Analysis of Exhaled Breath Condensate pH in Asthma among Indian Population: A Pilot Study

Abstract

Introduction: Asthma is an inflammatory disorder of lungs and analysis of Exhaled Breath Condensate (EBC) pH may give insights on control of asthma. To the best of our knowledge, this is the first study of EBC pH among Indian population. Aim: To study EBC pH among asthmatics in Indian population. Materials and Methods: In this cross-sectional study, EBC pH was compared with the control of asthma as well as severity of obstruction. There were 17 males and 33 females of bronchial asthma without exacerbation in a tertiary care hospital of a metro city. EBC pH was measured without deaeration using the Arterial Blood Gas (ABG) analyser and a pH electrode. Severity of asthma was defined as per Global Initiative of Asthma (GINA) guidelines into mild, moderate and severe based on treatment required to maintain control over asthma. Results: Mean age of participants was 36 years. Mean EBC pH of the study participants was 7.341. Mean EBC pH in males was 7.391. Mean EBC pH in females was 7.316. Mean EBC pH among well controlled asthmatics was 7.330. Mean EBC pH among partially controlled asthmatics was 7.354. There was no significant correlation between EBC pH in well controlled and partially controlled asthmatics (p=0.71). Among subjects with normal spirometry, mean EBC pH was 7.34. Mean EBC pH among patients with moderate obstruction was 7.30. There was a consistent difference in pH of EBC when measured by a pH electrode as compared to ABG machine. Samples measured by pH electrode were acidic by pH difference of 0.8. Conclusion: We found no correlation of EBC pH with asthma control. Method used for testing pH of EBC affects the result and has to be considered while interpreting studies.

Keywords

• bronchial asthma
• breath analysis
• spirometry