Thoracic gas volume, helium functional residual capacity and air-trapping in the first six hours of life: The effect of oxygen administration

1981 ◽  
Vol 5 (2) ◽  
pp. 157-166 ◽  
Author(s):  
A.W. Boon ◽  
J.M.C. Ward-Mcquaid ◽  
A.D. Milner ◽  
I.E. Hopkin
Keyword(s):  
Functional Residual Capacity ◽  
Air Trapping ◽  
Oxygen Administration ◽  
Thoracic Gas Volume ◽  
Residual Capacity ◽  
Effect Of Oxygen ◽  
Gas Volume

Problems in measurement of thoracic gas volume in infancy

1982 ◽  
Vol 52 (4) ◽  
pp. 995-999 ◽  
Author(s):  
C. S. Beardsmore ◽  
J. Stocks ◽  
M. Silverman
Keyword(s):  
Functional Residual Capacity ◽  
Clinical Status ◽  
Pleural Pressure ◽  
Whole Body ◽  
Airway Closure ◽  
Lung Volumes ◽  
Airway Occlusion ◽  
Thoracic Gas Volume ◽  
Residual Capacity ◽  
Gas Volume

Thoracic gas volume (TGV) was measured with a whole-body plethysmograph in 20 infants at functional residual capacity (FRC) and at a series of higher lung volumes achieved by artificial inflation of the lungs with known volumes of air after airway occlusion. There was a discrepancy between the corrected values of TGV measured at high and low lung volumes in nine infants; in six cases TGV measured at high lung volumes exceeded that measured at FRC, and in three cases it was reduced when compared with the measurement made at FRC. These changes were not related to age, size, or clinical status and could be explained by airway closure at FRC, combined with an uneven distribution of pleural pressure.

Concurrent measurements of functional residual capacity by three methods

1962 ◽  
Vol 17 (6) ◽  
pp. 871-873 ◽  
Author(s):  
Donald F. Tierney ◽  
Jay A. Nadel
Keyword(s):  
Functional Residual Capacity ◽  
Total Lung Capacity ◽  
Open Circuit ◽  
The Body ◽  
Lung Capacity ◽  
Thoracic Gas Volume ◽  
Nitrogen Dilution ◽  
Residual Capacity ◽  
The Mean ◽  
Gas Volume

We made concurrent measurements of the functional residual capacity (FRC) with the body plethysmograph (thoracic gas volume) and by 7-min and prolonged open-circuit nitrogen dilution methods (communicating gas volume). The mean difference between the 7-min communicating gas volume and the thoracic gas volume in 13 healthy subjects was only 0.13 liters. The thoracic gas volume averaged 0.99 liters larger than the communicating gas volume after 7 min of O2 breathing in 13 patients with emphysema. The communicating gas volume at 12–18 min was the same as the thoracic gas volume in 11 of 13 patients but was smaller in the other 2. When the thoracic gas volume was used to measure FRC, the total lung capacity averaged 142% of predicted normal in 13 patients with emphysema. Submitted on January 4, 1962

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.

scholarly journals Lung volumes and respiratory mechanics in elastase-induced emphysema in mice

2008 ◽  
Vol 105 (6) ◽  
pp. 1864-1872 ◽  
Author(s):  
Z. Hantos ◽  
Á. Adamicza ◽  
T. Z. Jánosi ◽  
M. V. Szabari ◽  
J. Tolnai ◽  
...  
Keyword(s):  
Mouse Model ◽  
Low Frequency ◽  
Forced Oscillations ◽  
Mechanical Parameters ◽  
Tissue Destruction ◽  
Lung Volumes ◽  
Lung Capacity ◽  
Thoracic Gas Volume ◽  
Residual Capacity ◽  
Gas Volume

Absolute lung volumes such as functional residual capacity, residual volume (RV), and total lung capacity (TLC) are used to characterize emphysema in patients, whereas in animal models of emphysema, the mechanical parameters are invariably obtained as a function of transrespiratory pressure (Prs). The aim of the present study was to establish a link between the mechanical parameters including tissue elastance (H) and airway resistance (Raw), and thoracic gas volume (TGV) in addition to Prs in a mouse model of emphysema. Using low-frequency forced oscillations during slow deep inflation, we tracked H and Raw as functions of TGV and Prs in normal mice and mice treated with porcine pancreatic elastase. The presence of emphysema was confirmed by morphometric analysis of histological slices. The treatment resulted in an increase in TGV by 51 and 44% and a decrease in H by 57 and 27%, respectively, at 0 and 20 cmH2O of Prs. The Raw did not differ between the groups at any value of Prs, but it was significantly higher in the treated mice at comparable TGV values. In further groups of mice, tracheal sounds were recorded during inflations from RV to TLC. All lung volumes but RV were significantly elevated in the treated mice, whereas the numbers and size distributions of inspiratory crackles were not different, suggesting that the airways were not affected by the elastase treatment. These findings emphasize the importance of absolute lung volumes and indicate that tissue destruction was not associated with airway dysfunction in this mouse model of emphysema.

scholarly journals Reproducibility of airway luminal size in asthma measured by HRCT

2017 ◽  
Vol 123 (4) ◽  
pp. 876-883 ◽  
Author(s):  
Robert H. Brown ◽  
Robert J. Henderson ◽  
Elizabeth A. Sugar ◽  
Janet T. Holbrook ◽  
Robert A. Wise
Keyword(s):  
High Resolution ◽  
Functional Residual Capacity ◽  
Total Lung Capacity ◽  
Ct Imaging ◽  
Disease State ◽  
Air Trapping ◽  
Lung Capacity ◽  
Residual Capacity ◽  
Normal Variability ◽  
Over Time

Brown RH, Henderson RJ, Sugar EA, Holbrook JT, Wise RA, on behalf of the American Lung Association Airways Clinical Research Centers. Reproducibility of airway luminal size in asthma measured by HRCT. J Appl Physiol 123: 876–883, 2017. First published July 13, 2017; doi:10.1152/japplphysiol.00307.2017.—High-resolution CT (HRCT) is a well-established imaging technology used to measure lung and airway morphology in vivo. However, there is a surprising lack of studies examining HRCT reproducibility. The CPAP Trial was a multicenter, randomized, three-parallel-arm, sham-controlled 12-wk clinical trial to assess the use of a nocturnal continuous positive airway pressure (CPAP) device on airway reactivity to methacholine. The lack of a treatment effect of CPAP on clinical or HRCT measures provided an opportunity for the current analysis. We assessed the reproducibility of HRCT imaging over 12 wk. Intraclass correlation coefficients (ICCs) were calculated for individual airway segments, individual lung lobes, both lungs, and air trapping. The ICC [95% confidence interval (CI)] for airway luminal size at total lung capacity ranged from 0.95 (0.91, 0.97) to 0.47 (0.27, 0.69). The ICC (95% CI) for airway luminal size at functional residual capacity ranged from 0.91 (0.85, 0.95) to 0.32 (0.11, 0.65). The ICC measurements for airway distensibility index and wall thickness were lower, ranging from poor (0.08) to moderate (0.63) agreement. The ICC for air trapping at functional residual capacity was 0.89 (0.81, 0.94) and varied only modestly by lobe from 0.76 (0.61, 0.87) to 0.95 (0.92, 0.97). In stable well-controlled asthmatic subjects, it is possible to reproducibly image unstimulated airway luminal areas over time, by region, and by size at total lung capacity throughout the lungs. Therefore, any changes in luminal size on repeat CT imaging are more likely due to changes in disease state and less likely due to normal variability. NEW & NOTEWORTHY There is a surprising lack of studies examining the reproducibility of high-resolution CT in asthma. The current study examined reproducibility of airway measurements. In stable well-controlled asthmatic subjects, it is possible to reproducibly image airway luminal areas over time, by region, and by size at total lung capacity throughout the lungs. Therefore, any changes in luminal size on repeat CT imaging are more likely due to changes in disease state and less likely due to normal variability.

Determinants of forced expiratory flows in newborn infants

1982 ◽  
Vol 53 (5) ◽  
pp. 1220-1227 ◽  
Author(s):  
L. M. Taussig ◽  
L. I. Landau ◽  
S. Godfrey ◽  
I. Arad
Keyword(s):  
Newborn Infants ◽  
Cross Sectional Area ◽  
Physiological Data ◽  
Sectional Area ◽  
Older Children ◽  
Cross Sectional ◽  
Thoracic Gas Volume ◽  
Residual Capacity ◽  
The Cross ◽  
Gas Volume

Maximal flows at functional residual capacity (VmaxFRC) from partial expiratory flow-volume (PEFV) curves (achieved with rapid compression of the chest) were obtained on 11 healthy newborn babies. Mean VmaxFRC, size corrected by dividing absolute values by measured thoracic gas volume, was 1.90 TGV's/s. Specific upstream conductances were high, and the cross-sectional area of the flow-limiting segment was estimated to be approximately 0.30 cm2 in the three infants on whom recoil pressures at FRC were also measured. The cross-sectional area of the major bronchi in the neonate is approximately 0.26–0.30 cm2. PEFV curves were convex to the volume axis. Many of the neonates increased their flows while breathing a helium-oxygen gas mixture. These results suggest 1) size-corrected flows are higher in the neonate than in older children or adults; 2) the site of the flow-limiting segment at FRC during maximal expiratory maneuvers is in large proximal airways, similar to the adult; and 3) the relationship of airway size to parenchymal size may be similar in neonates and adults or, in fact, airways may be larger, relative to parenchyma, in neonates. These physiological data do not support the hypothesis, based on pathological studies, that peripheral airways are disproportionately smaller (when compared with central airways) in infants than in adults.

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