Effects of Automated Adjustment of the Inspired Oxygen on Fluctuations of Arterial and Regional Cerebral Tissue Oxygenation in Preterm Infants with Frequent Desaturations

Objective To assess the effect of automated adjustment of the inspired oxygen fraction (FiO(2)) on arterial oxygen saturation (SpO(2)) and cerebral tissue oxygen saturation (SctO(2)) in very low birth weight infants with frequent fluctuations in oxygenation. Study design Fifteen infants (median gestational age, 25 weeks [range, 23-28 weeks]; median age, 34 days [range, 19-74 days]) were assigned in random sequence to 24 hours of automated adjustment of FiO(2) or manual adjustment of FiO(2). Primary outcome measurements were time within the SpO(2) target range and the area under the curve above and below a defined SctO(2) range. Results Percentage of time within the SpO(2) target range increased during automated FiO(2) control (76.3% +/- 9.2% vs 69.1% +/- 8.2% for manual; P < .01). Prolonged episodes with SpO(2) <88% of >60 seconds duration (median, 115 episodes [range, 67-240] vs 54 episodes [range, 7-184]; P < .01) and of >180 seconds duration (median, 13 episodes [range, 6-39] vs 2 episodes [range, 0-5]; P < .01) decreased significantly during the automated period. Percentage of time with SpO(2) >96% decreased during automated control (6.6% +/- 4.4% vs 10.4% +/- 3.3%; P < .02). There was no significant difference in FiO(2) exposure. The area (deviation +/- time) below and above the defined SctO(2) threshold did not differ between the 2 periods (median, 59.7%*seconds [range, 17.2%-208.3%] for manual vs 49.0%*seconds [range, 4.3%-193.7%] for automated; P = .36). Conclusion Automated FiO(2) control in preterm infants with frequent SpO(2) fluctuations significantly increased the time within the SpO(2) target range and reduced the incidence of prolonged hypoxemic events compared with manual FiO(2) adjustment, but did not significantly affect cerebral tissue oxygenation.