-
Jornal Brasileiro de Pneumologia :... 2022To assess respiratory system impedance (Zrs) and spirometric parameters in children and adolescents with and without a history of preterm birth.
OBJECTIVE
To assess respiratory system impedance (Zrs) and spirometric parameters in children and adolescents with and without a history of preterm birth.
METHODS
We evaluated a sample of 51 subjects between 11 and 14 years of age: 35 who had a history of preterm birth (preterm group) and 16 who had been born at term (full-term group). Lung function was measured by spirometry, spectral oscillometry, and intra-breath oscillometry.
RESULTS
Neither spirometry nor spectral oscillometry revealed any statistically significant differences between the preterm and full-term groups. However, intra-breath oscillometry demonstrated significant differences between the two groups in terms of the change in resistance, reactance at end-inspiration, and the change in reactance (p < 0.05 for all).
CONCLUSIONS
Our findings suggest that abnormalities in Zrs persist in children and adolescents with a history of preterm birth and that intra-breath oscillometry is more sensitive than is spectral oscillometry. Larger studies are needed in order to validate these findings and to explore the impact that birth weight and gestational age at birth have on Zrs later in life.
Topics: Adolescent; Adult; Child; Female; Forced Expiratory Volume; Humans; Infant, Newborn; Lung; Oscillometry; Pregnancy; Premature Birth; Spirometry
PubMed: 35137869
DOI: 10.36416/1806-3756/e20210290 -
Tobacco Regulatory Science Jul 2020Health warning messages could be an effective means of communicating the health risks associated with waterpipe (WP) smoking. The objective of this study was to select a...
OBJECTIVES
Health warning messages could be an effective means of communicating the health risks associated with waterpipe (WP) smoking. The objective of this study was to select a message that conveyed the risks associated with WP smoking.
METHODS
A mixed-methods approach was used to explore the effectiveness of the Food and Drug Administration's (FDA's) mandated message, and others, among young adults using focus groups and surveys. Two focus group studies and one convenience survey were conducted to examine the FDA's mandated message and 11 other WP warning messages. The final study, conducted with a random sample of first-year university students, examined the effectiveness and reactance of the chosen message using previously validated items (scored on a 1-5 scale).
RESULTS
The FDA's mandated message did not resonate well with focus group participants. In the random sample of students, the top message () had high effectiveness (M = 4.49) and a low reactance (M = 2.12).
CONCLUSIONS
Our studies suggest that other messages are more effective for communicating the risks associated with WP smoking than the FDA's message for WP tobacco.
PubMed: 34337105
DOI: 10.18001/trs.6.4.5 -
Animals : An Open Access Journal From... Feb 2022While the prevalence of asthma is higher in boys than in girls during childhood, this tendency reverses at puberty, suggesting an effect of sex hormones on the disease...
While the prevalence of asthma is higher in boys than in girls during childhood, this tendency reverses at puberty, suggesting an effect of sex hormones on the disease pathophysiology. Fluctuations of asthma severity concurring with the estrus cycle are reported in women, but this phenomenon has never been investigated in mares to date. The objective of this exploratory study was to determine whether the estrus cycle modulates airway obstruction in severe equine asthma (SEA). Five mares with SEA during exacerbation of the disease were studied. The whole breath, expiratory and inspiratory resistance, and reactance were compared during the follicular and luteal phases of the estrus cycle. The reproductive tract was evaluated by rectal palpation, ultrasound, and serum progesterone levels. The inspiratory resistance and reactance improved during the luteal phase of the estrus cycle, and variation in progesterone levels and the dominant follicle size correlated with several lung function parameters. The fluctuation of airway dysfunction during the estrus cycle is noteworthy as deterioration of the disease could perhaps be expected and prevented by horse owners and veterinarians. Further studies are required to determine if the equine species could be a suitable model to evaluate the effects of sex hormones on asthma.
PubMed: 35203202
DOI: 10.3390/ani12040494 -
Respiratory Research Mar 2024The clinical significance of the impulse oscillometry-defined small airway bronchodilator response (IOS-BDR) is not well-known. Accordingly, this study investigated the...
BACKGROUND
The clinical significance of the impulse oscillometry-defined small airway bronchodilator response (IOS-BDR) is not well-known. Accordingly, this study investigated the clinical characteristics of IOS-BDR and explored the association between lung function decline, acute respiratory exacerbations, and IOS-BDR.
METHODS
Participants were recruited from an Early Chronic Obstructive Pulmonary Disease (ECOPD) cohort subset and were followed up for two years with visits at baseline, 12 months, and 24 months. Chronic obstructive pulmonary disease (COPD) was defined as a post-bronchodilator forced expiratory volume in 1 s (FEV)/forced vital capacity (FVC) ratio < 0.70. IOS-BDR was defined as meeting any one of the following criteria: an absolute change in respiratory system resistance at 5 Hz ≤ - 0.137 kPa/L/s, an absolute change in respiratory system reactance at 5 Hz ≥ 0.055 kPa/L/s, or an absolute change in reactance area ≤ - 0.390 kPa/L. The association between IOS-BDR and a decline in lung function was explored with linear mixed-effects model. The association between IOS-BDR and the risk of acute respiratory exacerbations at the two-year follow-up was analyzed with the logistic regression model.
RESULTS
This study involved 466 participants (92 participants with IOS-BDR and 374 participants without IOS-BDR). Participants with IOS-BDR had higher COPD assessment test and modified Medical Research Council dyspnea scale scores, more severe emphysema, air trapping, and rapid decline in FVC than those without IOS-BDR over 2-year follow-up. IOS-BDR was not associated with the risk of acute respiratory exacerbations at the 2-year follow-up.
CONCLUSIONS
The participants with IOS-BDR had more respiratory symptoms, radiographic structural changes, and had an increase in decline in lung function than those without IOS-BDR.
TRIAL REGISTRATION
Chinese Clinical Trial Registry, ChiCTR1900024643. Registered on 19 July, 2019.
Topics: Humans; Asthma; Bronchodilator Agents; Forced Expiratory Volume; Oscillometry; Pulmonary Disease, Chronic Obstructive; Respiratory Function Tests; Spirometry
PubMed: 38555433
DOI: 10.1186/s12931-024-02765-7 -
The Journal of Allergy and Clinical... May 2023A recent study demonstrated a significant correlation between bronchial biopsy airway remodeling and quantitative computed tomography looking at bronchial wall thickness.
BACKGROUND
A recent study demonstrated a significant correlation between bronchial biopsy airway remodeling and quantitative computed tomography looking at bronchial wall thickness.
OBJECTIVE
To identify clinical associations with bronchial wall thickness in moderate to severe asthma.
METHODS
Ninety-two respiratory physician-diagnosed Global Initiative for Asthma-defined patients with moderate to severe asthma were included in this retrospective cohort study. Blinded to all clinical data, 2 senior thoracic radiologists independently measured airway lumen and total airway area at 4 different bronchopulmonary segments using high-resolution computed tomography imaging. We calculated adjusted odds ratios with regard to the association of bronchial wall thickness with spirometry, oscillometry, exacerbations, and nasal polyps.
RESULTS
The pooled analysis for all 4 bronchopulmonary segments showed that an area under reactance curve greater than or equal to 1.0 kPa/L, an R5-R20 ratio (resistance heterogeneity between 5 and 20 Hz divided by total resistance [R5]) of 25% or more, having 2 or more exacerbations per year, and presence of nasal polyposis exhibited adjusted odds ratios of 3.54 (95% CI, 1.22-10.32), 2.89 (95% CI, 1.03-8.05), 4.17 (95% CI, 1.25-13.90), and 9.85 (95% CI, 2.33-41.74), respectively, in their association with a wall area thickness of 50% or more. These translated into a respective 72%, 65%, 76%, and 90% increased likelihood for a wall area thickness of 50% or more.
CONCLUSIONS
Bronchial wall thickness is associated with peripheral airways resistance and reactance, severe exacerbations, and nasal polyposis in persistent asthma.
Topics: Humans; Retrospective Studies; Asthma; Lung; Bronchi; Spirometry
PubMed: 36639055
DOI: 10.1016/j.jaip.2022.12.040 -
Revista Da Associacao Medica Brasileira... 2023This study aimed to investigate if there is any correlation between the quantitative computed tomography and the impulse oscillometry or spirometry results of...
OBJECTIVE
This study aimed to investigate if there is any correlation between the quantitative computed tomography and the impulse oscillometry or spirometry results of post-COVID-19 patients.
METHODS
The study comprised 47 post-COVID-19 patients who had spirometry, impulse oscillometry, and high-resolution computed tomography examinations at the same time. The study group consisted of 33 patients with quantitative computed tomography involvement, while the control group included 14 patients who did not have CT findings. The quantitative computed tomography technology was used to calculate percentages of density range volumes. The relationship between percentages of density range volumes for different quantitative computed tomography density ranges and impulse oscillometry-spirometry findings was statistically analyzed.
RESULTS
In quantitative computed tomography, the percentage of relatively high-density lung parenchyma, including fibrotic areas, was 1.76±0.43 and 5.65±3.73 in the control and study groups, respectively. The percentages of primarily ground-glass parenchyma areas were found to be 7.60±2.86 and 29.25±16.50 in the control and study groups, respectively. In the correlation analysis, the forced vital capacity% predicted in the study group was correlated with DRV%[(-750)-(-500)] (volume of the lung parenchyma that has density between (-750)-(-500) Hounsfield units), but no correlation with DRV%[(-500)-0] was detected. Also, reactance area and resonant frequency were correlated with DRV%[(-750)-(-500)], while X5 was correlated with both DRV%[(-500)-0] and DRV%[(-750)-(-500)] density. Modified Medical Research Council score was correlated with predicted percentages of forced vital capacity and X5.
CONCLUSION
After COVID-19, forced vital capacity, reactance area, resonant frequency, and X5 correlated with the percentages of density range volumes of ground-glass opacity areas in the quantitative computed tomography. X5 was the only parameter correlated with density ranges consistent with both ground-glass opacity and fibrosis. Furthermore, the percentages of forced vital capacity and X5 were shown to be associated with the perception of dyspnea.
Topics: Humans; Oscillometry; COVID-19; Spirometry; Thorax; Tomography, X-Ray Computed
PubMed: 37222321
DOI: 10.1590/1806-9282.20221427 -
International Journal of Chronic... 2020Oscillometry is a tool to measure respiratory impedance that requires minimal patients' effort. In patients with chronic obstructive pulmonary disease (COPD), the...
BACKGROUND
Oscillometry is a tool to measure respiratory impedance that requires minimal patients' effort. In patients with chronic obstructive pulmonary disease (COPD), the correlation of respiratory impedance at rest with exertional ventilatory parameters, including exercise tolerance, has scarcely been reported. In addition, the utility of oscillometric parameters might differ between the inspiratory and expiratory phases due to airflow obstruction during expiration, but the hypothesis had not been validated. The aim of the present study was to investigate whether oscillometric parameters are associated with exertional ventilatory parameters in patients with COPD.
METHODS
Fifty-five subjects with COPD who attended clinics at the National Hospital Organization Osaka Toneyama Medical Center performed spirometry, oscillometry, and cardiopulmonary exercise testing (CPET) within 2 weeks. The correlations between parameters of spirometry, oscillometry, and CPET were analyzed using Spearman's rank correlation coefficient, univariate, and multivariate analyses.
RESULTS
Respiratory reactance had better correlations with the CPET parameters than respiratory resistance. Moreover, inspiratory reactance at rest correlated with the CPET parameters stronger than expiratory reactance. In particular, inspiratory resonant frequency (Fres-ins) correlated with peak oxygen uptake (r=-0.549, p<0.01) and dead space to tidal volume ratio at peak exercise (r=0.677, p<0.01) and the best predicted expiratory tidal volume (V ex) at peak exercise of all the oscillometric parameters (r=-0.679, p<0.01). However, the correlation between Fres-ins and ex at peak exercise became weak in subjects with severe and very severe COPD during exercise.
CONCLUSION
Measurement of respiratory reactance is useful for the effortless evaluation of not only exertional ventilatory parameters but exercise tolerance in patients with COPD. The correlation of respiratory impedance with exertional ventilatory parameters can become weak in patients with advanced COPD; thus, the measurement of oscillometry might not be appropriate for evaluating exertional ventilatory parameters of patients with advanced COPD.
Topics: Exercise Test; Exercise Tolerance; Forced Expiratory Volume; Humans; Oscillometry; Pulmonary Disease, Chronic Obstructive; Spirometry
PubMed: 32764915
DOI: 10.2147/COPD.S260735 -
Journal of Applied Physiology... Sep 2022There is a poor understanding of why some patients with asthma experience recurrent exacerbations despite high levels of treatment. We compared measurements of...
There is a poor understanding of why some patients with asthma experience recurrent exacerbations despite high levels of treatment. We compared measurements of peripheral ventilation heterogeneity and respiratory system mechanics in participants with asthma who were differentiated according to exacerbation history, to ascertain whether peripheral airway dysfunction was related to exacerbations. Three asthmatic groups: "stable" (no exacerbations for >12 mo, = 18), "exacerbation-prone" (≥1 exacerbation requiring systemic corticosteroids within the last 12 mo, but stable for ≥1-mo, = 9), and "treated-exacerbation" (exacerbation requiring systemic corticosteroids within the last 1 mo, = 12) were studied. All participants were current nonsmokers with <10 pack yr smoking history. Spirometry, static lung volumes, ventilation heterogeneity from multibreath nitrogen washout (MBNW), and respiratory system mechanics from oscillometry were measured. The exacerbation-prone group compared with the stable group had slightly worse spirometry [forced expired volume in 1 s or FEV -score -3.58(1.13) vs. -2.32(1.06), = 0.03]; however, acinar ventilation heterogeneity [ -score 7.43(8.59) vs. 3.63(3.88), = 0.006] and respiratory system reactance [ cmHO·s·L -2.74(3.82) vs. -1.32(1.94), = 0.01] were much worse in this group. The treated-exacerbation group had worse spirometry but similar small airway function, compared with the stable group. Patients with asthma who exacerbate have worse small airway function as evidenced by increases in measured by MBNW and Δ from oscillometry, both markers of small airway dysfunction, compared with those that do not. This study assessed the relationship between peripheral airway function, measured by multiple breath nitrogen washout and oscillometry impedance, and exacerbation history. We found that those with a history of exacerbation in the last year had worse peripheral airway function, whereas those recently treated for an asthma exacerbation had peripheral airway function that was comparable to the stable group. These findings implicate active peripheral airway dysfunction in the pathophysiology of an asthma exacerbation.
Topics: Adrenal Cortex Hormones; Asthma; Humans; Lung; Nitrogen; Spirometry
PubMed: 35861519
DOI: 10.1152/japplphysiol.00103.2022 -
International Journal of Chronic... 2020Pulmonary rehabilitation for chronic obstructive pulmonary disease (COPD) reduces dyspnoea and improves exercise capacity and quality of life. The improvement in... (Comparative Study)
Comparative Study Observational Study
RATIONALE
Pulmonary rehabilitation for chronic obstructive pulmonary disease (COPD) reduces dyspnoea and improves exercise capacity and quality of life. The improvement in exercise capacity is variable and unpredictable, however. Respiratory system impedance obtained by forced oscillation technique (FOT) as a measure of ventilatory impairment in COPD may relate to improvement in exercise capacity with pulmonary rehabilitation. We aimed to determine if baseline FOT parameters relate to changes in exercise capacity following pulmonary rehabilitation.
METHODS
At the start of rehabilitation, 15 COPD subjects (mean(SD) 75.2(6.1) years, FEV1 z-score -2.61(0.84)) had measurements by FOT, spirometry, plethysmographic lung volumes and 6-minute walk distance (6MWD). Respiratory system resistance (Rrs) and reactance (Xrs) parameters as the mean over all breaths (R, X), during inspiration only (R, X), and expiratory flow limitation (DeltaXrs = X-X), were calculated. FOT and 6MWD measurements were repeated at completion of rehabilitation and 3 months after completion.
RESULTS
At baseline, Xrs measures were unrelated to 6MWD. X improved significantly with rehabilitation (from mean(SD) -2.35(1.02) to -2.04(0.85) cmHO.s.L, p=0.008), while other FOT parameters did not. No FOT parameters related to the change in 6MWD at program completion. Baseline X DeltaXrs, and FVC z-score correlated with the change in 6MWD between completion and 3 months after completion of rehabilitation (r=0.62, p=0.03; r=-0.65, p=0.02; and r=0.62, p=0.03, respectively); with worse ventilatory impairment predicting loss of 6MWD. There were no relationships between Rrs parameters, FEV1 or FEV1/FVC z-scores and changes in 6MWD.
CONCLUSION
Baseline reactance parameters may be helpful in predicting those patients with COPD at most risk of loss of exercise capacity following completion of pulmonary rehabilitation.
Topics: Aged; Aged, 80 and over; Exercise Tolerance; Female; Forced Expiratory Volume; Humans; Lung; Male; Oscillometry; Pilot Projects; Predictive Value of Tests; Prospective Studies; Pulmonary Disease, Chronic Obstructive; Recovery of Function; Respiratory Function Tests; Time Factors; Treatment Outcome; Vital Capacity; Walk Test
PubMed: 32021155
DOI: 10.2147/COPD.S225543 -
Frontiers in Medicine 2023To use minimally-invasive transcatheter electrical impedance spectroscopy measurements for tissue differentiation among healthy lung tissue and pathologic lung tissue...
PURPOSE
To use minimally-invasive transcatheter electrical impedance spectroscopy measurements for tissue differentiation among healthy lung tissue and pathologic lung tissue from patients with different respiratory diseases (neoplasm, fibrosis, pneumonia and emphysema) to complement the diagnosis at real time during bronchoscopic procedures.
METHODS
Multi-frequency bioimpedance measurements were performed in 102 patients. The two most discriminative frequencies for impedance modulus (|Z|), phase angle (PA), resistance (R) and reactance (Xc) were selected based on the maximum mean pair-wise Euclidean distances between paired groups. One-way ANOVA for parametric variables and Kruskal-Wallis for non-parametric data tests have been performed with tests. Discriminant analysis has also been performed to find a linear combination of features to separate among tissue groups.
RESULTS
We found statistically significant differences for all the parameters between: neoplasm and pneumonia ( < 0.05); neoplasm and healthy lung tissue ( < 0.001); neoplasm and emphysema (p < 0.001); fibrosis and healthy lung tissue ( ≤ 0.001) and pneumonia and healthy lung tissue ( < 0.01). For fibrosis and emphysema ( < 0.05) only in |Z|, R and Xc; and between pneumonia and emphysema ( < 0.05) only in |Z| and R. No statistically significant differences ( > 0.05) are found between neoplasm and fibrosis; fibrosis and pneumonia; and between healthy lung tissue and emphysema.
CONCLUSION
The application of minimally-invasive electrical impedance spectroscopy measurements in lung tissue have proven to be useful for tissue differentiation between those pathologies that leads increased tissue and inflammatory cells and those ones that contain more air and destruction of alveolar septa, which could help clinicians to improve diagnosis.
PubMed: 37113605
DOI: 10.3389/fmed.2023.1108237