Peripheral lung resistance in normal and asthmatic subjects

Elizabeth Marie Wagner, Mark Chang Hwa Liu, G. G. Weinmann, S. Permutt, E. R. Bleecker

Research output: Contribution to journalArticle

Abstract

In obstructive lung disease, peripheral airways are a major site of pathologic abnormalities. However, resistance to airflow in small airways in the periphery of the lung accounts for only a small fraction of total airway resistance. Consequently, abnormalities of small airway function may not be readily detected using routine pulmonary function testing. In the present study, resistance of the peripheral lung was examined directly in six normal subjects and nine mildly asthmatic subjects. There were no significant differences between the normal and asthmatic groups in pulmonary function assessed by spirometry (FEV1, FVC) and body plethysmography (specific airway conductance). Direct measurements of peripheral lung function were made using a fiberoptic bronchoscope wedged into a subsegmental, right upper lobe bronchus. Using a double-lumen catheter inserted into the instrument channel of the bronchoscope, pressures (P(B)) produced by three or more different levels of gas flow (V̇) (5% CO2 in air) between 50 and 500 ml/min were measured. All pressure measurements were made at a constant lung volume (i.e., functional residual capacity) confirmed by monitoring transpulmonary pressure with an esophageal balloon. The pressure-flow relationship in both normal and asthmatic subjects could be approximated by a straight line through the origin, demonstrating these airways to be relatively nondistensible. Peripheral lung resistance (Rp) was defined by P(B/V̇) and averaged for three or more levels of flow. In contrast to spirometric results that showed no differences between the two groups, Rp was increased more than sevenfold in asthmatic subjects (0.069 ± .017 cm H2O/ml/min) (mean ± SEM) compared to normal subjects (0.009 ± .002 cm H2O/ml/min). Pretreatment of the asthmatic subjects (n = 5) with aerosolized isoproterenol did not decrease Rp to normal levels. These results demonstrate marked physiologic abnormalities in the peripheral lungs of asymptomatic asthmatic subjects and suggest that changes in the mechanical properties of these airways, although having a small influence on overall pulmonary function, may contribute to increased airway responsiveness in asthma.

Original languageEnglish (US)
Pages (from-to)584-588
Number of pages5
JournalAmerican Review of Respiratory Disease
Volume141
Issue number3 I
StatePublished - 1990

Fingerprint

Vascular Resistance
Lung
Pressure
Bronchoscopes
Obstructive Lung Diseases
Functional Residual Capacity
Airway Resistance
Plethysmography
Spirometry
Bronchi
Isoproterenol
Asthma
Catheters
Gases
Air

ASJC Scopus subject areas

  • Pulmonary and Respiratory Medicine

Cite this

Peripheral lung resistance in normal and asthmatic subjects. / Wagner, Elizabeth Marie; Liu, Mark Chang Hwa; Weinmann, G. G.; Permutt, S.; Bleecker, E. R.

In: American Review of Respiratory Disease, Vol. 141, No. 3 I, 1990, p. 584-588.

Research output: Contribution to journalArticle

Wagner, EM, Liu, MCH, Weinmann, GG, Permutt, S & Bleecker, ER 1990, 'Peripheral lung resistance in normal and asthmatic subjects', American Review of Respiratory Disease, vol. 141, no. 3 I, pp. 584-588.
Wagner, Elizabeth Marie ; Liu, Mark Chang Hwa ; Weinmann, G. G. ; Permutt, S. ; Bleecker, E. R. / Peripheral lung resistance in normal and asthmatic subjects. In: American Review of Respiratory Disease. 1990 ; Vol. 141, No. 3 I. pp. 584-588.
@article{8f62cc98cf874626abd9c15bbf245810,
title = "Peripheral lung resistance in normal and asthmatic subjects",
abstract = "In obstructive lung disease, peripheral airways are a major site of pathologic abnormalities. However, resistance to airflow in small airways in the periphery of the lung accounts for only a small fraction of total airway resistance. Consequently, abnormalities of small airway function may not be readily detected using routine pulmonary function testing. In the present study, resistance of the peripheral lung was examined directly in six normal subjects and nine mildly asthmatic subjects. There were no significant differences between the normal and asthmatic groups in pulmonary function assessed by spirometry (FEV1, FVC) and body plethysmography (specific airway conductance). Direct measurements of peripheral lung function were made using a fiberoptic bronchoscope wedged into a subsegmental, right upper lobe bronchus. Using a double-lumen catheter inserted into the instrument channel of the bronchoscope, pressures (P(B)) produced by three or more different levels of gas flow (V̇) (5{\%} CO2 in air) between 50 and 500 ml/min were measured. All pressure measurements were made at a constant lung volume (i.e., functional residual capacity) confirmed by monitoring transpulmonary pressure with an esophageal balloon. The pressure-flow relationship in both normal and asthmatic subjects could be approximated by a straight line through the origin, demonstrating these airways to be relatively nondistensible. Peripheral lung resistance (Rp) was defined by P(B/V̇) and averaged for three or more levels of flow. In contrast to spirometric results that showed no differences between the two groups, Rp was increased more than sevenfold in asthmatic subjects (0.069 ± .017 cm H2O/ml/min) (mean ± SEM) compared to normal subjects (0.009 ± .002 cm H2O/ml/min). Pretreatment of the asthmatic subjects (n = 5) with aerosolized isoproterenol did not decrease Rp to normal levels. These results demonstrate marked physiologic abnormalities in the peripheral lungs of asymptomatic asthmatic subjects and suggest that changes in the mechanical properties of these airways, although having a small influence on overall pulmonary function, may contribute to increased airway responsiveness in asthma.",
author = "Wagner, {Elizabeth Marie} and Liu, {Mark Chang Hwa} and Weinmann, {G. G.} and S. Permutt and Bleecker, {E. R.}",
year = "1990",
language = "English (US)",
volume = "141",
pages = "584--588",
journal = "American Journal of Respiratory and Critical Care Medicine",
issn = "1073-449X",
publisher = "American Thoracic Society",
number = "3 I",

}

TY - JOUR

T1 - Peripheral lung resistance in normal and asthmatic subjects

AU - Wagner, Elizabeth Marie

AU - Liu, Mark Chang Hwa

AU - Weinmann, G. G.

AU - Permutt, S.

AU - Bleecker, E. R.

PY - 1990

Y1 - 1990

N2 - In obstructive lung disease, peripheral airways are a major site of pathologic abnormalities. However, resistance to airflow in small airways in the periphery of the lung accounts for only a small fraction of total airway resistance. Consequently, abnormalities of small airway function may not be readily detected using routine pulmonary function testing. In the present study, resistance of the peripheral lung was examined directly in six normal subjects and nine mildly asthmatic subjects. There were no significant differences between the normal and asthmatic groups in pulmonary function assessed by spirometry (FEV1, FVC) and body plethysmography (specific airway conductance). Direct measurements of peripheral lung function were made using a fiberoptic bronchoscope wedged into a subsegmental, right upper lobe bronchus. Using a double-lumen catheter inserted into the instrument channel of the bronchoscope, pressures (P(B)) produced by three or more different levels of gas flow (V̇) (5% CO2 in air) between 50 and 500 ml/min were measured. All pressure measurements were made at a constant lung volume (i.e., functional residual capacity) confirmed by monitoring transpulmonary pressure with an esophageal balloon. The pressure-flow relationship in both normal and asthmatic subjects could be approximated by a straight line through the origin, demonstrating these airways to be relatively nondistensible. Peripheral lung resistance (Rp) was defined by P(B/V̇) and averaged for three or more levels of flow. In contrast to spirometric results that showed no differences between the two groups, Rp was increased more than sevenfold in asthmatic subjects (0.069 ± .017 cm H2O/ml/min) (mean ± SEM) compared to normal subjects (0.009 ± .002 cm H2O/ml/min). Pretreatment of the asthmatic subjects (n = 5) with aerosolized isoproterenol did not decrease Rp to normal levels. These results demonstrate marked physiologic abnormalities in the peripheral lungs of asymptomatic asthmatic subjects and suggest that changes in the mechanical properties of these airways, although having a small influence on overall pulmonary function, may contribute to increased airway responsiveness in asthma.

AB - In obstructive lung disease, peripheral airways are a major site of pathologic abnormalities. However, resistance to airflow in small airways in the periphery of the lung accounts for only a small fraction of total airway resistance. Consequently, abnormalities of small airway function may not be readily detected using routine pulmonary function testing. In the present study, resistance of the peripheral lung was examined directly in six normal subjects and nine mildly asthmatic subjects. There were no significant differences between the normal and asthmatic groups in pulmonary function assessed by spirometry (FEV1, FVC) and body plethysmography (specific airway conductance). Direct measurements of peripheral lung function were made using a fiberoptic bronchoscope wedged into a subsegmental, right upper lobe bronchus. Using a double-lumen catheter inserted into the instrument channel of the bronchoscope, pressures (P(B)) produced by three or more different levels of gas flow (V̇) (5% CO2 in air) between 50 and 500 ml/min were measured. All pressure measurements were made at a constant lung volume (i.e., functional residual capacity) confirmed by monitoring transpulmonary pressure with an esophageal balloon. The pressure-flow relationship in both normal and asthmatic subjects could be approximated by a straight line through the origin, demonstrating these airways to be relatively nondistensible. Peripheral lung resistance (Rp) was defined by P(B/V̇) and averaged for three or more levels of flow. In contrast to spirometric results that showed no differences between the two groups, Rp was increased more than sevenfold in asthmatic subjects (0.069 ± .017 cm H2O/ml/min) (mean ± SEM) compared to normal subjects (0.009 ± .002 cm H2O/ml/min). Pretreatment of the asthmatic subjects (n = 5) with aerosolized isoproterenol did not decrease Rp to normal levels. These results demonstrate marked physiologic abnormalities in the peripheral lungs of asymptomatic asthmatic subjects and suggest that changes in the mechanical properties of these airways, although having a small influence on overall pulmonary function, may contribute to increased airway responsiveness in asthma.

UR - http://www.scopus.com/inward/record.url?scp=0025332174&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0025332174&partnerID=8YFLogxK

M3 - Article

VL - 141

SP - 584

EP - 588

JO - American Journal of Respiratory and Critical Care Medicine

JF - American Journal of Respiratory and Critical Care Medicine

SN - 1073-449X

IS - 3 I

ER -