Cooling the brains of babies deprived of oxygen at birth can reduce the risk of brain damage and cerebral palsy, according to an international study published today (January 28) in the Lancet on-line.
To achieve cooling, the body temperature of babies in the trial was lowered by 3-4 degrees for 72 hours after birth, using a water-filled cap.
The research was undertaken in hospitals in North America, New Zealand and the UK, and the UK arm of the trial was carried out in University College London Hospital, the University of Bristol at St Michael’s and Southmead Hospitals, and Imperial College London at Hammersmith Hospital.
Babies were recruited if there was evidence that the infant had received an inadequate supply of oxygen to the brain during delivery, and when electrical activity from the brain indicated a high risk of brain injury.
The trial, which was supported by Olympic Medical from Seattle, USA indicates that, for some babies, cooling can significantly reduce brain damage. “This demonstrates for the first time that treatment may be possible for babies who suffer oxygen deprivation at birth”, comments Professor Marianne Thoresen from Bristol University. Most of the English babies were treated in the Bristol hospitals.
It was discovered some years ago that when the brain is starved of oxygen at birth damage does not occur immediately; instead, as Professor John Wyatt of University College London points out, “a chemical cascade is triggered leading to brain damage hours or days afterwards”.
The cooling study results from a long series of studies begun a decade ago when the UK researchers started to work on the problem together with a group from the University of Auckland in New Zealand. In experiments they found that cooling prevented the chemical cascade from causing permanent brain damage, and developed the discovery to the point where the treatment could be tested in babies.
“The success of this long scientific collaboration is a great example of UK institutions working together to be international leaders, able to collaborate effectively and fruitfully with researchers around the world”comments Professor David Edwards from Imperial College.
However, Bristol researcher Professor Andrew Whitelaw points out that: ‘We need to get further information on the timing and methods of cooling, as well as which babies are most suitable for treatment, before cooling becomes the standard of care for oxygen deprived babies”.
Imperial College and Bristol groups are currently teamed up with other researchers from the UK in the Total Body Hypothermia or‘TOBY’ Trial funded by the Medical Research Council. ”The TOBY trial will determine whether this simpler form of cooling has a beneficial effect, and could bring routine treatment a step closer”, said Principal Investigator Dr Denis Azzopardi.