Presented at the Neonatal Society 2005 Spring Meeting.

Saugstad OD

Department of Pediatric Research, Rikshospitalet University Hospital, University of Oslo, Oslo, Norway

The discussion of how the newly born infant should optimally be resuscitated has become more intensified the recent years. Several issues need to be clarified; among them is the question to what extent oxygen supplementation should be applied. In spite of the recommendations of ILCOR and AHA/AAP to use 100% O2 many centers even in the USA, have installed oxygen blender in the delivery room and therefore do not necessarily start with pure oxygen. This is due to the fact that both animal and clinical studies published the last 10-15 years seem to show that room air is as efficient as 100% oxygen for newborn resuscitation, For instance, the Swedish recommendations endorse to start out with 40% oxygen and increase or decrease the concentration according to the clinical needs. Another tendency is that those centers that still start out with pure oxygen probably reduce the oxygen supplementation faster than previously. New arguments to the debate have come the very last year or two and data now are accumulating indicating room air is not only as good as 100% oxygen for resuscitation but that a brief exposure of pure oxygen at birth in fact might be detrimental with potential negative long term effects.

Experimental data: Previous experimental studies have demonstrated that room air is as efficient as 100% oxygen for resuscitation of newborn. More recent studies have even indicated that there are differences between the groups favoring the use of 21% instead of 100% oxygen.

Clinical Studies: Five clinical studies including totally 1737 newborn infants in need of resuscitation have been published in which the resuscitation was randomized to either 21% or 100% oxygen. These studies confirm that resuscitation of the newly born infant can be performed by room air. Further, pure oxygen significantly delays the first breath by in median half a minute. The heart rate at 90 seconds and Apgar score at 5 min were also lowered in these infants compared with those given 21% O2. In the five studies we found a neonatal mortality of 13% in the 100% group versus 8% in the 21% group with odds ratio of 0.57 and 95% CI of 0.42-0.78. This indicates that room air resuscitation dramatically reduces neonatal mortality compared with the use of pure oxygen. When infants from Spain were analyzed separately neonatal mortality was reduced from 3.5% in the 100% group to 0.5% in the 21% group.

Conclusions: New knowledge has accumulated the recent years making it prudent to ask questions regarding current oxygenation policies and guidelines for resuscitation of the newly born. It seems that ambient air is safe. On the other range of the scale, regarding 100% O2, I believe we have sufficient data to conclude that this should not be given routinely at birth to depressed infants. Resuscitation with room air gives a more rapid early recovery and a significant reduced neonatal mortality indicating that ten thousands of new born infants even in industrialized countries can be saved each year.