A child falls off her bike while not wearing a helmet and hits her head. Does she need a CT scan at the hospital to check for serious brain injuries?
Many doctors err on the side of caution and order one regardless. But now, a team of Canadian researchers has come up with a set of guidelines to help doctors decide whether that child really needs that scan.
While CT scans are great for identifying serious brain injuries, such as brain swelling and bleeding, they also expose patients to high amounts of potentially harmful radiation.
These new guidelines should help doctors decide whether that radiation risk is worth it for young patients who may have minor injuries that could be treated with bedrest.
The guidelines -- dubbed the CATCH rules (Canadian Assessment of Tomography for Childhood Injury) – look for seven key signs that a head injury may be serious. They include:
- an open or depressed skull fracture
- a headache that worsens over time
- disorientation that lasts longer than two hours
- a dangerous cause of injury, such as a car crash
- a large, spongy bump on the scalp
Any one of these signs in a child with a recent head injury would alert a doctor that a CT scan should probably be done, says lead author Dr. Martin Osmond, an emergency room physician at the Children's Hospital of Eastern Ontario.
Each year, about 650,000 children show up in Canadian and U.S. emergency rooms with head injuries, reporting a loss of consciousness, vomiting, amnesia or disorientation.
Most of these children have minor injuries or even more serious injuries, such as concussions, that require bedrest and observation. But there is always the worry that the injury could have caused bleeding on the brain, which a CT scan would pick up.
"We know that one in 20 patients have bleeding inside the head and one in 200 will require neurosurgery. So physicians do not want to miss any one of those cases," Osmond told CTV's Canada AM Tuesday from Ottawa.
"On the other hand we also don't want to CT scan the entire population."
Osmond explained that his team came up with the guidelines after studying almost 3,900 kids under the age of 16 with head trauma, who were examined at 10 Canadian pediatric teaching hospitals. The researchers concluded that only about 30 per cent of the kids they looked at met their criteria for being at high risk of a serious brain injury and therefore requiring a CT scan.
His team now plans to test the guidelines on another 5,000 kids, "to make sure they're accurate before rolling them out in emergency departments across Canada," he said.
With CT scanners now widely available at many hospitals across the country, usage rates of the scans on kids with minor head injuries more than tripled between 2005 and 1995.
Not only do the scans significantly add to health-care costs, they also put out a lot of radiation – about 300 to 600 times a typical X-ray – which could raise their cancer risk.
"The data we have on radiation comes from the survivors of the atomic bomb blasts," Osmond explained. "And in children who were exposed to about the amount of radiation of one to two CT scans, it's been shown that later on in life, they had an increased number of fatal cancers."
He notes the risk for each child is relatively low – about one in 1,500 to one in 5,000 kids exposed to that kind of radiation develop cancer. But across a large population, those numbers can add up.
"So we want to make sure we've imaging only those children that are at high risk of bleeds inside the head. And those who have really negligible risk, we want to be able to say to them, ‘You don't really require a scan. Perhaps you need observation at home,'" Osmond explained.
The new CATCH guidelines appear in this week's issue of the Canadian Medical Association Journal.
