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Accession number;03A0567698
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| Title;Spectral Changes in Normal Breath Sounds Associated with Bronchodilator Response in Asthmatic Children |
| Author;
TAKASE MASATO
(Nihon'idai Tamanagayamabyoin Shonika)
SHIROTA KAZUHIKO
(Nihon'idai Tamanagayamabyoin Shonika)
IMAI TAKEHIDE
(Nihon'idai Tamanagayamabyoin Shonika)
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Journal Title;Clinical Pharmacology and Therapy
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Journal Code:L1701A
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ISSN:0917-3994
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VOL.13;NO.4;PAGE.339-346(2003)
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| Figure&Table&Reference;FIG.3, REF.4 |
| Pub. Country;Japan |
| Language;Japanese |
| Abstract;Background: Spectral analysis of inspiratory normal breath sounds (without wheezes) in asthmatic children often reveals attenuation of low frequency power (Plow: <300Hz) and accentuation of high frequency power (Phigh: >600Hz), which would result in an elevation of the spectral edge frequency (SEF). Such an abnormality is usually irreversible and could be normalized after bronchodilator inhalation (BI). Methods: We analyzed 58 pairs of lung sound recordings (with 2 contact sensors stuck on the right upper chest and the right lower back) from 35 asthmatic children (6-15y/o), before and after BI (salbutamol 200.MU.g). Method of recording and analysis was identical with our past reports. Results: Relationship between SEF and %FEF25-75 did not change before and after BI (r=-0.6576). Larger reductions in SEF were observed in cases with higher baseline SEF (r=-0.8529). After BI, Plow was increased in 85% of the cases, however, there were no relations between Plow and SEF. There were significant positive correlations between Phigh and SEF before and after BI (r=0.6256,r=0.4784). The changes in SEF were also correlated with the changes in Phigh (r=0.6004). Conclusion: Bronchodilator inhalation weakens and normalizes high frequency power, reflecting the presence of reversible airway narrowing. Low frequency power increased without relation to SEF, which may indicate increased low frequency sound transmission due to decreased airway wall tone by bronchodilator. (author abst.) |
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