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Respiratory Physiology & Neurobiology Feb 2024The forced oscillation technique (FOT) enables non-invasive measurement of respiratory system impedance. Limited data exists on how changes in operating lung volume...
BACKGROUND
The forced oscillation technique (FOT) enables non-invasive measurement of respiratory system impedance. Limited data exists on how changes in operating lung volume (OLV) impact FOT-derived measures of airway resistance (Rrs) and reactance (Xrs).
OBJECTIVES
This study examined the reproducibility and responsiveness of FOT-derived measures of Rrs and Xrs during simulated changes in OLV.
METHODS
Participants simulated breathing at six OLVs: total lung capacity (TLC), ∼50% of inspiratory reserve volume (IRV), ∼two-times tidal volume (VT), tidal volume (VT), ∼50% of expiratory reserve volume (ERV), and residual volume (RV), on a commercially available FOT device. Each simulated OLV manuever was performed in triplicate and in random order. Total Rrs and Xrs were recorded at 5, 11, and 19 Hz.
RESULTS
Twelve healthy participants (2 female) completed the study (weight: 76.5 ± 13.6 kg, height: 178.6 ± 9.7 cm, body mass index: 23.9 ± 3.1 kg/m). Reproducibility of Rrs and Xrs at VT, VT and IRV was good to excellent (Range: ICC: 0.89-0.98, 95% confidence interval (CI): 0.70-0.98), while reproducibility at TLC, RV, and ERV was poor to excellent (Range: ICC: 0.60-0.98, 95% CI: 0.36-0.97). Rrs and Xrs were not different between VT and VT at any frequency (P > .05). With lung hyperinflation from VT to TLC, Rrs and Xrs decreased at all three frequencies (e.g., At 5 Hz Rrs: mean difference (MD): - 0.89, 95%CI: - 0.03 to - 1.75, P = .04; Xrs: MD: - 0.56, 95%CI: - 0.25 to - 0.86, P < .01). With lung hypoinflated from VT to RV, Rrs increased, and Xrs decreased for all frequencies (e.g., MD at 5 Hz, Rrs: MD: 2.31, 95%CI: 0.94-3.67, P < .01; Xrs: MD: -2.53, 95%CI: -4.02 to -1.04, P < .01).
CONCLUSION
FOT-derived measures of airway Rrs and Xrs are reproducible across a range of OLV's, and are responsive to hyper- and hypo-inflation of the lung. To further understand the impact of lung hyper- and hypo-inflation on FOT-derived airway impedance additional study is required in individuals with pathological variations in operating lung volume.
Topics: Humans; Female; Reproducibility of Results; Electric Impedance; Respiratory Function Tests; Lung Volume Measurements; Airway Resistance; Lung
PubMed: 38036081
DOI: 10.1016/j.resp.2023.104200 -
Journal of Veterinary Internal Medicine 2024Salbutamol and hyoscine butylbromide (HBB) are commonly used bronchodilators in horses with severe asthma (SA). (Comparative Study)
Comparative Study
BACKGROUND
Salbutamol and hyoscine butylbromide (HBB) are commonly used bronchodilators in horses with severe asthma (SA).
OBJECTIVE
To compare the bronchodilation potency, duration, and adverse effects of salbutamol and HBB in SA.
ANIMALS
Six horses in exacerbation of SA.
METHODS
The effects of inhaled salbutamol (1000 μg) and HBB (150 mg, IV) were compared in a randomized, blinded, crossover experiment. Lung function, intestinal borborygmi and heart rate were assessed before and sequentially until 180 minutes after drug administration, and analyzed with 2-way repeated-measures ANOVA and Dunnett's multiple comparison tests.
RESULTS
Both treatments caused a similar improvement in lung function. Pulmonary resistance and reactance returned to baseline values within 30 minutes after HBB administration, whereas salbutamol improved reactance until 180 minutes (mean improvement at 180 minutes of 0.040 Kpa/L/s, 95% CI = 0.004 to 0.076; P = .02 for salbutamol and of 0.009 Kpa/L/s, 95% CI = -0.028 to 0.045; P = .98 for HBB for the resistance at 3 Hz and of 0.040 Kpa/L/s, 95% CI = 0.007 to 0.074; P = .01 for salbutamol and of 0.009 Kpa/L/s, 95% CI = -0.024 to 0.042; P = .97 for HBB for the reactance at 7 Hz). From 5 to 30 minutes after HBB administration, the heart rate accelerated (mean increase of 3.3 beats per minute, 95% CI = -6.6 to 13.1; P = .92 for salbutamol, and of 13.0 beats per minute, 95% CI = 3.6 to 22.4; P = .002 for HBB at 30 minutes) and the gut sounds decreased (mean reduction of 1.3, 95% CI = -0.1 to 2.8; P = .09 for salbutamol and of 2.8 for the gastrointestinal auscultation score, 95% CI = 1.4 to 4.3; P < .0001 for HBB at 30 minutes).
CONCLUSIONS AND CLINICAL IMPORTANCE
Both drugs have a similar bronchodilator potency but with a longer duration for salbutamol. Gastrointestinal and cardiovascular effects were noted only with HBB, suggesting the preferential use of salbutamol to relieve bronchoconstriction in horses with asthma.
Topics: Animals; Horses; Albuterol; Asthma; Horse Diseases; Bronchodilator Agents; Cross-Over Studies; Butylscopolammonium Bromide; Male; Female; Heart Rate; Administration, Inhalation
PubMed: 38609079
DOI: 10.1111/jvim.17057 -
Frontiers in Medicine 2023Severe coronavirus disease 2019 (COVID-19) may require veno-venous extracorporeal membrane oxygenation (V-V ECMO). While V-V ECMO is offered in severe lung injury to...
BACKGROUND
Severe coronavirus disease 2019 (COVID-19) may require veno-venous extracorporeal membrane oxygenation (V-V ECMO). While V-V ECMO is offered in severe lung injury to COVID-19, long-term respiratory follow-up in these patients is missing. Therefore, we aimed at providing comprehensive data on the long-term respiratory effects of COVID-19 requiring V-V ECMO support during the acute phase of infection.
METHODS
In prospective observational cohort study design, patients with severe COVID-19 receiving invasive mechanical ventilation and V-V ECMO (COVID group, = 9) and healthy matched controls ( = 9) were evaluated 6 months after hospital discharge. Respiratory system resistance at 5 and 19 Hz (R, R), and the area under the reactance curve (AX) was evaluated using oscillometry characterizing total and central airway resistances, and tissue elasticity, respectively. R and R difference (R-R) reflecting small airway function was also calculated. Forced expired volume in seconds (FEV), forced expiratory vital capacity (FVC), functional residual capacity (FRC), carbon monoxide diffusion capacity (DLCO) and transfer coefficient (KCO) were measured.
RESULTS
The COVID group had a higher AX and R-R than the healthy matched control group. However, there was no significant difference in terms of R or R. The COVID group had a lower FEV and FVC on spirometry than the healthy matched control group. Further, the COVID group had a lower FRC on plethysmography than the healthy matched control group. Meanwhile, the COVID group had a lower DLCO than healthy matched control group. Nevertheless, its KCO was within the normal range.
CONCLUSION
Severe acute COVID-19 requiring V-V ECMO persistently impairs small airway function and reduces respiratory tissue elasticity, primarily attributed to lung restriction. These findings also suggest that even severe pulmonary pathologies of acute COVID-19 can manifest in a moderate but still persistent lung function impairment 6 months after hospital discharge.
TRIAL REGISTRATION
NCT05812196.
PubMed: 38173937
DOI: 10.3389/fmed.2023.1288679 -
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 -
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 -
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 -
Lung India : Official Organ of Indian... Jan 2024The current morphological condition of an individual is described by a somatotype, which is a three-number scale. The endomorph, mesomorph and ectomorph components are...
BACKGROUND
The current morphological condition of an individual is described by a somatotype, which is a three-number scale. The endomorph, mesomorph and ectomorph components are presented in the same sequence, and each number corresponds to one of the three basic components of body composition.
METHODS
We recruited 50 healthy male subjects with a mean age of 24.10 ± 4.55 yrs. Somatotype was determined by the Heath and Carter method. Impulse oscillometry was performed followed by spirometry according to the European Respiratory Society (ERS) or American Thoracic Society (ATS) guidelines. Resistance at 5 Hz (R5) %pred, R20%pred, R5-R20, X5%pred, X20, area of reactance (Ax) and resonant frequency (Fres) were obtained by doing impulse oscillometry. Slow vital capacity (SVC), forced vital capacity (FVC), forced expiratory volume in the first second (FEV1), FEV1/FVC ratio and maximum mid-expiratory flow (MMEF) were assessed by doing spirometry.
RESULTS
Endomorphs (0.05 (0.00-0.09) vs 0.01 (0.00-0.04); P < 0.0001) and mesomorphs (0.04 (0.000.09) vs 0.01 (0.00-0.04); P = 0.002) had significantly higher R5-R20 than ectomorphs. Similarly, endomorphs (0.32 (0.07-0.82) vs 0.15 (0.08-0.35); P = 0.001) and mesomorphs (0.28 (0.17-0.64) vs 0.15 (0.08-0.35); P = 0.015) also showed significantly higher Ax than ectomorphs, Fres of endomorphs (15.37 (8.43-21.85) vs 10.08 (8.94-14.30); P < 0.0001) and mesomorphs (14.32 (10.24-20.86) vs 10.08 (8.94-14.30); P < 0.0001) were significantly high than ectomorphs. Moreover, spirometric measures reveal significant variation in which mesomorphs had significantly higher values of % predicted of FVC than ectomorphs (92.49 ± 7.211 vs 83.86 ± 7.861; P = 0.042) and the ratio of FEV1 to FVC was significantly higher in ectomorphs than in endomorphs (89.00 ± 5.80 vs 85.04 ± 5.73; P = 0.03).
CONCLUSION
Peripheral airway dysfunction was observed in endomorphs and mesomorphs as compared to ectomorphs. Mesomorphs had a relatively higher FVC that may be due to their greater muscular strength.
PubMed: 38160452
DOI: 10.4103/lungindia.lungindia_230_23 -
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 -
Journal of Clinical Medicine Apr 2024Several studies have demonstrated the positive clinical and functional impact of adding Long-Acting Muscarinic Antagonist (LAMA) to Inhaled Corticosteroids (ICS) and...
Several studies have demonstrated the positive clinical and functional impact of adding Long-Acting Muscarinic Antagonist (LAMA) to Inhaled Corticosteroids (ICS) and Long-Acting Beta-Agonists (LABA) therapy in the treatment of severe asthma. Aim and objectives: To demonstrate that treating Small Airways Disease (SAD) in severe asthma patients who are candidates for biologics can improve respiratory symptoms, lung function, and airways inflammation, potentially avoiding or delaying the use of biological therapy. Thirty-two severe asthma patients with SAD were transitioned from separate inhalers for ICS/LABA and LAMA to extrafine single-inhaler beclomethasone, formoterol, and glycopyrronium. None of these patients underwent biological therapy before the study. Follow-up evaluations were conducted at baseline (T0) and three months after initiation (T3). Assessments included clinical evaluations, spirometry, oscillometry, and inflammation markers. Transitioning to single-inhaler triple therapy from T0 to T3 resulted in significant improvements in Asthma Control Test (ACT) and SAD parameters, including increased Forced Expiratory Volume in the mid-range of lung capacity and improved airway resistance and reactance measurements using impulse oscillometry. A significant reduction in airway inflammation was evidenced by lower levels of Fractional Exhaled Nitric Oxide 350 (FeNO 350) ( < 0.001 for all). : Adopting a single-inhaler triple therapy notably enhanced clinical control and small airway function in patients with severe asthma and SAD, supporting the positive impact of target-therapy for the achievement of a stable state termed "Quiet Asthma".
PubMed: 38673593
DOI: 10.3390/jcm13082320 -
Journal of Clinical Medicine May 2024High-resolution computed tomography (HRCT) may lack sensitivity for the early detection of interstitial lung disease associated with systemic sclerosis (SSc-ILD). Lung...
High-resolution computed tomography (HRCT) may lack sensitivity for the early detection of interstitial lung disease associated with systemic sclerosis (SSc-ILD). Lung ultrasound is an emerging technique for the diagnosis of SSc-ILD. This cross-sectional study aimed to describe the prevalence of ultrasound interstitial syndrome in SSc patients with normal HRCT and pulmonary function tests (PFT). Thirty SSc patients with normal HRCT, FVC > 80% predicted and DLCO > 70% predicted were included. Echocardiography and PFT including impulse oscillometry and cardiopulmonary exercise testing were performed. Lung ultrasound was analyzed by two blinded operators. Patients were classified into two groups, according to the presence or absence of ultrasound interstitial syndrome, defined as the sum of B-lines in all thoracic areas ≥10 and/or pleural line thickness >3 mm on at least one thoracic area and/or a pleural line irregularity score >16%. Ultrasound interstitial syndrome was present in 12 patients (40%). Inter-reader agreement for the diagnosis of ultrasound interstitial syndrome defined by the Kappa coefficient was 0.93 (95%CI 0.79-1.00). Patients with ultrasound interstitial syndrome were younger (37 years vs. 53 years, = 0.009), more often had pitting scars ( = 7/12 vs. 3/18, = 0.045) and had lower FVC (102 vs. 110% pred, = 0.009), TLC (114 vs. 122% pred, = 0.042) and low-frequency respiratory system reactance (Xrs5 Z-score 0.16 vs. 1.02, = 0.018), while pulmonary gas exchange was similar. Ultrasound interstitial syndrome was detected in 12/30 SSc patients with normal HRCT and PFT. Patients with ultrasound interstitial syndrome had differences in lung function consistent with reduced respiratory compliance, suggesting minimal and/or early suspected SSc-ILD.
PubMed: 38792426
DOI: 10.3390/jcm13102885