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

Infants born preterm (before 36 weeks' gestation age) have immature lungs and struggle to breathe on their own. They are supported via respiratory machines like ventilators, as well as pharmaceutical aids like surfactant replacement therapy. Surfactant replacement therapy is an established therapy for the treatment of respiratory distress syndrome, which is a common illness in infants born preterm. Surfactant replacement therapy can be delivered to an infant's lungs a few ways, including via a small tube that is briefly placed down an infant's throat. This is considered the least invasive method currently available, and is becoming more popular. It is referred to as minimally invasive surfactant therapy (MIST). A baby can receive surfactant via MIST if they are receiving non-invasive respiratory support, like from a continuous positive airway pressure (CPAP) machine. Doctors and researchers are looking for simple ways to make MIST more effective. This clinical trial will investigate if briefly increasing the air pressure delivered by a CPAP machine before giving MIST therapy will make MIST more effective. This strategy is called a lung recruitment manoeuvre (LRM), because it opens up more of the lungs - 'recruits' them - to help with oxygenation. The CPAP setting that is briefly changed is called positive end expiratory pressure (PEEP) - it increases the amount of air left in the lungs at the end of a breath. This stops parts of the lung collapsing when exhaling, which commonly occurs in the lungs of infants born preterm as they are immature. The goal of this clinical trial is to investigate if a LRM prior to MIST improves ventilation and lung aeration in preterm infants born 24-32 weeks' gestation. The main question it aims to answer is: How a LRM prior to MIST might impact patterns of ventilation and lung aeration in preterm infants, compared to no LRM prior to MIST. The current standard of care is no LRM before MIST. Researchers will compare this current standard against a LRM before MIST to see if it potentially improves patterns of ventilation. Participants will be randomly placed (by chance) to receive either no LRM before MIST (control) or a LRM before MIST (intervention). Participants will be randomised once their treating clinical team have decided to give MIST.