Newborns with life-threatening congenital heart disease often need open-heart surgery with cardiopulmonary bypass, which carries a risk of damaging the brain. Critically ill newborns who are placed on ECMO are at even higher risk for brain injury. A new study, performed in a large animal model, suggests that adding a dash of hydrogen to the usual mix of respiratory gases could further protect babies’ brains. The researchers are now planning a small safety trial.