Specific Metabolome Profile of Exhaled Breath Condensate in Patients with Shock and Respiratory Failure: A Pilot Study

Abstract

Background: Shock includes different pathophysiological mechanisms not fully understood and remains a challenge to manage. Exhaled breath condensate (EBC) may contain relevant biomarkers that could help us make an early diagnosis or better understand the metabolic perturbations resulting from this pathological situation. Objective: we aimed to establish the metabolomics signature of EBC from patients in shock with acute respiratory failure in a pilot study. Material and methods: We explored the metabolic signature of EBC in 12 patients with shock compared to 14 controls using LC-HRMS. We used a non-targeted approach, and we performed a multivariate analysis based on Orthogonal Partial Least Square-Discriminant Analysis (OPLS-DA) to differentiate between the two groups of patients. Results: We optimized the procedure of EBC collection and LC-HRMS detected more than 1000 ions in this fluid. The optimization of multivariate models led to an excellent model of differentiation for both groups (Q2 > 0.4) after inclusion of only 6 ions. Discussion and conclusion: We validated the procedure of EBC collection and we showed that the metabolome profile of EBC may be relevant in characterizing patients with shock. We performed well in distinguishing these patients from controls, and the identification of relevant compounds may be promising for ICC patients.

Evolution of ARDS biomarkers: Will metabolomics be the answer?

“…Although the use of biological fluid metabolites for diagnosis of medical conditions has been in existence since ancient times, modern metabolomics analysis began in the mid-1980s with the development of higher-sensitivity nuclear magnetic resonance spectroscopes (47). Metabolites are small molecules up to~1,000 Da and include a spectrum of compounds such as organic acids, amino acids, carbohydrates, peptides, vitamins, steroids, and xenobiotics, among others (24). The fundamental premise in metabolomics analyses is that changes, whether physiological or pathological, cause alterations in the metabolome that are detected as variations in metabolite concentrations.…”

The influence of active and passive air humidification on exhaled breath condensate volume

“…In this regard, F ermier et al . [ 21 ] performed an EBC metabolomics study in which they accurately discriminated critically ill MV patients and MV surgical patients. The investigators, however, reported conflicting values of EBC yield (1 mL versus 2–3 mL per 20 min in their Methods and Results section, respectively, with no assignment to patient groups) and did not report the conditions of air humidification in their patient groups.…”

“…The lack of humidification guidelines has resulted in inconsistent methodologies in studies of EBC from MV patients. While some investigators have collected EBC with ongoing air humidification [ 8 – 12 ], others have removed the humidifier from the ventilatory circuit prior to sample collection [ 13 – 20 ], and yet others have not reported their humidification conditions [ 21 – 29 ]. Importantly, M üller et al .…”

Metabolomics in chronic lung diseases

“…Towards the discovery of biomarkers and in the pursuit of improved disease characterization, metabolomics has been employed in lung diseases to study a large number of sample types including urine, plasma and serum, cerebrospinal fluid, exhaled breath condensate (EBC), bronchoalveolar lavage fluid (BALF), saliva, intact tissue as well as cells and their extracts. Urine and blood are the most commonly used biofluids for metabolomic studies as both samples contain thousands of detectable metabolic features and can be collected using minimally invasive methods.…”