Exhaled breath compositions under varying respiratory rhythms reflects ventilatory variations: translating breathomics towards respiratory medicine

Abstract

control of breathing is automatic and its regulation is keen to autonomic functions. therefore, involuntary and voluntary nervous regulation of breathing affects ventilatory variations, which has profound potential to address expanding challenges in contemporary pulmonology. nonetheless, the fundamental attributes of the aforementioned phenomena are rarely understood and/or investigated. implementation of unconventional approach like breathomics may leads to a better comprehension of those complexities in respiratory medicine. We applied breath-resolved spirometry and capnometry, non-invasive hemodynamic monitoring along with continuous trace analysis of exhaled Vocs (volatile organic compounds) by means of real-time mass-spectrometry in 25 young and healthy adult humans to investigate any possible mirroring of instant ventilatory variations by exhaled breath composition, under varying respiratory rhythms. Hemodynamics remained unaffected. Immediate changes in measured breath compositions and corresponding variations occurred when respiratory rhythms were switched between spontaneous (involuntary/unsynchronised) and/or paced (voluntary/synchronised) breathing. Such changes in most abundant, endogenous and bloodborne Vocs were closely related to the minute ventilation and end-tidal co 2 exhalation. Unprecedentedly, while preceded by a paced rhythm, spontaneous rhythms in both independent setups became reproducible with significantly (P-value ≤ 0.005) low intra-and inter-individual variation in measured parameters. We modelled breath-resolved ventilatory variations via alveolar isoprene exhalation, which were independently validated with unequivocal precision. Reproducibility i.e. attained via our method would be reliable for human breath sampling, concerning biomarker research. thus, we may realize the actual metabolic and pathophysiological expressions beyond the everlasting in vivo physiological noise. consequently, less pronounced changes are often misinterpreted as disease biomarker in cross-sectional studies. We have also provided novel information beyond conventional spirometry and capnometry. Upon clinical translations, our findings will have immense impact on pulmonology and breathomics as they have revealed a reproducible pattern of ventilatory variations and respiratory homeostasis in endogenous Voc exhalations. Human breath is a timeless source of in vivo metabolic, physiological/pathophysiological information, especially for lung conditions 1-3. Practice in pulmonology and breathomics have gradually encountered ubiquitous confounders; among which subject's own respiratory physiology associated variations (intra-/inter-individual) are crucial and evident 4-6. As breathomics suffered from insufficient fundamental knowledge on the effects of ventilatory variations, despite many efforts, pilot findings differed during independent validations. Thereby, breathomics

Is a Mask That Covers the Mouth and Nose Free from Undesirable Side Effects in Everyday Use and Free of Potential Hazards?

“…For nitrogen oxides [ 47 ] and hydrogen sulfide [ 46 ], pathological effects relevant to disease have been described in environmental medicine even at a low but chronic exposure [ 46 , 47 , 48 ]. Among the volatile organic compounds in exhaled air, acetone and isoprene dominate in terms of quantity, but allyl methyl sulfide, propionic acid and ethanol (some of bacterial origin) should also be mentioned [ 171 ]. Whether such substances also react chemically with each other underneath masks and in the dead space volume created by masks ( Figure 3 ), and with the mask tissue itself, and in what quantities these and possible reaction products are rebreathed, has not yet been clarified.…”

Deficiency and absence of endogenous isoprene in adults, disqualified its putative origin

“…After 1 min of metronome controlled paced breathing (respiratory rate = 12/min) subjects performed spontaneous breathing for five more minutes. This sampling protocol significantly reduces ventilatory variations and breath samples from 3 rd minute (of spontaneous rhythm) onward were considered for analysis [ 36 ].…”

Identification of Metabolic Pathway Dysregulation in Diabetic Retinopathy: A Propensity Score-Matched Metabolomic Study

“…Though benzene homologues are not notably enriched in metabolic pathways, they are observed to be abnormally increased in DR-related metabolic network. Considering the existence potentially due to external sources, the module is not fully elaborated in this study (40).…”