Airway closure and reopening assessed by the alveolar capsule oscillation technique

David R. Otis, F. Peták, Z. Hantos, Jeffrey J. Fredberg, Roger D. Kamm

Research output: Contribution to journalArticle

39 Citations (Scopus)

Abstract

An alveolar capsule oscillation technique was used to determine 1) the lobe pressure and volume at which airways close and reopen, 2) the effect of expiration rate on closing volume and pressure, 3) the phase in the breathing cycle at which airway closure occurs, and 4) the site of airway closure. Experiments were conducted in excised dog lobes; closure was detected by an abrupt increase in the input impedance of surface-mounted alveolar capsules. Mean transpulmonary pressure (Ptp) at closure was slightly less than zero (Ptp = -2.3 cmH2O); the corresponding mean reopening pressure was Ptp = 14 cmH2O. The expiration rate varied between i and 20% of total lobe capacity per second and had no consistent effect on the closing volume and pressure. When lung volume was cycled up to frequencies of 0.2 Hz, closure generally occurred on expiration rather than inspiration. These observations support the conclusion that mechanical collapse, rather than meniscus formation, is the most likely mechanism producing airway closure in normal excised dog lungs. Analysis of measured acoustic impedances and reopening pressures suggests that closure occurs in the most peripheral airways. Reopening during inspiration was often observed to consist of a series of stepwise decreases in capsule impedance, indicating a sequence of opening events.

Original languageEnglish
Pages (from-to)2077-2084
Number of pages8
JournalJournal of Applied Physiology
Volume80
Issue number6
Publication statusPublished - Jun 1996

Fingerprint

Capsules
Pressure
Closing Volume
Electric Impedance
Dogs
Lung
Acoustics
Respiration

Keywords

  • airway liquid lining
  • alveolar capsule technique
  • closing capacity
  • closing volume
  • residual volume

ASJC Scopus subject areas

  • Physiology
  • Endocrinology
  • Orthopedics and Sports Medicine
  • Physical Therapy, Sports Therapy and Rehabilitation

Cite this

Airway closure and reopening assessed by the alveolar capsule oscillation technique. / Otis, David R.; Peták, F.; Hantos, Z.; Fredberg, Jeffrey J.; Kamm, Roger D.

In: Journal of Applied Physiology, Vol. 80, No. 6, 06.1996, p. 2077-2084.

Research output: Contribution to journalArticle

Otis, David R. ; Peták, F. ; Hantos, Z. ; Fredberg, Jeffrey J. ; Kamm, Roger D. / Airway closure and reopening assessed by the alveolar capsule oscillation technique. In: Journal of Applied Physiology. 1996 ; Vol. 80, No. 6. pp. 2077-2084.
@article{d325f0501e6246acbc378b1a1dc3cd70,
title = "Airway closure and reopening assessed by the alveolar capsule oscillation technique",
abstract = "An alveolar capsule oscillation technique was used to determine 1) the lobe pressure and volume at which airways close and reopen, 2) the effect of expiration rate on closing volume and pressure, 3) the phase in the breathing cycle at which airway closure occurs, and 4) the site of airway closure. Experiments were conducted in excised dog lobes; closure was detected by an abrupt increase in the input impedance of surface-mounted alveolar capsules. Mean transpulmonary pressure (Ptp) at closure was slightly less than zero (Ptp = -2.3 cmH2O); the corresponding mean reopening pressure was Ptp = 14 cmH2O. The expiration rate varied between i and 20{\%} of total lobe capacity per second and had no consistent effect on the closing volume and pressure. When lung volume was cycled up to frequencies of 0.2 Hz, closure generally occurred on expiration rather than inspiration. These observations support the conclusion that mechanical collapse, rather than meniscus formation, is the most likely mechanism producing airway closure in normal excised dog lungs. Analysis of measured acoustic impedances and reopening pressures suggests that closure occurs in the most peripheral airways. Reopening during inspiration was often observed to consist of a series of stepwise decreases in capsule impedance, indicating a sequence of opening events.",
keywords = "airway liquid lining, alveolar capsule technique, closing capacity, closing volume, residual volume",
author = "Otis, {David R.} and F. Pet{\'a}k and Z. Hantos and Fredberg, {Jeffrey J.} and Kamm, {Roger D.}",
year = "1996",
month = "6",
language = "English",
volume = "80",
pages = "2077--2084",
journal = "Journal of Applied Physiology",
issn = "0161-7567",
publisher = "American Physiological Society",
number = "6",

}

TY - JOUR

T1 - Airway closure and reopening assessed by the alveolar capsule oscillation technique

AU - Otis, David R.

AU - Peták, F.

AU - Hantos, Z.

AU - Fredberg, Jeffrey J.

AU - Kamm, Roger D.

PY - 1996/6

Y1 - 1996/6

N2 - An alveolar capsule oscillation technique was used to determine 1) the lobe pressure and volume at which airways close and reopen, 2) the effect of expiration rate on closing volume and pressure, 3) the phase in the breathing cycle at which airway closure occurs, and 4) the site of airway closure. Experiments were conducted in excised dog lobes; closure was detected by an abrupt increase in the input impedance of surface-mounted alveolar capsules. Mean transpulmonary pressure (Ptp) at closure was slightly less than zero (Ptp = -2.3 cmH2O); the corresponding mean reopening pressure was Ptp = 14 cmH2O. The expiration rate varied between i and 20% of total lobe capacity per second and had no consistent effect on the closing volume and pressure. When lung volume was cycled up to frequencies of 0.2 Hz, closure generally occurred on expiration rather than inspiration. These observations support the conclusion that mechanical collapse, rather than meniscus formation, is the most likely mechanism producing airway closure in normal excised dog lungs. Analysis of measured acoustic impedances and reopening pressures suggests that closure occurs in the most peripheral airways. Reopening during inspiration was often observed to consist of a series of stepwise decreases in capsule impedance, indicating a sequence of opening events.

AB - An alveolar capsule oscillation technique was used to determine 1) the lobe pressure and volume at which airways close and reopen, 2) the effect of expiration rate on closing volume and pressure, 3) the phase in the breathing cycle at which airway closure occurs, and 4) the site of airway closure. Experiments were conducted in excised dog lobes; closure was detected by an abrupt increase in the input impedance of surface-mounted alveolar capsules. Mean transpulmonary pressure (Ptp) at closure was slightly less than zero (Ptp = -2.3 cmH2O); the corresponding mean reopening pressure was Ptp = 14 cmH2O. The expiration rate varied between i and 20% of total lobe capacity per second and had no consistent effect on the closing volume and pressure. When lung volume was cycled up to frequencies of 0.2 Hz, closure generally occurred on expiration rather than inspiration. These observations support the conclusion that mechanical collapse, rather than meniscus formation, is the most likely mechanism producing airway closure in normal excised dog lungs. Analysis of measured acoustic impedances and reopening pressures suggests that closure occurs in the most peripheral airways. Reopening during inspiration was often observed to consist of a series of stepwise decreases in capsule impedance, indicating a sequence of opening events.

KW - airway liquid lining

KW - alveolar capsule technique

KW - closing capacity

KW - closing volume

KW - residual volume

UR - http://www.scopus.com/inward/record.url?scp=8944252336&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=8944252336&partnerID=8YFLogxK

M3 - Article

VL - 80

SP - 2077

EP - 2084

JO - Journal of Applied Physiology

JF - Journal of Applied Physiology

SN - 0161-7567

IS - 6

ER -