scholarly journals LUNG FUNCTION STUDIES. IV. POSTURAL CHANGES IN RESPIRATORY DEAD SPACE AND FUNCTIONAL RESIDUAL CAPACITY 1

1950 ◽  
Vol 29 (11) ◽  
pp. 1437-1438 ◽  
Author(s):  
Ward S. Fowler
1963 ◽  
Vol 18 (3) ◽  
pp. 519-522 ◽  
Author(s):  
M. C. Hart ◽  
M. M. Orzalesi ◽  
C. D. Cook

The respiratory anatomic dead space has been measured by the single breath nitrogen washout method of Fowler in 73 normal subjects ranging from 4 to 42 years of age. The volume of the anatomic dead space correlated closely with height (Vd (ml) = 7.585 x Ht (cm)2.363 x 10-4·ɣ = .917), but also with body weight, surface area, and functional residual capacity. When compared on the basis of any of these parameters there was no significant difference between the anatomic dead space values for males and females. Comparisons with available data for newborn infants suggest that the value of the anatomic dead space has a relatively constant relation to height from birth to adulthood. Dead space appears to increase more rapidly than weight, surface area, and functional residual capacity during, at least, the early period of somatic growth. Note: (With the Technical Assistance of J. H. Shaw) Submitted on October 25, 1962


2017 ◽  
Vol 242 ◽  
pp. 12-18 ◽  
Author(s):  
Chris D. Harrison ◽  
Phi Anh Phan ◽  
Cathy Zhang ◽  
Daniel Geer ◽  
Andrew D. Farmery ◽  
...  

2018 ◽  
Vol 124 (5) ◽  
pp. 1155-1163 ◽  
Author(s):  
Jason H. T. Bates ◽  
Ubong Peters

The multibreath nitrogen washout (MBNW) test, as it is currently practiced, provides parameters of potential physiological significance that are derived from the relationship between the volume-normalized Phase III slope of the exhaled nitrogen fraction ([Formula: see text]) vs. the cumulative change in lung volume (V). Reliable evaluation of these parameters requires, however, that the subject breathe deeply and evenly, so that Phase III can be clearly identified in every breath. This places a burden on the test subject that may prove troublesome for young children and those with lung disease. Furthermore, the determination of the slope of Phase III requires that a decision be made as to when Phase II ends and Phase III begins. In an attempt to get around these methodological limitations, we develop here an alternative method of analysis based on a multicompartment model of the lung that accounts for the entire exhaled nitrogen profile, including Phases I, II, and III. Fitting this model to [Formula: see text] and V measured during a MBNW provides an estimate of the coefficient of variation of specific ventilation, as well as functional residual capacity, dead space volume, and a parameter that reflects structural asymmetry at the acinar level in the lung. In the present study, we demonstrate the potential utility of this modeling approach to the analysis of MBNW data. NEW & NOTEWORTHY The multibreath nitrogen washout test potentially provides important physiological information about regional ventilation heterogeneity throughout the lung, but the conventional analysis requires the subject to breathe deeply and regularly, which is not always practical. We have developed a model-based analysis method that avoids this limitation and that also provides measures of functional residual capacity and dead space volume, thereby expanding the applicability and scope of the method.


2019 ◽  
Vol 2 (3) ◽  
pp. 91
Author(s):  
Arief Bakhtiar ◽  
Wirya Sastra Amran

Respiration or breathing is the body’s attempt to meet the needs of O2 in the metabolic process and emit CO2 as a result of intermediary metabolism by lung and respiratory organs together so that the resulting cardiovascular oxygen rich blood. Respiration has three phases: ventilation, diffusion, perfusion. The situation is said to somebody normal lung function if the work process of ventilation, diffusion, perfusion, and the relationship between ventilation to perfusion of the person is in a relaxed state resulted in the partial pressure of arterial blood gas (PaO2 and PaCO2) were normal. Examination of lung function has an important role in assessing a lung function. However, the thing to know that these checks are supporting and quite helpful in making a specific diagnosis. With spirometry examination can be known or determined all the static volume except residual volume and respiratory capacity than the capacity of residual volume that contains components such as total lung capacity and functional residual capacity. Functional residual capacity measured by special methods such as by using the inert gas helium (helium dilution test), N2 washout and bodyplethysmograph. Some static pulmonary function parameters can interpret any kind of disturbance in the lungs. In restrictive disorders in general decreased static lung volumes. While the obstruction interference parameters are quite significant, namely an increase in residual volume (RV), functional residual capacity (FRC) and the ratio of residual volume and total lung capacity (RV/TLC)


1980 ◽  
Vol 49 (4) ◽  
pp. 655-662 ◽  
Author(s):  
L. Forkert

The effect of impeding regional chest wall excursion on regional lung function was assessed. Fourteen subjects were studied while seated in a volume-displacement plethysmography. The lower rib cage and epigastrium were restricted with an inextensible binder. Because such restriction increases lung recoil and diminishes functional residual capacity (FRC), all measurements were made at the unstrapped FRC (FRCus). Regional excursion of the chest wall was measured with magnetometers placed anteroposteriorly at the sternomanubrial angle, the xyphoid, and umbilicus and transversely at the level of the xyphoid at the midaxillary line. Regional lung function was assessed by measuring the distribution of inspired boluses and washout of 133Xe with scintillation detectors positioned against the subject's back at the apical, middle, and basal regions. Restriction of the lower chest wall impeded expansion of the lower rib cage and diminished the distribution of inspired gas to and washout of the lung bases. The upper rib cage expanded normally and was associated with an increased distribution of inspired gas and normal distribution of washout to the apices. These results suggest that regional lung function was dependent on regional rib cage excursion.


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