For Researchers


Ventilator-associated pneumonia (VAP) is the leading cause of healthcare-associated infection (HCAI) in the Intensive Care Unit (ICU) with a prevalence of 10%. VAP is associated with an excess mortality, hospital and ICU length of stay and increased cost of care. Since delay in treatment has been shown to result in increased mortality, antibiotics are started as soon as VAP is suspected. However VAP is confirmed microbiologically in 30% of cases of 'suspected' VAP.

The widespread use of antibiotics has lead to increasing antibiotic resistance and this is a particular concern in the ICU, where critically ill patients are vulnerable to HCAI and infection by antibiotic-resistant pathogens. There is a need to improve antibiotic stewardship in all patient groups including those with suspected VAP. The difficulty with current diagnostic methods is that clinical decisions are limited by the time taken for culture and sensitivity testing in the microbiology lab, which typically takes 24-72 hours. 

New, rapid, biomarker-based diagnostics could improve this situation. Our study group has demonstrated that bronchoalveolar lavage fluid biomarkers can be used to effectively exclude VAP in both a single centre derivation study and more recently in a multi-centre validation study.

This RCT aims to test the clinical value of this bespoke VAP biomarker 'kit'.

Study hypothesis

This study tests the hypothesis that a ‘biomarker-guided recommendation on antibiotics’ will improve antibiotic stewardship in patients with suspected VAP while maintaining equivalent patient outcomes.

Study design 

A randomised controlled trial of ‘biomarker-guided recommendation on antibiotics’ versus ‘routine use of antibiotics’ in patients with suspected VAP. The intervention will be a biomarker-based diagnostic test for the exclusion of VAP.

Primary objective

To establish whether a ‘biomarker-guided recommendation on antibiotics’ will improve antibiotic stewardship in patients with suspected VAP.

Primary outcome

The frequency distribution of antibiotic-free days (AFD) in the 7 days following BAL.

Number of study sites

This study will be conducted in 23 adult ICUs.

Study population

Population will be patients aged 18 years or more, mechanically ventilated for 48hrs and with suspected VAP.

Sample size

Sample size will be 210 patients.