Background: It is discussed whether depressed newborn infants should be resuscitated with room air or 100% O2.
Objective: To perform a systematic review and meta-analysis including studies that report resuscitation of depressed newly born infants with 21 or 100% O2.
Methods: Inclusion criterion was randomized or pseudo-randomized, blinded or not, studies of depressed newborn infants resuscitated with either 21 or 100% O2. The literature was searched in Medline/Pubmed/EMBASE and The Cochrane library databases. All identified studies were included.
Results: Five studies fulfilled the inclusion criterion in which 881 infants were resuscitated with 21% O2 and 856 with 100% O2. Neonatal mortality was 8.0 vs. 13.0% in the 21 and 100% O2 groups respectively, OR 0.57, 95% CI 0.42-0.78. In term infants neonatal mortality was 5.9% in the 21% O2 group and 9.8% in the 100% O2 group, OR 0.59, 95% CI 0.40-0.87. The figures for the premature infants were very similar. In infants with 1-min Apgar score <4, OR for neonatal mortality was 0.81 (95% CI 0.54-1.21). Apgar score at 5 min and heart rate at 90 s were significantly higher, and time to first breath significantly earlier in infants given 21% O2 compared with 100% O2.
Conclusions: A systematic review and meta-analysis demonstrated that neonatal mortality is significantly reduced when depressed newly born infants are resuscitated with ambient air instead of pure oxygen. For infants with low 1-min Apgar score (<4), no significant difference in neonatal mortality was found. Recovery was faster in infants resuscitated with 21% O2 than 100% O2.