Do Hyperoxaemia and Hypocapnia Add to the Risk of Brain Injury After Intrapartum Asphyxia?

It is difficult to maintain a proper balance between hyperoxemia and hypoxemia, and between hypocapnia and hypercapnia, when resuscitating severely asphyxiated infants. Hyperoxemia may be especially dangerous to the brain during reperfusion after severe asphyxia. Infants with postasphyxia hypoxic ischemic encephalopathy (HIE) frequently have episodes of hyperoxemia and/or hypocapnia in the first hours of life. A retrospective cohort study was planned to determine whether such episodes, occurring in the first 2 postnatal hours, heighten the risk of brain injury after intrapartum asphyxia. Adverse outcomes at age 2 years included death, severe cerebral palsy, or any degree or cerebral palsy accompanied by blindness, deafness, or delayed development. Severe and moderate hyperoxemia were defined as a Pa02greater than 200 and 100 mm Hg, respectively. Severe and moderate hypocapnia were defined as a PaCO2less than 20 and 25 mm Hg.