scholarly journals Total lung capacity without plethysmography

2018 ◽  
Author(s):  
Ori Adam ◽  
Inon Cohen ◽  
Wai-Ki Yip ◽  
Robert J. Shiner ◽  
Peter Calverley ◽  
...  
Keyword(s):  
Total Lung Capacity ◽  
Airflow Obstruction ◽  
Heterogeneous Population ◽  
Repeated Measurements ◽  
Body Plethysmography ◽  
Individual Subject ◽  
Thoracic Imaging ◽  
Lung Inflation ◽  
Lung Capacity

ABSTRACTBackgroundAmong the most basic measures of respiratory function is the total lung capacity (TLC). TLC is the pulmonary gas volume at maximal lung inflation, which is the sum of the volume of gas that can be exhaled –the vital capacity (VC)– and the volume of gas that cannot –the residual volume (RV). Determination of VC requires only spirometry whereas determination of RV or TLC requires body plethysmography, gas dilution or washout, or thoracic imaging, each of which is more complex than spirometry, and none of which is suited to routine office practice, population screening, or community medicine. To fill this gap, we describe here a new approach to determine TLC without plethysmography.MethodsIn a heterogeneous population of 434 volunteers (265 male, 169 female; 201 healthy, 170 with airflow obstruction, and 63 with ventilatory restriction), we determined TLC in the standard fashion using conventional body plethysmography (TLCpleth). In the same individuals, we also determined TLC in a novel fashion using the MiniBox ™ (TLCMB). To obtain TLCMB, population-based data from traditional spirometry together with flow-interruption transients were subjected to data mining and machine-learning to create for each individual subject an unbiased statistical determination of TLC.ResultsFor the combined heterogeneous population, we found TLCpleth = 1.02TLCMB −0.091 L, adjusted r2=0.824. For the heterogeneous population as a whole, and for each subpopulation, TLCMB closely tracked TLCpleth. For 26 healthy subjects measured on different days, the coefficient of variation for repeated measurements in was 3.3% for TLCpleth versus 1.6% for TLCMB.ConclusionsThese results establish the validity and potential utility of a new method for rapid, accurate, and repeatable determination of TLC in a heterogeneous patient population, but without the need of a plethysmograph.

Ventilation Heterogeneity in Asthma and COPD: The Value of the Poorly Communicating Fraction as the Ratio of Total Lung Capacity to Alveolar Volume

Respiration ◽  
2021 ◽  
pp. 1-7
Author(s):  
Roberta Pisi ◽  
Marina Aiello ◽  
Luigino Calzetta ◽  
Annalisa Frizzelli ◽  
Veronica Alfieri ◽  
...  
Keyword(s):  
Total Lung Capacity ◽  
Airflow Obstruction ◽  
Diffusing Capacity ◽  
Body Plethysmography ◽  
Alveolar Volume ◽  
Asthmatic Patients ◽  
Lung Capacity ◽  
Copd Patients ◽  
Ventilation Heterogeneity ◽  
Patient Groups

<b><i>Background:</i></b> The ventilation heterogeneity (VH) is reliably assessed by the multiple-breath nitrogen washout (MBNW), which provides indices of conductive (<i>S</i><sub>cond</sub>) and acinar (<i>S</i><sub>acin</sub>) VH as well as the lung clearance index (LCI), an index of global VH. VH can be alternatively measured by the poorly communicating fraction (PCF), that is, the ratio of total lung capacity by body plethysmography to alveolar volume from the single-breath lung diffusing capacity measurement. <b><i>Objectives:</i></b> Our objective was to assess VH by PCF and MBNW in patients with asthma and with COPD and to compare PCF and MBNW parameters in both patient groups. <b><i>Method:</i></b> We studied 35 asthmatic patients and 45 patients with COPD. Each patient performed spirometry, body plethysmography, diffusing capacity, and MBNW test. <b><i>Results:</i></b> Compared to COPD patients, asthmatics showed a significantly lesser degree of airflow obstruction and lung hyperinflation. In asthmatic patients, both PCF and LCI and <i>S</i><sub>acin</sub> values were significantly lower than the corresponding ones of COPD patients. In addition, in both patient groups, PCF showed a positive correlation with LCI (<i>p</i> &#x3c; 0.05) and <i>S</i><sub>acin</sub> (<i>p</i> &#x3c; 0.05), but not with <i>S</i><sub>cond</sub>. Lastly, COPD patients with PCF &#x3e;30% were highly likely to have a value ≥2 of the mMRC dyspnea scale. <b><i>Conclusions:</i></b> These results showed that PCF, a readily measure derived from routine pulmonary function testing, can provide a comprehensive measure of both global and acinar VH in asthma and in COPD patients and can be considered as a comparable tool to the well-established MBNW technique.

Radiographie and Plethysmographie Determination of Total Lung Capacity

Radiology ◽  
1966 ◽  
Vol 86 (1) ◽  
pp. 7-30 ◽  
Author(s):  
Herbert M. Loyd ◽  
S. Timothy String ◽  
Arthur B. DuBois
Keyword(s):  
Total Lung Capacity ◽  
Lung Capacity

Factors determining degree of inflation in intratracheally fixed rat lungs

1980 ◽  
Vol 48 (2) ◽  
pp. 389-393 ◽  
Author(s):  
G. Hayatdavoudi ◽  
J. D. Crapo ◽  
F. J. Miller ◽  
J. J. O'Neil
Keyword(s):  
Slow Rate ◽  
Total Lung Capacity ◽  
Formaldehyde Solution ◽  
Initial Flow ◽  
Lung Inflation ◽  
Lung Capacity ◽  
Final Degree ◽  
Low Rate

The total lung capacity (TLC) of rats was measured in vivo and was compared to the displacement volume of the lungs following intratracheal fixation with glutaraldehyde or formaldehyde solution. When glutaraldehyde was used the speed of infusion of the fixative was an important factor in the final degree of lung inflation achieved. With a low rate of fixative infusion and a final pressure of 20 cm of fixative the glutaraldehyde-fixed lungs inflated to 55% TLC. With a high initial flow of glutaraldehyde and a final pressure of 20 cm of fixative the lungs inflated to 84% TLC. Fixation of lungs inside the intact chest wall was found to result in a higher degree of inflation. With a reservoir height of 20 cm and a low rate of fixative infusion lungs fixed in situ reached 74% TLC, whereas lungs fixed in situ, but from animals that have been exsanguinated prior to fixation, inflated to only 58% TLC. This suggests that the volume of the blood in the lungs prior to infusion of glutaraldehyde influences the degree of inflation achieved. Formaldehyde-fixed lungs required 72 h to be completely fixed and they were inflated to 90% TLC when a reservoir height of 20 cm was used. Because of the slow rate of fixation using with formaldehyde solution the rate of infusion was found not to limit the degree of inflation that could be achieved.

Radiographic determination of total lung capacity in patients with acromegaly

1987 ◽  
Vol 81 ◽  
pp. 280-286
Author(s):  
N.M. Siafakas ◽  
D. Zois ◽  
I. Arapis ◽  
G. Tsoukalas ◽  
I. Sigalas
Keyword(s):  
Total Lung Capacity ◽  
Lung Capacity

Regulation of bronchomotor tone by lung inflation in asthmatic and nonasthmatic subjects

1981 ◽  
Vol 50 (5) ◽  
pp. 1079-1086 ◽  
Author(s):  
J. E. Fish ◽  
M. G. Ankin ◽  
J. F. Kelly ◽  
V. I. Peterman
Keyword(s):  
Airway Obstruction ◽  
Total Lung Capacity ◽  
Base Line ◽  
Deep Inspiration ◽  
Lung Inflation ◽  
Lung Capacity ◽  
Impaired Ability ◽  
Before And After ◽  
Airway Conductance ◽  
Bronchomotor Tone

We examined the effects of lung inflation on induced airway obstruction in 14 atopic asthmatic and 14 atopic nonasthmatic subjects. Subjects were challenged with aerosols of methacholine (MCh) and pollen antigen (Ag), and the effects of inflation were assessed with partial ad full flow-volume curves and by comparing airway conductance measurements before and after deep inspiration to total lung capacity (TLC). Whereas bronchoconstriction was transiently abolished or reduced with inspiration in nonasthmatics, these effects were absent or diminished in asthmatic subjects. Dissimilarities could not be explained by differences in base-line lung function or degree of obstruction produced. Deep inspiration had a greater effect in reducing airway obstruction produced with MCh than with Ag in nonasthmatics. In addition, atropine pretreatment had no effect on inspiration responses in asthmatics given Ag, suggesting that vagal reflexes were not the cause of an impaired ability to reduce bronchomotor tone by lung inflation. Our findings reveal the existence of an intrinsic means of regulating bronchomotor toe by active changes in lung volume and that such a mechanism is impaired in asthma. We suggest that airway hyperactivity in asthma is perhaps less a reflection of enhanced end-organ responsiveness than a reflection of this impaired capacity.

Radiographic Determination of Total Lung Capacity in Patients with Pneumonectomy

1997 ◽  
Vol 12 (3) ◽  
pp. 212-214 ◽  
Author(s):  
Thomas G. Vrachliotis ◽  
Justin D. Pearlman ◽  
George Baltopoulos ◽  
George Vrachliotis ◽  
Ion Bellenis ◽  
...  
Keyword(s):  
Total Lung Capacity ◽  
Lung Capacity

Alveolar liquid pressure measured by micropipettes in isolated dog lung

1982 ◽  
Vol 53 (3) ◽  
pp. 737-743 ◽  
Author(s):  
S. J. Lai-Fook ◽  
K. C. Beck
Keyword(s):  
Interstitial Fluid ◽  
Total Lung Capacity ◽  
Fluid Pressure ◽  
Transpulmonary Pressure ◽  
Initial Weight ◽  
Liquid Pressure ◽  
Lung Inflation ◽  
Main Determinant ◽  
Lung Capacity ◽  
Alveolar Surface

Micropipettes (2–5 microns), in conjunction with a servo-nulling system, were used to measure liquid pressure (Pliq) in subpleural alveoli of lobes of dog lungs made edematous by perfusing with plasma to a constant extravascular weight gain (W). Pliq was measured at fixed transpulmonary pressure (Ptp) in lungs whose W was more than 0.5 that of the initial weight (Wi). In six lobes at W/Wi = 0.6, Pliq, relative to alveolar pressure (Palv), was -2.6 +/- 0.4 cmH2O (mean +/- SE), -11.8 +/- 0.6, and -17.5 +/- 1.7 at deflation Ptp values of 5, 15, and 25 cmH2O, respectively. The Pliq increased to -2, -7, and -13.7, respectively, at W/Wi = 2.8. Based on a mean alveolar radius of 50 micron at Ptp at 25 cmH2O and values of Palv - Pliq, values for alveolar surface tension (tau) at W/Wi = 0.6 were 6, 30, and 44 dyn/cm at Ptp of 5, 15, and 25 cmH2O, respectively. In five other lobes at W/Wi = 0.5 and at 65 and 84% total lung capacity, tau was much higher on lung inflation than on deflation. If pericapillary interstitial fluid pressure (Pi) and Pliq were identical under edematous conditions, tau would be the main determinant of Pi.

scholarly journals Estimation of total lung capacity from chest radiography and chest CT in children: comparison with body plethysmography.

1995 ◽  
Vol 165 (1) ◽  
pp. 151-154 ◽  
Author(s):  
A E Schlesinger ◽  
D K White ◽  
G B Mallory ◽  
C F Hildeboldt ◽  
C B Huddleston
Keyword(s):  
Chest Radiography ◽  
Total Lung Capacity ◽  
Chest Ct ◽  
Body Plethysmography ◽  
Lung Capacity
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