Children don't always need CT scans after head injury
Period of observation can avoid unnecessary exposure to radiation
A multicenter study of more than 40,000 children with minor blunt head trauma, led by Children’s Hospital Boston and UC Davis Health System, shows that allowing a period of observation reduces the use of head computed tomography (CT) scans by as much as half without compromising care and without exposing children to the dangers of ionizing radiation.
The results, which appear online May 9, and in the June 2011 issue of Pediatrics, show that roughly half of the children taken to hospital emergency rooms for head injuries receive a head CT scan. Yet true traumatic brain injury is uncommon.
“Only 2 to 3 percent of children with head trauma really have something serious going on,” said Lise Nigrovic, assistant professor of pediatrics at Harvard Medical School and a pediatric emergency specialist at Children’s Hospital Boston, who co-authored the study with Nathan Kuppermann, professor of pediatrics and professor and chair of emergency medicine at UC Davis. “If you can be watched in the emergency department for a few hours, you may not need a CT.”
The study noted that cranial CT scans present additional risks to children with head injuries because of the radiation exposure involved in the scan. A child’s growing brain tissue is more sensitive to radiation. Additionally, because of their longer life expectancy, the risk of a child developing a radiation-induced malignancy is greater.
"There is a clear need to develop appropriate and safe guidelines for decreasing the number of inappropriate head CT scans that we do on children,” said Kuppermann. “The results of this analysis demonstrate that a period of observation before deciding to use head CT scans on many injured children can spare them from inappropriate radiation when it is not called for, while not increasing the risk of missing important brain injuries.”
The results stem from a sub-analysis of a large prospective study published in 2009 by the national Pediatric Emergency Care Applied Research Network (PECARN) and led by Kuppermann, which showed that a substantial percentage of children who get CT scans after apparently minor head trauma do not need them, and as a result are put at unnecessary risk of cancer due to radiation exposure. That study, published in the Lancet, analyzed the outcomes of children presenting at 25 different emergency departments around the country.
Today’s Pediatrics article went back and looked at those 40,113 children whose records could be analyzed with regard to an observation period before CT decision-making and found that 5,433 (14 percent) were observed before making a decision about CT use. Observation times varied, as did the severity of head trauma.
Overall, the children who were observed had a lower rate of CT than those not observed (31 vs. 35 percent). Clinically important traumatic brain injury, resulting in death, neurosurgical intervention, intubation for more than 24 hours or hospital admission for two nights or more, was equally uncommon in the observed and non-observed groups (0.75 vs. 0.87 percent).
When the researchers matched the two groups for severity of head injury and the practice style of different hospitals, the benefits of allowing an observation period were much more pronounced: The observed group received CT scans only about half as often as similar non-observed patients (odds ratio, 0.53). In particular, children whose symptoms improved during observation were less likely to eventually have CT.
“It’s not that a CT is bad if you really need it, but you don’t want to use it in children who are at low risk,” said Nigrovic. “For parents, this means spending a couple of extra hours in the emergency department in exchange for not getting a CT. It’s the middle-risk group of children – those who aren’t totally normal at the start of the ED visit, but whose injury also isn’t obviously severe – where observation before deciding on a CT can really help.”
The researchers were unable to determine the actual observation times in the hospitals they studied, a question they would like to investigate in the future. Practice guidelines from the American Academy of Pediatrics recommend a child be carefully observed for 4 to 6 hours after injury.
The authors offer the following general guidelines for parents whose child has a head injury:
- Check with your primary care clinician before taking the child to the emergency department.
- If your child has headache, vomiting and/or confusion, or symptoms that worsen over time, an ED visit is appropriate.
- The ED clinician may reasonably choose to observe your child for several hours once you arrive before deciding about a head CT.
- The change of symptoms over time is an important factor in deciding whether to obtain a cranial CT.
Other authors on the paper included James Holmes, professor of emergency medicine at UC Davis Health System.
The study was funded by the U.S. Department of Health and Human Services’ Health Resources and Services Administration/Maternal and Child Health Bureau, Division of Research, Training, and Education, and the agency’s Emergency Medical Services for Children Program.