Practical Importance of a Preceding Full Inhalation or Exhalation upon the Measurement of Airway Resistance

1980 ◽  
Vol 58 (3) ◽  
pp. 249-253 ◽  
Author(s):  
T. Higenbottam ◽  
T. J. H. Clark
Keyword(s):  
Airway Resistance ◽  
Practical Importance ◽  
Normal Male ◽  
Indirect Measurements ◽  
Lung Capacity ◽  
Airway Function ◽  
Before And After ◽  
Residual Capacity ◽  
Normal Men ◽  
Male Subjects

1. Airway resistance was measured close to functional residual capacity before and after a full inhalation of total lung capacity, as well as before and after a full exhalation to residual volume. 2. The effects of these volume manoeuvres upon airway resistance (and associated lung volume) were determined in four resting normal male subjects and in six normal men during experimentally induced bronchoconstriction after breathing an air/histamine mist from a Wright's nebulizer. 3. In four men the duration of the effect of a full inhalation upon airway resistance after induced bronchoconstriction was assessed separately. 4. Neither a full inhalation nor a full exhalation altered airway resistance under normal conditions. However, a full inhalation reduced airway resistance in the presence of bronchoconstriction and this effect lasted for a period of 45 s. Even with bronchoconstriction, a full exhalation had no effect on airway resistance. 5. Account must therefore be taken of the potential reduction in airway resistance which may result from a full inhalation, particularly when indirect measurements of airway function which involve a full inhalation, such as forced spirometry, are used to assess airway obstruction.

Pulmonary response to threshold levels of sulfur dioxide (1.0 ppm) and ozone (0.3 ppm)

1985 ◽  
Vol 58 (6) ◽  
pp. 1783-1787 ◽  
Author(s):  
L. J. Folinsbee ◽  
J. F. Bedi ◽  
S. M. Horvath
Keyword(s):  
Sulfur Dioxide ◽  
Pulmonary Response ◽  
Rest Periods ◽  
Pollutant Concentrations ◽  
Thoracic Gas Volume ◽  
Exercise Ventilation ◽  
Before And After ◽  
Residual Capacity ◽  
Gas Volume ◽  
Male Subjects

We exposed 22 healthy adult nonsmoking male subjects for 2 h to filtered air, 1.0 ppm sulfur dioxide (SO2), 0.3 ppm ozone (O3), or the combination of 1.0 ppm SO2 + 0.3 ppm O3. We hypothesized that exposure to near-threshold concentrations of these pollutants would allow us to observe any interaction between the two pollutants that might have been masked by the more obvious response to the higher concentrations of O3 used in previous studies. Each subject alternated 30-min treadmill exercise with 10-min rest periods for the 2 h. The average exercise ventilation measured during the last 5 min of exercise was 38 1/min (BTPS). Forced expiratory maneuvers were performed before exposure and 5 min after each of the three exercise periods. Maximum voluntary ventilation, He dilution functional residual capacity, thoracic gas volume, and airway resistance were measured before and after the exposure. After O3 exposure alone, forced expiratory measurements (FVC, FEV1.0, and FEF25–75%) were significantly decreased. The combined exposure to SO2 + O3 produced similar but smaller decreases in these measures. There were small but significant differences between the O3 and the O3 + SO2 exposure for FVC, FEV1.0, FEV2.0, FEV3.0, and FEF25–75% at the end of the 2-h exposure. We conclude that, with these pollutant concentrations, there is no additive or synergistic effect of the two pollutants on pulmonary function.

Nonuniform expansion of constricted dog lungs

1996 ◽  
Vol 80 (2) ◽  
pp. 522-530 ◽  
Author(s):  
R. D. Hubmayr ◽  
M. J. Hill ◽  
T. A. Wilson
Keyword(s):  
Airway Resistance ◽  
Lower Lobe ◽  
Lung Parenchyma ◽  
Frequency Dependent ◽  
Lung Capacity ◽  
Before And After ◽  
Radiopaque Markers ◽  
Video Fluoroscopy ◽  
Control State ◽  
Tissue Elastance

The parenchymal marker technique was used to measure regional tidal volumes of samples of lung parenchyma in four open-chest supine dogs. Radiopaque markers that had been implanted in the lower lobe were tracked by biplane video fluoroscopy during sinusoidal volume oscillations at tidal volumes of approximately 20% of total lung capacity and frequencies of 1-40 breaths/min before and after methacholine was administered by aerosol. The volumes of tetrahedrons with apexes at four markers were computed, and sine waves were fit to the data for volume vs. time for each tetrahedron. The ratio of mean regional volume to mean airway pressure decreased by 10-45% after exposure to methacholine. Dynamic lung elastance and resistance of the constricted lungs were larger than control, and both were frequency dependent. Regional elastance and resistance varied considerably among tetrahedrons, and these were also frequency dependent. The data were fit by a model in which tissue elastance was uniform and nearly equal to elastance in the control state, but small-airway resistance was high and variable. We conclude that the lung contracts under bronchoconstriction but that the increased dynamic elastance and resistance of the constricted lung may be primarily the result of nonuniform increased airway resistance at the level of the terminal bronchioles.

Effects of a General Osteopathic treatment on asthmatic children

2020 ◽  
pp. 137-145
Author(s):  
B. Ernoult ◽  
H. Job
Keyword(s):  
Asthmatic Child ◽  
Daily Basis ◽  
Short Term ◽  
Asthmatic Children ◽  
Lung Capacity ◽  
Before And After ◽  
Osteopathic Treatment ◽  
Residual Capacity ◽  
Term Basis ◽  
The Impact

Aim. Up to 10 % of population suffer from asthma. Asthma often means managing a treatment with limited action on a daily basis. The study aim was to assess the impact of a General Osteopathic treatment (GOT) on the respiratory function in asthmatic children.Method. 15 asthmatic subjects, aged 4 to 15, diagnosed by an allergologist, received one GOT session. Objective results were obtained through a bodyplethysmography measure before and after treatment. Variables observed were: Tiffeneau′s coefficient, mean expiratory fl ow from small bronchial tubes, bronchial resistances and residual capacity.Results. Comparison between result before and after treatment showed a significant improvement of all measures after the GOT.Conclusions. On a short term basis, a session of GOT allows to asthmatic child to improve its lung capacity. Including Osteopathy in the pluridisciplinary care of asthmatic children appears to be relevant. 

Dynamic airway function during exercise in COPD assessed via impulse oscillometry before and after inhaled bronchodilators.

2021 ◽  
Author(s):  
Nicholas B. Tiller ◽  
Min Cao ◽  
Fang Lin ◽  
Wei Yuan ◽  
Chu-yi Wang ◽  
...  
Keyword(s):  
Healthy Subjects ◽  
Airway Resistance ◽  
Pulmonary Ventilation ◽  
Peak Exercise ◽  
Impulse Oscillometry ◽  
Airway Function ◽  
Volume Curve ◽  
Copd Patients ◽  
Before And After ◽  
Flow Volume Curve

Introduction. Assessing airway function during exercise provides useful information regarding mechanical properties of the airways and extent of ventilatory limitation in COPD. The primary aim of this study was to use impulse oscillometry (IOS) to assess dynamic changes in airway impedance across a range of exercise intensities in GOLD 1-4 patients, before and after albuterol. A secondary aim was to assess reproducibility of IOS measures during exercise. Methods. Fifteen COPD patients (8 male; age=66±8 y; pre-bronchodilator FEV1=54.3±23.6%Pred) performed incremental cycle ergometry before and 90-min after inhaled albuterol. Pulmonary ventilation and gas exchange were measured continuously, and IOS-derived indices of airway impedance were measured every 2 min immediately preceding inspiratory capacity manoeuvres. Test-retest reproducibility of exercise IOS was assessed as mean difference between replicate tests in five healthy subjects (3 male). Results. At rest and during exercise, albuterol significantly increased airway reactance (X5), and decreased airway resistance (R5, R5-20), impedance (Z5), and end-expiratory lung volume (60±12 vs. 58±12%TLC, main effect p=0.003). At peak exercise, there were moderate-to-strong associations between IOS variables and IC, and between IOS and concavity in the expiratory limb of the flow-volume curve. Exercise IOS exhibited moderate reproducibility in healthy subjects which was strongest with R5 (mean diff. -0.01±0.05 kPa/L/s; ICC=0.68), R5-20 (mean diff. -0.004±0.028 kPa/L/s; ICC=0.65), and Z5 (mean diff. -0.006±0.021 kPa/L/s; ICC=0.69). Conclusions. Exercise evoked increases in airway resistance and decreases in reactance that were ameliorated by inhaled bronchodilators. The technique of exercise IOS may aid in the clinical assessment of dynamic airway function during exercise.

Relationship between airway microvascular leakage, edema, and baseline airway functions

1998 ◽  
Vol 84 (1) ◽  
pp. 77-81
Author(s):  
Melissa Matheson ◽  
Ann-Christine Rynell ◽  
Melissa McClean ◽  
Norbert Berend
Keyword(s):  
Evans Blue ◽  
Airway Resistance ◽  
Respiratory Physiology ◽  
Blue Dye ◽  
Wall Area ◽  
Evans Blue Dye ◽  
Microvascular Leakage ◽  
Airway Function ◽  
Significant Difference ◽  
Before And After

Matheson, Melissa, Ann-Christine Rynell, Melissa McClean, and Norbert Berend. Relationship between airway microvascular leakage, edema, and baseline airway functions. J. Appl. Physiol. 84(1): 77–81, 1998.—This study was designed to examine the relationship among microvascular leakage, edema, and baseline airway function. Microvascular leakage was induced in the airways of anesthetized, tracheostomized New Zealand White rabbits ( n = 22) by using nebulized N-formyl-methionyl-leucyl-phenylalanine (10 mg) and was measured in the trachea by using the Evans blue dye technique. Airway wall thickness was assessed morphometrically in the right main bronchus after Formalin fixation at a pressure of 25 cmH2O. Areas calculated included the mucosal wall area, the adventitial wall area, the total wall area, and the percentage of total wall area consisting of blood vessels. A neutrophil count was also performed by analyzing numbers of cells in both the mucosal wall area and the adventitial wall area. Airway function was assessed before and 30 min after challenge with N-formyl-methionyl-leucyl-phenylalanine by determining airway resistance, functional residual capacity, specific airway resistance, and flow-volume and pressure-volume curves (after paralysis of the animals with suxamethonium). The concentration of Evans blue dye in tracheal tissue ranged from 31.3 to 131.2 μg. There was a significant correlation between this concentration and both the adventitial wall area ( P < 0.01) and mucosal neutrophil numbers ( P < 0.005). There was no correlation between Evans blue concentration and either blood vessel area or changes in respiratory physiology parameters before and after challenge. There was no significant difference between any respiratory physiology measurements before and after challenge. We conclude that an increase in microvascular leakage correlates with airway edema in the adventitia; however, these airway changes have no significant effect on airway elastic or resistive properties.

Effect of a previous deep inspiration on airway resistance in man

1961 ◽  
Vol 16 (4) ◽  
pp. 717-719 ◽  
Author(s):  
Jay A. Nadel ◽  
Donald F. Tierney
Keyword(s):  
Airway Resistance ◽  
Healthy Adult ◽  
Transpulmonary Pressure ◽  
The Body ◽  
Deep Inspiration ◽  
Thoracic Gas Volume ◽  
Before And After ◽  
Residual Capacity ◽  
Gas Volume ◽  
Control State

We measured airway resistance and thoracic gas volume by the body plethysmograph technique, and transpulmonary pressure in seven healthy, adult subjects, before and after induction of bronchoconstriction. A deep inspiration never altered airway resistance, measured at functional residual capacity in the control state, but always reduced it for 1—2 min when bronchoconstriction was present. Discrepancies in data published on airway resistance may be due to use of methods which require a deep inspiration, or to occurrence of a spontaneous deep inspiration shortly before the test. Submitted on January 13, 1961

Effects of mass loading on the upper airway

1988 ◽  
Vol 64 (6) ◽  
pp. 2294-2299 ◽  
Author(s):  
J. S. Koenig ◽  
B. T. Thach
Keyword(s):  
Airway Resistance ◽  
Sleep Apnea Syndrome ◽  
Upper Airway ◽  
Mass Loading ◽  
Handheld Device ◽  
Upper Airway Resistance ◽  
Airway Function ◽  
Obstructive Sleep ◽  
Before And After ◽  
And Function

To learn how increased cervical adipose tissue might affect upper airway function, we studied effects of mass loading on upper airway dimensions, stability, and resistance. Eight rabbits were studied (anesthetized and postmortem) using lard-filled bags to simulate cervical fat accumulation. Additionally, a handheld device was used to apply measured loads at localized sites along the airway. Upper airway resistance and closing pressure (a reflection of airway stability) were determined before and after loading. Endoscopy revealed concentric narrowing of the pharynx during loading in anesthetized and postmortem preparations. Upper airway resistance was increased by mass loads, with larger loads having greater effects. Loading caused decreased airway stability as reflected by closing pressures. The area over the thyrohyoid membrane was more vulnerable to mass loading than adjacent areas. Because mass loading of the upper airway causes changes in its configuration and function similar to those seen in obstructive sleep apnea syndrome (OSA), we speculate that such loading may contribute to the pathogenesis of OSA associated with obesity.

Effects of sustained and repetitive isocapnic hypoxia on ventilation and genioglossal and diaphragmatic EMGs

1996 ◽  
Vol 81 (2) ◽  
pp. 866-875 ◽  
Author(s):  
R. D. McEvoy ◽  
R. M. Popovic ◽  
N. A. Saunders ◽  
D. P. White
Keyword(s):  
Airway Resistance ◽  
Ventilatory Response ◽  
Supraglottic Airway ◽  
Normal Male ◽  
Biphasic Response ◽  
Hypoxic Episode ◽  
Arterial O2 Saturation ◽  
Male Subjects ◽  
Marked Suppression ◽  
Biphasic Responses

We compared the effects of sustained isocapnic hypoxia (SIH; 20 min) and repetitive isocapnic hypoxia (RIH; 10 2-min episodes) on ventilation (VI), genioglossal (EMGgg) and diaphragmatic electromyographic (EMGdi) activities, and supraglottic airway resistance in 11 normal supine male subjects (36.6 +/- 2.2 yr) during wakefulness. Seven of the subjects had control measurements on a separate day. Desaturation was similar (arterial O2 saturation 80–84%) in the SIH and RIH protocols. SIH and RIH caused a biphasic ventilatory response: early augmentation of VI (169.5 +/- 6.9 and 168.9 +/- 4.3% of baseline, respectively; not significant) followed by a significant roll-off (VI after 20 min of cumulative hypoxia 153 +/- 4.0 and 150.8 +/- 10.2% respectively; not significant). Moving-time-average EMGdi signals (peak inspiratory and phasic) demonstrated a similar biphasic response in the two protocols. Mean EMGgg responses, however, differed. During SIH, peak inspiratory EMGgg increased early and remained elevated. Phasic and tonic EMGgg signals showed a similar trend. During RIH, early augmentation of peak inspiratory and phasic EMGgg signals was followed by a marked roll-off in activity such that by the 10th hypoxic episode neither value increased above baseline. In the 2-min periods between hypoxic episodes, there was a progressive suppression of peak inspiratory and phasic EMGgg values below baseline. Supraglottic airway resistance did not change significantly during either SIH or RIH. VI and phasic EMGs did not change during control experiments. We conclude that in awake normal male subjects SIH and RIH cause similar biphasic responses in VI and EMGdi activity. Phasic EMGgg activity responses differ between SIH and RIH: EMGgg remains augmented during SIH, whereas during RIH early augmentation is followed by marked suppression.

The Retention of Lung Secretions during the Night in Normal Subjects

1978 ◽  
Vol 55 (6) ◽  
pp. 523-527 ◽  
Author(s):  
J. R. M. Bateman ◽  
D. Pavia ◽  
S. W. Clarke
Keyword(s):  
Diurnal Variation ◽  
Chronic Bronchitis ◽  
Mucociliary Clearance ◽  
Normal Subjects ◽  
Early Morning ◽  
Normal Male ◽  
Related Phenomenon ◽  
Before And After ◽  
Male Subjects

1. Mucociliary clearance has been measured over a 6 h period by using the radioaerosol technique in seven normal male subjects lying supine, both during the day when awake, and during the night when asleep. 2. The percentage of radioaerosol cleared during the night, when asleep, was significantly less than during the day when awake (P < 0.02). 3. A comparison of radioaerosol clearance before and after the time of onset of sleep demonstrates that reduced clearance occurred during sleep, indicating that this is probably a sleep-related phenomenon and not merely a result of diurnal variation. 4. This finding has important implications for patients with chronic bronchitis or asthma, in whom early morning cough or wheeze may be a predominant feature.

O2 cost of inspiratory and expiratory resistive breathing in humans

1988 ◽  
Vol 65 (6) ◽  
pp. 2518-2523 ◽  
Author(s):  
D. S. Dodd ◽  
J. Yarom ◽  
S. H. Loring ◽  
L. A. Engel
Keyword(s):  
Normal Subjects ◽  
Normal Male ◽  
O2 Uptake ◽  
Pressure Time ◽  
Resistive Breathing ◽  
Before And After ◽  
Expiratory Muscles ◽  
Variable Recruitment ◽  
Equivalent Load ◽  
Male Subjects

In six normal male subjects we compared the O2 cost of resistive breathing (VO2 resp) between equivalent external inspiratory (IRL) and expiratory loads (ERL) studied separately. Each subject performed four pairs of runs matched for tidal volume, breathing frequency, flow rates, lung volume, pressure-time product, and work rate. Basal O2 uptake, measured before and after pairs of loaded runs, was subtracted from that measured during resistive breathing to obtain VO2 resp. For an equivalent load, the VO2 resp during ERL (184 +/- 17 ml O2/min) was nearly twice that obtained during IRL (97 +/- 9 ml O2/min). This twofold difference in efficiency between inspiratory and expiratory resistive breathing may reflect the relatively lower mechanical advantage of the expiratory muscles in overcoming respiratory loads. Variable recruitment of expiratory muscles may explain the large variation of results obtained in studies of respiratory muscle efficiency in normal subjects.

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