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Diagnosis of hidden bronchial obstruction using computer‐assessed tracheal forced expiratory noise time
Author(s) -
Pochekutova Irina A.,
Korenbaum Vladimir I.
Publication year - 2013
Publication title -
respirology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 85
eISSN - 1440-1843
pISSN - 1323-7799
DOI - 10.1111/resp.12035
Subject(s) - medicine , spirometry , asthma , vital capacity , receiver operating characteristic , airway obstruction , cardiology , surgery , airway , lung , diffusing capacity , lung function
Background and objective Increased forced expiratory time was first recognized as a marker of obstruction half a century ago. However, the reported diagnostic capabilities of both auscultated forced expiratory time ( FET as ) and spirometric forced expiratory time are contradictory. Computer analysis of respiratory noises provides a precise estimation of acoustic forced expiratory noise time ( FET a ) being the object‐measured analogue of FET as . The aim of this study was to analyse FET a diagnostic capabilities in patients with asthma based on the hypothesis that FET a could reveal hidden bronchial obstruction. Methods A group of asthma patients involved 149 males aged 16–25 years. In this group, 71 subjects had spirometry features of bronchial obstruction, meanwhile, the remaining 78 had normal spirometry. A control group involved 77 healthy subjects. Spirometry and forced expiratory tracheal noise recording were sequentially measured for each participant. FET a values were estimated by means of a developed computer procedure, including bandpass filtration (200–2000 Hz ), waveform envelope calculation with accumulation period of 0.01 s, automated measurement of FET a at 0.5% level from the peak amplitude. Results Specificity, sensitivity and area under Receiver Operating Characteristic curve of FET a and its ratios to squared chest circumference, height, weight were indistinguishable with baseline spirometry index FEV 1 /forced vital capacity. Meanwhile, acoustic features of obstruction were revealed in 41%–49% of subgroup of patients with asthma but normal spirometry. Conclusions FET a of tracheal noise and its ratio to anthropometric parameters seem to be sensitive and specific tests of hidden bronchial obstruction in young male asthma patients.