Non-invasive lung function measurements in infants using Forced Oscillation Technique and diaphragm electromyography.

At the Neonatal Intensive Care Unit (NICU) newborn infants may need mechanical
ventilation (MV). During MV it is very important that the ventilator pressure
levels that are used are be titrated according to the infant's lung function,
to prevent atelectasis and improve oxygenation. However, lung function changes
due to developing (patho)physiology. In clinical practice, titrating the level
of respiratory support is difficult, as there is no standard used technique to
monitor the infant*s lung function. Therefore, peripheral oxygen saturation
(SpO2) and oxygen demand (FiO2) are used as secondary measures for adequate gas
exchange. However, SpO2 and FiO2 are not solely dependent on current lung
function and therefore less accurate than desired. With the Forced Oscillation
Technique (FOT) an existing lung function measurement has recently become
available for neonatal use. Recent studies in infants show that FOT is a
feasible method to acquire information on lung mechanics (i.e. airway/lung
resistance/reactance), which might prove useful in optimizing respiratory
support. Nowadays, FOT is implemented in a neonatal ventilator, which makes it
easily accessible. When FOT is performed daily, lung function can be observed
over time, is the general hypothesis. In addition, measuring the level of
diaphragm activity (measured with transcutaneous electromyography (dEMG)) could
prove highly valuable to clinical practice as well. However, never before has
this unique and non-invasive combination of methods been investigated in
(mechanically ventilated) infants.

This study's first objective is to assess lung mechanics (measured with FOT) in
mechanically ventilated infants, in the clinical practice of the NICU, with
intermittent measurements during the entire period of mechanical ventilation.
The FOT results will be compared with changes in SpO2 and FiO2. The second
objective is to measure diaphragm activity after the first day of MV and prior
to the ceasing of mechaincal ventilation (extubation), to assess how diaphragm
activity changes with the recovery of the patient. Lastly, exploratory analysis
will be performed to determine to what extent a combination of information
acquired with EMG and FOT could be of additional value in care for ventilated
infants.

Prospective, observational cohort study

This is a non-invasive observational, prospective study that only uses
certified techniques. No changes are made to the caregiving routine. The study
population will not benefit from participating in this study. This study will
expand our knowledge on non-invasive ways to measure lung function, which could
improve the respiratory support in the future.