TOBY Xenon: Neuroprotective effects of hypothermia combined with inhaled xenon following perinatal asphyxia

Summary

Perinatal asphyxia severe enough to cause neonatal hypoxic-ischaemic encephalopathy (HIE) occurs in approximately 3/1,000 births in the UK, and over 1,000 moderate to severe cases of HIE are expected every year. The risk of death or severe handicap in survivors of moderate or severe HIE is approximately 25 and 75% respectively. Until recently no specific treatment for perinatal asphyxia was available, but trials of mild hypothermia have recently proved that in principle neuroprotective therapy after delivery is possible. However, the therapeutic benefit of hypothermia is modest and further neuroprotective interventions are urgently needed.

This was a proof-of-concept study to test if following perinatal asphyxia treatment with a combination of hypothermia and inhaled xenon reduces cerebral biochemical abnormality (assessed by Magnetic Resonance Spectroscopy), preserves cerebral structures (assessed by visual and computational analysis of MRI), and leads to improved clinical outcomes at hospital discharge, compared to standard care (therapeutic hypothermia treatment).

Publications

Journal Articles

• Azzopardi D, Robertson NJ, Kapetanakis A, Griffiths J, Rennie JM, Mathieson SR, Edwards AD. Anticonvulsant effect of xenon on neonatal asphyxial seizures. Arch Dis Child Fetal Neonatal Ed. 2013;98(5):F437-9.
• Azzopardi D, Robertson NJ, Bainbridge A, Cady E, Charles-Edwards G, Deierl A, Fagiolo G, Franks NP, Griffiths J, Hajnal J, Juszczak E, Kapetanakis B, Linsell L, Maze M, Omar O, Strohm B, Tusor N, Edwards AD. Moderate hypothermia within 6 h of birth plus inhaled xenon versus moderate hypothermia alone after birth asphyxia (TOBY-Xe): a proof-of-concept, open-label, randomised controlled trial. The Lancet Neurology. 2015;15(2):145-53.