Optimal Target Range of Closed-Loop Inspired Oxygen Support in Preterm Infants: A Randomized Cross-Over Study

Objective: 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. Study design: 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%. Results: 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. Conclusions: 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. Trial registration: www.trialregister.nl: NTR4368.