May 9, 2011— -- Nearly half of all children who are brought into the emergency room for head injuries undergo CT scans, according to the CDC's National Center for Injury Prevention and Control. But a new study suggests for many of these cases, a CT scan may be unnecessary.
Instead, children should be observed in the emergency room for a few hours longer before the physicians make a decision to send them for a CT scan, according to the study published Monday in the journal Pediatrics.
"The general conundrum is that blunt head trauma in children is common. Serious traumatic brain injury is less common," said Dr. Lise Nigrovic, emergency medicine pediatrician at Children's Hospital in Boston and lead author of the study. "But in some cases, it's hard to tell the difference."
CT scans are generally safe, Nigrovic said. But studies suggest repeated radiation exposure from the scans over time raises the risk of some forms of cancer. It's unclear how big a risk the scans pose.
Some children may show symptoms of head injury such as headache or dizziness which warrant further attention. But for many, it may just be a bump on the head and the signs could wane within a few hours. While the study didn't assess how long doctors should wait, numerous studies suggest four to six hours can reveal telltale signs of injury.
"It's a question of degree and number of collective symptoms," said Nigrovic.
More serious signs of brain injury include vomiting, loss of consciousness, and impaired memory over a longer period of time. These signs are less common among children who end up in the emergency room. According to Nigrovic, physicians should spend more time monitoring for trauma symptoms than skipping straight to scans.
However, according to Dr. Richard O'Brien, spokesperson for the American College of Emergency Physicians, most children that are sent for a CT scan immediately from the emergency room are likely significantly ill or injured, in which case Nigrovic's study may not apply.
"In reality, virtually all patients are observed to some degree before they get to the CT scanner and for a period of time thereafter," said O'Brien. "It is the rare child with a minor injury who is immediately rushed to CT scan from the triage area."
Still, Nigrovic said emergency physicians do face pressure about when to perform a CT scan, even when it may not be necessary.
"The parents' wishes do play a role in the CT scan decision," said Nigrovic, who added that some physicians are persuaded by parents who ask for further tests. "But a physician can be reassuring to the family that the risk of brain injury is small."
"You're not saying, 'we're not going to do anything,' you're saying 'the risk is low, but we're going to keep them in the ER and monitor them and see if they're getting better," she said.