Dispersal kinetics of deuterated water in the lungs and airways following mouth inhalation: real-time breath analysis by flowing afterglow mass spectrometry (FA-MS).

Pulmonary oedema is a medical condition characterized by abnormal accumulation of fluid in the extravascular space in the alveoli. Effective oxygenation is impaired and this leads to significant short- and long-term morbidity and mortality. The detection and monitoring of pulmonary oedema by measuring lung water volume is therefore crucial in the initiation and guidance of therapeutic intervention. The current gold standard bedside measurement of extravascular lung water volume (EVLW) is the dilution method using various indicators, but despite the good correlation of the results with those obtained using the post-mortem gravimetric method, the invasiveness of the dilution technique limits its general application in the wider clinical setting. In the present preliminary experiments, the dispersal kinetics of deuterium (actually HDO) in exhaled breath of three healthy participants following the inhalation of deuterium oxide (D(2)O) vapour are explored as monitored using flowing afterglow mass spectrometry (FA-MS). Here, we present the basic ideas of lung water estimation using this novel technique, and briefly discuss its limitations and required future work.