Thoracic Gas Volume Measurements in Chronic Obstructive Pulmonary Disease by Low Frequency Ambient Pressure Changes

1988 ◽  
Vol 137 (2) ◽  
pp. 277-280 ◽  
Author(s):  
R. Peslin ◽  
B. Hannhart ◽  
C. Duvivier ◽  
J. M. Polu ◽  
C. Gallina
1988 ◽  
Vol 65 (3) ◽  
pp. 1444-1448
Author(s):  
B. D. Lyttle ◽  
C. Duvivier ◽  
G. M. Glass ◽  
M. E. Wohl ◽  
J. J. Fredberg

R. Peslin et al. measured thoracic gas volume (TGV) in adults using a new method employing low-frequency ambient pressure changes (APC) (J. Appl. Physiol. 62: 359-363, 1987). We extended that methodology and then tested the hypothesis that this technique was applicable to small mammals. TGV [at functional residual capacity (FRC)] by APC and by conventional Boyle's law was compared in 12 rabbits. The rabbits were anesthetized, tracheostomized, intubated, and placed in a pressure plethysmograph. Although in the method of Peslin et al. box pressure was oscillated at a single frequency, in our extension box pressure was oscillated simultaneously at two frequencies (0.1 and 0.2 Hz). Flow at the airway opening consisted of rapid events due to spontaneous breathing, superposed on slower events due to the alveolar gas compression. The slower events were analyzed to yield alveolar gas compliance and, by Boyle's law, FRC. FRC by APC was highly correlated to FRC by conventional plethysmography (r = 0.85). Compared with the methodology of Peslin et al., our extension relaxes a key limitation and yields systematically higher estimates of FRC. We conclude that this method is applicable to small mammals, despite an inherently more compliant chest wall, and that the methodological extension improves the estimate of FRC.


1987 ◽  
Vol 62 (1) ◽  
pp. 359-363
Author(s):  
R. Peslin ◽  
C. Duvivier ◽  
B. Hannhart ◽  
C. Gallina

When the whole body is exposed to sinusoidal variations of ambient pressure (delta Pam) at very low frequencies (f), the resulting compression and expansion of alveolar gas is almost entirely achieved by gas flow through the airways (Vaw). As a consequence thoracic gas volume (TGV) may be computed from the imaginary part (Im) of the delta Pam/Vaw relationship: TGV = PB/[2 pi f X Im(delta Pam/Vaw)], where PB is barometric minus alveolar water vapor pressure. The method was tested in 35 normal subjects and compared with body plethysmography. The subjects sat in a chamber connected to a large-stroke-volume reciprocating pump that brought about pressure swings of 40 cmH2O at 0.05 Hz. delta Pam and Vaw were digitally processed by fast Fourier transform to extract the low-frequency component from the much larger respiratory flow. Total lung capacities (TLC) obtained by ambient pressure changes and by plethylsmography were highly correlated (r = 0.959, p less than 0.001) and not significantly different (6.96 +/- 1.38 l vs. 6.99 +/- 1.38). TLC obtained by ambient pressure changes were not influenced by lowering the frequency to 0.03 Hz, adding an external resistance at the mouth, or increasing abdominal gas volume. We conclude that the method is practical and in agreement with body plethysmography in normal subjects.


2020 ◽  
Vol 30 (2) ◽  
pp. 184-191
Author(s):  
D. A. Punin ◽  
V. A. Milyagin ◽  
O. A. Kovaleva

The aim of the study was to identify the correlation between ventilation disorders of the lungs and the development of arterial stiffness in patients with chronic obstructive pulmonary disease (COPD).Methods. The following parameters were evaluated in the patients (n = 61) enrolled in the study: spirometry, bodyplethysmography, cardiac-ankle vascular index (CAVI) and an ancho-brachial vascular index. Additionally, the pulse wave propagation velocity was calculated in the area from the ostium of the aorta to the infragenicular arteries.Results. According to the study results, a direct correlation, characterized by moderate to noticeable strength, was found between the parameters of pulmonary ventilation (bronchial resistance, intrathoracic gas volume, residual lung volume (RLV), total lung capacity (TLC), RLV/TLC) and the CAVI parameter, characterizing vascular stiffness on the section from the aorta ostium to the infragenicular arteries. It was shown that the best method for assessing changes in blood vessels is CAVI, which is independent of the level of blood pressure at the moment of the study.Conclusion. It has been established that if there is a correlation between impaired ventilation and arterial stiffness, the systemic nature of the lesion in COPD is confirmed, which explains the high incidence of cardiovascular diseases in patients with COPD. 


PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7829 ◽  
Author(s):  
Ming-Lung Chuang ◽  
I-Feng Lin

Background In patients with chronic obstructive pulmonary disease (COPD), the independent contributions of individual lung function variables to outcomes may be lower when they are modelled together if they are collinear. In addition, lung volume measurements may not be necessary after spirometry data have been obtained. However, these hypotheses depend on whether forced vital capacity (FVC) can predict total lung capacity (TLC). Moreover, the definitions of hyperinflation and air trapping according to lung function variables overlap and need be clarified. Therefore, the aim of this study was to evaluate the relationships among various lung function parameters to elucidate these issues. Methods Demographic data and 26 parameters of full lung function were measured in 94 men with COPD and analyzed using factor and correlation analyses. Results Factor analysis revealed five latent factors. Inspiratory capacity (IC)/TLC and residual volume (RV)/TLC were most strongly correlated with all other lung volumes. IC/TLC, RV/TLC, and functional residual capacity (FRC)/TLC were collinear and were potential markers of air trapping, whereas TLC%, FRC%, and RV% were collinear and were potential markers of hyperinflation. RV/TLC >0.4 (or IC/TLC <0.4) was comparable with the ratio of forced expiratory volume in one second (FEV1) and FVC <0.7. FVC% and FEV1% were poorly correlated with TLC%. The correlation study showed that TLC%, RV/TLC, and FEV1% could be used to represent individual latent factors for hyperinflation, air trapping, inspiration, expiration, and obstruction. Combined with diffusion capacity%, these four factors could be used to represent comprehensive lung function. Conclusions This study identified collinear relationships among individual lung function variables and thus selecting variables with close relationships for correlation studies should be performed with caution. This study also differentiated variables for air trapping and lung hyperinflation. Lung volume measurements are still required even when spirometry data are available. Four out of 26 lung function variables from individual latent factors could be used to concisely represent lung function.


Author(s):  
O.S. Tyaglaya

According to numerous reports, the prevalence rate of systemic arterial hypertension in patients with chronic pulmonary diseases varies from 0.4 to 27.7%. The number of authors have shown a decrease in heart rate variability against the background of hypertension, mainly due to the SDNN (the standard deviation of the normal-to-normal RR intervals) and RMSSD (the root mean square of successive RR-interval differences), indicating a decrease in parasympathetic effects on the heart rhythm and a relative increase in sympathetic tone. Objective: to study changes in heart rate variability parameters depending on the level of apoptotic processes in patients with arterial hypertension against the background of chronic obstructive pulmonary disease. Materials and methods. We examined 25 men with a diagnosis of arterial hypertension stage II and chronic obstructive pulmonary disease stage II without clinically significant comorbidities, whose average age was 51.72±1.22; more than 80% of them were active smokers, pack-years index was 17.06±2.41, the harmful professional factor were indicated by 1/4 people. The verification of arterial hypertension was carried out in accordance with the Order of the Ministry of Health of Ukraine dated May 24, 2012 № 384. All patients were diagnosed with stage II of hypertension. Arterial hypertension degree was diagnosed in 12% patients – first, in 28% patients – second and in 60% patients, respectively, third. Participants expressed their willingness to be included in medical research. Results. Index SDNN statistically significantly (p<0.05) in parallel with the elevation of the values ​​of the marker of apoposis of caspase-9 decreased by 13.68%, comparing between groups of patients less and more than IV quartile according to the values ​​of caspase-9. The LF (Low Frequency power: frequency activity in the 0.04 - 0.15Hz range) value in patients with a cohort of less and more than IV quartile according to the values ​​of caspase-9 showed a statistically significant decrease by 32.67% (p <0.05). HF (High Frequency power: frequency activity in the 0.15 - 0.40Hz range) with an increase in the activity of apoptosis processes according to the values ​​of caspase-9 decreased most significantly significant, by 48.92% (p <0.05). To assess the direction, the tightness and the nature of the relationship between the indices between the studied variables, a regression analysis was conducted to construct a functional dependence. As independent argument (X) considered the level of caspase-9 activity, and as a dependent variable (Y) considered the indicator LF / HF (LF/HF Ratio: A ratio of Low Frequency to High Frequency). The obtained data indicated that the correlation between numerical variables in patients with caspase-9 level less than 4 quartiles had an unreliable character, while in patients with high expression of this cysteine ​​protease the correlation obtained with a high degree of accuracy and adequacy was approximated by the model of exponential form, and namely: Y = 4,0578 * exp (0,0901 * X) at R = 0,547, R2 = 0,30, normalized R2 = 0,29, p = 0,0083). Conclusion. Elevation of the state of the sympathetic part of the autonomic nervous system and a decrease in the activity of the parasympathetic part of the autonomic support, which can potentially be associated with an increased risk of serious cardiovascular cases in patients with this comorbidity, were found in patients with chronic obstructive pulmonary disease against the background of arterial hypertension.


2020 ◽  
Vol 29 (2) ◽  
pp. 864-872
Author(s):  
Fernanda Borowsky da Rosa ◽  
Adriane Schmidt Pasqualoto ◽  
Catriona M. Steele ◽  
Renata Mancopes

Introduction The oral cavity and pharynx have a rich sensory system composed of specialized receptors. The integrity of oropharyngeal sensation is thought to be fundamental for safe and efficient swallowing. Chronic obstructive pulmonary disease (COPD) patients are at risk for oropharyngeal sensory impairment due to frequent use of inhaled medications and comorbidities including gastroesophageal reflux disease. Objective This study aimed to describe and compare oral and oropharyngeal sensory function measured using noninstrumental clinical methods in adults with COPD and healthy controls. Method Participants included 27 adults (18 men, nine women) with a diagnosis of COPD and a mean age of 66.56 years ( SD = 8.68). The control group comprised 11 healthy adults (five men, six women) with a mean age of 60.09 years ( SD = 11.57). Spirometry measures confirmed reduced functional expiratory volumes (% predicted) in the COPD patients compared to the control participants. All participants completed a case history interview and underwent clinical evaluation of oral and oropharyngeal sensation by a speech-language pathologist. The sensory evaluation explored the detection of tactile and temperature stimuli delivered by cotton swab to six locations in the oral cavity and two in the oropharynx as well as identification of the taste of stimuli administered in 5-ml boluses to the mouth. Analyses explored the frequencies of accurate responses regarding stimulus location, temperature and taste between groups, and between age groups (“≤ 65 years” and “> 65 years”) within the COPD cohort. Results We found significantly higher frequencies of reported use of inhaled medications ( p < .001) and xerostomia ( p = .003) in the COPD cohort. Oral cavity thermal sensation ( p = .009) was reduced in the COPD participants, and a significant age-related decline in gustatory sensation was found in the COPD group ( p = .018). Conclusion This study found that most of the measures of oral and oropharyngeal sensation remained intact in the COPD group. Oral thermal sensation was impaired in individuals with COPD, and reduced gustatory sensation was observed in the older COPD participants. Possible links between these results and the use of inhaled medication by individuals with COPD are discussed.


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