Use of an electronic nose to identify asthma in subjects with respiratory symptoms: from bench to bedside

• Autor(a) principal: Farraia, Mariana Valente
• Data de Publicação: 2018
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10773/24473
• topic: Electronic nose; Exhaled breath; Asthma; Diagnosis; Cyranose 320; Volatile organic compounds

Exhaled breath volatile organic compounds (VOC) have shown promising results when discriminating individuals with asthma from healthy controls. This study aims to provide a systematic review of the use of electronic nose (eNose) technology to diagnosis diseases and to assess if the exhaled VOC analysis using an eNose may be applied to identify individuals with asthma in a population with respiratory symptoms. A systematic search for published studies using the eNose as a diagnostic tool in medicine was performed. Then, a cross-sectional study was conducted and breath samples from 199 participants recruited from an outpatient clinic were collected and analysed using an electronic nose composed by 32 sensors (Cyranose 320®). Lung function parameters and CARAT questionnaire to assess level of control of airways disease were performed. A multivariate cluster analysis model, using resistance data from the 32 sensors, was built to discriminate the VOC patterns between individuals separating the population in 2 clusters. Adjusted generalized linear models (GLM) for confounders were used to test the developed model. Forty-eight studies were selected for qualitative analysis and Cyranose 320® was the most used device. Proof-of-concept studies were already performed in several diseases and good accuracy values (CVV>80%) for some respiratory diseases, like asthma and COPD, were found. Regarding the cross-sectional study, study population was composed by 67.8% of individuals with a medical diagnosis of asthma. Smell-prints were able to distinguish participants with uncontrolled asthma-like symptoms from those with controlled symptoms (p= 0.01). Individuals with symptoms of uncontrolled airways disease were discernible using the developed hierarchical cluster model. The results from the revised studies suggests that eNoses can be promising diagnostic devices. However, confirmatory clinical trials in intend-to-treat populations are urgent. In a population with respiratory diseases, the analysis of the VOC profile by eNose may be used as a fast and non-invasive complementary diagnostic agent for screening individuals in search of uncontrolled asthma-like symptoms. This may lead to an enhanced management and treatment of disease and encourages the design of confirmatory trials