Early versus late discontinuation of oxygen in preterm or low birth weight infants

It has been hypothesized that the duration of supplemental oxygen administration, independent of the oxygen concentration, gestational age and/or birth weight, is influential in the development of severe retinopathy of prematurity. Concern regarding the possible deleterious effects of prolonged oxygen supplementation has lead many clinicians to wean infants from oxygen therapy as early as possible in their neonatal course. However recent work in feline models has suggested that visual outcomes may be improved by continuing oxygen supplementation during the recovery phase of ROP. The effect of duration of oxygen supplementation on the long term growth and development of preterm or low birth weight infants remains unclear.

In preterm or low birth weight infants, does early versus late weaning from supplementary oxygen influence mortality, retinopathy of prematurity, lung function, growth or development?

The standard search strategy of the Neonatal Review Group was used. This included searches of the Oxford Database of Perinatal Trials, MEDLINE, previous reviews including cross references, abstracts, conferences and symposia proceedings, expert informants, journal handsearching mainly in the English language. An additional literature search of the MEDLINE and CINAHL databases was conducted in order to locate any trials in addition to those provided by the Cochrane Controlled Trials Register (CENTRAL/CCTR).

All trials utilising random or quasi-random patient allocation, in which early weaning was compared with late discontinuation of supplemental oxygen in preterm or low birth weight infants, were eligible for inclusion.

The methodological quality of the one eligible trial was assessed independently by each author for the degree of selection, performance, attrition and detection bias. Data regarding clinical outcomes including mortality, retinopathy of prematurity, and long term growth and development were extracted and reviewed independently by each author. Results were compared and differences resolved as required. Data analysis was conducted according to the standards of the Cochrane Neonatal Review Group.

In the single eligible trial of 99 infants with birthweights less than 1650g, there were no significant differences in neonatal death rates or retrolental fibroplasia (any grade or severe) for all infants, or among infants with birth weights of less than 1000g. No other outcome measures specified a priori as clinically meaningful were reported in enough detail or with satisfactory follow-up rates to include in the analysis (early death; chronic lung disease; and long term growth, development, lung or visual function).

The results of this systematic review do not provide strong evidence for either the benefits or harms of early oxygen weaning in preterm/LBW infants. Future research should be directed toward addressing the question of what are the most appropriate target levels of oxygenation, in both the early and late neonatal periods, rather than whether oxygen should be weaned early or late.