| Title: | Exhaled isoprene for monitoring recovery from acute hypoxic stress |
| Author(s): | Harshman SW; Geier BA; Qualley AV; Drummond LA; Flory LE; Fan M; Pitsch RL; Grigsby CC; Phillips JB; Martin JA; |
| Address: | "UES Inc., Air Force Research Laboratory, 711th Human Performance Wing/RHXBC, 2510 Fifth Street, Area B, Building 840, Wright- Patterson AFB, OH 45433, United States of America" |
| ISSN/ISBN: | 1752-7163 (Electronic) 1752-7155 (Linking) |
| Abstract: | "Hypoxia-like incidents in-flight have increased over the past decade causing severe safety concerns across the aviation community. As a result, the need to monitor flight crews in real-time for the onset of hypoxic conditions is paramount for continued aeronautical safety. Here, hypoxic events were simulated in the laboratory via a reduced oxygen-breathing device to determine the effect of recovery gas oxygen concentration (21% and 100%) on exhaled breath volatile organic compound composition. Data from samples collected both serially (throughout the exposure), prior to, and following exposures yielded 326 statistically significant features, 203 of which were unique. Of those, 72 features were tentatively identified while 51 were verified with authentic standards. A comparison of samples collected serially between recovery and hypoxia time points shows a statistically significant reduction in exhaled breath isoprene (2-methyl-1,3-butadiene, log(2) FC -0.399, p = 0.005, FDR = 0.034, q = 0.033), however no significant difference in isoprene abundance was observed when comparing recovery gases (21% or 100% O(2), p = 0.152). Furthermore, examination of pre-/post-exposure 1 l bag breath samples illustrate an overall increase in exhaled isoprene abundance post-exposure (log(2) FC 0.393, p = 0.005, FDR = 0.094, q = 0.033) but again no significant difference between recovery gas (21% and 100%, p = 0.798) was observed. A statistically significant difference in trend was observed between isoprene abundance and recovery gases O(2) concentration when plotted against minimum oxygen saturation (p = 0.0419 100% O(2), p = 0.7034 21% O(2)). Collectively, these results suggest exhaled isoprene is dynamic in the laboratory ROBD setup and additional experimentation will be required to fully understand the dynamics of isoprene in response to acute hypoxic stress" |
| Keywords: | "Adult Breath Tests/*methods Butadienes/*analysis *Exhalation Hemiterpenes/*analysis Humans Hypoxia/blood/*diagnosis Male Oxygen/blood Pentanes/*analysis Reference Standards *Stress, Physiological Time Factors Young Adult;" |
| Notes: | "MedlineHarshman, Sean W Geier, Brian A Qualley, Anthony V Drummond, Leslie A Flory, Laura E Fan, Maomian Pitsch, Rhonda L Grigsby, Claude C Phillips, Jeffrey B Martin, Jennifer A eng Clinical Trial England 2017/10/12 J Breath Res. 2017 Nov 29; 11(4):047111. doi: 10.1088/1752-7163/aa927d" |
