Consequences of pulmonary inflations (sighs) on cerebral haemodynamics in neonates ventilated by high-frequency oscillation

High-frequency oscillation (HFO) is a technique frequently used in neonatal resuscitation, but which has yet to be evaluated. The use of intrathoracic pressures may have an effect on the cerebral circulation of immature neonates. The aim of this study was to examine the variations in cerebral blood velocity and oxygenation during brief pulmonary inflations (sighs), by focusing on alveolar recruitment. In this prospective study performed in 13 intubated and ventilated neonates (alpha = 5%; 1-beta = 80%), mean blood velocity and Doppler Resistance Index were measured, and variations in chromophores concentrations were evaluated by near infrared spectroscopy. Brief inflations at 4 cm H2O above the mean regulated intra-thoracic pressure did not cause any variation in the parameters measured. An explanation for this discordance with animal studies may be the level of pressure chosen, which could be more appropriate for the pulmonary compliance of neonates.