the smell of hypoxia: using an electronic nose at altitude and proof of concept of its role in the prediction and diagnosis of acute mountain sickness
低氧氣味：在高海拔地區(qū)使用電子鼻，并證明其在急性高山病的預(yù)測(cè)和診斷中的作用
jonathan r. n. lacey carlos kidel jildou m. van der kaaij paul brinkman edward t. gilbert‐kawai michael p. w. grocott michael g. mythen daniel s. martin for the xtreme everest 2 research group
abstract
electronic nose (e‐nose) devices may be used to identify volatile organic compounds (vocs) in exhaled breath. vocs generated via metabolic processes are candidate biomarkers of (patho)physiological pathways. we explored the feasibility of using an e‐nose to generate human “breathprints” at high altitude. furthermore, we explored the hypothesis that pathophysiological processes involved in the development of acute mountain sickness (ams) would manifest as altered voc profiles. breath analysis was performed on sherpa and lowlander trekkers at high altitude (3500 m). the lake louise scoring (lls) system was used to diagnose ams. raw data were reduced by principal component (pc) analysis (pca). cross validated linear discriminant analysis (cv‐lda) and receiver‐operating characteristic area under curve (roc‐auc) assessed discriminative function. breathprints suitable for analysis were obtained from 58% (37/64) of samples. pca showed significant differences between breathprints from participants with, and without, ams; cv‐lda showed correct classification of 83.8%, roc‐auc 0.86; pc 1 correlated with ams severity. there were significant differences between breathprints of participants who remained ams negative and those whom later developed ams (cv‐lda 68.8%, roc‐auc 0.76). pca demonstrated discrimination between sherpas and lowlanders (cv‐lda 89.2%, roc‐auc 0.936). this study demonstrated the feasibility of breath analysis for vocs using an e‐nose at high altitude. furthermore, it provided proof‐of‐concept data supporting e‐nose utility as an objective tool in the prediction and diagnosis of ams. e‐nose technology may have substantial utility both in altitude medicine and under other circumstances where (mal)adaptation to hypoxia may be important (e.g., critically ill patients).
電子鼻(e-nose)裝置可用于識(shí)別呼出氣體中的揮發(fā)性有機(jī)化合物(voc)。通過(guò)代謝過(guò)程產(chǎn)生的voc是(病理)生理途徑的候選生物標(biāo)志物。我們探討了在高空使用電子鼻產(chǎn)生人類(lèi)“呼吸印記”的可行性。此外，我們還探討了一種假說(shuō)，即參與急性山病(ams)發(fā)展的病理生理過(guò)程表現(xiàn)為voc圖譜的改變。對(duì)海拔3500米的夏爾巴和低地徒步者進(jìn)行呼吸分析。路易斯湖評(píng)分(lls)系統(tǒng)用于診斷ams。通過(guò)主成分分析(pca)減少原始數(shù)據(jù)。交叉驗(yàn)證線性鑒別分析(cv-lda)和曲線下接收器操作特征面積(roc-auc)評(píng)估了鑒別功能。從58%(37/64)的樣本中獲得適合分析的呼吸圖?；加泻筒换加衋ms的參與者的呼吸圖pca顯示出顯著差異；cv-lda顯示出83.8%的正確分類(lèi)，roc-auc 0.86；pc 1與ams嚴(yán)重程度相關(guān)。仍為ams陰性的受試者和后來(lái)發(fā)展為ams的受試者的呼吸圖存在顯著差異(cv-lda 68.8%，roc-auc 0.76)。pca顯示夏爾巴人和低地人之間存在歧視(cv-lda 89.2%，roc-auc 0.936)。本研究證明了在高空使用電子鼻進(jìn)行揮發(fā)性有機(jī)化合物呼吸分析的可行性。此外，它還提供了概念驗(yàn)證數(shù)據(jù)，支持電子鼻作為預(yù)測(cè)和診斷ams的客觀工具。電子鼻技術(shù)在高原醫(yī)學(xué)和其他對(duì)低氧適應(yīng)很重要的情況下(如危重病患者)都有很大的實(shí)用性。
figure 1. photograph of e-nose (cyranose 320) and breath analysis apparatus.