1.   Median and minimum arterial-alveolar oxygen tension ratios for ventilated infants on the first day were significantly lower in the random group.

2.   Tarnow-Mordi etal found the mean arterial-alveolar oxygen tension ratio more closely associated with death than the worst arterial-alveolar oxygen tension ratio.

3.   The arterial-alveolar oxygen tension ratio is a useful prognostic indicator.

4.   This accords with our finding that median arterial-alveolar oxygen tension ratio predicts respiratory outcome better than the minimum ratio.