• Oxygen
• neonatal intensive care
• very low birthweight infant

Oxygen is one of the drugs most frequently used in neonates, yet often with the highest concentrations given to those with the least developed defence mechanisms to its potentially toxic side effects. To what extent even minor variations in blood oxygen levels may affect longer-term outcomes such as mortality, retinopathy of prematurity (ROP) or necrotising enterocolitis (NEC) was recently shown in the large trials contributing to the NEOPROM collaboration.1

In addition to the importance of closely maintaining an assigned baseline target range, avoiding intermittent hypoxaemia or hyperoxaemia (eg, a pulse oximeter saturation (SpO₂)<80% or >95%) may be equally important.2 Given this situation, combined with the high workload the nursing staff caring for preterm infants often face, close control of oxygen levels is a task that may best be left to a computer algorithm rather than the bedside nurse.

The properties required of such algorithms, however, are manifold: they should be able to respond to both, a gradual change in oxygen requirements and sudden hypoxaemia, and should also be capable of avoiding the build-up of increasing fluctuations in FiO₂/SpO₂ during periods with oscillating SpO₂ values (eg, during periodic breathing). Given these requirements, it may not come as a surprise that studies validating such devices are only slowly becoming available, while comparative data on their effectiveness are yet lacking altogether.

Most FiO₂ controllers currently available are rule-based, that is, respond to any deviation from target SpO₂ according to a set …