Observing some kids after a Head injury may help doctors decide which ones need a head x-ray, according to a new study published in Pediatrics.

That’s important because researchers still aren’t sure whether too many of those x-rays, called computed tomography, or CT scans, might trigger cancer years later.

CT scans can help doctors recognize more serious head injuries that need treatment. But observation is probably a good strategy for kids who have some risk of a serious brain injury, but aren’t showing serious symptoms, said Dr. Lise Nigrovic of Children’s Hospital Boston, who worked on the study.

If a kids shows up at the ER very soon after a Head injury, “you may just not have had enough time for symptoms to develop,” she told Reuters Health. Or, a kid “may have some symptoms that make you a little concerned, but you just want some time” before making a decision about doing an x-ray.

“We all want to make sure that we use CT scanning in the cases where it’s likely to be positive and that we save children from the radiation for those that we know are very unlikely to be positive,” Dr. Martin Osmond, of the Children’s Hospital of Eastern Ontario, told Reuters Health.

“This study adds important new information about who to observe” before making that decision, added Osmond, who has no ties to the new study.

Nigrovic and her colleagues reviewed data on over 40,000 kids with a Head injury who were taken to one of 25 different emergency rooms.

The original data had been collected by the Pediatric Emergency Care Applied Research Network. Doctors treating the kids made a note in their records about whether each kid was kept in the hospital and observed by doctors and nurses before they decided whether or not to perform a CT scan.

About 5,400 kids - or 1 in 7 -were observed. Those kids were slightly less likely to get a CT scan: 31 percent of them had the head x-ray, versus 35 percent of kids when doctors made that decision right away.

In both groups, fewer than 1 of every hundred kids had a serious brain injury.

Twenty-six kids who were observed and sent home without a CT scan came back later for an x-ray - and 1 of them ended up having a brain injury diagnosed by the x-ray.

The research team concluded from that finding that observing some kids before making the decision about a CT scan might be a safe and effective way to cut back on the number of those scans.

Nigrovic gave the example of a 4-year-old who fell off a swing. “They’re complaining of a headache (and) they vomited once at home,” she said. But, they are awake and talking 2 hours after the injury, making doctors less fearful. “That’s a great patient for observation,” she said.

Osmond thinks the study is an accurate picture of how doctors are now treating these patients: In severe cases doctors will get a scan right away, in cases where they believe the symptoms are sufficiently mild, they’re likely to send the patients home, but in cases of doubt they’ll observe the child to see if there are any changes, he explained.

Still, Osmond added, a few questions remain. For example, it’s unclear just how long it makes sense for doctors to observe kids before deciding whether or not to do a CT scan or send them home.

That, as well as how safe it is to put off CT scans while observing an injured kid, will be the focus of future research, Nigrovic said.

SOURCE: Pediatrics, online May 9, 2011.