Drug detection in breath: effects of pulmonary blood flow and cardiac output on propofol exhalation

Abstract

Breath analysis could offer a non-invasive means of intravenous drug monitoring if robust correlations between drug concentrations in breath and blood can be established. In this study, propofol blood and breath concentrations were determined in an animal model under varying physiological conditions. Propofol concentrations in breath were determined by means of two independently calibrated analytical methods: continuous, real-time proton transfer reaction mass spectrometry (PTR-MS) and discontinuous solid-phase micro-extraction coupled with gas chromatography mass spectrometry (SPME-GC-MS). Blood concentrations were determined by means of SPME-GC-MS. Effects of changes in pulmonary blood flow resulting in a decreased cardiac output (CO) and effects of dobutamine administration resulting in an increased CO on propofol breath concentrations and on the correlation between propofol blood and breath concentrations were investigated in seven acutely instrumented pigs. Discontinuous propofol determination in breath by means of alveolar sampling and SPME-GC-MS showed good agreement (R(2)=0.959) with continuous alveolar real-time measurement by means of PTR-MS. In all investigated animals, increasing cardiac output led to a deterioration of the relationship between breath and blood propofol concentrations (R(2)=0.783 for gas chromatography-mass spectrometry and R(2)=0.795 for PTR-MS). Decreasing pulmonary blood flow and cardiac output through banding of the pulmonary artery did not significantly affect the relationship between propofol breath and blood concentrations (R(2)>0.90). Estimation of propofol blood concentrations from exhaled alveolar concentrations seems possible by means of different analytical methods even when cardiac output is decreased. Increases in cardiac output preclude prediction of blood propofol concentration from exhaled concentrations.

Time course of expiratory propofol after bolus injection as measured by ion molecule reaction mass spectrometry

“…Kamysek et al investigated the influence of changes in cardiac output on expiratory propofol concentrations in seven pigs [5]. Using on-line PTR-MS and discontinuous solid-phase micro-extraction coupled with gas chromatography mass spectrometry they found that a decrease in cardiac output during continuous propofol infusion did not deteriorate the relationship between propofol breath and blood concentrations.…”

“…However, there is currently no method of doing so. In contrast, propofol concentration in exhaled breath can be detected and measured during anesthesia by various techniques [1][2][3][4][5][6][7][8]. These techniques range from discontinuous techniques like thermal desorption gas chromatography-mass spectrometry (analytical time hours to days) [2,9] to fast discontinuous methods like solid-phase microextraction coupled with gas chromatography mass spectrometry or ion mobility spectrometry coupled to a multicapillary column for pre-separation (analytical time within minutes) [10,11].…”

“…These techniques range from discontinuous techniques like thermal desorption gas chromatography-mass spectrometry (analytical time hours to days) [2,9] to fast discontinuous methods like solid-phase microextraction coupled with gas chromatography mass spectrometry or ion mobility spectrometry coupled to a multicapillary column for pre-separation (analytical time within minutes) [10,11]. Very fast on-line methods like ion molecule reaction mass spectrometry, selective ion flow tube mass spectrometry, or proton transfer reaction mass spectrometry (analytical time within milliseconds to seconds) can also be used [1,4,5,8,12,13].…”

FEV manoeuvre induced changes in breath VOC compositions: an unconventional view on lung function tests

“…Such improvements in sampling, analysis and statistical validation have led to the indication that concentration changes are more important than unique breath biomarkers111213. At present, online monitoring of instant physiological changes in exhaled VOC profiles is possible with the required analytical sensitivity or resolution, which also enables clinicians to relate different biochemical and metabolic processes to exhaled VOCs2891415161718.…”

Analysis of volatile organic compounds in compost samples: A potential tool to determine appropriate composting time

“…There are few reports on specific compounds and the analysis of volatile organic compounds during the whole composting process (Li and Huang, 2006;Nasini et al, 2016;Shen et al, 2012;Tiquia and Tam, 1998). HS-SPME-GC-MS has strong analytical capabilities for volatile organic substances and has qualitative and quantitative analysis applications in medical (Gentili et al, 2004;Kamysek et al, 2011), environmental (Higashikawa et al, 2013;Kotowska et al, 2012;Menendez et al, 2004), agricultural (Soto et al, 2015;Sun et al, 2015;Zhang et al, 2010), micro-organism (Stoppacher et al, 2010;Strobel et al, 2008), soil (Durovic et al, 2012;Eriksson et al, 2001), water Martínez et al, 2013;Morales et al, 2012), cosmetics (Ortiz and Tena, 2006;Yang et al, 2010), and food safety fields (Sang et al, 2013;Silva et al, 2015;Tait et al, 2014).…”