Use and abuse of oxygen in the newborn.

Hypoxia must be prevented in the newborn. It causes atelectasis, acidosis and pulmonary vasoconstriction, which leads to further hypoxia and, ultimately, brain damage. On the other hand, retrolental fibroplasia and bronchopulmonary dysplasia may result from too-vigorous use of oxygen therapy. Frequent blood gas measurements are required. Administered oxygen must be humidified and heated, and the oxygen concentration must be monitored with each delivery system. It is not enough to know the oxygen flow rate; an oxygen analyzer is essential.