Search

Abstract Introduction The usual interstitial pneumonia (UIP) pattern, hallmark of idiopathic pulmonary fibrosis (IPF), may induce harmful local overdistension during mechanical ventilation given the juxtaposition of different tissue elasticities. Mechanotransduction, linking mechanical stress and strain to molecular pro-fibrotic pathways, likely contributes to fibrosis progression. Understanding the mechanical forces and aeration patterns in the lungs of IPF patients is crucial for unraveling potential mechanisms of disease progression. Quantitative lung computed tomography (CT) can accurately assess the air content of lung regions, thus informing on zonal distension. This study aims to investigate radiological evidence of lung over aeration in spontaneously breathing UIP patients compared to healthy controls during maximal inspiration. Methods Patients with IPF diagnosis referred to the Center for Rare Lung Diseases of the University Hospital of Modena (Italy) in the period 2020–2023 who underwent High Resolution Computed Tomography (HRCT) scans at residual volume (RV) and total lung capacity (TLC) using standardized protocols were retrospectively considered eligible. Patients with no signs of lung disease at HRCT performed with the same image acquisition protocol nor at pulmonary function test (PFTs) served as controls. Lung segmentation and quantitative analysis were performed using 3D Slicer software. Lung volumes were measured, and specific density thresholds defined over aerated and fibrotic regions. Comparison between over aerated lung at RV and TLC in the two groups and according to lung lobes was sought. Further, the correlation between aerated lung and the extent of fibrosis was assessed and compared at RV and TLC. Results IPF patients (N = 20) exhibited higher over aerated lung proportions than controls (N = 15) both at RV and TLC (4.5% vs. 0.7%, p

Introduction: The usual interstitial pneumonia (UIP) pattern, hallmark of idiopathic pulmonary fibrosis (IPF), may induce harmful local overdistension during mechanical ventilation given the juxtaposition of different tissue elasticities. Mechanotransduction, linking mechanical stress and strain to molecular pro-fibrotic pathways, likely contributes to fibrosis progression. Understanding the mechanical forces and aeration patterns in the lungs of IPF patients is crucial for unraveling potential mechanisms of disease progression. Quantitative lung computed tomography (CT) can accurately assess the air content of lung regions, thus informing on zonal distension. This study aims to investigate radiological evidence of lung over aeration in spontaneously breathing UIP patients compared to healthy controls during maximal inspiration. Methods: Patients with IPF diagnosis referred to the Center for Rare Lung Diseases of the University Hospital of Modena (Italy) in the period 2020–2023 who underwent High Resolution Computed Tomography (HRCT) scans at residual volume (RV) and total lung capacity (TLC) using standardized protocols were retrospectively considered eligible. Patients with no signs of lung disease at HRCT performed with the same image acquisition protocol nor at pulmonary function test (PFTs) served as controls. Lung segmentation and quantitative analysis were performed using 3D Slicer software. Lung volumes were measured, and specific density thresholds defined over aerated and fibrotic regions. Comparison between over aerated lung at RV and TLC in the two groups and according to lung lobes was sought. Further, the correlation between aerated lung and the extent of fibrosis was assessed and compared at RV and TLC. Results: IPF patients (N = 20) exhibited higher over aerated lung proportions than controls (N = 15) both at RV and TLC (4.5% vs. 0.7%, p < 0.0001 and 13.8% vs. 7%, p < 0.0001 respectively). Over aeration increased significantly from RV to TLC in both groups, with no intergroup difference (p = 0.67). Sensitivity analysis revealed significant variations in over aerated lung areas among lobes when passing from RV to TLC with no difference within lobes (p = 0.28). Correlation between over aeration and fibrosis extent was moderate at RV (r = 0.62, p < 0.0001) and weak at TLC (r = 0.27, p = 0.01), being the two significantly different at interpolation analysis (p < 0.0001). Conclusions: This study provides the first evidence of radiological signs of lung over aeration in patients with UIP-pattern patients when passing from RV to TLC. These findings offer new insights into the complex interplay between mechanical forces, lung structure, and fibrosis and warrant larger and longitudinal investigations. [ABSTRACT FROM AUTHOR]

Purpose: Air trapping, often attested in humans by elevated residual volume (RV) and ratio of RV on total lung capacity (RV/TLC), is frequently observed in asthma. Confirming these alterations in experimental asthma would be important for translational purposes. Herein, lung volumes were investigated in a mouse model of pulmonary allergic inflammation. Methods: Eight- to 10-week-old male C57BL/6 and BALB/c mice were exposed once daily to intranasal house dust mite (HDM) for 10 consecutive days. All readouts were measured 24 h after the last exposure. Lung volumes were assessed with the flexiVent using a new automated method consisting of degassing the lungs followed by a full-range pressure–volume maneuver. The weight and the volume of the lungs were also measured ex vivo and a lobe was further processed for histological analyses. Results: HDM exposure led to tissue infiltration with inflammatory cells, goblet cell hyperplasia, thickening of the airway epithelium, and elevated ex vivo lung weight and volume. It also decreased TLC and vital capacity but without affecting RV and RV/TLC. These observations were similar between the two mouse strains. Conclusion: Alterations of lung volumes in a murine model of pulmonary allergic inflammation are inconsistent with observations made in human asthma. These discrepancies reflect the different means whereby lung volumes are measured between species. The invasive method used herein enables RV to be measured more precisely and without the confounding effect of air trapping, suggesting that changes in RV and RV/TLC using this method in mice should be interpreted differently than in humans. [ABSTRACT FROM AUTHOR]

Objective: The frequency of obstructive sleep apnea (OSA) in patients with idiopathic pulmonary fibrosis (IPF) is high. The clinical course of non-IPF interstitial lung disease (ILD) can be similar to that of IPF. We sought to assess the frequency and predictors of OSA in patients with non-IPF fibrotic ILD, as well as the impact of positive airway pressure (PAP) therapy on the quality of life of such patients. Methods: This was a prospective study in which non-IPF fibrotic ILD patients underwent a home sleep apnea test. The patients with and without OSA were compared, and a multivariate logistic regression model was used to identify independent predictors of OSA. At 3 months after initiation of PAP therapy, we evaluated the participating patients for respiratory events, nocturnal hypoxemia, and changes in quality of life. Results: Of a total of 50 patients, 50% were male, and 76% were diagnosed with OSA. The mean age was 67.8 ± 8.3 years. The patients with OSA had significantly lower TLC (p = 0.033) and awake SpO2 (p = 0.023) than did those without OSA. In the multivariate logistic regression model, SpO2 (OR = 0.46; p = 0.016) and TLC (OR = 0.95; p = 0.026) remained significantly associated with OSA risk. A total of 12 patients received PAP therapy. At 3 months after initiation of PAP therapy, 91.7% were well controlled, Epworth Sleepiness Scale scores decreased significantly (p = 0.006), and emotional well-being tended to improve (p = 0.068). PAP therapy corrected nocturnal hypoxemia in all patients. Conclusions: We found a high frequency of OSA in patients with non-IPF fibrotic ILD. A low TLC was an independent predictor of a higher risk of OSA. PAP therapy can correct nocturnal hypoxemia. There should be a low threshold for suspicion of OSA and initiation of PAP therapy in patients with non-IPF fibrotic ILD. [ABSTRACT FROM AUTHOR]

ABSTRACT Objective: The frequency of obstructive sleep apnea (OSA) in patients with idiopathic pulmonary fibrosis (IPF) is high. The clinical course of non-IPF interstitial lung disease (ILD) can be similar to that of IPF. We sought to assess the frequency and predictors of OSA in patients with non-IPF fibrotic ILD, as well as the impact of positive airway pressure (PAP) therapy on the quality of life of such patients. Methods: This was a prospective study in which non-IPF fibrotic ILD patients underwent a home sleep apnea test. The patients with and without OSA were compared, and a multivariate logistic regression model was used to identify independent predictors of OSA. At 3 months after initiation of PAP therapy, we evaluated the participating patients for respiratory events, nocturnal hypoxemia, and changes in quality of life. Results: Of a total of 50 patients, 50% were male, and 76% were diagnosed with OSA. The mean age was 67.8 ± 8.3 years. The patients with OSA had significantly lower TLC (p = 0.033) and awake SpO2 (p = 0.023) than did those without OSA. In the multivariate logistic regression model, SpO2 (OR = 0.46; p = 0.016) and TLC (OR = 0.95; p = 0.026) remained significantly associated with OSA risk. A total of 12 patients received PAP therapy. At 3 months after initiation of PAP therapy, 91.7% were well controlled, Epworth Sleepiness Scale scores decreased significantly (p = 0.006), and emotional well-being tended to improve (p = 0.068). PAP therapy corrected nocturnal hypoxemia in all patients. Conclusions: We found a high frequency of OSA in patients with non-IPF fibrotic ILD. A low TLC was an independent predictor of a higher risk of OSA. PAP therapy can correct nocturnal hypoxemia. There should be a low threshold for suspicion of OSA and initiation of PAP therapy in patients with non-IPF fibrotic ILD.

Introduction Whole-body plethysmography is the preferred method for measuring the static lung volumes: total lung capacity (TLC), functional residual capacity (FRC) and residual volume (RV), as it also incorporates trapped gas – a common finding in chronic obstructive pulmonary disease (COPD). Quantitative computed tomography (CT) is a promising alternative to plethysmography, which can be challenging to perform for patients with severely impaired lung function. The present systematic review explores the agreement between lung volumes measured by plethysmography and CT, as well as the attempts being made to optimize alignment between these two methods.Methods A literature search was performed on the PubMed database using the block search strategy. Articles were included if they provided both CT based and plethysmography based TLC. Risk of bias was evaluated using the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) checklist.Results 22 articles were included. On average, CT-derived TLC (CT-TLC) was 709 mL lower compared to plethysmography TLC (p-TLC) with a 12.1% deviation from the reference standard, p-TLC. This discrepancy (ΔTLC) appeared slightly larger in obstructive patients (obstructive: 781 mL, non-obstructive: 609 mL), whereas percent deviation was slightly smaller (obstructive: 11.4%, non-obstructive: 13.5%). CT-based RV analyses primarily based on COPD patients measured 603 mL higher than plethysmography (p-RV) with 17.8% deviation from p-RV. Studies utilizing spirometry-gating for CT acquisition reported good agreement between modalities (ΔTLC: 70–280 mL), and one study demonstrated noticeable improvements compared to conventional breath-hold instructions in an otherwise identical study setting.Conclusion CT quantifications routinely underestimate TLC and overestimate RV in comparison to plethysmography. Spirometry gating reduces the level of disagreement and can be of assistance when patients are already undergoing CT. However, further studies are needed to confirm these results.

Physiological methods for measuring total lung capacity (TLC), including body-box plethysmography (BBP), are costly and require specialized expertise. Computed tomography (CT)-based TLC assessment is essential in clinical practice for candidates of lung transplantation and those unable to undergo standard lung function testing. While CT-based algorithms were studied to estimate TLC, their accuracy should be further evaluated. This study aimed to compare the BBP measurement of TLC (TLCpleth) with three CT-based methods for measuring TLC, one of them is an innovative virtual reality (VR)-based method. Additionally, we aimed to develop an adjustment factor that will allow a new, non-invasive, cost-effective estimation of the TLCpleth. TLC was calculated for 24 adult patients using three different CT-based volumetric assessment methods: an older region-growing algorithm (TLCrg), a more recent convolutional neural network-based algorithm (TLCcnn), and a VR-based method (TLCvr). Agreement between each method and TLCpleth was evaluated, and an adjustment factor was developed using linear regression. The correlation between the three CT-based methods and TLCpleth ranged from 0.91 to 0.92 (p < 0.001). TLCvr measurements were 80.13% (CI:75.08–85.18%, P < 0.001) of TLCpleth measures, whereas TLCcnn and TLCrg estimates were 71.3% and 77.1% of TLCpleth, respectively. An adjustment factor is proposed to estimate TLCpleth based on the three CT-based methods. This study is the first to evaluate the correlation between BBP, VR volumetric analysis, and two iterations of CT volumetric software for measuring total lung capacity (TLC). After being corrected by an adjustment factor, VR- and CT-based assessments provide accurate estimates of TLCpleth. [ABSTRACT FROM AUTHOR]

We measured resting metabolic rate (RMR), tidal volume (VT), breathing frequency (fR), respiratory flow, and end‐expired gases in rough‐toothed dolphins (Steno bredanensis) housed in managed care after an overnight fast and 1–2 hr following a meal. The measured average (± standard deviation) VT (4.0 ± 1.3 L) and fR (1.9 ± 1.0 breaths/min) were higher and lower, respectively, as compared with estimated values from both terrestrial and aquatic mammals, and the average VT was 43% of the estimated total lung capacity. The end‐expired gas levels suggested that this species keep alveolar O2 (10.6% or 80 mmHg) and CO2 (7.6% or 57 mmHg), and likely arterial gas tensions, low and high, respectively, to maximize efficiency of gas exchange. We show that following an overnight fast, the RMR (566 ± 158 ml O2/min) was 1.8 times the estimated value predicted by Kleiber for terrestrial mammals of the same size. We also show that between 1 and 2 hr after ingestion of a meal, the metabolic rate increases an average of 29% (709 ± 126 ml O2/min). Both body mass (Mb) and fR significantly altered the measured RMR and we propose that both these variables should be measured when estimating energy use in cetaceans. [ABSTRACT FROM AUTHOR]

Copyright of Fisioterapia Brasil is the property of Atlantica Editora and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: Total lung capacity (TLC) is the volume of air in the lungs at the end of a maximal inhalation. TLC mainly depends on various factors/predictors such as height, age, gender, and ethnicity, and therefore, population-specific reference equations should be used. Currently, in India, we use the (European committee for coal and steel [ECCS], published in the year 1993) reference equation with no correction factor for TLC. It is recommended that the reference equation should be tested on a sample of local healthy participants, differences between the measured values and the predicted values are determined to see if the reference equation is a suitable/good fit for the population. Aim: The aim of this study was to compare the actual values of TLC from the healthy male and female volunteers from Pune city with the reference values obtained from the ECCS equations in these participants and determine the correction factor/percent differences between the mean values for different age and height groups. Design and Setting: A prospective, cross-sectional study of lung function measurements (TLC) by body plethysmography was carried out in a research center. Methodology: TLC was measured by Jaeger's Body Plethysmograph (model: Master scope) according to the recommendation of the American Thoracic Society's/European Respiratory Society's standards 2005 in a sample of 241 healthy nonsmoking volunteers (150 men and 82 women) aged 20-70 years, living in Pune city of Maharashtra, India. Statistical Analysis: The mean of actual TLC and the reference TLC were plotted against the different age groups and height groups and percentage difference was determined. Multiple linear regression was carried out to find the predictive equations for TLC parameter measured by the body plethysmography. Age, height, and weight were used as the predictors (independent variables) in the multiple regression analysis. Since sex is also a predictor of TLC, separate models were run for men and women. Results: There were statistically significant differences between the measured TLC and the reference TLC obtained from the ECCS equation in both males (5.05 L ± 0.69 vs. 6.3 L ± 0.50) and females (3.69 L ± 0.54 vs. 4.39 L ± 0.36), respectively. Males have higher TLC as compared to females of the same age and height. The mean of actual TLC and the reference TLC was plotted against different age groups and height groups, and percentage difference was determined. The percentage differences ranged from 17% to 21% in males and 13%-17% in females. Conclusion: The ECCS equation is not suitable for Pune population and may lead to misinterpretation of restrictive lung diseases and hyperinflation. A correction factor of 18.5% in males and 15% in females may be used for the ECCS equation for TLC in Pune population. [ABSTRACT FROM AUTHOR]

One quarter of individuals with Preserved Ratio Impaired Spirometry (PRISm) will develop airflow obstruction, but there are no established methods to identify these individuals. We examined the utility of FVC/TLC in identifying features of obstructive lung disease. The ratio of post-bronchodilator FVC and TLCCT from chest CT (FVC/TLCCT) among current and former smokers with PRISm (FEV1/FVC ≥ 0.7 and FEV1

Abstract Background Some evidences have shown the association between air pollution exposure and the development of interstitial lung diseases. However, the effect of air pollution on the progression of restrictive ventilatory impairment and diffusion capacity reduction is unknown. This study aimed to evaluate the effects of long-term exposure to ambient air pollution on the change rates of total lung capacity, residual volume, and diffusion capacity among the elderly. Methods From 2016 to 2018, single-breath helium dilution with the diffusion capacity of carbon monoxide was performed once per year on 543 elderly individuals. Monthly concentrations of ambient fine particulate matters (PM2.5) and nitric dioxide (NO2) at the individual residential address were estimated using a hybrid Kriging/Land-use regression model. Linear mixed models were used to evaluate the association between long-term (12 months) exposure to air pollution and lung function with adjustment for potential covariates, including basic characteristics, indoor air pollution (second-hand smoke, cooking fume, and incense burning), physician diagnosed diseases (asthma and chronic airway diseases), dusty job history, and short-term (lag one month) air pollution exposure. Results An interquartile range (5.37 ppb) increase in long-term exposure to NO2 was associated with an additional rate of decline in total lung volume (− 1.8% per year, 95% CI: − 2.8 to − 0.9%), residual volume (− 3.3% per year, 95% CI: − 5.0 to − 1.6%), ratio of residual volume to total lung volume (− 1.6% per year, 95% CI: − 2.6 to − 0.5%), and diffusion capacity (− 1.1% per year, 95% CI: − 2.0 to − 0.2%). There is no effect on the transfer factor (ratio of diffusion capacity to alveolar volume). The effect of NO2 remained robust after adjustment for PM2.5 exposure. Conclusions Long-term exposure to ambient NO2 is associated with an accelerated decline in static lung volume and diffusion capacity in the elderly. NO2 related air pollution may be a risk factor for restrictive lung disorders.

Introduction: Gaseous air pollutants can cause oxidative stress, which can lead to lung damage by inducing inflammation. Polymorphisms in the glutathione S-transferase (GST) gene are involved in the pathogenesis of many diseases, including lung disease. Two glutathione S-transferase Mu 1 (GSTM1) and glutathione S-transferase theta 1 (GSTT1) genes belong to this family, in which deletions occur and the resulting alleles are unable to produce active enzymes. Materials and Methods: In this study, 41 steel plant workers with impaired lung function were selected. Multiplex PCR technique was used to identify the genotyping of GST M1 and T1. Results: The results of the frequency of gene deletion among 41 patients showed that there were 10 individuals (17.2%) with deletion of GSTM1 gene, 4 individuals (11.8%) with deletion of GSTT1 gene. The results of the frequency of gene deletion among 50 healthy individuals (control group) also showed that there were 8 individuals (8.5%) with deletion of GSTM1 gene, and 12 individuals (8.3%) with deletion of GSTT1 gene. There were 7 individuals (14%) without deletion of GSTM1 and GSTT1 removal. The results of Chi-square test between healthy and sick groups showed no significance at the level of p < 0.05. Conclusion: According to the results, it can be concluded that the sensitivity to lung function abnormalities in steel workers is directly related to the duration of employment.

Background and objectiveSpirometry patterns can suggest that a patient has a restrictive ventilatory impairment; however, lung volume measurements such as total lung capacity (TLC) are required to confirm the diagnosis. The aim of the study was to train a supervised machine learning model that can accurately estimate TLC values from spirometry and subsequently identify which patients would most benefit from undergoing a complete pulmonary function test.MethodsWe trained three tree-based machine learning models on 51,761 spirometry data points with corresponding TLC measurements. We then compared model performance using an independent test set consisting of 1,402 patients. The best-performing model was used to retrospectively identify restrictive ventilatory impairment in the same test set. The algorithm was compared against different spirometry patterns commonly used to predict restriction.ResultsThe prevalence of restrictive ventilatory impairment in the test set is 16.7% (234/1402). CatBoost was the best-performing machine learning model. It predicted TLC with a mean squared error (MSE) of 560.1 mL. The sensitivity, specificity, and F1-score of the optimal algorithm for predicting restrictive ventilatory impairment was 83, 92, and 75%, respectively.ConclusionA machine learning model trained on spirometry data can estimate TLC to a high degree of accuracy. This approach could be used to develop future smart home-based spirometry solutions, which could aid decision making and self-monitoring in patients with restrictive lung diseases.

Background: The evaluation of COVID‐19 systemic consequences is a wide research field in which respiratory function assessment has a pivotal role. However, the available data in the literature are still sparse and need further strengthening. Aim: To assess respiratory function 4–6 months after hospital discharge based on lung disease severity in patients who overcome COVID‐19 pneumonia. Methods: Patients hospitalised either in the Internal Medicine Department (IMD) for moderate to severe disease or in the Intensive Care Unit (ICU) for critical disease underwent spirometry with maximal flow‐volume curve, lung volumes, lung diffusion capacity (DLCO) and six‐minute walking test (6‐MWT). Results: Eighty‐eight patients were analysed: 40 from the IMD and 48 from the ICU. In both cohorts, there was a greater prevalence of male patients. In the IMD cohort, 38% of patients showed at least one altered respiratory parameter, while 62% in the ICU cohort did so (P < 0.05). Total lung capacity (TLC) and DLCO were the most frequently altered parameters: 15% and 33% from IMD versus 33% and 56% from ICU, respectively (P < 0.05). In IMD patients, 5% had only restrictive deficit, 22% had only lung diffusion impairment and 10% had both. In ICU patients, 6% had only restrictive deficit, 29% had only lung diffusion impairment and 27% had both (P < 0.05). ICU patients showed a higher frequency of abnormal 6‐MWT (P < 0.05). Conclusion: Lung function tests and 6‐MWT are highly informative tools for monitoring the negative consequences of COVID‐19 pneumonia, which were more frequent and more complex in patients discharged from ICU. [ABSTRACT FROM AUTHOR]

Copyright of Revista Brasileira de Medicina do Esporte is the property of Redprint Editora Ltda. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background/aim: Chronic obstructive pulmonary disease (COPD) is often complicated by sarcopenia, a condition of reduced muscle mass and function that adversely affects quality of life, lung function, and exacerbation rates. Ultrasonography could be an effective tool for detecting sarcopenia, notably by assessing diaphragmatic function, which may indicate muscle health in COPD patients. This study aims to evaluate the effectiveness of diaphragmatic ultrasound in detecting sarcopenia among COPD patients., Materials and Methods: Thirty-five patients with COPD, with a forced expiratory volume in one second (FEV1) between 30% and 80%, were consecutively enrolled in this cross-sectional and double-blind study. Sarcopenia was defined using the European Working Group on Sarcopenia in Older People 2 (EWGSOP2) criteria. Muscle mass was assessed with bioelectrical impedance analysis (BIA), muscle strength was assessed using the handgrip test and physical performance was assessed using a 4-meter gait speed test. Pulmonary function tests (PFT) (including maximum inspiratory pressure-MIP and maximum expiratory pressure-MEP) were performed. Diaphragm excursion and thickness at residual volume, functional residual capacity, and total lung capacity were measured using ultrasound. The diaphragm thickening fraction was calculated during normal (TF) and deep breathing (TLC-TF)., Results: Seventeen of 35 patients (48.6%) were found to be sarcopenic. Diaphragm thickness did not show significant variation between the groups. Both TF (27.43%) and TLC-TF (39.7%) were found to be lower in the sarcopenic group (p<0.05). The diaphragmatic excursion in the sarcopenic group was found to be 1.38 cm (p=0.078). There was no difference in median MIP and MEP values between the groups., Conclusion: Diaphragmatic TF may be a valuable tool for detecting sarcopenia in COPD patients, which may vary independently of PFTs. This study highlights TF as a potential auxiliary measure, but further research with larger sample sizes and additional parameters is needed to confirm its clinical utility., Competing Interests: The authors report no conflicts of interest in this work., (© 2025 Yetkin et al.)

Objectives: In patients with interstitial lung disease (ILD), the diaphragm typically rises as the lungs chronically shrink. However, the grade of restriction differs in each patient. It is currently unknown, how disparities between actual and predicted recipient total lung capacity (TLC), impact changes in lung function parameters and long-term outcomes following lung transplantation (LTx)., Methods: This retrospective study included 170 LTx for the patients with ILD performed in a European high-volume LTx center between 09/2011 and 12/2022. The preoperative median ratio of recipient actual to predicted (a/p) TLC was 0.55. Patients were stratified into two groups: low a/p TLC ratio group, corresponding to a more restricted chest cavity (< 0.55: n = 85), and high a/p TLC ratio group, corresponding to a more preserved chest cavity (≥ 0.55: n = 85). Perioperative and long-term outcomes, including lung function and overall survival, were analyzed., Results: Between the two groups, tracheostomy and reintubation rates, length of mechanical ventilation, ICU-stay and hospital-stay were not significantly different. Although lung function measurements obtained early after LTx were better in the high a/p TLC ratio group, no significant differences were observed in the long term. 5-year overall survival was not significantly different between the two groups., Conclusions: Although LTx for ILD patients with a restricted chest is considered technically more challenging, the perioperative course is similar to ILD patients with a preserved chest. In addition, no significant differences were observed between both groups in long-term lung function and overall survival, suggesting an improvement in chest wall compliance., (© The Author(s) 2024. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.)

Purpose To examine the effect of lung volume on the size and volume of pulmonary subsolid nodules (SSNs) measured on CT. Materials and Methods A total of 42 SSNs from 31 patients were included. CT examination was first performed at total lung capacity (TLC), and a section containing the nodule was additionally scanned at tidal volume (TV). The diameter and volume of each SSN, as well as the crosssectional lung area containing the nodule, were measured. The significance of the changes in measurements between TLC and TV within the same individuals was evaluated. Results The lung area and the diameter and volume of SSNs decreased significantly at TV by 12.7 cm2, 0.5 mm, and 46.4 mm3 on average, respectively (p < 0.001), compared to those at TLC. Changes in lung area between TV and TLC were positively correlated with the change in SSN diameter (p = 0.027) and volume (p = 0.014). However, after correction (by considering the change in lung area), the changes in SSN diameter (p = 0.124) and volume (p = 0.062) were not significantly different. Conclusion SSN size and volume can be significantly affected by lung volume during CT scans of the same individuals.

BackgroundSpirometric Z-scores from the Global Lung Initiative (GLI) rigorously account for age-related changes in lung function and are thus age-appropriate when establishing spirometric impairments, including a restrictive pattern and air-flow obstruction. However, GLI-defined spirometric impairments have not yet been evaluated regarding associations with static lung volumes (total lung capacity [TLC], functional residual capacity [FRC], and residual volume [RV]) and gas exchange (diffusing capacity).MethodsWe performed a retrospective review of pulmonary function tests in subjects ≥40 y old (mean age 64.6 y), including pre-bronchodilator measures for: spirometry (n = 2,586), static lung volumes by helium dilution with inspiratory capacity maneuver (n = 2,586), and hemoglobin-adjusted single-breath diffusing capacity (n = 2,508). Using multivariable linear regression, adjusted least-squares means (adjLSMeans) were calculated for TLC, FRC, RV, and hemoglobin-adjusted single-breath diffusing capacity. The adjLSMeans were expressed with and without height-cubed standardization and stratified by GLI-defined spirometry, including normal (n = 1,251), restrictive pattern (n = 663), and air-flow obstruction (mild, [n = 128]; moderate, [n = 150]; and severe, [n = 394]).ResultsRelative to normal spirometry, restrictive-pattern had lower adjLSMeans for TLC, FRC, RV, and hemoglobin-adjusted single-breath diffusing capacity (P ≤ .001). Conversely, relative to normal spirometry, mild, moderate, and severe air-flow obstruction had higher adjLSMeans for FRC and RV (P < .001). However, only mild and moderate air-flow obstruction had higher adjLSMeans for TLC (P < .001), while only moderate and severe air-flow obstruction had higher adjLSMeans for RV/TLC (P < .001) and lower adjLSMeans for hemoglobin-adjusted single-breath diffusing capacity (P < .001). Notably, TLC (calculated as FRC + inspiratory capacity) was not increased in severe air-flow obstruction (P ≥ .11) because inspiratory capacity decreased with increasing air-flow obstruction (P < .001), thus opposing the increased FRC (P < .001). Finally, P values were similar whether adjLSMeans were height-cubed standardized.ConclusionsA GLI-defined spirometric restrictive pattern is strongly associated with a restrictive ventilatory defect (decreased TLC, FRC, and RV), while GLI-defined spirometric air-flow obstruction is strongly associated with hyperinflation (increased FRC) and air trapping (increased RV and RV/TLC). Both spirometric impairments were strongly associated with impaired gas exchange (decreased hemoglobin-adjusted single-breath diffusing capacity).

Background: Some evidences have shown the association between air pollution exposure and the development of interstitial lung diseases. However, the effect of air pollution on the progression of restrictive ventilatory impairment and diffusion capacity reduction is unknown. This study aimed to evaluate the effects of long-term exposure to ambient air pollution on the change rates of total lung capacity, residual volume, and diffusion capacity among the elderly.Methods: From 2016 to 2018, single-breath helium dilution with the diffusion capacity of carbon monoxide was performed once per year on 543 elderly individuals. Monthly concentrations of ambient fine particulate matters (PM2.5) and nitric dioxide (NO2) at the individual residential address were estimated using a hybrid Kriging/Land-use regression model. Linear mixed models were used to evaluate the association between long-term (12 months) exposure to air pollution and lung function with adjustment for potential covariates, including basic characteristics, indoor air pollution (second-hand smoke, cooking fume, and incense burning), physician diagnosed diseases (asthma and chronic airway diseases), dusty job history, and short-term (lag one month) air pollution exposure.Results: An interquartile range (5.37 ppb) increase in long-term exposure to NO2 was associated with an additional rate of decline in total lung volume (- 1.8% per year, 95% CI: - 2.8 to - 0.9%), residual volume (- 3.3% per year, 95% CI: - 5.0 to - 1.6%), ratio of residual volume to total lung volume (- 1.6% per year, 95% CI: - 2.6 to - 0.5%), and diffusion capacity (- 1.1% per year, 95% CI: - 2.0 to - 0.2%). There is no effect on the transfer factor (ratio of diffusion capacity to alveolar volume). The effect of NO2 remained robust after adjustment for PM2.5 exposure.Conclusions: Long-term exposure to ambient NO2 is associated with an accelerated decline in static lung volume and diffusion capacity in the elderly. NO2 related air pollution may be a risk factor for restrictive lung disorders. [ABSTRACT FROM AUTHOR]

Background/Aims Air trapping is associated with unfavorable outcomes in chronic obstructive pulmonary disease (COPD). The present study evaluated the association between longitudinal changes in air trapping with pulmonary function, computed tomography (CT) parameters and exacerbation. Methods Patients enrolled in the Korean Obstructive Lung Disease (KOLD) study cohort from June 2005 to October 2015 were included. The study patients were categorized into four groups according to the change in residual volume to total lung capacity ratio (RV/TLC) over 3 years. The RV/TLC was considered abnormal when it was ≥ 40% and normal when it was < 40%. Results A total of 279 patients were categorized into four groups: 76 in the “normal to normal” (N→N) group, 34 in the “abnormal to normal” (A→N) group, 33 in the “normal to abnormal” (N→A) group, and 136 in the “abnormal to abnormal” (A→A) group. For forced expiratory volume in 1 second and forced vital capacity (FVC), respectively, group A→N showed a large increase of 266 mL (p < 0.001) and 381 mL (p < 0.001), group N→A showed a marked decrease of 216 mL (p < 0.001) and 332 mL(p = 0.029), and group A→A showed a decrease of 16 mL (p = 0.426) and 6 mL (p = 0.011) compared to group N→N. Group A→N showed a significant decrease of −0.013 in expiratory to inspiratory ratio of the mean lung density (p < 0.001), while group A→N showed an increase of 0.005 (p < 0.001). Conclusions Patients with COPD whose RV/TLC changed from normal to abnormal showed deterioration of pulmonary function and worsening of CT parameters simultaneously.

Abstract Introduction: The aim of this study was to evaluate the delayed chest closure (DCC) results in patients who underwent lung transplantation. Methods: Sixty patients were evaluated retrospectively. Only bilateral lung transplantations and DCC for oversized lung allograft (OLA) were included in the study. Six patients who underwent single lung transplantation, four patients who underwent lobar transplantation, two patients who underwent retransplantation, and four patients who underwent DCC due to bleeding risk were excluded from the study. Forty-four patients were divided into groups as primary chest closure (PCC) (n=28) and DCC (n=16). Demographics, donor characteristics, and operative features and outcomes of the patients were compared. Results: The mean age was 44.5 years. There was no significant difference between the demographics of the groups (P>0.05). The donor/recipient predicted total lung capacity ratio was significantly higher in the DCC group than in the PCC group (1.06 vs. 0.96, P=0.008). Extubation time (4.3 vs. 3.1 days, P=0.002) and intensive care unit length of stay (7.6 vs. 5.2 days, P=0.016) were significantly higher in the DCC group than in the PCC group. In the DCC group, postoperative wound infection was significantly higher than in the PCC group (18.6% vs. 0%, P=0.19). Median survival was 14 months in all patients and there was no significant difference in survival between the groups (16 vs. 13 months, P=0.300). Conclusion: DCC is a safe and effective method for the management of OLA in lung transplantation.

Background: Restrictive lung function may indicate various underlying diseases. The aim of this study was to evaluate the accuracy of different restrictive spirometry patterns (RSPs) to identify restrictive lung function (total lung capacity [TLC] < lower limit of normal [LLN]) according to reference values by the Global Lung Function Initiative (GLI) in a wide age‐ranged, general population sample. Methods: A general population sample (n = 607, age 23–72 years, smokers 18.8%) with proper dynamic spirometry and TLC measurements, was included. Accuracy of two main categories of RSP to identify TLC < LLN were evaluated: traditional RSPs (definition 1: FVC < 80% of predicted and FEV1/FVC ≥ 0.7 and definition 2: FVC < LLN and FEV1/FVC ≥ LLN) and RSPs defined by Youden's method (definition 3: FVC < 85.5% of predicted and FEV1/FVC ≥ LLN and definition 4: FVC Z‐score < −1.0 and FEV1/FVC ≥ LLN). Results: The prevalence of restrictive lung function (TLC < LLN) was 5.3%. The most accurate cut‐offs for FVC to identify TLC < LLN were 85.5% for FVC% of predicted, and −1.0 for FVC Z‐score. The traditional RSP definitions 1 and 2 had higher specificity (95.0% and 96.9%) but substantially lower sensitivity compared to RSP definitions 3 and 4. Conclusion: Based on the GLI reference values, the RSP definition FVC < LLN and FEV1/FVC ≥ LLN yielded the highest specificity and may appropriately be used to rule out restrictive lung function. The RSP definition with the most favourable trade‐off between sensitivity and specificity, FVC < 85.5% of predicted and FEV1/FVC ≥ LLN, may serve as an alternative with higher sensitivity for screening. [ABSTRACT FROM AUTHOR]

Total lung capacity is usually measured by a body plethysmograph or helium dilution methods. In this study an alternative approach to obtain total lung capacity of spontaneous breathing subjects is introduced. The device utilises an optoelectronic plethysmograph and a small tube, which measures mouth pressure and allows total lung capacity to be obtained, which differs less than 0.4 L from the total lung capacity of the body plethysmograph. The method shows potential to be a less burdensome method to estimate total lung capacity determination than the body plethysmograph.

Background and AimsAir trapping is a predictive index for a decline in lung function and mortality in patients with chronic obstructive pulmonary disease (COPD). However, the role of air trapping in COPD exacerbation has rarely been studied. Therefore, this study aimed to investigate the impact of air trapping as a continuous parameter on COPD exacerbation.Materials and MethodsTo evaluate air trapping, we identified the ratio of residual volume (RV) to total lung capacity (TLC) of patients with COPD from the Korean COPD Subgroup Study (KOCOSS) cohort, which is a multicenter-based, prospective, consecutive cohort in Korea. The primary outcome was a development of COPD exacerbation during 3 years of follow-up.ResultsOf 2,181 participants, 902 patients measured the RV/TLC ratio in the baseline enrollment, and 410 were evaluated for assessing the development of COPD exacerbation. Of 410 patients, the rate of moderate to severe exacerbation and severe exacerbation was 70.7% and 25.9%. A 10% increase of RV/TLC ratio increased the risk of the moderate to severe exacerbation by 35% and severe exacerbation by 36%. In subgroup analysis, an interaction effect between triple inhaled therapy and the RV/TLC ratio for severe exacerbation nullified the association between the RV/TLC ratio and severe exacerbation (p for interaction = 0.002).ConclusionsIn this prospective cohort study, we found that air trapping (representing RV/TLC ratio as a continuous parameter) showed an association with an increased risk of COPD exacerbation, particularly in patients who have not undergone triple inhaler therapy.

Background: Idiopathic Pulmonary Fibrosis (IPF) is a progressive fibrotic lung disease. However, the field of quantitative CT scan analysis in conjunction with pulmonary function test for IPF patients remains relatively understudied. In this study, we evaluated the diagnostic value of features derived high-resolution computed tomography (HRCT) for patients with IPF and correlated them with pulmonary function tests., Methods: We retrospectively analyzed the chest HRCT images and pulmonary function test results of 52 patients with IPF during the same period (1 week) and selected 52 healthy individuals, matched for sex, age, and body mass index (BMI) and with normal chest HRCT as controls. HRCT scans were performed using a Philips 256-row Brilliance iCT scanner with standardized parameters. Lung function tests were performed using a Jaeger volumetric tracer for forced vital capacity (FVC), total lung capacity (TLC), forced expiratory volume in first second (FEV1), FEV1/FVC, carbon monoxide diffusing capacity (DLCO), and maximum ventilation volume (MVV) metrics. CT quantitative analysis, including tissue segmentation and threshold-based quantification of lung abnormalities, was performed using 3D-Slicer software to calculate the percentage of normal lung areas (NL%), percentage of ground-glass opacity areas (GGO%), percentage of fibrotic area (F%) and abnormal lesion area percentage (AA%). Semi-quantitative analyses were performed by two experienced radiologists to assess disease progression. The aortic-to-sternal distance (ASD) was measured on axial images as a standardized parameter. Spearman or Pearson correlation analysis and multivariate stepwise linear regression were used to analyze the relationship between the data in each group, and the ROC curve was used to determine the optimal quantitative CT metrics for identifying IPF and controls., Results: ROC curve analysis showed that F% distinguished the IPF patient group from the control group with the largest area under the curve (AUC) of 0.962 (95% confidence interval: 0.85-0.96). Additionally, with F% = 4.05% as the threshold, the Youden's J statistic was 0.827, with a sensitivity of 92.3% and a specificity of 90.4%. The ASD was significantly lower in the late stage of progression than in the early stage (t = 5.691, P < 0.001), with a mean reduction of 2.45% per month. Quantitative CT indices correlated with all pulmonary function parameters except FEV1/FVC, with the highest correlation coefficients observed for F% and TLC%, FEV1%, FVC%, MVV% (r = - 0.571, - 0.520, - 0.521, - 0.555, respectively, all P-values < 0.001), and GGO% was significantly correlated with DLCO% (r = - 0.600, P < 0.001). Multiple stepwise linear regression analysis showed that F% was the best predictor of TLC%, FEV1%, FVC%, and MVV% (R 2  = 0.301, 0.301, 0.300, and 0.302, respectively, all P-values < 0.001), and GGO% was the best predictor of DLCO% (R 2  = 0.360, P < 0.001)., Conclusions: Quantitative CT analysis can be used to diagnose IPF and assess lung function impairment. A decrease in the ASD may indicate disease progression., (© 2024. The Author(s).)

Background: Patients with SARS-CoV-2 present signs and symptoms that primarily involve the respiratory system. The sequelae result in impaired quality of life, pneumonia, dyspnea, fatigue, and joint pain. Objective: To sustain with scientific evidence the importance of respiratory physiotherapy and its effects on post-acute COVID-19 adult patients. Material and methods: A systematic review was conducted in four databases (Scopus, Web of Science, PubMed, and ScienceDirect). The searching period was carried out in February 2021 with a total of 1229 potential studies. Finally, 5 studies that met the eligibility criteria were included: two clinical trials, two case reports and one cross-sectional study. The methodological quality of the articles was evaluated. Results: Respiratory muscle training, targeted breathing, and strength training provide significant data of improvement of functional performance. Evidence shows positive effects of respiratory physiotherapy in post-acute COVID-19 adult patients, since it increases resistance to exercise, it decreases fatigue, reduces dyspnea, improves functionality and quality of life. Conclusions: More future studies, such as randomized controlled trials, studies including lower age range groups, and individualized approaches, need to be developed. [ABSTRACT FROM AUTHOR]

Background: Whole-body plethysmography (WBP) is the gold standard for measuring lung volume, but its clinical application is limited as it requires expensive equipment and is not simple to use. Studies have shown that the single-breath helium dilution (SBHD) method, which is commonly used in clinical practice, significantly underestimates lung volume in patients with obstructive lung disease (OLD). By comparing the differences in lung volume measured using SBHD and WBP, we aimed to establish a correction equation for the SBHD method to determine the total lung volume in patients with OLD of different severities.Methods: From 628 patients with OLD simultaneously subjected to SBHD and WBP, 407 patients enrolled between January 2018 and November 2019 were in the training group and 221 enrolled between December 2019 and December 2020 were in the prospective verification cohort. The multiple linear regression equation was used for data in the training group to establish a correction equation for SBHD to determine the total lung volume, and this was validated in the prospective validation cohort.Results: There was a moderate positive correlation between total lung capacity (TLC) determined using the SBHD [TLC (SBHD)] and WBP methods [TLC (WBP)] (r = 0.701; P < 0.05), and the differences between TLC (SBHD) and TLC (WBP) (ΔTLC) were related to the severity of obstruction. As the severity of obstruction increased, the TLC was underestimated by the SBHD method. We established the following correction equation: TLC (adjusted SBHD) (L) = −0.669 + 0.756*TLC(SBHD)(L) – 0.047*FEV1FVC+0.039*height (cm)–0.009*weight(kg)(r2 = 0.753 and adjusted r2 = 0.751). Next, we validated this equation in the validation cohort. With the correction equation, no statistical difference was observed between TLC (adjusted SBHD) and TLC (WBP) among the obstruction degree groups (P > 0.05).Conclusions: The SBHD method is correlated with WBP to measure the total lung volume, but the SBHD method presents limitations in determining the total lung volume in patients with obstructive lung disease. Here, we established an effective and reliable correction equation in order to accurately assess the total lung volume of patients with OLD using the SBHD method.

Introduction: The aim of this study was to evaluate the delayed chest closure (DCC) results in patients who underwent lung transplantation. Methods: Sixty patients were evaluated retrospectively. Only bilateral lung transplantations and DCC for oversized lung allograft (OLA) were included in the study. Six patients who underwent single lung transplantation, four patients who underwent lobar transplantation, two patients who underwent retransplantation, and four patients who underwent DCC due to bleeding risk were excluded from the study. Forty-four patients were divided into groups as primary chest closure (PCC) (n=28) and DCC (n=16). Demographics, donor characteristics, and operative features and outcomes of the patients were compared. Results: The mean age was 44.5 years. There was no significant difference between the demographics of the groups (P>0.05). The donor/recipient predicted total lung capacity ratio was significantly higher in the DCC group than in the PCC group (1.06 vs. 0.96, P=0.008). Extubation time (4.3 vs. 3.1 days, P=0.002) and intensive care unit length of stay (7.6 vs. 5.2 days, P=0.016) were significantly higher in the DCC group than in the PCC group. In the DCC group, postoperative wound infection was significantly higher than in the PCC group (18.6% vs. 0%, P=0.19). Median survival was 14 months in all patients and there was no significant difference in survival between the groups (16 vs. 13 months, P=0.300). Conclusion: DCC is a safe and effective method for the management of OLA in lung transplantation. [ABSTRACT FROM AUTHOR]

Copyright of Revista Argentina de Cardiología is the property of Sociedad Argentina de Cardiologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

BackgroundForced expiratory volume in 1 second (FEV1) grades severity of COPD and predicts survival. We hypothesize that the inspiratory capacity/total lung capacity (IC/TLC) ratio, a sensitive measure of static lung hyperinflation, may have a significant association with survival in an emphysematous phenotype of COPD.ObjectivesTo access the association between IC/TLC and survival in an emphysematous phenotype of COPD.MethodsWe performed a retrospective analysis of a large pulmonary function (PF) database with 39,050 entries, from April 1978 to October 2009. Emphysematous COPD was defined as reduced FEV1/forced vital capacity (FVC), increased TLC, and reduced diffusing capacity of the lungs for carbon monoxide (DLCO; beyond 95% confidence intervals [CIs]). We evaluated the association between survival in emphysematous COPD patients and the IC/TLC ratio evaluated both as dichotomous (≤25% vs >25%) and continuous predictors. Five hundred and ninety-six patients had reported death dates.ResultsUnivariate analysis revealed that IC/TLC ≤25% was a significant predictor of death (hazard ratio [HR]: 2.39, P

Abstract Objective: To verify the concurrent validity between the inspiratory muscle strength (IMS) values obtained in static (maximal inspiratory pressure [MIP]) and dynamic (S-Index) assessments. Methods: Healthy individuals were submitted to two periods of evaluation: i) MIP, static maneuver to obtain IMS, determined by the Mueller’s maneuver from residual volume (RV) until total lung capacity (TLC); ii) and S-Index, inspiration against open airway starting from RV until TLC. Both measures were performed by the same evaluator and the subjects received the same instructions. Isolated maneuvers with differences < 10% were considered as reproducible measures. Results: Data from 45 subjects (21 males) were analyzed and that showed statistical difference between MIP and S-Index values (133.5 ± 33.3 and 125.6 ± 32.2 in cmH2O, respectively), with P=0.014. Linear regression showed r2=0.54 and S-Index prediction formula = 39.8+(0.75×MIP). Pearson’s correlation demonstrated a strong and significant association between the measures with r=0.74. The measurements showed good concordance evidenced by the Bland-Altman test. Conclusion: S-Index and MIP do not present similar values since they are evaluations of different events of the muscular contraction. However, they have a strong correlation and good agreement, which indicate that both are able to evaluate the IMS of healthy individuals.

PurposeThe pulmonary complications of sickle cell disease (SCD) are a leading cause of morbidity and mortality (MacLean et al. Am J Respir Crit Care Med 178:1055-1059, 2008; Klings et al. Am J Respir Crit Care Med 173:1264-1269, 2006; National Heart, Lung, and Blood Institute, 2009). Despite this recognition, predictive markers of lung dysfunction progression remain elusive (Klings et al. Am J Respir Crit Care Med 173:1264-1269, 2006; Platt et al. N Engl J Med 330:1639-1644, 1994; Caboot et al. Curr Opin Pediatr 20:279-287, 2008; Field et al. Am J Hematol 83:574-576, 2008; Shirlo et al. Peadiatr Respir Review 12:78-82, 2011). This study was designed describe the longitudinal progression and identify specific markers that influence bronchial disease in SCD.MethodsA retrospective, chart review of 89 patients with SCD was conducted. All patients underwent spirometry in conjunction with body plethysmography as part of routine care. Eleven lung function variables were assessed, five of which were selected to establish patterns of normal, obstructive, restrictive, or mixed obstructive-restrictive physiology (Klings et al. Am J Respir Crit Care Med 173:1264-1269, 2006; Field et al. Am J Hematol 83:574-576, 2008).ResultsIn the unadjusted model, forced expiratory volume in one second (FEV1)% of predicted trended downward with age, while total lung capacity (TLC)% of predicted showed a bimodal distribution and carbon monoxide diffusion capacity corrected for hemoglobin (DLCOcor)% of predicted remained stable. Adjusting for acute chest syndrome (ACS) episodes, medication status, and growth velocity (GV), the final model demonstrated that the downward trend between FEV1% of predicted with age was further influenced by the latter two factors.ConclusionsInitial decline in FEV1% of predicted is associated with worsening pulmonary dysfunction over time. Independent of ACS episodes, the factors most influential on the progression of FEV1% predicted include the introduction of medications as well as the promotion of adequate prepubertal growth. Efforts to ensure normal prepubertal GV and treatment with bronchodilators, such as short-acting beta(2) agonists and inhaled corticosteroids (ICS), should be considered at an early age to delay progression of pulmonary dysfunction.

Background: Current techniques for measuring absolute lung volumes rely on bulky and expensive equipment and are complicated to use for the operator and the patient. A novel method for measurement of absolute lung volumes, the MiniBox method, is presented.Research Question: Across a population of patients and healthy participants, do values for total lung capacity (TLC) determined by the novel compact device (MiniBox, PulmOne Advanced Medical Devices, Ltd.) compare favorably with measurements determined by traditional whole body plethysmography?Study Design and Methods: A total of 266 participants (130 men) and respiratory patients were recruited from five global centers (three in Europe and two in the United States). The study population comprised individuals with obstructive (n = 197) and restrictive (n = 33) disorders as well as healthy participants (n = 36). TLC measured by conventional plethysmography (TLCPleth) was compared with TLC measured by the MiniBox (TLCMB).Results: TLC values ranged between 2.7 and 10.9 L. The normalized root mean square difference (NSD) between TLCPleth and TLCMB was 7.0% in healthy participants. In obstructed patients, the NSD was 7.9% in mild obstruction and 9.1% in severe obstruction. In restricted patients, the NSD was 7.8% in mild restriction and 13.9% in moderate and severe restriction. No significant differences were found between TLC values obtained by the two measurement techniques. Also no significant differences were found in results obtained among the five centers.Interpretation: TLC as measured by the novel MiniBox system is not significantly different from TLC measured by conventional whole body plethysmography, thus validating the MiniBox method as a reliable method to measure absolute lung volumes. [ABSTRACT FROM AUTHOR]

Purpose: The present study aimed to investigate the clinical characteristics and lung function impairment in young people diagnosed with chronic obstructive pulmonary disease (COPD)., Patients and Methods: We retrospectively enrolled patients with COPD who underwent symptom assessment and comprehensive pulmonary function tests at the First Affiliated Hospital of Guangzhou Medical University between August 2017 and March 2022. The patients were categorized into two groups based on age: a young COPD group (aged 20-50 years) and an old COPD group (aged > 50 years)., Results: A total of 1282 patients with COPD were included in the study, with 76 young COPD patients and 1206 old COPD patients. Young COPD patients exhibited a higher likelihood of being asymptomatic, lower rates of smoking, and a lower smoking index compared to old COPD patients. Although young COPD patients had higher median post-bronchodilator forced expiratory volume in 1 s (post-BD FEV 1 ) (1.4 vs.1.2 L, P = 0.019), diffusing capacity of the lung for carbon monoxide (D L CO) (7.2 vs. 4.6, P<0.001), and a lower median residual volume to total lung capacity ratio (RV/TLC) compared to their older counterparts, there were no differences observed in severity distribution by GOLD categories or the proportion of lung hyperinflation (RV/TLC%pred > 120%) between two groups. Surprisingly, the prevalence of reduced D L CO was found to be 71.1% in young COPD, although lower than in old COPD (85.2%)., Conclusion: Young COPD showed fewer respiratory symptoms, yet displayed a similar severity distribution by GOLD categories. Furthermore, a majority of them demonstrated lung hyperinflation and reduced D L CO. These results underscore the importance of a comprehensive assessment of lung function in young COPD patients., (© 2024. The Author(s).)

Background: In advanced chronic obstructive pulmonary disease (COPD), hypercapnia may occur due to severe bronchial obstruction with lung hyperinflation. Non-invasive ventilation (NIV) provides the standard of care intended to achieve physiological PCO 2 levels, thereby reducing overall mortality. The present study aimed to evaluate pulmonary function parameters derived from spirometry (forced vital capacity [FVC], forced expiratory volume in 1 s [FEV1]), body plethysmography (residual volume [RV], total lung capacity [TLC]), and lung diffusion capacity for carbon monoxide (single-breath method [DCO-SB], alveolar-volume corrected values [DCO-VA]) as predictors of chronic hypercapnia in patients with advanced COPD., Methods: This monocentric, retrospective observational study included 423 COPD patients. Receiver operating characteristic (ROC) curve analysis and cross-validation were used to assess lung function parameters' diagnostic accuracy for predicting chronic hypercapnia, with the resulting performance expressed as area under the ROC curve (AUROC). We performed univariable and multivariable binary logistic regression analysis to determine if these parameters were independently associated with chronic hypercapnia, with probabilities reported as odds ratios [OR] with 95% confidence intervals [95%CI]., Results: FVC% (AUROC 0.77 [95%CI 0.72-0.81], P < 0.01) and FEV1% (AURIC 0.75 [95%CI 0.70-0.79], P < 0.01) exhibited reasonable accuracy in the prediction of chronic hypercapnia, whereas lung diffusion capacity performed poorly (AUROC 0.64 [95%CI 0.58-0.71] for DCO-SB%, P < 0.01). FVC% (OR 0.95 [95%CI 0.93-0.97], P < 0.01) and FEV1% (OR 0.97 [95%CI 0.94-0.99], P = 0.029) were the only parameters associated independently with chronic hypercapnia in logistic regression analysis. FVC and FEV1 thresholds that best separated hypercapnic from normocapnic subjects reached 56% and 33% of predicted values., Conclusions: Routinely collected pulmonary function parameters, particularly FVC% and FEV1%, may predict chronic hypercapnia during COPD progression., (© 2024. The Author(s).)

Size-matching donors to recipients in lung transplantation continues to be a clinical challenge. Predicted total lung capacity equations, or more simply, donor and recipient heights, while widely used, are imprecise and may not be representative of the pool of donors and recipients. These inherent limitations may result in size discrepancies. The advent of easily accessible software and the widespread availability of computed tomography (CT) imaging in donor assessments have made it possible to directly measure lung volumes in donors and recipients. As a result, there is a growing interest in adopting personalized CT volumetry as an alternative. This article explores both methods and underscores the potential benefits and precision offered by CT., Competing Interests: Declaration of competing interest The authors of this manuscript have no conflicts of interest to disclose, as described by the American Journal of Transplantation., (Copyright © 2024 American Society of Transplantation & American Society of Transplant Surgeons. Published by Elsevier Inc. All rights reserved.)

Objective: To verify the concurrent validity between the inspiratory muscle strength (IMS) values obtained in static (maximal inspiratory pressure [MIP]) and dynamic (S-Index) assessments. Methods: Healthy individuals were submitted to two periods of evaluation: i) MIP, static maneuver to obtain IMS, determined by the Mueller’s maneuver from residual volume (RV) until total lung capacity (TLC); ii) and S-Index, inspiration against open airway starting from RV until TLC. Both measures were performed by the same evaluator and the subjects received the same instructions. Isolated maneuvers with differences < 10% were considered as reproducible measures. Results: Data from 45 subjects (21 males) were analyzed and that showed statistical difference between MIP and S-Index values (133.5 ± 33.3 and 125.6 ± 32.2 in cmH2O, respectively), with P=0.014. Linear regression showed r² =0.54 and S-Index prediction formula = 39.8+(0.75×MIP). Pearson’s correlation demonstrated a strong and significant association between the measures with r=0.74. The measurements showed good concordance evidenced by the Bland-Altman test. Conclusion: S-Index and MIP do not present similar values since they are evaluations of different events of the muscular contraction. However, they have a strong correlation and good agreement, which indicate that both are able to evaluate the IMS of healthy individuals. [ABSTRACT FROM AUTHOR]

Introduction: Pulmonary hypertension (PH) is a well-recognised complication of interstitial lung diseases (ILD), which worsens prognosis and impairs exercise capacity. Echocardiography is the most widely used, non-invasive method for PH assessment. The aim of our study was to identify the factors predictive for echocardiographic signs of PH in newly recognised ILD patients. Methods: Ninety-three consecutive patients (28F/65M) with different ILD were prospectively evaluated from January 2009 to March 2014. Pulmonary function testing, 6-min walk distance (6MWD), initial and sixth minute room air oxygen saturation, NT-proBNP and echocardiography were assessed in each patient. Echocardiographic PH probability was determined according to the 2009 ESC/ERS guidelines. Results: In 41 patients (Group B) increased PH possibility has been diagnosed on echocardiography, in 52 patients (Group A)—low PH probability. Most pronounced differences (p ≤ 0.0005) between groups B and A concerned: age, 6MWD, room air oxygen saturation at 6 min, DLCO and TLC/DLCO index (57.6 vs 43.8 years; 478 vs 583 m; 89.1% vs 93.4%; 54.8% predicted vs 70.5% predicted and 1.86 vs 1.44; respectively). Univariate analysis showed four-fold increased probability of PH when TLC/DLCO exceeded 1.67. A scoring system incorporating age, TLC/DLCO index, 6MWD and room air oxygen saturation at 6 min provided high diagnostic utility, AUC 0.867 (95% CI 0.792–0.867). Conclusion: ILD patients with TLC/DLCO index > 1.67 have a high likelihood of PH and should undergo further evaluation. The composite model of PH prediction, including age, 6-min walk test and TLC/DLCO was highly specific for recognition of PH on echocardiography. [ABSTRACT FROM AUTHOR]

CONTEXT: Lung hyperinflation is defined as an abnormal increase in the volume of air remaining in the lungs at the end of normal expiration caused by the permanently destructive changes of emphysema and expiratory flow limitation. All the rehabilitation exercise programs have some reinforcement on hyperinflation mechanism directly or indirectly without any associated feedback. AIMS: This study aims to study the effect of visual biofeedback training on lung hyperinflation in chronic obstructive pulmonary disease (COPD) patients. SUBJECTS AND METHODS: 104 mild to moderate (global initiative for chronic obstructive lung disease) COPD patient of age group 40-60 years were recruited and randomly allocated to control and experimental group using random reviewer software 3.3 versions. The baseline and postoutcomes were analyzed by an external observer who is blinded. The visual training group receives biofeedback training on expiratory flow limitation. Both experimental and control group receives aerobic exercise training of 50%-60% of maximum heart rate intensity where all received cycling as a mode for 20-40 min with a warm and cool-down period. All the patients were trained for 4 days a week for 8 weeks. STATISTICAL ANALYSIS USED: Descriptive statistics, independent sample t-test, and repeated measures of analysis of variance. RESULTS: Residual volume and total lung capacity significantly reduced statistics F = 12.23 with P < 0.001 between the group. Breath hold time and maximum expiratory pressure showed increase response with significant statistics of F = 8.53 with P < 0.05 between the group. CONCLUSION: Visual feedback exercise training is one of the effective training methods to relieve the hyperinflation in stable COPD patients thereby improves exercise tolerance and quality of life. [ABSTRACT FROM AUTHOR]

BackgroundCT scan measures of emphysema and airway disease have been correlated with lung function in cohorts of subjects with a range of COPD severity. The contribution of CT scan-assessed airway disease to objective measures of lung function and respiratory symptoms such as dyspnea in severe emphysema is less clear.MethodsUsing data from 338 subjects in the National Emphysema Treatment Trial (NETT) Genetics Ancillary Study, densitometric measures of emphysema using a threshold of -950 Hounsfield units (%LAA-950) and airway wall phenotypes of the wall thickness (WT) and the square root of wall area (SRWA) of a 10-mm luminal perimeter airway were calculated for each subject. Linear regression analysis was performed for outcome variables FEV(1) and percent predicted value of FEV(1) with CT scan measures of emphysema and airway disease.ResultsIn univariate analysis, there were significant negative correlations between %LAA-950 and both the WT (r = -0.28, p = 0.0001) and SRWA (r = -0.19, p = 0.0008). Airway wall thickness was weakly but significantly correlated with postbronchodilator FEV(1)% predicted (R = -0.12, p = 0.02). Multivariate analysis showed significant associations between either WT or SRWA (beta = -5.2, p = 0.009; beta = -2.6, p = 0.008, respectively) and %LAA-950 (beta = -10.6, p = 0.03) with the postbronchodilator FEV(1)% predicted. Male subjects exhibited significantly thicker airway wall phenotypes (p = 0.007 for WT and p = 0.0006 for SRWA).ConclusionsAirway disease and emphysema detected by CT scanning are inversely related in patients with severe COPD. Airway wall phenotypes were influenced by gender and associated with lung function in subjects with severe emphysema.

Abstract The small airways of the lungs are commonly affected in pediatric and adult asthma. Small airways disease has been related to asthma control, severity, and risk of exacerbation. Diagnosis of small airways disease can be best made through evaluation of surgical lung specimens. Noninvasive techniques including spirometry, plethysmography, nitrogen washout, impulse oscillometry, and cross-sectional imaging have been utilized to assess and infer the extent of small airways disease in asthma and can be used longitudinally to assess response to treatment. Patients with small airways disease seem to benefit from inhaled asthma medications that have improved capacity to reach the distal lung compartment. This is especially important for patients with severe asthma, who rely upon high doses of inhaled corticosteroid and bronchodilators for asthma control. This review will describe the techniques which may be utilized to assess small airways disease, discuss the prevalence and characteristics of small airways disease in severe asthma, and highlight how small airway disease may complicate severe asthma treatment.