Exhaled Breath Metabolomic Biomarkers in the Acutely Breathless Patient

A prospective real world observational study carried out across three acute admissions units. Participants with self-reported acute breathlessness, with a confirmed primary diagnosis of either acute heart failure, community acquired pneumonia and acute exacerbation of asthma or COPD will be recruited within 24 hours of admission. These will be matched to healthy volunteers from a similar environment. Additionally, school age children admitted with severe asthma will be evaluated and breath samples will be collected. All participants will undergo breath sampling on admission and upon recovery, up to six months following discharge. A range of online technologies including: proton-transfer-reaction mass spectrometry (PTR-MS), gas chromatography ion mobility spectrometry (GC-IMS), atmospheric pressure chemical ionisation- mass spectrometry (APCI-MS) and offline technologies including gas chromatography mass spectroscopy (GC-MS) and comprehensive two-dimensional gas chromatography-mass spectrometry (GCxGC-MS) will be utilised for VOC discovery and replication. For offline technologies a standardised CE marked breath sampling device (ReCIVA®) will be used. All recruited participants will be characterised using existing blood biomarkers including C - reactive protein (CRP), brain derived natriuretic peptide (BNP), Troponin-I and blood eosinophil levels and further evaluated using a range of standardised questionnaires, lung function testing including hand held forced oscillation technique (FOT) and fractional exhaled nitric oxide (FeNO), sputum cell counts and echocardiography for heart failure and COPD patients. Additional samples will be collected for bio-banking including urine, serum, plasma and sputum supernatants and plugs.