To investigate the effect of different pulse oximetry (SpO₂) target range settings during automated fraction of inspired oxygen control (A-FiO₂) on time spent within a clinically set SpO₂ alarm range in oxygen-dependent infants on noninvasive respiratory support.

Forty-one preterm infants (gestational age [median] 26 weeks, age [median] 21 days) on FiO₂ >0.21 receiving noninvasive respiratory support were subjected to A-FiO₂ using 3 SpO₂ target ranges (86%-94%, 88%-92%, or 89%-91%) in random order for 24 hours each. Before switching to the next target range, SpO₂ was manually controlled for 24 hours (washout period). The primary outcome was the time spent within the clinically set alarm limits of 86%-94%.

The percent time within the 86%-94% SpO₂ alarm range was similar for all 3 A-FiO₂ target ranges (74%). Time spent in hyperoxemia was not significantly different between target ranges. However, the time spent in severe hypoxemia (SpO₂ <80%) was significantly reduced during the narrowed target ranges of A-FiO₂ (88%-92%; 1.9%, 89%-91%; 1.7%) compared with the wide target range (86%-94%; 3.4%, P < .001). There were no differences between the 88%-92% and 89-91% target range.

Narrowing the target range of A-FiO₂ to the desired median ±2% is effective in reducing the time spent in hypoxemia, without increasing the risk of hyperoxemia.

www.trialregister.nl: NTR4368.