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Canadian Respiratory Journal 2022Impairment of pulmonary function was evaluated in chronic bronchitis patients with preserved ratio impaired spirometry (PRISm). We retrospectively collected clinical...
Impairment of pulmonary function was evaluated in chronic bronchitis patients with preserved ratio impaired spirometry (PRISm). We retrospectively collected clinical data from 157 chronic bronchitis (CB) and 186 chronic obstructive pulmonary disease (COPD) patients between October 2014 and September 2017. These patients were assigned to three groups: control (normal pulmonary function), PRISm (forced expiratory volume in 1 second [FEV1]/forced vital capacity [FVC] ≥ 0.7, FEV1 < 80% of predicted value), and COPD (FEV1/FVC <0.7) groups. Because small airway function was the main focus, in the COPD group, only patients in accordance with the Global Initiative for Chronic Obstructive Lung Disease (GOLD) grades 1 and 2 were included. Evaluation of pulmonary function (including impulse oscillometry) was performed and compared among these groups. Compared with the control group, the PRISm and COPD groups showed statistically significant differences in the predicted FEV1% ( < 0.001), maximal expiratory flow (MEF) 25% ( < 0.001), MEF50% ( < 0.001), maximal midexpiratory flow (MMEF) 25-75% ( < 0.001), residual volume (RV)/total lung capacity (TLC; < 0.001), FVC% ( < 0.001), total respiratory resistance and proximal respiratory resistance (R5-R20; < 0.001), respiratory system reactance at 5 Hz (X5; < 0.001), resonant frequency (Fres; < 0.001), and area of reactance (Ax; < 0.001). However, the predicted FEV1% and RV/TLC were similar between the PRISm and COPD groups (=0.992 and 0.122, respectively). PRISm is a nonspecific pattern of pulmonary function that indicates small airway dysfunction and may increase the risk of transformation to obstructive ventilation dysfunction. This trial is registered with ChiCTR-OCH-14004904.
Topics: Bronchitis, Chronic; Forced Expiratory Volume; Humans; Lung; Oscillometry; Pulmonary Disease, Chronic Obstructive; Retrospective Studies; Spirometry
PubMed: 36060828
DOI: 10.1155/2022/4201786 -
International Journal of Chronic... 2021To explore the correlation of respiratory resistance in stable COPD patients measured by broadband 3-dimensional impulse oscillometry (3D-IOS) and traditional pulmonary...
OBJECTIVE
To explore the correlation of respiratory resistance in stable COPD patients measured by broadband 3-dimensional impulse oscillometry (3D-IOS) and traditional pulmonary function test (PFT). To access the diagnostic value of 3D-IOS in COPD.
METHODS
A total of 107 COPD patients and 61 healthy subjects as controls were chosen to collect and statistically analyze the data of R5, R5-R20, R20, X5 and Fres measured by broadband 3D-IOS and FEV1%pred, FVC%pred and FEV1/FVC by PFTs. The diagnostic value of broadband 3D-IOS parameters in COPD was evaluated by receiver operating characteristic curve (ROC). 3D-colored images used to show dynamic changes of respiratory resistance in COPD.
RESULTS
The COPD group showed significant increases in R5, R20, R5-R20 and Fres, and a decrease in X5 (<0.05). With the increase of GOLD grade, R5, R5-R20 and Fres increased whereas X5 decreased (<0.05). Compared with FEV1%pred, FVC%pred and FEV1/FVC in the COPD group, R5, R5-R20 and Fres were negatively collated (<0.05), whereas X5 was positively collated (<0.01). R20 was uncorrelated with the traditional lung function parameters (>0.05). Fres and FEV1/FVC (r=-0.467), and X5 and FEV1%pred (r=0.412) showed the strongest correlation. The AUC of R5, R5-R20, X5 and Fres was 0.7808, 0.7659, 0.8947 and 0.9095, respectively. Typical 3D-colored images of COPD displayed a green pattern in the inhalation phase and yellow-red-blue graduation in the expiration phase.
CONCLUSION
R5, R5-R20, X5 and Fres measured by broadband 3D-IOS can reflect the change of respiratory resistance in COPD. And they have good correlation with the traditional lung function parameters (FEV1%pred, FVC%pred, FEV1/FVC). Fres has the highest diagnostic accuracy. Comprehensive analysis of R5, R5-R20, Fres and X5 helps to determine the degree of respiratory obstruction in COPD. X5 and Fres can reflect changes in lung tissue compliance. 3D-colored images can visually show the change of respiratory resistance and reactance in COPD.
Topics: Forced Expiratory Volume; Humans; Oscillometry; Pulmonary Disease, Chronic Obstructive; Respiratory Function Tests; Spirometry
PubMed: 33574662
DOI: 10.2147/COPD.S285927 -
Environmental Research Nov 2022The small size and large surface area of ultrafine particles (UFP) enhance their ability to deposit in the lung periphery and their reactivity. The Ultrafine Particles...
The small size and large surface area of ultrafine particles (UFP) enhance their ability to deposit in the lung periphery and their reactivity. The Ultrafine Particles from Traffic Emissions and Children's Health (UPTECH) cross-sectional study was conducted in 8-11-year-old schoolchildren attending 25 primary (elementary) schools, randomly selected from the Brisbane Metropolitan Area, Queensland, Australia. Main study findings outlined indirect evidence of distal airway deposition (raised C reactive protein) but as yet, there is no direct evidence in the literature of effects of UFP exposure on peripheral airway function. We present further UPTECH study data from two sensitive peripheral airway function tests, Oscillometry and Multiple Breath Nitrogen Washout (MBNW), performed in 577 and 627 children (88% and 96% of UPTECH study cohort) respectively: mean(SD) age 10.1(0.9) years, 46% male, with 50% atopy and 14% current asthma. Bayesian generalised linear mixed effects regression models were used to estimate the effect of UFP particle number count (PNC) exposure on key oscillometry (airway resistance, (Rrs), and reactance, (Xrs)) and MBNW (lung clearance index, (LCI) and functional residual capacity, (FRC)) indices. We adjusted for age, sex, and height, and potential confounders including socio-economic disadvantage, PM and NO exposure. All models contained an interaction term between UFP PNC exposure and atopy, allowing estimation of the effect of exposure on non-atopic and atopic students. Increasing UFP PNC was associated with greater lung stiffness as evidenced by a decrease in Xrs [mean (95% credible interval) -1.63 (-3.36 to -0.05)%] per 1000#.cm]. It was also associated with greater lung stiffness (decrease in Xrs) in atopic subjects across all models [mean change ranging from -2.06 to -2.40% per 1000#.cm]. A paradoxical positive effect was observed for Rrs across all models [mean change ranging from -1.55 to -1.70% per 1000#.cm] (decreases in Rrs indicating an increase in airway calibre), which was present for both atopic and non-atopic subjects. No effects on MBNW indices were observed. In conclusion, a modest detrimental effect of UFP on peripheral airway function among atopic subjects, as assessed by respiratory system reactance, was observed extending the main UPTECH study findings which reported a positive association with a biomarker for systemic inflammation, C-reactive protein (CRP). Further studies are warranted to explore the pathophysiological mechanisms underlying increased respiratory stiffness, and whether it persists through to adolescence and adulthood.
Topics: Air Pollutants; Bayes Theorem; Biomarkers; Child; Cross-Sectional Studies; Female; Humans; Male; Particle Size; Particulate Matter
PubMed: 35820650
DOI: 10.1016/j.envres.2022.113860 -
Pediatric Pulmonology Aug 2020Several studies have shown that exposure to air pollutants affects lung growth and development and can result in poor respiratory health in early life.
BACKGROUND
Several studies have shown that exposure to air pollutants affects lung growth and development and can result in poor respiratory health in early life.
METHODS
We included a subsample of 772 Mexican preschoolers whose mothers participated in a Prenatal Omega-3 fatty acid Supplements, GRowth, And Development birth cohort study with the aim to evaluate the impact of prenatal exposure to volatile organic compounds and nitrogen oxides on lung function measured by oscillation tests. The preschoolers were followed until 5 years of age. Anthropometric measurements and forced oscillation tests were performed at 36, 48, and 60 months of age. Information on sociodemographic and health characteristics was obtained during follow up. Prenatal exposure to volatile organic compounds and nitrogen oxides was evaluated using a land use regression models and the association between them was tested using a lineal regression and longitudinal linear mixed effect models adjusting for potential confounders.
RESULTS
Overall, the mean (standard deviation) of the measurements of respiratory system resistance and respiratory system reactance at 6, 8, and 10 Hz during the follow-up period was 11.3 (2.4), 11.1 (2.4), 10.3 (2.2) and -5.2 (1.6), -4.8 (1.7), and -4.6 hPa s L (1.6), respectively. We found a significantly positive association between respiratory resistance (β = 0.011; 95%CI: 0.001, 0.023) (P < .05) and prenatal exposure to nitrogen dioxide and a marginally negatively association between respiratory reactance (β = -11.40 95%CI: -25.26, 1.17 and β = -11.91 95%CI: -26.51, 1.43) (P = .07) and prenatal exposure to xylene.
CONCLUSION
Prenatal exposure to air pollutants was significantly associated with the alteration of lung function measured by oscillation tests in these preschool children.
Topics: Air Pollutants; Child, Preschool; Cohort Studies; Environmental Exposure; Female; Humans; Lung; Male; Maternal-Fetal Exchange; Nitrogen Oxides; Pregnancy; Prenatal Exposure Delayed Effects; Respiratory Function Tests; Volatile Organic Compounds
PubMed: 32510180
DOI: 10.1002/ppul.24889 -
Scientific Reports Nov 2022The effect of anti-vascular endothelial growth factor on neonatal lung development was inconclusive. To evaluate pulmonary function in school-age children who have...
The effect of anti-vascular endothelial growth factor on neonatal lung development was inconclusive. To evaluate pulmonary function in school-age children who have received intravitreal bevacizumab (IVB) for retinopathy of prematurity (ROP), this study included 118 school-aged children who were grouped into three groups: full-term control children (group 1), preterm children who had not received IVB treatment (group 2) and preterm children with ROP who had received IVB treatment (group 3). Pulmonary function was measured by spirometry and impulse oscillometry. Pulmonary function was significantly better in group 1 than in groups 2 and 3 (all p < 0.05 in forced vital capacity (FVC), forced expiratory volume in 1 s (FEV), forced expiratory flow between 25 and 75% of FVC (FEF), and respiratory resistance at 5 Hz and difference between respiratory resistance at 5 and 20 Hz (R5-R20). There were no statistically significant differences between group 2 and group 3 in all pulmonary function parameters, including FVC, FEV, ratio of FEV to FVC, FEF, R5, R20, R5-R20, and respiratory reactance at 5 Hz. In conclusion, our study revealed that preterm infants receiving IVB for ROP had comparable pulmonary function at school age to their preterm peers who had not received IVB treatment.
Topics: Infant; Child; Humans; Infant, Newborn; Bevacizumab; Retinopathy of Prematurity; Intravitreal Injections; Infant, Premature; Forced Expiratory Volume; Lung
PubMed: 36335152
DOI: 10.1038/s41598-022-22338-2 -
Journal of Applied Physiology... Dec 2019Bronchodilation alters both respiratory system resistance (Rrs) and reactance (Xrs) in asthma, but how changes in Rrs and Xrs compare, and respond differently in health...
Bronchodilation alters both respiratory system resistance (Rrs) and reactance (Xrs) in asthma, but how changes in Rrs and Xrs compare, and respond differently in health and asthma, in reflecting the contributions from the large and small airways has not been assessed. We assessed reversibility using spirometry and oscillometry in healthy and asthma subjects. Using a multibranch airway-tree model with the mechanics of upper airway shunt, we compared the effects of airway dilation and small airways recruitment to explain the changes in Rrs and Xrs. Bronchodilator decreased Rrs by 23.0 (19.0)% in 18 asthma subjects and by 13.5 (19.5)% in 18 healthy subjects. Estimated respiratory system elastance (Ers) decreased by 23.2 (21.4)% in asthma, with no significant decrease in healthy subjects. With the use of the model, airway recruitment of 15% across a generation of the small airways could explain the changes in Ers in asthma with no recruitment in healthy subjects. In asthma, recruitment accounted for 40% of the changes in Rrs, with the remaining explained by airway dilation of 6.8% attributable largely to the central airways. Interestingly, the same dilation magnitude explained the changes in Rrs in healthy subjects. Shunt only affected Rrs of the model. Ers was unaltered in health and unaffected by shunt in both groups. In asthma, Ers changed comparably to Rrs and could be attributed to small airways, while the change in Rrs was split between large and small airways. This implies that in asthma Ers sensed through Xrs may be a more effective measure of small airways obstruction and recruitment than Rrs. This is the first study to quantify to relative contributions of small and large airways to bronchodilator response in healthy subjects and patients with asthma. The response of the central airways to bronchodilator was similar in magnitude in both study groups, whereas the response of the small airways was significant among patients with asthma. These results suggest that low-frequency reactance and derived elastance are both sensitive measures of small airway function in asthma.
Topics: Adult; Airway Resistance; Asthma; Bronchioles; Bronchodilator Agents; Female; Humans; Male; Middle Aged; Models, Biological; Young Adult
PubMed: 31647721
DOI: 10.1152/japplphysiol.01131.2018 -
Respirology (Carlton, Vic.) Nov 2021The link between respiratory and vascular health is well documented in adult populations. Impaired lung function is consistently associated with thicker arteries and...
BACKGROUND AND OBJECTIVE
The link between respiratory and vascular health is well documented in adult populations. Impaired lung function is consistently associated with thicker arteries and higher incidence of cardiovascular disease. However, there are limited data on this relationship in young children and the studies that exist have focussed on populations at high risk of cardiorespiratory morbidity. We determined if an association exists between respiratory and cardiovascular function in young children and, if so, whether it is confounded by known cardiorespiratory risk factors.
METHODS
Respiratory and vascular data from a prospective cohort study established to evaluate the health implications 3 years after coal mine fire smoke exposure in children aged 3-5 years were used. Respiratory function was measured using the forced oscillation technique and included resistance at 5 Hz (R ), reactance at 5 Hz (X ) and area under the reactance curve (AX). Vascular health was measured by carotid intima-media thickness (ultrasound) and pulse wave velocity (arterial tonometry). Regression analyses were used to examine the relationship between the respiratory Z-scores and cardiovascular measures. Subsequent analyses were adjusted for potential confounding by maternal smoking during pregnancy, maternal education and exposure to fine particulate matter <2.5 μm in aerodynamic diameter (PM ).
RESULTS
Peripheral lung function (X and AX), but not respiratory system resistance (R ), was associated with vascular function. Adjustment for maternal smoking, maternal education and early life exposure to PM had minimal effect on these associations.
CONCLUSION
These observations suggest that peripheral lung stiffness is associated with vascular stiffness and that this relationship is established early in life.
Topics: Adult; Carotid Intima-Media Thickness; Child; Child, Preschool; Female; Fires; Humans; Particulate Matter; Pregnancy; Prospective Studies; Pulse Wave Analysis
PubMed: 34339550
DOI: 10.1111/resp.14117 -
Respiratory Care Jan 2024Jet nebulizers are commonly used for bronchodilator therapy in COPD. High-flow nasal cannula with vibrating mesh nebulizer (HFNC-VMN) is a recently developed system;... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
Jet nebulizers are commonly used for bronchodilator therapy in COPD. High-flow nasal cannula with vibrating mesh nebulizer (HFNC-VMN) is a recently developed system; however, few studies have compared the efficacy of bronchodilator administration via HFNC-VMN to jet nebulizer in stable COPD. This study aimed to compare the effect of salbutamol administered via HFNC-VMN versus jet nebulizer on airway and lung function in subjects with stable COPD.
METHODS
This randomized non-inferiority crossover physiologic study enrolled subjects with stable COPD. Salbutamol was nebulized via HFNC-VMN or jet nebulizer in random order with a 4-h washout period between crossover sequences. Spirometry, lung volume, and impulse oscillometry were performed at baseline and after each intervention. The primary outcome was change in FEV from baseline. Secondary outcomes included changes in other respiratory-related parameters and nebulization time compared between the 2 devices.
RESULTS
Seventeen subjects were enrolled. HFNC-VMN and jet nebulizer both significantly improved FEV from baseline ( = .005 and = .002, respectively). The difference between respiratory resistance at 5 Hz and 20 Hz significantly decreased after HFNC-VMN compared to baseline ( = .02), while no significant change was observed after jet nebulizer ( = .056). Area of reactance and resonant frequency of reactance were both significantly decreased ( = .035 and = .03, respectively), and respiratory reactance at 5 Hz significantly increased ( = .02) in the HFNC-VMN group compared to baseline indicating improved lung mechanics, with no significant changes with the jet nebulizer. HFNC-VMN had a shorter nebulization time (6 [5-9] min vs 20 [16-22] min, respectively, < .001).
CONCLUSIONS
Bronchodilator therapy via HFNC-VMN was not inferior to jet nebulizer for subjects with stable COPD and can significantly improve airway oscillometry mechanics and decrease nebulization time compared to jet nebulizer.
Topics: Humans; Administration, Inhalation; Albuterol; Bronchodilator Agents; Cannula; Nebulizers and Vaporizers; Pulmonary Disease, Chronic Obstructive; Respiratory Aerosols and Droplets; Cross-Over Studies
PubMed: 37607815
DOI: 10.4187/respcare.11139 -
The Clinical Respiratory Journal Feb 2022The literature provides some evidence of peripheral airways key role in the pathogenesis of asthma. However, the extent to which lung periphery including acinar zone...
OBJECTIVE
The literature provides some evidence of peripheral airways key role in the pathogenesis of asthma. However, the extent to which lung periphery including acinar zone contribute to asthma activity and control in pediatric population is unclear. Therefore, the aim of the study was to estimate peripheral airways involvement in children with asthma exacerbation and stable asthma simultaneously via different pulmonary function tests.
METHODS
Children with asthma exacerbation (n = 20) and stable asthma (n = 22) performed spirometry, body plethysmography, exhaled nitric oxide, impulse oscillometry (IOS), and multiple-breath washout (MBW).
RESULTS
Peripheral airway's function indexes were increased in children with asthma, particularly in group with asthma exacerbation when compared with stable asthma group. The prevalence of abnormal results was significantly higher in asthma exacerbation. All children with asthma exacerbation had conductive ventilation inhomogeneity; 76% had acinar ventilation inhomogeneity. According to IOS measurements, resistance and reactance were within normal range, but other IOS parameters were significantly higher in children with asthma exacerbation compared with stable asthma group. The 36% of children with acute asthma had air trapping.
CONCLUSION
Significant involvement of peripheral airways was observed in children with asthma, particularly in asthma exacerbation, which determine lung periphery as important additional target for therapy and provide new insights into pathophysiological process of pediatric asthma.
Topics: Asthma; Child; Exhalation; Humans; Lung; Respiratory Function Tests; Spirometry
PubMed: 34676678
DOI: 10.1111/crj.13456 -
Journal of Thoracic Disease Mar 2021Respiratory function declines after lung resection. However, perioperative changes in respiratory impedance and their clinical significance are unclear. The forced...
BACKGROUND
Respiratory function declines after lung resection. However, perioperative changes in respiratory impedance and their clinical significance are unclear. The forced oscillation technique can measure respiratory impedance during quiet breathing and possibly early after surgery. We investigated respiratory impedance changes before and after lung lobectomy and examined the correlation of impedance with clinical factors.
METHODS
We prospectively included patients who underwent lobectomy between February 2018 and March 2020 and measured respiratory impedance by forced oscillation preoperatively and postoperative days 1 and 7. We statistically analyzed changes in perioperative forced oscillation measurements and their correlation with clinical factors, including subjective symptoms. The modified British Medical Research Council scale and the chronic obstructive pulmonary disease (COPD) assessment test were used for scoring subjective symptoms.
RESULTS
Forty-four subjects were included, in whom respiratory impedance could be measured from postoperative day 1. The respective mean values for forced oscillation measurements preoperatively and at postoperative days 1 and 7 were as follows: respiratory resistance, 5 Hz: 2.28, 2.77, and 2.75; respiratory resistance, 20 Hz: 2.00, 2.36, and 2.32; difference in respiratory resistance at 5 and 20 Hz: 0.28, 0.40, and 0.43; respiratory reactance, 5 Hz: -0.31, -0.65, and -0.56; resonant frequency: 7.45, 10.41, and 9.81; and low-frequency reactance area: 1.33, 3.27, and 2.84. These changes were statistically significant (P<0.01). Besides the difference in respiratory resistance at 5 and 20 Hz, all other measurements on postoperative day 7 were relatively weakly correlated with the modified Medical Research Council scale score at this time point (all P<0.05). Respiratory complications correlated with the respiratory resistance difference, respiratory reactance, and resonant frequency on day 7 (R =0.415, -0.421, and 0.441), while the latter also correlated with postoperative hypoxemia on day 1 (R =0.433).
CONCLUSIONS
Respiratory impedance was measurable even early after surgery and significantly changed postoperatively. As the sample size was small and appeared to be biased, assessing respiratory impedance and clinical factors in detail was difficult. Since respiratory impedance is suggested to be associated with clinical factors that affect the postoperative course, it is necessary to accumulate cases and observe them over longer periods.
PubMed: 33841928
DOI: 10.21037/jtd-20-3090