Optimal target range of closed loop inspired oxygen support in preterm infants

Both hypoxia and hyperoxia can lead to organ damage in preterm infants. For
this reason the transcutaneously measured oxygen saturation (SpO2) is kept
within a range between 86% and 95%. Hypoxia is mainly caused by immature or
impaired control of breathing (apnea) and/or a compromised lung function.
Hypoxia is often treated with supplemental oxygen, which is manually adjusted
to keep the SpO2 within the target range. However, due to clinical instability
and the limited time nurses have to adjust the amount of oxygen, preterm
infants only spent approximately 50% of the time within the SpO2 target range.
Recent studies have shown that the automatic fractional inspired oxygen (FiO2)
function of the AVEA ventilator is more capable of maintaining preterm infants
within preset saturation ranges than manual adjustment. However, it is unknown
to what extent narrowing the SpO2 target range during automated control will
result in a tighter control of the SpO2.

To assess the optimal target range of the automatic FiO2 function by
maintaining the same mean, and narrowing the upper and lower limits of the
target range.

Randomized controlled cross-over trial. In order to find the optimal target
range of the automatic FiO2 function of the AVEA ventilator, the target ranges
will be set at random order to 86-94%, 88-92%, and 89-91%, respectively for 24
hours each.

Burden: There is no additional burden for the patient. All infants
participating in the study are subjected to routine neonatal intensive care and
are already treated with the AVEA ventilator. The CLIO2 function can be switch
on and adjusted without disturbing the patient. As part of standard care,
cardio-respiratory and oxygenation status will be monitored continuously. This
study does not require extra investigations or interventions.

Benefit and risks: Previous studies have shown that using automatic FiO2
function to keep the patient within preset saturation ranges is feasible and
safe. This study will evaluate the efficacy of such a tool narrowing those
target ranges. Avoiding hyperoxemia and hypoxia by tight control of the
saturation ranges could be a potential benefit for the included patients, as
there is now a considerable body of evidence showing that both hypoxia and
hyperoxemia can damage multiple organ systems in the preterm infant.
There are no additional known risks to the infant other than those experienced
routinely by the premature infants who require supplemental oxygen while in the
newborn intensive care nursery.
There are specific alarms and user alerts built in the automatic FiO2 function
to improve patient safety in addition to the standard alarms of the pulse
oximeter. These alarms will alert the routine caregivers of conditions that
require assessment and possible intervention.

Group relatedness: Respiratory instability for which supplemental oxygen is
required is a complication occurring exclusively in preterm infants. Any
intervention aiming to reduce the risk of hyperoxemia or hypoxia therefore
needs to be studied in this specific population at risk.