Does using 100 percent oxygen for neonatal resuscitation increase morbidity and mortality?
Based on limited evidence, it appears that mortality is lower in infants resuscitated with room air than in those given 100 percent oxygen. However, these results should be treated with caution because one fourth of studies used back-up supplementary oxygen.
Because excessive oxygen can increase free radical levels and decrease cerebral blood flow, it is thought that it may increase ischemic injury. Many deliveries occur outside of hospitals, where access to oxygen supplementation is limited. In hospital deliveries, early cord clamping often is performed to bring the newborn closer to an oxygen source for resuscitation. Delayed cord clamping has been shown to be beneficial in preterm infants to allow perfusion after delivery.1
Tan and colleagues reviewed the literature to determine whether neonatal resuscitation with room air improves outcomes compared with 100 percent oxygen. They found five randomized and quasirandomized studies including 1,302 infants in total. A reduction in death rate was evident for infants resuscitated with room air (number needed to treat = 20). One study found that infants given room air had better five-minute Apgar scores; however, the difference was small and there were no significant differences in 10-minute Apgar scores or rates of grade 2 or 3 hypoxic ischemic encephalopathy. Another meta-analysis2 came to similar conclusions.
Based on current evidence, 100 percent oxygen should be used with caution during neonatal resuscitation. Routine use of oxygen should not supersede interventions with known benefit such as delayed cord clamping. Evidence supports the routine use of room air.