Automated control of inspired oxygen in ventilated preterm infants: crossover physiological study

AimTo evaluate the efficacy of automated control of the fraction of inspired oxygen (FiO(2)) in comparison with manual FiO(2) control in maintaining target pulse oxygen saturation (SpO(2)) range. MethodsCrossover physiological study involving preterm infants requiring mechanical ventilation and supplemental oxygen. Each infant was studied for two consecutive 12hours in a random sequence. Outcome measures included the proportion of time with SpO(2) within and outside the target range of 90-95%, extreme hypoxaemia (<80%) and hyperoxaemia (98%). ResultsComplete data set was available in 27 infants. The percentage of time (median, IQR) within the target range was higher during automated control 72.8 (58.8-82.6) compared to manual control 59.6 (49.3-73.3), p=0.031. Corresponding reduction in per cent time below the target range was 18.1 (12.7-23.6) versus 25.9 (17.8-30.7), p=0.028, and above the target range 4.8 (3-16) versus 10.1 (6.4-22.5), p=0.026. Median (IQR) per cent time spent with severe hypoxaemia (SpO(2)<80%) and severe hyperoxaemia (SpO(2)98%) was 1.3 (0.1-2.9) versus 3.2 (1.4-6.1), p=0.022 and 0.08 (0.05-0.36) versus 1.7 (0.7-6.8), p=0.001, respectively. Median number of manual adjustments of FiO(2) per 12hour was 0 and 63, respectively. ConclusionAutomated control of FiO(2) significantly improved compliance of oxygen saturation targeting and significantly reduced exposure to hypoxaemia as well as hyperoxaemia.