UK Study Finds No Benefit of Surfactant Treatment for Severe Bronchiolitis in Infants
A large-scale clinical trial led by researchers in the UK has revealed that surfactant treatment offers no additional benefit for infants with severe bronchiolitis who require life support. The findings, published on March 21, 2026, in The Lancet Respiratory Medicine, challenge current practices and could lead to a reassessment of treatment protocols for this common respiratory illness in babies.
What is Bronchiolitis?
Bronchiolitis is a common viral infection of the lungs, most often caused by respiratory syncytial virus (RSV). It primarily affects babies under one year traditional and can be particularly severe in premature infants. The infection causes inflammation and swelling of the small airways in the lungs, leading to difficulty breathing. While most cases resolve with supportive care like oxygen and fluids, a significant number of infants—around a thousand in the UK each winter—require intensive care and mechanical ventilation.
The BESS Trial: A Landmark Study
The Bronchiolitis Endotracheal Surfactant Study (BESS) trial, funded by the UKRI Medical Research Council (MRC), the National Institute for Health and Care Research (NIHR) and Chiesi Farmaceutici SpA, Italy, is the largest randomized study ever conducted on the use of surfactant for bronchiolitis. Researchers enrolled 232 critically ill babies across 15 children’s hospitals in England, Scotland, and Northern Ireland over six winter seasons (2019-2024).
Surfactant: A Common Treatment for Premature Babies
Surfactant is a substance that coats the lungs and helps them inflate properly. It is routinely used to treat respiratory distress syndrome in premature babies, who often lack sufficient surfactant. Given the similarities between the lung condition in premature infants and those with severe bronchiolitis, the BESS trial aimed to determine if surfactant could also improve outcomes for babies hospitalized with bronchiolitis.
Key Findings: No Significant Improvement
Despite being safe for use, the study found that surfactant did not reduce the amount of time babies needed to remain on a ventilator. Professor Calum Semple OBE, lead researcher from the University of Liverpool and Alder Hey Children’s NHS Foundation Trust, stated, “The treatment was safe, but it didn’t produce any difference to how long babies stayed on ventilators. We had hoped that surfactant might speed up recovery for these very sick babies, but the evidence doesn’t support this.”
Implications and Future Research
The findings suggest that surfactant should not be routinely used as a treatment for severe bronchiolitis in infants on life support. Researchers emphasize that surfactant remains a vital treatment for premature newborns. Further research is needed to identify targeted therapies for bronchiolitis, and the study team continues to explore better ways to care for these critically ill infants.
Preventing Bronchiolitis: The Role of Vaccination
While there is no specific treatment for RSV infection, a vaccine is now available for pregnant women to protect their newborns from severe bronchiolitis. Professor Semple urges expectant mothers to accept the offer of the RSV vaccine during pregnancy.
About the Funding Organizations
The Medical Research Council (MRC), part of UK Research and Innovation, funds world-leading research to improve human health. The National Institute for Health and Care Research (NIHR) aims to improve the health and wealth of the nation through research, funding high-quality studies and translating discoveries into improved treatments and services.
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