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J Breath Res

Title:		Applied upper-airway resistance instantly affects breath components: a unique insight into pulmonary medicine
Author(s):		Sukul P; Schubert JK; Kamysek S; Trefz P; Miekisch W;
Address:		"Rostock Medical Breath Research Analytics and Technologies (ROMBAT), Dept. of Anaesthesiology and Intensive Care, University Medicine Rostock, Schillingallee 35, D-18057 Rostock, Germany"
Journal Title:		J Breath Res
Year:		2017
Volume:		20171101
Issue:		4
Page Number:		47108 -
DOI:		10.1088/1752-7163/aa8d86
ISSN/ISBN:		1752-7163 (Electronic) 1752-7155 (Linking)
Abstract:		"Respiratory parameters such as flow or rate have complex effects on the exhalation of volatile substances and can hamper clinical interpretation of breath biomarkers. We have investigated the effects of progressively applied upper-airway resistances on the exhalation of volatile organic compounds (VOCs) in healthy humans. We performed real-time mass-spectrometric determination of breath volatiles in 50 subjects with parallel, non-invasive hemodynamic monitoring, breath-resolved spirometry and capnometry during controlled tidal breathing (12 breaths/min). Airway resistance was increased by changing the mouthpiece diameters from 2.5 cm to 1.0 cm and to 0.5 cm. At the smallest diameter, oxygen uptake increased (35% upward arrow). Cardiac output decreased (6% downward arrow) but end-tidal PCO(2) (8% upward arrow) and exhalation of blood-borne isoprene (19% upward arrow) increased. Carbon dioxide production remained constant. Furan, hydrogen sulphide mirrored isoprene. Despite lowered minute ventilation (4% downward arrow) acetone concentrations decreased (3% downward arrow). Exogenous acetonitrile, propionic acid, isopropanol, limonene mimicked acetone. VOC concentration changes could be modelled through substance volatility. Airway resistance-induced changes in hemodynamics, and ventilation can affect VOC exhalation and thereby interfere with breath biomarker interpretation. The effects of collateral ventilation, intra-alveolar pressure gradients and respiratory mechanics had to be considered to explain the exhalation kinetics of CO(2) and VOCs. Conventional breath sampling via smaller mouthpiece diameters (
Keywords:		Adult *Airway Resistance Biomarkers/analysis Breath Tests/methods Exhalation Female Hemodynamics Humans Lung/chemistry Male Middle Aged *Pulmonary Medicine Regression Analysis *Respiration Volatile Organic Compounds/analysis Volatilization Young Adult;
Notes:		"MedlineSukul, Pritam Schubert, Jochen K Kamysek, Svend Trefz, Phillip Miekisch, Wolfram eng England 2017/09/20 J Breath Res. 2017 Nov 1; 11(4):047108. doi: 10.1088/1752-7163/aa8d86"