Touching Lives - June 2004
Cool caps for babies
The conventional wisdom has always been that newborn babies need to be kept warm at all costs. As soon as they’re born they’re rushed underneath heaters, dressed in a jumpsuit and have a woolly hat plonked unceremoniously on their heads. Of course, this is the best way to treat the vast majority of newborn babies.
But for the small numbers of babies injured by a lack of oxygen during labour, an Action Medical Research team has turned orthodoxy on its head and shown that actually cooling the brain can have remarkable healing properties.
Sadly, even with healthy, full-term pregnancies there is still a significant chance that something might go wrong during labour that could cause harm to the newborn. It’s often said that the most dangerous journey you’ll ever make is the short one from your mother’s womb, down the birth canal and into the outside world.
About 1-2 per 1,000 babies suffer serious problems during labour, usually because something goes dramatically wrong: the baby gets trapped or stuck; the womb ruptures; or the placenta still providing the child with its oxygen peels away too early. This equates to ^over 1,000 children dying or suffering permanent brain damage each year in the UK because of shortage of oxygen during the delivery process.^ The problem affects full-term babies — not premature babies — and the rates are much higher in developing countries.
This is a particularly devastating thing to happen for any mother that has carried her child full-term without incident, and is looking forward to a new life with her baby. Those babies who don’t die are likely to experience major disabilities throughout life, such as severe cerebral palsy, learning difficulties, and epilepsy. Until now there has been no treatment available for these babies.
Researchers led by Professor John Wyatt at University College London Hospitals (UCLH) have received over £500,000 from Action Medical Research since the mid-90s. They found that the damage caused when the baby’s brain was deprived of oxygen did not, as was previously thought, happen immediately.
The shortage of oxygen triggered a whole cascade of damaging reactions — but crucially there was a ‘window of opportunity’ of a few hours before the damage became lasting. Therefore, in theory, it was possible to intervene to block the chemical chain reaction and minimise any permanent damage.
For a number of years doctors had been aware of a ‘folk-remedy’ found in Scandinavia and parts of northern Russia. If a baby was short of oxygen at birth it would be placed in a cold bath to cool it down.
The UCLH team showed in their experimental studies that there was a great deal in the folk-remedy — cooling the brain down by 3-4 degrees Celsius seemed to ‘switch off’ many of the damaging chain reactions. Why this is so is still not fully understood, but the contention is that cooling slows down the chemical reactions in the brain and gives brain cells’ natural repair mechanisms a chance to work.
The UCLH team joined forces with researchers in Bristol, New Zealand, Imperial College, London, and with Olympic Medical, a US medical technology company, to develop a water-cooled cap for babies’ heads that could be used with a minimum of fuss on ward. In total, 234 babies from around the world were included in trials of the new technique: half received the new cooling treatment and half received standard intensive care.
Professor Wyatt explains, “The first baby we used the cooling cap on was born at full-term, but deprived of oxygen during a difficult birth. He was at very high risk of either dying, or being permanently brain-damaged.
“We brought his temperature down, and maintained the cooling effect for 72 hours, after which we very gradually brought his temperature back up to normal. He survived, and we were encouraged by his progress — the cooling didn’t seem to have done any harm and may indeed have helped. But of course, this was a particularly nerve-racking time for us and his parents.”
Both groups of babies in the trials were followed up and assessed for 18 months by paediatricians who were unaware which babies had been cooled and which had not. The cooled babies fared better than their non-cooled counterparts.
Not all babies responded to treatment, but in those with less severe illness there was a significant reduction in the number of babies who died or were severely disabled at 18-months of age. Results suggested that for every six to eight babies suitable for treatment with the cooling cap, one would be saved from death or serious brain damage.
“^This is the first time that any kind of treatment after birth has been shown to make a difference to this devastating problem^,” Professor Wyatt continues. “For the first time there is hope for babies who are profoundly at risk. I’m encouraged and very excited — this is the culmination of 20 years of research, much of it funded by Action Medical Research.
“I’m delighted that we’ve stumbled on this new way of helping babies and reducing the terrible damage caused by shortage of oxygen. It’s because of charities like Action Medical Research that children like these are surviving, and we hope more will survive in future.”
Work still to be done
The study is likely to affect clinical practice, here in the UK and abroad. So it’s vital that the results are checked and confirmed before the use of cooling caps can become standard procedure in NHS hospitals. The Medical Research Council is carrying out further trials into whole-body cooling, the results of which will be important in deciding how cooling treatment can be used to best effect.
There is still work to be done to determine the best method of cooling, the perfect temperature, and the optimal length of treatment. The manufacturers of the cooling cap who sponsored the trials — Olympic Medical of Seattle — also need time now to turn their basic prototype into something which can be used by paediatricians in hospitals across the world.
Professor Wyatt confirms that it will “probably be at least a year, maybe longer, before the cooling cap treatment is readily available.” But cooling caps do seem likely to make their debut in the NHS, after decades of the belief, at least in this country, that warming babies was the only viable treatment for newborns.
This research was generously supported by the Garfield Weston Foundation.