deMISTify: The Impact of Ventilator Pressure Levels During Minimally Invasive Surfactant Therapy on Lung Aeration in Preterm Infants

Inclusion Criteria: * Born between 24 to 31+6 weeks' gestation, by best obstetric estimate * Admitted to a participating NICU * A parent/guardian who can provide informed consent * Receiving CPAP respiratory support * Planned to receive MIST by clinicians as standard clinical care * Clinically stable (as determined by clinical team) * Infant less than 72 hours of age * MIST can be administered within 90 min of allocating assigned interventional arm Exclusion Criteria: * Receiving any form of respiratory support other than CPAP * Receiving more than 8 cmH2O PEEP via CPAP in the 4 hours prior to surfactant administration (except in the Delivery Room as part of resuscitation at birth) * The infant's clinical team has concern regarding clinical stability and tolerability of EIT * The infant's skin integrity will not tolerate the EIT belt and gel * Refusal of informed consent by their parent/guardian/legally acceptable representative * The infant does not have a parent/guardian who can provide informed consent. * Major congenital anomaly involving the cardiac, respiratory, gastrointestinal systems, or a known genetic syndrome or diagnosis that might affect respiratory course and outcomes * Severe pulmonary hypoplasia due to anhydramnios or oligohydramnios before 24 weeks in which the neonatal clinician anticipates that pulmonary hypoplasia related respiratory failure will be the major respiratory problem in early post-natal life * Suspected or confirmed air leak or pneumothorax * Previous treatment with surfactant or mechanical ventilation via an endotracheal tube * Urgent need for intubation and mechanical ventilation as determined by the treating clinician * Not receiving full active intensive care (i.e. palliative/comfort care)