-
Clinics (Sao Paulo, Brazil) 2024Studies suggest peripheral airway abnormalities in Pulmonary Arterial Hypertension (PAH). Impulse Oscillometry (IOS) is a noninvasive and sensitive technique for...
INTRODUCTION
Studies suggest peripheral airway abnormalities in Pulmonary Arterial Hypertension (PAH). Impulse Oscillometry (IOS) is a noninvasive and sensitive technique for assessing the small airways. It evaluates the impedance of the respiratory system ‒ Resistance (R) and reactance (X) ‒ to a pulse of sound waves sent to the lungs, in a range of frequencies (5‒20 Hz).
METHOD
Resistance variables: R5, R20, R5-R20 and reactance variables: AX (reactance area) and Fres (resonance frequency). The aim is to evaluate R and X in patients with idiopathic PAH (IPAH) and to investigate whether there is a correlation between IOS and spirometry.
RESULTS
Thirteen IPAH patients and 11 healthy subjects matched for sex and age underwent IOS and spirometry. IPAH patients had lower FVC and FEV values (p < 0.001), VEF/CVF (p = 0.049) and FEF 25-75 (p = 0.006) than healthy patients. At IOS, IPAH patients showed lower tidal volumes and higher AX (p < 0.05) compared to healthy individuals, and 53.8 of patients had R5-R20 values ≥ 0.07 kPa/L/s. Correlation analysis: X5, AX, R5-R20 and Fres showed moderate correlation with FVC (p = 0.036 r = 0.585, p = 0.001 r = -0.687, p = 0.005 r = -0.726 and p = 0.027 r = -0.610); Fres (p = 0.012 r = -0.669) and AX (p = 0.006 r = -0.711) correlated with FEV; [R5 and R20, (R5-R20)] also correlated with FEV (p < 0.001 r = -0.573, p = 0.020 r = -0.634 and p = 0.010 r = -0.683, respectively) in the IPAH group. There were also moderate correlations of FEF 25-75 % with Z5 (p = 0.041), R5 (p = 0.018), Fres (p = 0.043) and AX (p = 0.023).
DISCUSSION
Patients showed changes suggestive of increased resistance and reactance in the IOS compared to healthy individuals, and the IOS findings showed a good correlation with spirometry variables.
Topics: Humans; Pulmonary Arterial Hypertension; Oscillometry; Forced Expiratory Volume; Respiratory Function Tests; Lung; Spirometry
PubMed: 38490138
DOI: 10.1016/j.clinsp.2023.100313 -
Journal of Equine Veterinary Science Apr 2024Equine asthma (EA) is a respiratory syndrome associated with the increase of different leukocyte populations in the bronchoalveolar lavage fluid (BALF). Its pathogenetic...
Equine asthma (EA) is a respiratory syndrome associated with the increase of different leukocyte populations in the bronchoalveolar lavage fluid (BALF). Its pathogenetic mechanisms remain unclear. This study aimed to evaluate the associations between the mRNA expression of different cytokines in the BALF, different EA subtypes and lung function. Fifteen horses underwent physical examination, airway endoscopy, BALF cytology and lung function testing (8/15). One horse did not have evidence of EA and was used as healthy reference, while the others were classified as affected by neutrophilic or mixed granulocytic EA. Cells isolated from the residual BALF were used for IL-1β, IL-2, IFN-γ, IL-4, IL-17A genes expression by quantitative RT-PCR., Cytokine expression was compared between groups, and their correlations with BALF leukocyte and lung function were evaluated. IL-1β expression was positively correlated with BALF neutrophils count (p=0.038, r=0.56) and with increased expiratory resistance (p=0.047, r=0.76). IFN-γ was correlated with BALF mast cells (p=0.029, r=0.58). IL-4 was higher in horses with mixed granulocytic EA than neutrophilic (p=0.008), positively correlated with BALF mast cells (p=0.028, r=0.59) and inversely with whole-breath (p=0.046, r=-0.76) and expiratory reactance (p=0.003, r=-0.93). Finally, IL-17A was inversely correlated with expiratory reactance (p=0.009, r=-0.92). These results support that multiple immune responses are involved in EA pathogenesis; innate, Th2, and Th17 responses. Innate immunity appeared associated with neutrophilic inflammation, and Th2 response with increased mast cells. The role of Th1 response in EA remains questionable.
Topics: Horses; Animals; Cytokines; Interleukin-17; Interleukin-4; Bronchoalveolar Lavage; Asthma; RNA, Messenger; Horse Diseases
PubMed: 38423374
DOI: 10.1016/j.jevs.2024.105033 -
Scientific Reports Feb 2024Airborne transmission of pathogens plays a major role in the spread of infectious diseases. Aerosol particle production from the lung is thought to occur in the...
Airborne transmission of pathogens plays a major role in the spread of infectious diseases. Aerosol particle production from the lung is thought to occur in the peripheral airways. In the present study we investigated eighty lung-healthy subjects of two age groups (20-39, 60-76 years) at rest and during exercise whether lung function parameters indicative of peripheral airway function were correlated with individual differences in aerosol particle emission. Lung function comprised spirometry and impulse oscillometry during quiet breathing and an expiratory vital capacity manoeuvre, using resistance (R5) and reactance at 5 Hz (X5) as indicators potentially related to peripheral airway function. The association between emission at different ventilation rates relative to maximum ventilation and lung function was assessed by regression analysis. In multiple regression analyses including age group, only vital capacity manoeuvre R5 at 15% to 50% of end-expiratory vital capacity as well as quiet breathing X5 were independently linked to particle emission at 20% to 50% of maximum ventilation, in addition to age group. The fact that age as predictive factor was still significant, although to a lower degree, points towards further effects of age, potentially involving surface properties not accounted for by impulse oscillometry parameters.
Topics: Humans; Young Adult; Adult; Airway Resistance; Oscillometry; Lung; Respiratory Function Tests; Spirometry; Forced Expiratory Volume
PubMed: 38409397
DOI: 10.1038/s41598-024-55117-2 -
Respiratory Research Feb 2024Intra-breath oscillometry has been proposed as a sensitive means of detecting airway obstruction in young children. We aimed to assess the impact of early life wheezing...
BACKGROUND
Intra-breath oscillometry has been proposed as a sensitive means of detecting airway obstruction in young children. We aimed to assess the impact of early life wheezing and lower respiratory tract illness on lung function, using both standard and intra-breath oscillometry in 3 year old children.
METHODS
History of doctor-diagnosed asthma, wheezing, bronchiolitis and bronchitis and hospitalisation for respiratory problems were assessed by questionnaires in 384 population-based children. Association of respiratory history with standard and intra-breath oscillometry parameters, including resistance at 7 Hz (R), frequency-dependence of resistance (R), reactance at 7 Hz (X), area of the reactance curve (AX), end-inspiratory and end-expiratory R (R, R) and X (X, X), and volume-dependence of resistance (ΔR = R-R) was estimated by linear regression adjusted on confounders.
RESULTS
Among the 320 children who accepted the oscillometry test, 281 (88%) performed 3 technically acceptable and reproducible standard oscillometry measurements and 251 children also performed one intra-breath oscillometry measurement. Asthma was associated with higher R, R, ΔR and R and wheezing was associated with higher ΔR. Bronchiolitis was associated with higher R and AX and lower X and bronchitis with higher R. No statistically significant association was observed for hospitalisation.
CONCLUSIONS
Our findings confirm the good success rate of oscillometry in 3-year-old children and indicate an association between a history of early-life wheezing and lower respiratory tract illness and lower lung function as assessed by both standard and intra-breath oscillometry. Our study supports the relevance of using intra-breath oscillometry parameters as sensitive outcome measures in preschool children in epidemiological cohorts.
Topics: Humans; Child, Preschool; Respiratory Sounds; Spirometry; Respiratory System; Asthma; Respiratory Mechanics; Bronchiolitis; Bronchitis
PubMed: 38402379
DOI: 10.1186/s12931-024-02701-9 -
The Medical Journal of Malaysia Jan 2024Spirometry is considered as a 'gold standard' for diagnosis of asthma. Impulse oscillometry (IOS) is an alternative diagnostic tool which requires less cooperation by...
INTRODUCTION
Spirometry is considered as a 'gold standard' for diagnosis of asthma. Impulse oscillometry (IOS) is an alternative diagnostic tool which requires less cooperation by the participants. We performed a study to determine the correlation of IOS with bronchodilator reversibility from spirometry in asthmatic participants. We studied the correlation between forced expiratory flow (FEF) and differences between the resistance at 5Hz and 20Hz (R-R) in small airway disease (SAD) and the proportion of SAD diagnosed using IOS.
MATERIALS AND METHODS
This was a cross-sectional study involving 82 asthmatic participants in Hospital Canselor Tuanku Muhriz (HCTM), Universiti Kebangsaan Malaysia (UKM) conducted between December 2020 till January 2022. Participants performed pre- and post-bronchodilator IOS and spirometry within the same day. Correlation between spirometry and IOS parameters and FEF with IOS were determined and analysed.
RESULTS
The change of forced expiratory volume in 1 second (FEV1) was statistically correlated with a change of R5 in IOS. A decrement of 14.5% in R5 can be correlated with positive bronchodilator response (BDR) with a sensitivity of 63.9% and specificity of 60.9%, p=0.007. Pre-bronchodilator FEF correlated with all parameters of SAD in IOS, e.g., R-R, reactance at 5Hz (X5) and area of reactance (AX), p < 0.05. IOS detection for SAD is higher compared to FEF in the BDR negative group (91.3% vs 58.7%).
CONCLUSION
IOS detected both bronchodilator reversibility and SAD hence can be considered as an alternative tool to spirometry for diagnosis of asthma in adults. IOS detected SAD more than FEF, especially in BDR-negative group.
Topics: Adult; Humans; Bronchodilator Agents; Oscillometry; Tertiary Care Centers; Cross-Sectional Studies; Forced Expiratory Volume; Asthma; Pulmonary Disease, Chronic Obstructive
PubMed: 38287753
DOI: No ID Found -
Frontiers in Pediatrics 2023Evaluating oscillometry parameters separately for the inspiratory and expiratory breath phases and their within-breath differences can help to identify exercise-induced...
BACKGROUND
Evaluating oscillometry parameters separately for the inspiratory and expiratory breath phases and their within-breath differences can help to identify exercise-induced bronchoconstriction (EIB) in pediatric outpatients disclosing exercise-induced symptoms (EIS).
AIMS
To assess the response in impedance parameters following an exercise challenge in patients reporting EIS.
METHODS
Sixty-eight patients reporting EIS (34 asthmatics and 34 suspected of asthma, age mean = 10.8 years, range = 6.0-16.0) underwent an incremental treadmill exercise test. Spirometry was performed at baseline and 1, 5-, 10-, 15-, and 20-min post exercise. Oscillometry was performed at baseline and at 3- and 18-min post exercise. Bronchodilator response to 200 µg albuterol was then assessed. EIB was defined as a forced expiratory volume in 1 s (FEV) fall ≥10% from baseline. Expiratory and inspiratory resistance (Rrs) and reactance (Xrs), their -score (Ducharme et al. 2022), and their mean within-breath differences (ΔRrs = Rrs-Rrs, ΔXrs =Xrs-Xrs) were calculated. Receiver operating characteristic (ROC) curves and their areas (AUCs) were used to evaluate impedance parameters' performances in classifying EIB.
RESULTS
Asthmatic patients developed EIB more frequently than those suspected of asthma [18/34 (52.9%) vs. 2/34 (5.9%), < 0.001]. In the 20 subjects with EIB, Rrs, Rrs, Xrs, and Xrs peaked early (3'), and remained steady except for Xrs which recovered faster afterward. ΔXrs widened 18 min following the exercise and reversed sharply after bronchodilation (BD) (-1.81 ± 1.60 vs. -0.52 ± 0.80 cmHO × s/L, < 0.001). Cutoffs for EIB leading to the highest AUCs were a rise of 0.41 in -score Rrs (Se: 90.0%, Sp: 66.7%), and a fall of -0.64 in -score Xrs (Se: 90.0%, Sp: 75.0%). Accepting as having "positive" postexercise oscillometry changes those subjects who had both -scores beyond respective cutoffs, sensitivity for EIB was 90.0% (18/20) and specificity, 83.3% (40/48).
CONCLUSION
Oscillometry parameters and their within-breath differences changed markedly in pediatric patients presenting EIB and were restored after the bronchodilator. Strong agreement between -scores of inspiratory oscillometry parameters and spirometry supports their clinical utility, though larger studies are required to validate these findings in a broader population.
PubMed: 38274467
DOI: 10.3389/fped.2023.1324413 -
Tuberculosis and Respiratory Diseases Apr 2024The prevalence of small airway dysfunction (SAD) in patients with chronic obstructive pulmonary disease (COPD) across different ethnicities is poorly understood. This...
BACKGROUND
The prevalence of small airway dysfunction (SAD) in patients with chronic obstructive pulmonary disease (COPD) across different ethnicities is poorly understood. This study aimed to estimate the prevalence of SAD in stable COPD patients.
METHODS
We conducted a cross-sectional study of 196 consecutive stable COPD patients. We measured pre- and post-bronchodilator (BD) lung function and respiratory impedance. The severity of COPD and lung function abnormalities was graded in accordance with the Global Initiative for Chronic Obstructive Lung Disease (GOLD) guidelines. SAD was defined as either difference in whole-breath resistance at 5 and 19 Hz > upper limit of normal or respiratory system reactance at 5 Hz < lower limit of normal.
RESULTS
The cohort consisted of 95.9% men, with an average age of 66.3 years. The mean forced expiratory volume 1 second (FEV1) % predicted was 56.4%. The median COPD assessment test (CAT) scores were 14. The prevalence of post-BD SAD across the GOLD grades 1 to 4 was 14.3%, 51.1%, 91%, and 100%, respectively. The post-BD SAD and expiratory flow limitation at tidal breath (EFLT) were present in 62.8% (95% confidence interval [CI], 56.1 to 69.9) and 28.1% (95% CI, 21.9 to 34.2), respectively. COPD patients with SAD had higher CAT scores (15.5 vs. 12.8, p<0.01); poor lung function (FEV1% predicted 46.6% vs. 72.8%, p<0.01); lower diffusion capacity for CO (4.8 mmol/min/kPa vs. 5.6 mmol/min/kPa, p<0.01); hyperinflation (ratio of residual volume to total lung capacity % predicted: 159.7% vs. 129%, p<0.01), and shorter 6-minute walk distance (367.5 m vs. 390 m, p=0.02).
CONCLUSION
SAD is present across all severities of COPD. The prevalence of SAD increases with disease severity. SAD is associated with poor lung function and higher symptom burden. Severe SAD is indicated by the presence of EFLT.
PubMed: 38225686
DOI: 10.4046/trd.2023.0139 -
Respirology (Carlton, Vic.) Apr 2024Chronic, low-intensity air pollution exposure has been consistently associated with reduced lung function throughout childhood. However, there is limited research...
BACKGROUND AND OBJECTIVE
Chronic, low-intensity air pollution exposure has been consistently associated with reduced lung function throughout childhood. However, there is limited research regarding the implications of acute, high-intensity air pollution exposure. We aimed to determine whether there were any associations between early life exposure to such an episode and lung growth trajectories.
METHODS
We conducted a prospective cohort study of children who lived in the vicinity of the Hazelwood coalmine fire. Lung function was measured using respiratory oscillometry. Z-scores were calculated for resistance (R ) and reactance at 5 Hz (X ) and area under the reactance curve (AX). Two sets of analyses were conducted: (i) linear regression to assess the cross-sectional relationship between post-natal exposure to mine fire-related particulate matter with an aerodynamic diameter of less than 2.5 micrometres (PM ) and lung function at the 7-year follow-up and (ii) linear mixed-effects models to determine whether there was any association between exposure and changes in lung function between the 3- and 7-year follow-ups.
RESULTS
There were no associations between mine fire-related PM and any of the lung function measures, 7-years later. There were moderate improvements in X (β: -0.37 [-0.64, -0.10] p = 0.009) and AX (β: -0.40 [-0.72, -0.08] p = 0.014), between the 3- and 7-year follow-ups that were associated with mean PM , in the unadjusted and covariance-adjusted models. Similar trends were observed with maximum PM .
CONCLUSION
There was a moderate improvement in lung stiffness of children exposed to PM from a local coalmine fire in infancy, consistent with an early deficit in lung function at 3-years after the fire that had resolved by 7-years.
Topics: Child; Humans; Smoke; Air Pollutants; Prospective Studies; Particulate Matter; Air Pollution; Lung; Environmental Exposure
PubMed: 38219238
DOI: 10.1111/resp.14657 -
Scientific Reports Jan 2024Proper functioning of the respiratory system is one of the most important determinants of human health. According to current knowledge, the diaphragmatic breathing...
Proper functioning of the respiratory system is one of the most important determinants of human health. According to current knowledge, the diaphragmatic breathing pattern seems to be the most favourable. However, recent reports indicate that athletes often have dysfunctional breathing patterns, which may be associated with an increased risk of musculoskeletal injuries. The influence of the type of breathing pattern on the mechanical airways in athletes has not been investigated. The aim of the present study was to determine the characteristics and relationships between breathing patterns and respiratory function in athletes. This study included 69 Polish elite endurance athletes (♂40, ♀29) in different sports disciplines and 44 (♂17, ♀27) healthy nonathletes as a control group. All participants underwent pulmonary function tests (spirometry, plethysmography, diffusion capacity for carbon monoxide) with assessment of breathing patterns by the Hi-Lo test. Inspiratory and expiratory resistance (R) and reactance (X) of the respiratory system at a given frequency (5 Hz, 11 Hz, and 19 Hz) were measured by a noninvasive forced oscillation technique. In this study, almost half of the athletes (44.92%) had dysfunctional breathing patterns, although at a lower rate than that in the control group. Diaphragmatic breathing patterns were characterized by higher spirometric, plethysmographic and DLCO values compared to thoracic or abdominal breathing patterns. Similarly, lower inspiratory reactance at 5 Hz (X5%pred.) was observed in the diaphragmatic pattern compared to the thoracic pattern. A diaphragmatic breathing pattern is associated with better pulmonary function test results. However, this study revealed a dysfunctional breathing pattern in almost half of the athletes. These results suggest that the assessment of breathing patterns and the implementation of breathing exercises in athletes are essential to promote proper breathing patterns.
Topics: Humans; Lung; Respiration; Respiratory Function Tests; Breathing Exercises; Athletes
PubMed: 38212427
DOI: 10.1038/s41598-024-51758-5 -
Heliyon Jan 2024Pulmonary function test, particularly in patients with COVID-19, is problematic because it involves forced expiration. Impulse oscillometry (IOS) reduces the potential...
BACKGROUND
Pulmonary function test, particularly in patients with COVID-19, is problematic because it involves forced expiration. Impulse oscillometry (IOS) reduces the potential exposure of health-care staff to infectious droplets. In this study, we investigated the correlation between IOS and spirometry and whether IOS can precisely predict spirometry-based diagnoses of chronic obstructive pulmonary disease (COPD).
METHODS
We retrospectively analyzed the data (January 1 to December 31, 2021) of patients who underwent both spirometry and IOS on the same date. One-way analysis of variance was performed to evaluate the IOS results of patients stratified into two (COPD and non-COPD) groups by spirometry results. IOS results were also analyzed using receiver operator characteristics curves to diagnose advanced COPD, which was indicated by a postbronchodilator (BD) forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC) ratio of <0.6. We further evaluated the accuracy of oscillometry as a predictor of spirometry-based COPD diagnosis.
RESULTS
A total of 115 patients were included in the analysis. The best parameters assessed for spirometry-based COPD diagnosis were area under reactance (AX) and airway resistance (predicted R5% × resonant frequency) in relation to body mass index (BMI). However, when the post-BD FEV1/FVC ratio was <0.6, BMI-adjusted airway resistance had an area under curve (0.782; 95 % confidence interval: 0.620-0.945) value larger than the corresponding AX. A BMI-adjusted airway resistance value of >160 moderately predicted spirometry-based COPD diagnosis.
CONCLUSIONS
BMI-adjusted airway resistance is a potential predictor of spirometry-based COPD diagnosis; the cutoff values of this parameter differ between individuals with and without obesity.
PubMed: 38187302
DOI: 10.1016/j.heliyon.2023.e23627