or offer information as well as older children can, and they are more sensitive to the effects of radiation.
Children younger than 2 who fell into the very low risk group showed normal mental status, no scalp swelling, no significant loss of consciousness, and no palpable skull fracture, were normal-acting (according to the parent); and had an injury that was sustained in a non severe way.
Key indicators for children older than 2 who were at low risk for brain injury included normal mental status, no loss of consciousness, no vomiting, no signs of fracture of the base of skull, and no severe headache along with the fact the injury was not sustained in a severe accident and they did not sustain the injury in a serious accident.
Severe accidents, which excluded children from the low risk group, included motor vehicle crashes in which the patient was ejected, and bicycle accidents involving automobiles, in which the patient was not wearing a helmet.
All patients in the high risk group, defined by the presence of abnormal mental status or signs for a skull fracture, should receive CT scans, the researchers wrote.
The researchers then validated these rules by applying them to data from a second population of more than 8,600 children. In more than 99.9 percent of the cases, the rules accurately predicted children who were not diagnosed with serious brain injuries and were therefore indeed at low risk. The PECARN team is currently working on refining recommendations.
Helen DeVos Children’s Hospital, a member of Spectrum Health, is a Grand Rapids-based hospital serving children throughout Michigan . A teaching hospital, it includes more than 150 pediatric specialty physicians with specialized training in providing medical and surgical care to children in more than 40 pediatric specialties.