Automated control of inspired oxygen (FiO₂) in preterm infants: Literature review

Abstract

The vast majority (95%) of very preterm infants receive oxygen‐therapy monitored by oxygen pulse saturation (SpO2). However, they spend a significant percentage of time out of the SpO2 target with a high risk of severe complications such as bronchopulmonary dysplasia (BPD) and retinopathy of prematurity (ROP). Recently, systems allowing the automated control of inspired oxygen (FiO2) for patient delivery to maintain target SpO2 has been become commercially available. We reviewed literature and individuated sixteen studies on the effectiveness of automated control of FiO2 in preterm infants. These studies demonstrate that automated devices are significantly more effective than manual control in maintaining target SpO2 and in preventing hyperoxia, while they seem to be less effective in preventing hypoxia. The studies were very heterogeneous for design, population size, duration, and device used, and this precludes firm conclusions regarding effectiveness and best setting of these systems. Moreover, none of the studies investigated if automated control of FiO2 can actually improve outcome in preterm infants. We conclude that further large‐scale studies are warranted to assess the actual clinical relevance of these devices and to decide if they should become the standard of care.

Model of SpO2 signal of the neonate

“…The advantages of automatic control of the fraction of inspired oxygen in neonates, especially in comparison with manual control, have been documented in recently published clinical trials [1,2]. Many control algorithms are available, but the comparison of their efficiency is missing in the literature [2].…”

“…The advantages of automatic control of the fraction of inspired oxygen in neonates, especially in comparison with manual control, have been documented in recently published clinical trials [1,2]. Many control algorithms are available, but the comparison of their efficiency is missing in the literature [2]. Due to safety and ethical risks of clinical tests on newborns, a mathematical model of neonatal oxygen transport could be a useful tool for testing of robustness and reliability of the automatic control algorithms, or for their preliminary comparison with manual control schemes of the fraction of inspired oxygen [3].…”

Computer model of oxygenation in neonates

“…Failure to maintain the desired SpO2 range increases the risk of tissue and organ damage due to hypoxemia, but also the risk of oxidative damage due to hyperoxemia. These issues are a result of variation in cardiorespiratory stability of patients, as well as differing inspired fraction of oxygen (FiO2) titration practices among caregivers and centers [2]. Therefore, algorithms for automatic feedback control of SpO2 are being developed and tested, that would adapt to the changing neonatal organism and better maintain the required SpO2 target range [3].…”

Commentary on “Oxygen desaturations in the early neonatal period predict development of bronchopulmonary dysplasia” by Fairchild et al.

“…Up and coming modalities such as closed-loop automated FiO2 (A-FiO2) systems could, in theory, markedly improve time spent in target SpO2 ranges and decrease burden on bedside caregivers. Although the studies of A-FiO2 systems in preterm infants are heterogeneous for sample size, type of A-FiO2 system used, and duration of observation, they do demonstrate significant improvement in time spent within target ranges as well as decreased time spent above target ranges 11 . However, evidence for prevention of hypoxia episodes is less consistent, and none evaluate longer term outcomes in preterm infants 11 .…”

“…Although the studies of A-FiO2 systems in preterm infants are heterogeneous for sample size, type of A-FiO2 system used, and duration of observation, they do demonstrate significant improvement in time spent within target ranges as well as decreased time spent above target ranges 11 . However, evidence for prevention of hypoxia episodes is less consistent, and none evaluate longer term outcomes in preterm infants 11 . Therefore, it is of the utmost importance that moving forward, research continues to focus on the clinical significance and optimal modalities to identify, prevent, and safely treat desaturation events in VLBW infants.…”