Effect of small changes in set oxygen saturation target range during routine use of automated FiO2 control: a randomized physiological study

Background The study aimed to determine what effect small changes in the set target range of an automated FiO 2 system would have on SpO 2 exposure. Methods Single center randomized crossover design, with auto SpO 2 targets switched between 3 settings (standard, narrow and higher) every 12 h. VLBW infants needing extended respiratory support were studied. Primary outcomes were time in the intended range (88%–93% < 29 weeks PMA, otherwise 90%–95%) and time at SpO 2 extremes (≤80%, >98% with supplemental oxygen). Additional levels of SpO 2 above and below the target range were also evaluated. Results Ten infants, birth weight 820 grams (IQR 673–943), were evaluated. At entry they were 14 days old (IQR 13–18) and participated for 9–30 days. Four hundred and thirty-one 12-hour epochs were evaluated. The oxygen demand was relatively low [FiO 2 0.24 (IQR 0.22–0.30)] and oxygen saturation well controlled. They spent a median of 80% (IQR 68–87) of the time in the intended target range, with differences among the three settings not statistically significant. In contrast the % time with SpO 2 ≤ 80% during the higher setting was reduced and the % time with SpO 2 > 98% with the higher setting was increased. Narrow compared to the standard SpO 2 exposures were not different. The descriptive levels of hyperoxemia and hypoxemia were consistent with the two primary SpO 2 extremes. Conclusions Narrowing the target range had little impact, however shifting the target range up just one point had a marked impact of decreasing hypoxemia and increasing hyperoxemia. Clinical Trial Registration ClinicalTrials.gov , identifier NCT06207994.