In:
Journal of Applied Physiology, American Physiological Society, Vol. 64, No. 4 ( 1988-04-01), p. 1387-1396
Abstract:
We investigated the relationship between the site of airway obstruction and the frequency dependence (FD) of lung acoustic impedance (ZL). The real (RL) and imaginary (XL) parts of ZL were measured by forced random noise in excised left pig lungs, before (base line) and after 1) no airway obstruction (controls, n = 10), 2) insufflation of 1-mm (B1, n = 5) or 2-mm (B2, n = 7) beads, and 3) partial reversible obstruction of lower lobar (LL) and then main-stem (MS) bronchus (n = 4). The beads caused both partial and total obstruction of airways with internal diameters of 2 mm (B1) and 2-6 mm (B2). Compared with base line, a negative FD of RL appeared from 4 to 10 Hz in LL, B1, and B2 obstructions. The FD of XL greater than 20 Hz increased in MS and LL obstruction exclusively and was the ZL feature that most clearly differentiated central from peripheral obstruction. In this experimental model, the anatomic limit distal from which obstruction no longer causes the "central" type of ZL change lies in airways with internal diameters notably greater than 2 mm.
Type of Medium:
Online Resource
ISSN:
8750-7587
,
1522-1601
DOI:
10.1152/jappl.1988.64.4.1387
Language:
English
Publisher:
American Physiological Society
Publication Date:
1988
detail.hit.zdb_id:
1404365-8
SSG:
12
SSG:
31
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