New bronchiolitis trial launched to seek the best breathing support for babies


The £1.7 million BACHbtrial will recruit more than 1500 infants over 30 months from children’s emergency departments and wards in 50 hospitals. It is led by researchers at Imperial College London and clinicians at Imperial College Healthcare NHS Trust in collaboration with experts across the UK. This national trial will aim to determine the most effective breathing support for babies hospitalised with bronchiolitis.

Funded by the NIHR supported by the NIHR Imperial BRC, the BACHbtrial is the largest trial of bronchiolitis involving children in this age group to be conducted in the UK and researchers hope the findings could inform national and international guidelines on the care of infants with the condition.

Bronchiolitis is a viral chest infection that affects babies and children under two. It is usually mild and can be treated at home but each year nearly 30,000 infants under the age of one are admitted to hospitals in England with bronchiolitis due to symptoms such as difficulty breathing. There are a range of treatments and most babies recover well, but it is not clear which treatment is the most effective for moderate and severe cases.

The current lack of evidence means there can be variation in practice across the UK, and researchers believe that finding the most effective breathing support may lead to babies recovering more quickly with less discomfort and shorter hospital stays.

Dr Padmanabhan Ramnarayan, Chief Investigator of the trial from the Department of Surgery and Cancer at Imperial College London, who is also an Honorary Consultant in Paediatric Intensive Care at Imperial College Healthcare NHS Trust, said:

“There are a range of options to treat breathing difficulties in babies with bronchiolitis but there is a lack of evidence about which patients would benefit most from each type of treatment. This has led to varying approaches to treating the condition, based on little evidence.

“The treatments we use across the NHS work well but we are aiming to find the best approach to treating bronchiolitis so that babies recover faster.”

“The findings from the trial could lead to a change in guidelines on how we treat this condition as well as a reduction in hospital stays. This is particularly vital during the winter period where demands for NHS services increase significantly.”

Half of children admitted to hospital with bronchiolitis need oxygen, which they receive through thin tubes inserted into the nostrils. Most infants respond well and so do not need further treatment but some will need more breathing support. High-Flow Nasal Cannula (HFNC) oxygen delivers oxygen in the same way but more quickly. This is often the first treatment for these infants as it improves symptoms for many and is also thought to be more comfortable, which is a key factor for doctors making decisions about treatments for young children.

Alternatives include Humidified Standard Oxygen (HSO), which has been moistened with water to avoid irritation in the lungs and Continuous Positive Airwave Pressure (CPAP), for which patients wear an oxygen mask over their nose and mouth. There is currently little evidence about whether these alternative treatments may be more beneficial in some cases than HFNC so they tend to be offered when an infant has not responded well to HFNC.
Researchers will conduct two clinical trials at the same time to determine the effectiveness of each treatment. Infants will be randomly allocated to start one of the three oxygen treatments, depending on the severity of their condition. All other treatment decisions will be left to the clinical team and patients will be quickly switched to an alternative treatment if the one they start with is not found to be effective so that it does not impact their recovery.

The team will compare the treatments by measuring how quickly infants are discharged from hospitals, comfort, parent/carer satisfaction, how often infants need admission to intensive care and their health status one and three months later. They will also assess the comparative costs of each treatment.

Katy Bridges is a research nurse who will be recruiting patients to the trial at Imperial College Healthcare NHS Trust and also supporting the delivery of the trial at other NHS sites. She said: “Health research can only improve treatment with the help of families.

“Our teams are available in hospitals to support patients every step of the way, by explaining the treatments their child is receiving, helping them to take in information about their child’s condition and answering any questions they may have about the study or more widely.

“The patient’s best interests are always the priority.”

Two parent representatives from the National Institute of Clinical Excellence (NICE) bronchiolitis guideline committee helped to develop the study and an independent parent advisory group with six parents whose children were treated for bronchiolitis will also continue advising the research team throughout.

Clinical trials at Imperial College Healthcare are supported by funding from the NIHR Imperial Biomedical Research Centre (BRC), a translational research partnership between Imperial College Healthcare NHS Trust and Imperial College London, which was awarded £95m in 2022 to continue developing new experimental treatments and diagnostics for patients.

Amanda and Aria’s story

“Your focus is your child first and foremost but, for us, it was also about improving the experience in the future. We didn’t know if this could happen to our daughter again.”

Amanda’s eldest daughter developed bronchiolitis at three months old. After a worrying trip to the hospital, the family came home to care for her and thankfully she made a full recovery. So, when their second daughter, Aria, developed similar symptoms at six months old, Amanda thought they knew exactly what they would be up against. Aria was also sent home from urgent care to recover from the nasty virus that caused the bronchiolitis. She initially got better but caught another virus a couple of weeks later.

“When Aria woke overnight coughing and unsettled again, we got ready for more sleepless nights taking care of her until she got better. We knew the signs to look out for and we knew what the doctors had told us a couple of weeks ago.”

“Such a frightening experience as a parent”

But this time was different. Amanda still wanted to check with her GP about Aria’s symptoms given her young age and, when she called the surgery the next morning, the doctor she spoke to was so concerned about the grunting noises she could hear Aria making that she asked Amanda to call an ambulance.

“The GP heard Aria on the phone and was really concerned about how she sounded. We drove her to the hospital immediately and her oxygen levels were frighteningly low. She was taken to resus so they could get her oxygen back up they were also concerned about the possibility of sepsis because her skin had become mottled. It was such a frightening experience as a parent.”

Aria was transferred to a children’s ward where she received high-flow nasal oxygen for two days and was able to return home. But two weeks later Aria was admitted to hospital yet again with similar symptoms. This time, her condition deteriorated and the oxygen she had previously did not help.

Aria was transferred to St Mary’s Hospital, part of Imperial College Healthcare NHS Trust, where she was put on a ventilator to help with her breathing for a few days.

“Aria was really unwell. Doctors were concerned about the risk of her collapsing as she was not maintaining oxygen despite the oxygen treatments she had received, but doctors at our local hospital were unable to offer alternatives. When she was put onto the ventilator, the muscles in her airways also tightened and made it even more difficult for her to try and breathe which meant that her oxygen levels dropped dangerously low. We were so worried about how she would recover.”

After further treatment at St Mary’s, Aria’s condition finally started to improve. After being discharged from the hospital, the family were approached by the COSMIC charity, which supports the paediatric intensive care units at Imperial College Healthcare. They were looking for parent advisers for a new study on treatments for bronchiolitis.

“We think it’s so important that hospitals do research”

The trial had not yet been funded but to ensure the design and consent process was appropriate for families going through such a distressing emergency involving their child the study team were looking for parents to advise them.

“While she was being treated, we had actually agreed for Aria to be recruited into one trial and declined another so between that and our extensive experience with bronchiolitis we were in a good position to give a parent’s view of the process. We met with the research team who asked us lots of questions about our experience and how we felt being asked to be involved in a trial. They used this information to design the study and make sure parents would feel reassured when they were asked to take part.

“We think it’s so important that hospitals do research to improve the treatment of children with respiratory diseases. But we also know how daunting it can be to be asked about research during one of the scariest times in your life. Your focus is your child first and foremost but, for us, it was also about improving the experience in the future. We didn’t know if this could happen to our daughter again.”

One of the things that reassured Amanda and her family was that it would be clear to prospective parents they could opt out at any point.

“Bronchiolitis is an acute illness and in an emergency there isn’t time to consent parents before they agree for their child to be in a study like this. So it’s really important that parents understand they can opt-out at any time and that the doctors and nurses looking after their child can also override the trial treatments if they are not working.

“Doctors and nurses will always do what is best for their patients and this does not change just because they are part of a trial. If the treatment your child is receiving in the trial is not helping they will change it – getting your child better is the ultimate priority but if we can use this as an opportunity to improve treatments for others, then that is even better.”