Evaluation of a standardized collection device for exhaled breath sampling onto thermal desorption tubes

Abstract

The Respiration Collector for In Vitro Analysis (ReCIVA) sampler, marketed by Owlstone Medical, provides a step forward in exhaled breath sampling through active sampling directly onto thermal desorption (TD) tubes. Although an improvement to the issues surrounding breath bag sampling, the ReCIVA device, first released in 2015, is a relatively new research and clinical tool that requires further exploration. Here, data are presented comparing two distinct ReCIVA devices. The results, comparing ReCIVA serial numbers #33 and #65, demonstrate that overall statistically insignificant results are obtained via targeted isoprene quantitation (p > 0.05). However, when the data are parsed by the TD tube type used to capture breath volatiles, either Tenax TA or the dual bed Tenax/Carbograph 5TD (5TD), a statistical difference (p < 0.05) among the two different TD tubes was present. These data, comparing the two ReCIVA devices with both Tenax TA and 5TD tubes, are further supported by a global metabolomics analysis yielding 85% of z-scores, comparing ReCIVA devices, below the limit for significance. Experiments to determine the effect of breathing rate on ReCIVA function, using guided breathing for low (7.5 breaths min−1) and high (15 breaths min−1) breathing rates, demonstrate the ReCIVA device shows no statistical difference among breathing rates for quantitated isoprene (p > 0.05). Global metabolomics analysis of the guided breathing rate data shows more than 87% of the z-scores, comparing high and low breathing rates using both the Tenax and the 5TD tubes, are below the level for significance. Finally, data are provided from a single participant who displayed background levels of isoprene while illustrating levels of acetone consistent with the remaining participants. Collectively, these data support the use of multiple ReCIVA devices for exhaled breath collection and provide evidence for an instance where exhaled isoprene is consistent with background levels.

Breath Analysis: Comparison among Methodological Approaches for Breath Sampling

“…Taking into account that the values of ratios between a normalized peak area of the most of VOCs detected in ambient air samples (AA) collected by using Mistral were even more than four times higher than those determined in AA samples simultaneously collected by ReCIVA ( Figure 4 ), further investigations are needed to deepen the sampling performances and technical characteristics of ReCIVA. In fact, these results confirm the preliminary ones obtained by Harshaman et al for the isoprene comparing ReCIVA with Altef Bag and two different ReCIVA devices [ 32 , 33 ]. Although the previously mentioned authors recommended an impractical “in-house” flow calibration for each TD tube type and each ReCIVA bank used for collection, in our opinion, a better and online flow mass control should be installed in a ReCIVA device in order to correct the variability in real time associated with the flow impedance through TD tubes.…”

“…Although the previously mentioned authors recommended an impractical “in-house” flow calibration for each TD tube type and each ReCIVA bank used for collection, in our opinion, a better and online flow mass control should be installed in a ReCIVA device in order to correct the variability in real time associated with the flow impedance through TD tubes. Moreover, although Harshaman et al [ 33 ] in their subsequent study found that the data related to isoprene concentrations resulted in comparable values between two different ReCIVA units, guaranteeing the comparability of results obtained by ReCIVA until now. Further investigations should be performed in order to evaluate their comparability while both considering a wide range of VOCs and with the other studies on breath analysis conducted so far, using bags.…”

“…Although the ReCIVA and Mistral devices represent a significant step toward easy and effective exhaled breath sampling, the cost of these devices is not comparable with exhaled breath bags. Moreover, until now, only two studies focused only on isoprene for ReCIVA [ 32 , 33 ] and none for Mistral were conducted aiming to assess the performances of these devices and their comparability with the most diffuse breath sampling method based on a bag’s use. Therefore, the ambitious aim of this study is to compare, for the first time, three different breath sampling approaches and, more specifically, the whole breath sampling by means Tedlar bags, the end-tidal breath collection using a Mistral sampler, and the simultaneous sampling of the whole and alveolar breath by using ReCIVA.…”

Beyond liquid biopsy: Toward non-invasive assays for distanced cancer diagnostics in pandemics

“…Respiratory droplets are generally collected has exhaled breath condensate by asking the patient to exhale steadily and slowly at a normal breathing rate for 5 min into a dedicated device. This could be represented by a gas sampling bag, usually made of polypropylene or PTFE or Teflon or devices holding an adsorbent pad able to fix VOC molecules ( Harshman et al, 2020 ). This method could be a double-edged sword in times of pandemics, as most of them are disposable objects, but some others which contain only a disposable portion should be carefully sterilized, as they come in contact with aerosols which can be the vectors for Sars-CoV 2 particles.…”

3D-printed mouthpiece adapter for sampling exhaled breath in medical applications

“…Due to the broad nature of breath research, whereby a wide variety of analytical technologies are used to target an extensive range of compounds for a diverse assortment of illnesses, a standardised approach to sampling for off-line analysis does not exist [ 26 ]. Off-line sampling methods include the collection of breath into inflatable bags, or its collection and pre-concentration onto adsorbent materials, allowing for trace level detection of breath-borne volatiles [ 27 ]. The most common approach utilises thermal desorption (TD) tubes – i.e., hollow tubes containing an adsorbent material with a high affinity to organic compounds – for sample collection, which are then interfaced with a gas chromatography-mass spectrometry (GC-MS) analyser, whereby the tubes are heated to liberate the trapped compounds into the analyser, i.e., thermal desorption, to enable their subsequent detection [ 28 ].…”