Nitrous oxide elimination by the newborn.

The elimination of nitrous oxide by ten infants whose mothers had received 50% nitrous oxide in oxygen and enflurane 0.6-1% during general anaesthesia for Caesarean section was studied. The concentration of nitrous oxide detected in end-expired gas ranged from 1 to 4 vol% (mean 1.9 vol%). These levels are too low to produce significant diffusion hypoxia in vigorous neonates. However, a minority of infants may be adversely affected and it is recommended that oxygen-enriched air be administered to infants whose mothers have received nitrous oxide.