To the Editor:
Srivatsa et al showed improvement in neonatal mortality and morbidity following implementation of the automated oxygen saturation targeting (OST) strategy.1 The authors showed a reduction in any stage retinopathy of prematurity (ROP) and bronchopulmonary dysplasia (BPD) from epoch 1 to epoch 2, without any significant change in mortality. If we ignore the overall secular trend of improving neonatal outcomes, this reduction can be attributed to change in the lower range of saturation targets (from 85% to 89%). This finding is contrary (but reassuring) to a recent meta-analysis.2 We ask for clarification on the following points. (1) The authors showed significant improvement in adverse outcomes during epoch 3 (compared with epoch 1). During these 2 phases, there were major differences in saturation targets, use of automated OST strategy, and other neonatal practices.3 Therefore, it is difficult to say that the improvement was solely due to the implementation of the OST strategy. Though the authors showed a significant downtrend, a head-to-head comparison of epoch 2 and 3 can better assess whether the improvement was solely due to an automated OST strategy. (2) There was a significant difference in the mode of delivery and multiple gestations (higher in epoch 1) across the epochs. Both parameters can have a direct impact on studied outcomes and warrant their inclusion in adjusted analysis.3, 4, 5 (3) The discrepancy in the denominator of ROP outcomes requires clarification. (4) A recent meta-analysis has shown that despite the use of automated control of oxygenation, the meantime spent within the target saturation range is 55.8 %.6 In this study, though the data on time spent in saturation range during the first epoch is missing, the authors should compare second and third epochs (the authors have histograms for the second epoch) to see whether implementation of automated OST led to improvement in time spent in desired saturation range. If the authors find significantly higher compliance rates in the third epoch, the conclusion of this study will be further strengthened.
References
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