CO<sub>2</sub>-controlled sampling of alveolar gas in mechanically ventilated patients

Schubert, Jochen K.; Spittler, Karl-Heinz; Braun, Guenther; Geiger, K.; Guttmann, J.

doi:10.1152/jappl.2001.90.2.486

Cited by 103 publications

(77 citation statements)

References 24 publications

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“…Breath analysis is a promising field for non-invasive diagnosis ( [208]; [183]) but the necessity for large screening studies to find markers for diseases and validate the results brings logistic challenges with: (1) the storage of breath samples for off-line analysis [193]; [209]) and (2) the standardization of the sampling method ( [210]; [34]). With a small scale test, the first point is addressed by looking at specific volatiles known to be present in elevated or decreased levels.…”

Section: Resultsmentioning

confidence: 99%

Proton Transfer Reaction Mass Spectrometry: Applications in the Life Sciences

Gonzalez

2012

Mass Spectrometry Handbook

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Section: Resultsmentioning

confidence: 99%

Proton Transfer Reaction Mass Spectrometry: Applications in the Life Sciences

Gonzalez

2012

Mass Spectrometry Handbook

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“…In a next development, e.g. for use during anaesthesia, the patients were ventilated and the sampling was automated from concentrations of respired carbon dioxide (CO 2 ) [8][9][10][11]. Since these sensors are comparable expensive and slow responding with times of about 300 ms, already within the range of a single expiration at high respiratory rates, a comprehensive investigation was merited on the suitability of parameters and sensors (including CO 2 , humidity, flow and volume of the exhaled breath) in breath sampling.…”

Section: Introductionmentioning

confidence: 99%

Breath sampling control for medical application

Vautz

Baumbach

Westhoff

et al. 2010

Int. J. Ion Mobil. Spec.

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Sampling of breath under human control or automated control with sensors was combined with chemical determination of a synthetic sample using multicapillary column ion mobility spectrometry to measure quantitative variability. Variation was 19 % with an automated inlet and 33 % with human control. Sensors to operate an automated inlet were also evaluated with human subjects and included carbon dioxide (CO 2 ), flow (direction and velocity), volume (integrated from the flow rate) and humidity, all operating in the mainstream of exhaled air. The flow sensor provided a measure of sampling of breath from the upper airways and other sensors gauged exclusive sampling of the end-tidal volume as well. Sensors for volume and CO 2 exhibited identical profiles, using appropriate threshold values, in reference to inspiration and expiration. A sensor for humidity lagged inspiration and expiration with a delay of 300 ms and therefore is diminished in value. The sensors recommended for an automated inlet for breath sampling are CO 2 and the exhaled or tidal volume though tidal volume varies significantly with personal physiognomy. This necessitates an evaluation of a subject to establish a threshold setting and CO 2 is the single best parameter providing the availability of sensor signal within 50 ms.

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“…This allows quasi-continuous monitoring of the gas sample; in the case of breath tests, for example, suboptimal exhalations can be immediately identified and discarded. Additionally, information about the ethane exhalation during different exhalation phases and the sloping alveolar plateau is directly accessible via fast online measurements, whereas offline methods integrate over a complete exhalation and require an extra effort to separate alveolar gas from dead-space gas, e.g., via CO 2 -controlled sampling (28). However, up to now, there is no online technique available that allows real-time monitoring of ppb ethane traces in exhaled breath.…”

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Online recording of ethane traces in human breath via infrared laser spectroscopy

Basum

Dahnke

Halmer

et al. 2003

Journal of Applied Physiology

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A method is described for rapidly measuring the ethane concentration in exhaled human breath. Ethane is considered a volatile marker for lipid peroxidation. The breath samples are analyzed in real time during single exhalations by means of infrared cavity leak-out spectroscopy. This is an ultrasensitive laser-based method for the analysis of trace gases on the sub-parts per billion level. We demonstrate that this technique is capable of online quantifying of ethane traces in exhaled human breath down to 500 parts per trillion with a time resolution of better than 800 ms. This study includes what we believe to be the first measured expirograms for trace fractions of ethane. The expirograms were recorded after a controlled inhalation exposure to 1 part per million of ethane. The normalized slope of the alveolar plateau was determined, which shows a linear increase over the first breathing cycles and ends in a mean value between 0.21 and 0.39 liter Ϫ1 . The washout process was observed for a time period of 30 min and was modelled by a threefold exponential decay function, with decay times ranging from 12 to 24, 341 to 481, and 370 to 1,770 s. Our analyzer provides a promising noninvasive tool for online monitoring of the oxidative stress status. alveolar slope; breath analysis; cavity leak-out spectroscopy; lipid peroxidation; oxidative stress; washout AMONG THE VARIOUS VOLATILE hydrocarbons found in breath, the alkanes ethane (C 2 H 6 ) and pentane (C 5 H 12 ) have been extensively studied since they were identified as end products of the oxidative degradation (lipid peroxidation) of polyunsaturated fatty acids. The process of lipid peroxidation has gained interest as one of the important features of free radical-induced damage in biology and medicine (29). During peroxidation of omega-3 and omega-6 fatty acids, ethane and pentane, respectively, are formed and excreted via the lungs and thus can be detected in exhaled breath. Because lipid peroxidation is considered as the major, probably the only endogenous source of pentane and ethane, these volatile compounds may serve as specific markers for oxidative damage (8,25).The first report of breath ethane as a marker of in vivo lipid peroxidation was published by Riely et al. in 1974 (24). During the past decade, several studies provided evidence that ethane and pentane in exhaled air are useful markers of in vivo lipid peroxidation under certain clinical conditions (1-4, 8, 19, 20, 26, 27). Because pentane is metabolized in the liver, ethane is considered as the more reliable marker (10).Despite the growing number of reports on breath ethane and pentane, the development of rapid and sensitive analysis techniques for measurements of these markers in exhaled breath still remains a challenge. Ethane and pentane fractional concentrations in expired air are in the parts per billion (ppb; 1:10 9 ) range, which is below the detection limit of most analytical methods.The technique usually applied for quantifying these hydrocarbons in exhaled breath is gas chromatography (...

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CO₂-controlled sampling of alveolar gas in mechanically ventilated patients

Cited by 103 publications

References 24 publications

Proton Transfer Reaction Mass Spectrometry: Applications in the Life Sciences

Proton Transfer Reaction Mass Spectrometry: Applications in the Life Sciences

Breath sampling control for medical application

Online recording of ethane traces in human breath via infrared laser spectroscopy

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CO2-controlled sampling of alveolar gas in mechanically ventilated patients

Cited by 103 publications

References 24 publications

Proton Transfer Reaction Mass Spectrometry: Applications in the Life Sciences

Proton Transfer Reaction Mass Spectrometry: Applications in the Life Sciences

Breath sampling control for medical application

Online recording of ethane traces in human breath via infrared laser spectroscopy

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CO₂-controlled sampling of alveolar gas in mechanically ventilated patients