A major UK-led clinical trial has revealed that surfactant treatment, commonly used to aid premature babies with breathing difficulties, offers no additional benefit for infants on life support battling severe bronchiolitis. The findings, published today, March 21, 2026, in The Lancet Respiratory Medicine, represent the largest-ever randomized study of surfactant use in treating bronchiolitis, a seasonal viral infection that leads to thousands of hospitalizations each year.
Bronchiolitis, most often caused by respiratory syncytial virus (RSV), is a leading cause of infant hospital admissions, particularly during the winter months in the UK. While most of the approximately 25,000 babies admitted with the condition recover with supportive care like oxygen and fluids, around 1,000 require intensive care and mechanical ventilation. The study aimed to determine if surfactant, a substance that helps keep the lungs inflated, could improve outcomes for these critically ill infants, mirroring its successful use in premature babies with underdeveloped lungs.
Surfactant Shows No Improvement in Ventilator Time
The Bronchiolitis Endotracheal Surfactant Study (BESS) trial, funded by the UK Research and Innovation (UKRI) Medical Research Council (MRC) and the National Institute for Health and Care Research (NIHR), alongside support from Chiesi Farmaceutici SpA, involved 232 critically ill babies across 15 children’s hospitals in England, Scotland and Northern Ireland. Researchers found that administering surfactant did not significantly reduce the length of time babies needed to remain on a ventilator.
“The treatment was safe, but it didn’t make any difference to how long babies stayed on ventilators,” explained Professor Calum Semple OBE, the study’s lead from the University of Liverpool and Alder Hey Children’s NHS Foundation Trust. Professor Semple added, “We had hoped that surfactant might speed up recovery for these very sick babies, but the evidence doesn’t support this.”
Understanding Bronchiolitis and Current Treatment Options
Bronchiolitis occurs when a virus, most commonly RSV, infects the small airways in the lungs. This causes inflammation and mucus buildup, making it hard for babies to breathe. Premature infants are particularly vulnerable to severe bronchiolitis due to their smaller airways and less developed immune systems. The condition often presents with symptoms like a runny nose, cough, and difficulty feeding, progressing to more severe respiratory distress in some cases.
Currently, there is no specific antiviral treatment for RSV infection. Management focuses on supportive care, including oxygen therapy, hydration, and, in severe cases, mechanical ventilation. However, a recent RSV vaccine is now being offered to pregnant women in the final months of pregnancy, aiming to protect their newborns from severe illness. The UK government announced the rollout of the vaccine in August 2023, marking a significant step forward in preventing severe bronchiolitis.
The Importance of the BESS Trial
The BESS trial ran over six winter seasons, from 2019 to 2024, to ensure robust data collection across varying RSV seasons. Researchers designed the study to provide clear guidance for clinicians and families facing the difficult decisions surrounding the care of critically ill infants with bronchiolitis. The trial’s large scale and rigorous methodology strengthen the reliability of its findings.
Professor Semple emphasized the continued need for research into better treatments for bronchiolitis, stating, “While we continue to research better ways to care for these sick babies, I urge Mums-to-be to accept the offer of the RSV vaccine during pregnancy, which will protect their newborn babies from severe bronchiolitis.”
Future Research and Continued Surfactant Use in Premature Infants
The researchers underscore that surfactant therapy remains a vital treatment for premature newborns, who often lack sufficient natural surfactant production. The BESS trial’s findings do not alter this established practice. Instead, they highlight the need for targeted research to identify more effective therapies specifically for bronchiolitis.
Further studies are needed to explore potential treatments that address the underlying inflammation and viral load associated with bronchiolitis. Researchers are also investigating the potential role of immunomodulatory therapies and novel antiviral agents in managing the condition. The MRC and NIHR continue to fund research aimed at improving the care of infants with respiratory illnesses.
Disclaimer: This article provides information for general knowledge and informational purposes only, and does not constitute medical advice. It is essential to consult with a qualified healthcare professional for any health concerns or before making any decisions related to your health or treatment.
The next key development to watch for will be the ongoing analysis of data from the BESS trial, which may reveal further insights into the potential benefits of surfactant in specific subgroups of infants with bronchiolitis. We encourage readers to share this information with their networks and to discuss any concerns with their healthcare providers.
