Cooling kids after brain injuries could be risky, experts caution

The practice of cooling children with severe head injuries to prevent potentially fatal brain swelling should be undertaken with caution, say researchers, who found the treatment fails to alter the neurological outcome of patients and may actually increase their risk of death.

An international study led by researchers at Toronto's Hospital for Sick Children compared children with severe brain injury who had their core body temperature dropped for 24 hours and similarly injured children who weren't cooled.

The study, involving 225 children at 17 centres in Canada, France and the United Kingdom, found no difference in how the patients in each group fared when it came to neurological damage.

"We were very surprised by these findings, since preliminary research in adults with traumatic brain injury had demonstrated the potential benefit of hypothermia therapy," said principal investigator Dr. Jamie Hutchison, director of critical care research at Sick Kids.

However, there were more deaths among the children who had been cooled than those not treated using hypothermia — 23 versus 14. "There was a trend towards an increase in death rates," Hutchison said in an interview. "We're not sure what to make of that."

While not statistically significant from a research point of view — a study with a larger number of children would be needed to determine its validity — Hutchison called the finding "significant clinically."

When a patient is rewarmed, blood pressure can plummet because blood vessels that were constricted while cold begin to rapidly dilate as core temperature rises, he said. And that can lead to death.

"So we're advising people (doctors) who are still using hypothermia that during rewarming they do it more slowly and be careful about that."

In the study, published Thursday in the New England Journal of Medicine, the children who underwent hypothermia were treated within six hours of injury and kept on ice, as it were, at 32 C to 33 C before being rewarmed to a normal temperature of 37 C.

Hutchison said hypothermia — induced with cooling blankets and often with towel-covered packs of ice — might work better if started sooner after an injury occurs and perhaps for a longer period.

"It's still not determined whether it should work or not. There still needs to be further research into an optimal way of cooling," he said.

In adults with head trauma, chilling the body has been found to reduce swelling of the brain and intracranial pressure, leading to better outcomes for patients.

The same has been true of using hypothermia for some spinal cord injuries: cooling can limit swelling and prevent further damage from chemicals the body naturally secretes at the injury site.

Buffalo Bills tight end Kevin Everett, who suffered a spinal cord injury during an NFL game that left him initially paralyzed from the neck down, was started on hypothermia treatment in the ambulance after being carried from the field.

Since his accident last September, Everett has made remarkable progress and is now able to walk unassisted.

Kids' responses to treatment different than adults

But Dr. Peter Rumney, head of the brain injury rehabilitation team at Bloorview Kids Rehab in Toronto, said children and adolescents seem to respond differently than adults to treatments, in part perhaps because their brains are still developing.

"The other key thing is the long-term recovery is different for children than adults," he explained Wednesday. "The kids tend to do better physically but recover differently cognitively and behaviourally."

Severe traumatic brain injuries — from motor vehicle collisions, falls and sports-related accidents — are the leading cause of death among Canadian children and teens and the most common cause of acquired disability, said Rumney.

Up to 90 youngsters with severe brain trauma come to live at Bloorview for rehabilitation while another 40 or 50 with less-severe injuries enter out-patient treatment annually.

While they typically make some progress over time, their lives and the lives of their families are forever changed, he said.

"In fact, there's a process called 'mobile mourning' that the families go through because, in essence, their image of their child dies and then they have to be reacquainted with the new child, who now looks and talks much the same way as their child did before but now behaves differently and progresses differently."

That's certainly been the case for 17-year-old Sasha Ferriman of Toronto and his family.

In March 2006, Sasha sustained a severe brain injury in a snowboarding accident at a resort near Collingwood, Ont., northwest of Toronto. He lost control after manoeuvring his board mid-jump in order to avoid crashing into a young girl who had wandered onto the downhill run after losing a ski.

The teen fell and smashed his head — and doctors said the helmet he was wearing likely saved his life.

"It's every parent's worst nightmare," said his mother, Lies Ferriman, explaining that Sasha was taken to a local hospital, then airlifted to Sick Kids Hospital, where he was in a coma for 10 days. She does not know whether he received hypothermia treatment.

Sasha, once a triple-A hockey player, has been left with impairments from the injury, including weakness on his left side that has limited use of his hand and left him walking with a limp.

Although the Grade 11 student has returned to school, he has difficulty concentrating and organizing his thoughts. His speech is slower than it was, and he has undergone personality changes, his mother said.

"He has done amazing things," said Ferriman, who also has an older son with her husband, Bill. "But he still is recovering and we've been told that with this type of a brain injury the recovery will be pretty well lifelong. He will never be 100 per cent again."

Yet he's "very independent" and forward-looking, she said. "It's my desire in the next year or two to really have him become more self-sufficient, because I want him to go out there and be able to get a job, be able to live on his own, meet a nice girl, just continue as if he'd never had his accident."

"And, well ... we'll see. We'll see what happens."