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A trial into the effects of low ventilator flows compared with standard flows, to attempt to reduce lung injury in extremely preterm babies, thereby improving long-term health.

Dr Kitty Bach
University of Auckland

What is the problem and who does it affect?

When babies are born extremely pre-term, mechanical ventilation is often necessary to assist their breathing and aid their survival but it can contribute to ventilator-induced lung injury, thereby predisposing them to the chronic respiratory condition, bronchopulmonary dysplasia (BPD).

BPD affects up to 70% of babies born before 28 weeks’ gestation in New Zealand and has lifelong consequences for respiratory function.

The researchers recently have demonstrated in experimental studies that gas flows in the ventilation circuit may be one factor contributing to lung injury and that low flows provide better ventilation with less injury.

The results of the initial studies have generated significant interest when presented and published internationally. Clinical evidence is needed to determine whether lowering ventilator gas flows reduces lung injury in extremely pre-term babies.

What is the research hoping to achieve?

The study, a randomised controlled trial (RCT) in infants born before 28 weeks’ gestation or with a birth-weight of less than 1,000g, will compare low gas flows with standard flows as soon as the need for ventilation is established.

Lung injury will be assessed by measuring biomarkers in both blood and easily obtained lung fluid, as well as by duration and intensity of respiratory support.

This study has the potential to reduce lung injury in extremely pre-term babies, improving both their short-term and long-term health. Reduction in respiratory morbidity reduces length of hospital stay, re-admission rates and risk of asthma. As the intervention – alteration of the ventilator gas flow – is at no additional cost, effectiveness would translate to a sustainable economic benefit for the healthcare industry.