Abstract
BACKGROUND: High frequency oscillation (HFO) is a lung protective ventilation strategy for newborn infants due to the small tidal volume delivery at fast frequencies, but has been associated with an increased risk of brain injury. High-frequency oscillation with volume-targeted ventilation (HFO&VTV) is a new mode of HFO that applies a targeted tidal volume (VThf) set by the clinician and achieves less fluctuations of carbon dioxide levels and therefore reduces the risk of brain injury. The optimal starting VThf values, however, have not been explored to date. This study investigates the optimum starting settings in newborn infants receiving HFO by comparing the cerebral blood flow velocity and cardiac output at different tidal volume targets of HFO&VTV. METHODS: This randomised crossover trial performed at a single tertiary neonatal unit will be recruiting 25 infants of any gestation and at any postnatal age receiving HFO. Each infant will receive three targeted tidal volumes on HFO&VTV in random order with control periods in between. The resistive index (RI) as an indicator of cerebral blood flow in term-born infants and the cardiac output for all infants in the study will be assessed in each period. The primary outcome will be the reduction in the RI that will be measured on term-born infants using the anterior cerebral artery Doppler. The secondary outcome will be the improvement in cardiac output that will be assessed in all infants with bedside ECHO. The study will be performed following informed parental consent and was approved by the London-Hampstead research ethics committee (Protocol version 2, 22/01/25). DISCUSSION: This trial will investigate the effect of HFO&VTV on cerebral blood flow velocity and cardiac output to further elucidate the optimal volume targeting range in newborn infants. TRIAL REGISTRATION: ClinicalTrials.Gov, NCT06719284 , registered on 04/12/2024.