Virtually every resuscitation guideline mandates use of oxygen in neonates. However, adverse effects of pure oxygen on cerebral perfusion have been noted in newborns. An international collaboration of investigators conducted a meta-analysis of five prospective clinical trials (2 randomized, 3 quasi-randomized; 2 blinded, 3 unblinded) in which air was compared with 100% oxygen in 1302 asphyxiated (low heart rate, apneic) newborn infants (average weight, >2400 g). Most infants were born near term in developing countries.
No single study showed a difference in mortality risk, but pooled analysis showed a significant reduction in mortality risk among infants who were resuscitated with air (relative risk, 0.71; number needed to treat to prevent 1 death, 20). No significant differences were noted in the occurrence of encephalopathy, cerebral palsy, or developmental outcomes.
Comment: Are these results real? An editorialist notes they are consistent with findings of a previous meta-analysis, but whether the results can be generalized to infants born in developed countries is unclear. No information is provided about meconium aspiration, sepsis, or gestational age at birth. In addition, care was provided largely in hospitals with limited postnatal resources. Nevertheless, these results should make us rethink the use of pure oxygen therapy for full-term infants who are asphyxiated. We have been wrong about oxygen therapy in the past (as with retinopathy of prematurity), and it is quite possible that we are wrong again.
Published in Journal Watch October 29, 2004