Automating inspired oxygen to targeted SpO2 in preterm infants

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

Mithilesh Lal1, Win Tin1,and Sunil Sinha



Aim


To evaluate the efficacy of automated control of the fraction of inspired oxygen (FiO2) in comparison to manual FiO2 control in maintaining target pulse oxygen saturation (SpO2) range.


Methods


Crossover physiologic study involving preterm infants requiring mechanical ventilation and supplemental oxygen. Each infant was studied for 2 consecutive 12-hour in a random sequence. Outcome measures included the proportion of time with SpO2 within and outside the target range of 90-95%, extreme hypoxaemia (<80%) and hyperoxaemia (≥98%).


Results


Complete dataset 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 percent 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) percent time spent with severe hypoxaemia (SpO2<80%) and severe hyperoxaemia (SpO2≥98%) were 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 FiO2 per 12-hour was 0 and 63 respectively.


Conclusion


Automated control of FiO2 significantly improved compliance of oxygen saturation targeting and significantly reduced exposure to hypoxaemia as well as hyperoxaemia.