Life-saver cooling cap shines in global trial

By SIMON COLLINS, science reporter

A head-cooling cap developed in Auckland is expected to save the lives of thousands of brain-damaged babies worldwide, after a successful international trial proved its effectiveness.

The $100 skull cap, first tried on babies such as Thomas Wilkie of Balmoral, cools the head to stop brain cells dying after a bruising birth.

Thomas, now aged 6, had the treatment after his oxygen supply was cut off in his mother's womb during the birth of his twin sister, Georgina, in July 1997.

Despite being so brain-damaged that he could not start breathing on his own when he was born, the cooling cap helped Thomas to recover completely. This week, when the Herald caught up with him at a tennis lesson in Mt Eden, he showed no lasting effects.

"It was fantastic - no brain damage at all," said his mother, Jane de Borchgrave.

A four-year trial at 28 hospitals in four countries has found that the cooling cap saved the lives of a quarter of lightly brain-damaged babies.

It could do nothing for the 46 most severely damaged babies out of the 218 involved in the trial.

But for the 172 others, the cap cut the death rate from 39 to 29 per cent.

Even more dramatically, the rate of cerebral palsy and other movement disabilities among those who survived was cut from 28 to 11 per cent.

The cap pumped cold water round the baby's head for 72 hours after potential brain damage was recognised and after the parents had given their consent for the experiment - usually from about four hours after birth.

Auckland University's Dr Peter Gluckman, who led the US$5-7 million ($8-11 million) trial, said brain cells took time to die after an injury such as losing oxygen at birth.

"Cooling slows body processes down. One of the body processes it slows down is the process by which cells actually die," he said.

"We think the cooling slows the cell death down for long enough for protective mechanisms to repair the brain.

"This is the first time ever that people have shown that brain damage can be reversed in newborn babies."

One or two babies in every 1000 born in New Zealand, or about 100 babies a year, are at risk of brain damage during birth.

The international trial suggests that the cooling cap will save the lives of about eight of those babies and ward off cerebral palsy or a similar disability in another eight.

Worldwide, the cap could save thousands of newborn babies every year.

The Auckland team is not taking any commercial gain from the research and has sold its cooling cap design to a Seattle company, Olympic Medical, which paid for the trial and is expected to sell caps for about $100 apiece.

"There are no patents because it's easy to make babies cold," Dr Gluckman said.

In the trial, a baby's head was cooled to just under 34C. The rest of the body was kept under heat lamps to make sure the body temperature did not fall below about 34.5C - still a chilly 3.3C colder than normal.

Dr Gluckman believes the sudden drop in temperature that all babies experience when they leave the womb may explain why there is not a lot more brain damage during normal births.

"Every baby has a risk of lack of oxygen at birth, but most do very well," he said.

Dr Gluckman and the late Professor Tania Gunn, who died of cancer in 1999, tried cooling caps on newborn lambs and rats before testing them on the first babies such as Thomas Wilkie.

Researchers at Auckland University's Liggins Institute and elsewhere will keep trying variations of the technique and work on the tricky problem of how to apply the cooling method to premature babies, who are much less robust.

But Dr Gluckman expects that hospitals will not wait for the perfect system now that the first big trial has shown that cooling can save lives.

"There is no doubt that cooling will be used in the treatment of brain damage," he said.

"This is the dream that every scientist like myself has. There are not many people in science who have the chance to have a basic idea, to do the experimental work in animals to prove that it works, then to develop a way to do it in humans and do the human study and see that it does work.

"I started this work in the early '80s, and 23 years later it has come to fruition.

"It's a life's work, isn't it?"

How it works

* Cold water is pumped round a skull cap to cool a baby's head from 37.8C to 34C.

* The rest of the baby's body is kept under a heat lamp to maintain the body temperature above 34.5C.

* Cooling slows down all body processes.

* In particular, cooling stops some brain cells that were damaged during birth from dying - helping the baby to recover.