Breath volatile analysis from patients diagnosed with harmful drinking, cirrhosis and hepatic encephalopathy: a pilot study

Hepatic encephalopathy (HE) is a neuropsychiatric state potentially complicating cirrhosis following the accumulation of toxic compounds that cross the blood–brain barrier and affect brain function; the compounds may undergo alveolar gas exchange and be partially excreted by exhalation. Thus breath analysis as a non-invasive means of diagnosing HE, cirrhosis and harmful drinking was investigated in a pilot study. One litre samples of breath were collected from patients with alcohol-related cirrhosis (n = 34) with HE (n = 11) and without HE (n = 23), non-alcoholic cirrhosis without HE (n = 13), harmful drinkers without cirrhosis (n = 7), and healthy controls (n = 15) in a hospital setting. Breath compounds trapped on adsorbent tubes were released via thermal desorption and analysed by gas chromatography mass spectrometry for separation and detection. Multivariate discriminant analysis was used to identify volatile organic compounds to differentiate patients according to disease status and build models for disease classification. HE was correctly identified in 90.9 % of alcoholic cirrhotic patients and liver cirrhosis in 100 % of alcoholic patients. In patients without clinical HE, alcohol was correctly predicted as the cause of cirrhosis in 78.3 % of patients and non-alcoholic causes of cirrhosis were correctly determined in 69.2 %. Non-alcoholic cirrhosis, alcoholic cirrhosis, and harmful drinking could be discriminated from healthy controls with a sensitivity of 92.3, 97.1 and 100 %, respectively. Breath volatile analysis has the potential to aid the diagnosis of HE and a range of liver disorders.