Detection and quantification of exhaled volatile organic compounds in mechanically ventilated patients

comparison of two sampling methods

Pouline M. van Oort (Author), I. R. White (Author), Waqar Ahmed (Author), Craig Johnson (Author), Jonathan Bannard-Smith (Author), Timothy Felton (Author), Lieuwe D. Bos (Author), Royston Goodacre (Author), Paul Dark (Author), Stephen J Fowler (Author)

Abstract

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.

Keywords

volatile organic compounds;infection;breath;ventilator associated pneumonia;

Data

Language:	English
Year of publishing:	2021
Typology:	1.01 - Original Scientific Article
Organization:	UNG - University of Nova Gorica
UDC:	611
COBISS:	42126339
ISSN:	1364-5528
Views:	1675
Downloads:	0
Average score:	0 (0 votes)
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Other data

URN:	URN:SI:UNG
Type (COBISS):	Not categorized
Pages:	str. 222-231
Volume:	ǂVol. ǂ146
Issue:	ǂno. ǂ1
Chronology:	2021
DOI:	10.1039/C9AN01134J
ID:	12241971