Flow-synchronized Nasal IMV in Preterm Infants

The use of non-invasive methods of respiratory support to reduce complications of prolonged
invasive mechanical ventilation in preterm infants has increased.

The most common mode is nasal intermittent mandatory ventilation (NIMV). In NIMV, the
interval between mechanical breaths is fixed and is determined by the frequency dialed by the
clinician. Asynchrony between the infant's spontaneous breathing may exist since mechanical
breaths delivered at fixed intervals can occur at different times over the inspiratory or
expiratory phases of the infant's spontaneous breathing. Synchronized-NIMV is a mode similar
to NIMV where the ventilator cycle is delivered in synchrony with the infant's spontaneous
inspiration. This has been achieved by using techniques to detect the infant's spontaneous
inspiration.

The advantages or disadvantages of synchronized compared to non-synchronized NIMV remain to
be determined.

This study seeks to evaluate the effect of synchronized NIMV versus non-synchronized NIMV on
ventilation and gas exchange in premature infants who require supplemental oxygen.

The hypothesis is that the use of flow synchronized nasal intermittent mandatory ventilation
(S-NIMV) in comparison to non-synchronized NIMV will improve ventilation and gas exchange and
reduce breathing effort.

The objective of the study is to compare the effect of flow synchronized-NIMV to
non-synchronized-NIMV on tidal volume (VT), minute ventilation (VE), gas exchange, breathing
effort, apnea and chest wall distortion in preterm neonates with lung disease.