BackgroundWhile assumed to protect against coronavirus transmission, face-masks may have effects on respiratory-haemodynamic parameters. Within this pilot study, we investigated immediate and progressive effects of FFP2 and surgical masks on exhaled breath constituents and physiological attributes in 30 adults at rest.MethodsWe continuously monitored exhaled breath profiles within mask space in older (age: 60–80 years) and young to mid-aged (age: 20–60 years) adults over the period of 15 and 30 min, respectively by high-resolution real-time mass-spectrometry (PTR-ToF-MS). Peripheral oxygen saturation, respiratory- and haemodynamic parameters were measured (non-invasively) simultaneously.ResultsProfound, consistent and significant (p-value≤0.001) changes in SpO2 (Adults>60_FFP2-15 min: 5.8±1.3%↓, Adults>60_surgical-15 min: 3.6±0.9%↓, Adults<60_FFP2-30 min: 1.9±1.0%↓, Adults<60_surgical-30 min: 0.9±0.6%↓) and pET-CO2 (Adults>60_FFP2-15 min: 19.1±8.0%↑, Adults>60_surgical-15 min: 11.6±7.6%↑, Adults<60_FFP2- 30 min: 12.1±4.5%↑, Adults<60_surgical- 30 min: 9.3±4.1%↑) indicate ascending deoxygenation and hypercarbia. Secondary changes (p-value≤0.005) to hemodynamic parameters (e.g. MAP: Adults>60_FFP2-15 min: 9.8±10.4%↑) were found. Exhalation of blood-borne volatile metabolites e.g. aldehydes, hemiterpene, organosulfur, short-chain fatty acids, alcohols, ketone, aromatics, nitrile and monoterpene mirrored behaviour of cardiac output, MAP, SpO2, respiratory rate and pET-CO2. Exhaled humidity (e.g. Adults>60_FFP2-15 min: 7.1±5.8%↑) and exhaled oxygen (e.g. Adults>60_FFP2-15 min: 6.1±10.0%↓) changed significantly (p-value≤0.005) over time.ConclusionsBreathomics allows unique physio-metabolic insights into immediate and transient effects of face-mask wearing. Physiological parameters and breath profiles of endogenous and/or exogenous volatile metabolites indicated putative cross-talk between transient hypoxemia, oxidative stress, hypercarbia, vasoconstriction, altered systemic microbial activity, energy homeostasis, compartmental storage and washout. FFP2 masks affected more pronouncedly than surgical masks. Older adults were more vulnerable to FFP2 mask induced hypercarbia, arterial oxygen decline, blood pressure fluctuations and concomitant physiological and metabolic effects.

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While protecting against the coronavirus transmission, face-masks may have adverse effects on respiratory-haemodynamic parameters. We investigated immediate and progressive effects of FFP2 and surgical masks on exhaled breath constituents and physiological attributes in 30 healthy volunteers at rest. We continuously monitored exhaled breath profiles in the mask space in elderly (age: 60–80 years) and adults (age: 20–60 years) over a period of 30 min by high-resolution real-time mass-spectrometry (PTR-ToF-MS). Peripheral oxygen saturation, respiratory- and haemodynamic parameters were measured (non-invasively) continuously in parallel. Profound and consistent decrease in SpO2 and increase in pET-CO2 indicates ascending deoxygenation and inadequate ventilation in subjects. Cardiac output and MAP changed as secondary. Exhalation of blood-borne volatile metabolites mirrored behaviour of cardiac output, MAP, SpO2, respiratory rate and pET-CO2. FFP2 masks affected more pronouncedly than surgical masks. Elderly cohort was more vulnerable to those effects. Exhaled humidity increased and exhaled oxygen decreased significantly over time. Breath profiles of endogenous aldehydes, hemiterpene, organosulfur, short-chain fatty acids, alcohols and ketone indicated cross-talks between physio-metabolic effects such as hypoxia, oxidative stress, hypoventilation, compartmental vasoconstriction, altered systemic bacterial activity and energy homeostasis. Concentrations of exogenous VOCs such as aromatics, nitrile and monoterpene depicted compartmental storage and washout. Breathomics allows unique physio-metabolic insights into side effects of face-mask wearing. Mask induced deoxygenation, oxidative stress, CO2 rebreathing, vasoconstriction and blood pressure fluctuations in elderly were clinically concerning (as leading towards hypoxia and hypoventilation). Intelligible global-pandemic policies should reconsider the type and wearing durations of recommended face-masks, based upon age and/or cardio-pulmonary conditions.

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Background Due to their immediate exhalation after generation at the cellular/microbiome levels, exhaled volatile organic compounds (VOCs) may provide real-time information on pathophysiological mechanisms and host response to infections. In recent years, metabolic profiling of most frequent respiratory infection gained interest as it holds potential for early non-invasive detection of pathogens and monitoring of disease progression and response to therapy. Methods In contrast to previous studies with pre-selected patient groups, we conducted a real-time mass-spectrometry based breath profiling in hundreds of consecutive subjects under an actual respiratory infection screening scenario. Recruited subjects were grouped for further comparisons, based on multiplex-PCR confirmed infection (infected by common respiratory pathogen(s) and healthy) and presence or absence of flu like symptoms. Results Amongst recruitments, we obtained 256 healthy cases and 223 infected/coinfected (171 mono-infections, 52 coinfections) with Haemophilus influenza, Streptococcus pneumoniae and Rhinovirus. We observed multiple effects of these mono-infections and co-infections onto the exhaled VOC profiles and variations, especially on endogenous ketone, short-chain fatty acid, organosulfur, aldehyde and terpene concentrations. Based on VOCs origins, we encountered changes in patient’s energy metabolism, systemic microbial immune homeostasis, inflammation, oxidative stress and antioxidative defense. Presence of bacterial pathogens depicted more complex metabolic effects and cross-talk – most likely due to their own metabolism. Conclusion Alike our recent reports on COVID-19 and in line with other recent multi-omics and clinical microbiological reports, these results offered unique insight into common respiratory infections, pathogenesis, ‘host-microbiome-pathogen’ interactions. Breathomics depicted the non-invasive potential for ‘monitoring’ respiratory mono-infections and coinfections.