"Today, wonderful operations can be performed on babies to repair heart defects. This includes "blue babies." During the corrective procedure, high levels of oxygen are typically administered by a heart-lung machine... But... lung and heart damage may worsen. ...[O]ne cause of the problem were the high levels of oxygen administered ...as toxic substances are produced when such oxygen concentrations are metabolized. Babies are particularly vulnerable... Yet we found this "re-oxygenation injury" could be avoided by lowering oxygen levels delivered... There was excellent recovery of heart function without lung or body swelling. ...A 2012 overview on reoxygenation injury was published in the World Journal for Pediatric and Congenital Heart Surgery that summarized international papers from others... [R]aising such questions to traditionalists garners vehement rejection, along with counterarguments that keeping oxygen levels high is a strategy ..."proven..." over many decades (since not all blue babies suffer damage...) They perceive the greater risk is losing the baby because of "insufficient... oxygen"... and... blame... unforeseen complications on other factors."