Multicenter Crossover Study of Automated Control of Inspired Oxygen in Ventilated Preterm Infants

Abstract

OBJECTIVE: To determine the efficacy and safety of automated adjustment of the fraction of inspired oxygen (Fio2) adjustment in maintaining arterial oxygen saturation (Spo2) within an intended range for mechanically ventilated preterm infants with frequent episodes of decreased Spo2. METHODS: Thirty-two infants (gestational age [median and interquartile range]: 25 weeks [24–27 weeks]; age: 27 days [17–36 days]) were studied during 2 consecutive 24-hour periods, one with Fio2 adjusted by clinical staff members (manual) and the other by an automated system (automated), in random sequence. RESULTS: Time with Spo2 within the intended range (87%–93%) increased significantly during the automated period, compared with the manual period (40% ± 14% vs 32% ± 13% [mean ± SD]). Times with Spo2 of >93% or >98% were significantly reduced during the automated period (21% ± 20% vs 37% ± 12% and 0.7% vs 5.6% [interquartile ranges: 0.1%–7.2% and 2.7%–11.2%], respectively). Time with Spo2 of <87% increased significantly during the automated period (32% ± 12% vs 23% ± 9%), with more-frequent episodes with Spo2 between 80% and 86%, whereas times with Spo2 of <80% or <75% did not differ between periods. Hourly median Fio2 values throughout the automated period were lower and there were substantially fewer manual Fio2 changes (10 ± 9 vs 112 ± 59 changes per 24 hours; P < .001), compared with the manual period. CONCLUSIONS: In infants with fluctuations in Spo2, automated Fio2 adjustment improved maintenance of the intended Spo2 range led to reduced time with high Spo2 and more-frequent episodes with Spo2 between 80% and 86%.