The PLUSS Trial is investigating whether a steroid treatment could prevent lung disease in very preterm babies.

Most babies born at less than 28 weeks have very immature lungs and need help with breathing. The lungs are stiff and poorly expanded because of low levels of a natural substance called surfactant. This is termed respiratory distress syndrome (RDS). These babies often need treatment with surfactant, which is placed in the trachea or windpipe.

Around half of extremely preterm babies also develop chronic lung disease. Babies with chronic lung disease need breathing support for many weeks or months and are more likely to have chest infections and wheezing illnesses in childhood and beyond.

Airway inflammation is thought to be responsible for the development of chronic lung disease. Some babies receive systemic steroids (given with feeds or intravenous drip) to reduce lung inflammation. However, giving steroids in this way can cause problems with how preterm babies grow and develop and this is usually avoided.  

What is the PLUSS Trial trying to find out?

The PLUSS trial is trying to find out if installation of budesonide (a steroid) with surfactant to the lungs of extremely preterm babies will help to prevent lung disease. The trial is investigating whether giving budesonide early, as Respiratory Distress Syndrome (RDS) develops, can prevent chronic lung disease without the side effects of systemic steroids.

The trial is being led by a team of researchers at the Liggins Institute and Royal Women’s Hospital, Melbourne.  

What does participation in the PLUSS Trial involve?

This study will investigate whether budesonide, given with surfactant directly into the lungs, is better than treatment with surfactant alone (standard or usual treatment) to prevent chronic lung disease. Your baby will be randomly selected to be in one of these groups.

Budesonide is approved to treat asthma. Budesonide is not approved to prevent or treat chronic lung disease. Therefore, budesonide is a new treatment for chronic lung disease. This means it must be tested to see if it is effective and safe for chronic lung disease.
We will monitor your baby closely after birth and do an assessment at 36 weeks to check for chronic lung disease. Your baby will also be followed up when they are two years old.  

Are there any risks in taking part?

We cannot promise that your baby will get any benefits from this study, but they may be less likely to develop chronic lung disease if the budesonide helps. The results of this study will be used to improve the care of extremely premature babies in the future.

All medical treatments have the ability to cause side effects and there may be effects we do not expect or do not know about. We believe that giving budesonide mixed with surfactant directly into the lungs has fewer side effects than giving it systemically. If a severe side effect or reaction occurs, the study doctor may need to stop your baby’s treatment. Your baby’s study doctor will discuss the best way of managing any side effects with you.  

Find out more

In New Zealand, the PLUSS trial is recruiting extremely preterm babies born at Auckland City and Middlemore Hospitals. For more information email the team at