Detection and quantification of exhaled volatile organic compounds in mechanically ventilated patients–comparison of two sampling methods
Exhaled breath analysis is a promising new diagnostic tool, but currently no standardised method for sampling is available in mechanically ventilated patients. We compared two breath sampling methods, first using an artificial ventilator circuit, then in “real life” in mechanically ventilated patients on the intensive care unit. In the laboratory circuit, a 24-component synthetic-breath volatile organic compound (VOC) mixture was injected into the system as air was sampled: (A) through a port on the exhalation limb of the circuit and (B) through a closed endo-bronchial suction catheter. Sorbent tubes were used to collect samples for analysis by thermal desorption-gas chromatography-mass spectrometry. Realistic mechanical ventilation rates and breath pressure–volume loops were established and method detection limits (MDLs) were calculated for all VOCs. Higher yields of VOCs were retrieved using the closed suction catheter; however, for several VOCs MDLs were compromised due to the background signal associated with plastic and rubber components in the catheters. Different brands of suction catheter were compared. Exhaled VOC data from 40 patient samples collected at two sites were then used to calculate the proportion of data analysed above the MDL. The relative performance of the two methods differed depending on the VOC under study and both methods showed sensitivity towards different exhaled VOCs. Furthermore, method performance differed depending on recruitment site, as the centres were equipped with different brands of respiratory equipment, an important consideration for the design of multicentre studies investigating exhaled VOCs in mechanically ventilated patients.
2020
2020-12-10 11:51:39
1033
Volatile organic compounds, infection, breath, ventilator associated pneumonia
r6
Iain R.
White
70
Pouline M. van
Oort
70
Waqar
Ahmed
70
Craig
Johnson
70
Jonathan
Bannard-Smith
70
Timothy
Felton
70
Lieuwe D.
Bos
70
Royston
Goodacre
70
Paul
Dark
70
Stephen J.
Fowler
70
COBISS_ID
3
42126339
DOI
15
DOI: 10.1039/c9an01134j
NUK URN
18
URN:SI:UNG:REP:30UP2PTT
RAZ_White_Iain_R._i2020.pdf
1691417
Predstavitvena datoteka
2020-12-10 12:48:01