Experience of the use of bronchophonography in the diagnosis of hyperventilation syndrome

Aim. To study the capability of applying the method of acoustic analysis of respiration (bronchophonography) in the diagnosis of hyperventilation syndrome and mild bronchial asthma and in differential diagnosis between them. Methods. 97 subjects were examined (35 men and 62 women, average age 36.4±13.4 years), divided into the groups: control (healthy subjects) - 38 subjects (18 men and 20 women, average age 33.6±14.0 years), patients with mild bronchial asthma - 37 subjects (12 men and 25 women, average age 40.7±13.7 years), patients with hyperventilation syndrome - 22 subjects (5 men and 17 women, average age 35.0±12.6 years). All patients, except for general clinical examination, underwent spirometry, bronchophonography and Nijmegen questionnaire. Results. Acoustic breathing patterns of all groups were formed, spirometric and bronchophonographic indicators were analyzed. Bronchophonography revealed significant intergroup differences in different frequency ranges in groups of patients with bronchial asthma and hyperventilation syndrome as well as the absence of those between healthy individuals and patients with hyperventilation syndrome. At the same time, the data of spirometry did not allow differentiation of mild bronchial asthma and hyperventilation syndrome and in most cases did not differ from those of healthy individuals. Conclusion. Spirometry cannot serve as a reliable diagnostic criterion in the diagnosis and differential diagnosis of hyperventilation syndrome and mild bronchial asthma; differences in acoustic indices of respiration in bronchophonography allow such differentiation.