Background Oxygen under- and overexposure has detrimental effects on preterm infants. Controlling the oxygen saturation manually within strict targets is a notoriously difficult and time consuming task which can be facilitated by automated control.
Aims To evaluate the performance of a closed loop fraction of inspired oxygen (FiO2) controller based on oxygen saturation (SpO2) targets when compared to dedicated manual control.
Methods Prematurely delivered lambs (128–132 days of gestation, term 150 d) were intubated and ventilated with volume guaranteed ventilation (Fabian HFO, Acutronic®) adjusted to arterial pCO2. SpO2 was measured via pulse oximetry (Radical 7, Masimo®). After a stabilisation period of 30 min, lambs were randomised to three hours of ventilation with automated or manual FiO2 control (caretaker-lamb ratio 1:1). Saturation targets were 90–95% according to European guidelines. Data is represented as median [IQR].
Results Twenty-two lambs were included, 11 in each group. Time spend within the target range was significantly better when the automated controller was used (93.2% [80.6–98.9%] vs. 84.0% [63.8–89.4%], p2 adjustments per hour was higher when the automated controller was used (13.0 [3.0–16.4] vs. 5.7 [2.3–9.8], n.s.).
Conclusions Automated FiO2 control was effective in this model. These results are especially promising as we compared our device to animals receiving 1:1 care in the manual control group. In a clinical setting, the combination of automated control and dedicated caretakers might even be more effective.