Biomarker-based Exclusion of VAP for Improved Antibiotic Stewardship

Critically ill patients whose lungs are supported by breathing machines (ventilators) commonly develop a new lung infection, called ventilator-associated pneumonia (VAP). Because VAP is often fatal, antibiotics are administered whenever it is suspected. However VAP is hard to distinguish from several non-infective lung conditions and most patients with suspected VAP do not have pneumonia. Therefore many patients receive unnecessary antibiotics for several days, promoting emergence of 'superbugs'. Laboratory test results for diagnosing VAP typically only reach the doctors after 3 days. A simple test rapidly and confidently excluding VAP should improve patient care, reduce unnecessary antibiotics and decrease costs. We recently showed that low levels of specific proteins in fluid from the lungs of patients with suspected VAP effectively excluded VAP, using a test that may yield results within 6 hours. The test used is an extension of existing technology produced by our commercial partner Becton Dickinson (BD) Biosciences. Our previous findings were derived from a single hospital's intensive care unit. We have recently confirmed this finding across many intensive care units, which will help show that the test can be used in 'real life'. The aim of this study is to take the new test to the next step and determine whether it can improve the care of patients by reducing the amount of unnecessary antibiotics prescribed. This will be done using a 'randomised controlled trial', the best tool for scientifically testing a new diagnostic test. To do this we shall identify patients with suspected VAP, all of whom will have a lung sample - half of the patients will receive 'usual care' for suspected VAP, the other half will have the new test performed on their lung fluid. If the new test suggests no lung infection, the doctors will be asked to consider not giving antibiotics. We shall test how much antibiotic is given to each group.