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Acute lung injury i.e. ALI and its serious form acute respiratory distress syndrome (ARDS) are incurable medical conditions associated with significant global mortality and morbidity. The objective of the present research was to repurpose cilostazol, an antiplatelet drug with anti-inflammatory, antioxidant and antiapoptotic effect, as a potential approach for treatment of ALI. Its multifaceted effects make it promising candidate but its mechanism against ALI remains elusive. Hence it is needed to elucidate its mechanism of action to revealed its therapeutic potential and improve its clinical outcomes. This study investigated the potential inflammatory therapeutic targets of cilostazol with its protective effect against lipopolysaccharide (LPS)-induced ALI. We have identified 10 inflammatory target proteins of cilostazol i.e. PDK1, RAC1, PTK6, KDR, EGFR, endothelin-I, caspase-3, TNF-α, NF-κB1/BTK, a TLR/IRAK4 by molecular docking and validated by in vivo evaluation to demonstrate its therapeutic efficacy. In vivo experiment was performed in two sets; first to determine cellular inflammation by analysing the biomarkers in both lung homogenate and bronchoalveolar fluid and second set to study lung edema with dexamethasone as a standard. Additionally, respiratory parameters, related mRNA expressions and histopathology was evaluated. Our results, molecular docking showed that cilostazol binds to identified inflammatory target proteins with the same binding affinity as that of experimental inhibitors. In vivo, downregulated oxidative stress, and inflammation i.e. attenuated the pulmonary edema and vascular leakage, release of inflammatory mediators i.e. IL-6, TNF-α, NO, C-reactive protein (CRP), lactate dehydrogenase (LDH) myeloperoxidase (MPO), Krebs von den Lungen 6 (KL-6), and the recruitment of inflammatory cells; downregulated the m-RNA gene expressions of tumour necrosis factor alpha (TNF-α), nuclear factor kappa B( NF-kB), Toll-like receptor 4 (TLR4), Janus kinase/signal transducer, and activator of transcription 3 (JAK and STAT3); and improved total lung capacity in LPS-challenged rats. These findings revealed the cilostazol's efficacy as promising therapeutic agent for ALI by inhibiting the NF-κB/TLR4/JAK-STAT3 signalling pathway., Competing Interests: Declarations. Ethics approval: All experimental methods were carried out with the permission of the Committee for the Purpose of Control and Supervision of Experiments on Animals (CPCSEA) guidelines and regulations with approval number SCI/IAEC/2022–23/41. Competing interests: The authors declare no competing interests., (© 2025. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

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.)

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., (© 2024. The Author(s).)

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., (© 2024. The Author(s).)

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).)

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., Competing Interests: No potential conflict of interest was reported by the author(s)., (© 2024 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.)

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.)

Back Ground: Knowledge concerning pulmonary function in adult patients with onset of idiopathic scoliosis before age 10 is sparse. A long-term follow-up (FU, mean 26 years, > 12 years after treatment) of pulmonary function (PF) in patients treated with brace or surgery due to idiopathic scoliosis with onset before the age of 10 was earlier performed. To evaluate whether a more severe reduction in pulmonary function leads to more rapid deterioration within a four-year period, this study was performed., Methods: Twenty patients with the most reduced pulmonary function and 19 out of those with normal PF found at the long-term FU were reexamined 4 years later to evaluate further changes in pulmonary function. Patients underwent spirometry and arterial blood gas analysis and answered pulmonary symptom questionnaires., Results: 70% of the reduced pulmonary function group had undergone surgery vs. 26% of the normal group. The mean age (47 vs. 43 years) at this FU and curve size (37° vs. 35°) at the 26-year FU were similar. The decline in forced vital capacity (FVC) % of predicted was similar in both groups over the four-year period, from 67 to 65% in the reduced PF group vs. 96 to 94% in the normal PF group. The total lung capacity (TLC) % of predicted did not change over time in either group. No patient reported worsening dyspnea symptoms. Only one patient in the reduced PF group showed low arterial oxygen tension, 8.4 kPa, not signifying respiratory insufficiency., Conclusion: The age-related decline in FVC and TLC % of predicted did not differ between those with reduced and those with normal pulmonary function at the 26-year follow-up. Thus, these data do not infer increased rate of decline in the most deteriorated patients., (© 2024. The Author(s).)

Background: Reference values for lung volumes are necessary to identify and diagnose restrictive lung diseases and hyperinflation, but the values have to be validated in the relevant population. Our aim was to investigate the Global Lung Function Initiative (GLI) reference equations in a representative healthy Austrian population and create population-derived reference equations if poor fit was observed., Methods: We analysed spirometry and body plethysmography data from 5371 respiratory healthy subjects (6-80 years) from the Austrian LEAD Study. Fit with the GLI equations was examined using z-scores and distributions within the limits of normality. LEAD reference equations were then created using the LMS method and the generalized additive model of location shape and scale package according to GLI models., Results: Good fit, defined as mean z-scores between + 0.5 and -0.5,was not observed for the GLI static lung volume equations, with mean z-scores > 0.5 for residual volume (RV), RV/TLC (total lung capacity) and TLC in both sexes, and for expiratory reserve volume (ERV) and inspiratory capacity in females. Distribution within the limits of normality were shifted to the upper limit except for ERV. Population-derived reference equations from the LEAD cohort showed superior fit for lung volumes and provided reproducible results., Conclusion: GLI lung volume reference equations demonstrated a poor fit for our cohort, especially in females. Therefore a new set of Austrian reference equations for static lung volumes was developed, that can be applied to both children and adults (6-80 years of age)., (© 2024. The Author(s).)

We present the case of a 74-year-old woman with a past medical history (PMH) significant for anxiety, depression, and hypertension who presented to the pulmonary clinic for consultation regarding progressive shortness of breath, which started five months ago after developing COVID-19. Further history-taking revealed that she had been started on nitrofurantoin two months ago for recurrent urinary tract infections (UTIs). Her pulmonary function tests (PFTs) demonstrated a moderately restrictive disease. A CT chest was obtained, showing pleural thickening with bilateral pleural-based ground glass opacities. Nitrofurantoin was then discontinued, and she was started on a prednisone taper for suspected nitrofurantoin-induced interstitial lung disease (ILD). At a follow-up clinic visit six months later, she showed great improvement in her shortness of breath, marked improvement in forced vital capacity (FVC) on PFTs, and near resolution of pleural-based lesions and basal ground glass opacities on CT chest. This case emphasizes the importance of keeping the diagnosis of nitrofurantoin-induced ILD in mind, as well as the need to implement guidelines for the monitoring of this potential pulmonary adverse effect., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2024, Akopyan et al.)

Background: The 2017 ATS/ERS technical standard for measuring the single-breath diffusing capacity (DLCO) proposed the "rapid-gas-analyzer" (RGA) or, equivalently, "total-breath" (TB) method for the determination of total lung capacity (TLC). In this study, we compared DLCO and TLC values estimated using the TB and conventional method, and how estimated TLC using these two methods compared to that determined by body plethysmography., Method: A total of 95 people with COPD (GOLD grades 1-4) and 23 healthy subjects were studied using the EasyOne Pro (ndd Medical Technologies, Switzerland) and Master Screen Body (Vyaire Medical, Höchberg, Germany)., Results: On average the TB method resulted in higher values of DLCO (mean ± SD Δ = 0.469 ± 0.267; 95%CI: 0.420; 0.517 mmol*min-1*kPa-1) and TLC (Δ = 0.495 ± 0.371; 95%CI: 0.427; 0.562 L) compared with the conventional method. In healthy subjects the ratio between TB and conventional DLCO was close to one. TLC estimated using both methods was lower than that determined by plethysmography. The difference was smaller for the TB method (Δ = 1.064 ± 0.740; 95%CI: 0.929; 1.199 L) compared with the conventional method (Δ = 1.558 ± 0.940; 95%CI: 1.387; 1.739 L). TLC from body plethysmography could be estimated as a function of TB TLC and FEV 1 Z-Score with an accuracy (normalized root mean square difference) of 9.1%., Conclusion: The total-breath method yielded higher values of DLCO and TLC than the conventional analysis, especially in subjects with COPD. TLC from the total-breath method can also be used to estimate plethysmographic TLC with better accuracy than the conventional method. The study is registered under clinicaltrial.gov NCT04531293., (© 2024. The Author(s).)

Background: Lung hyperinflation is a typical clinical feature of patients with COPD. Given the association between breathing at elevated lung volumes and the manifestation of severe debilitating symptoms, therapeutic interventions such as positive expiratory pressure (PEP) therapy and its variations (temporary, oscillatory) have been devised to mitigate lung hyperinflation. However, the efficacy of these interventions remains to be conclusively demonstrated., Methods: A systematic review with meta-analysis of randomized trials was conducted following the PRISMA guidelines. Seven databases were screened with no date or language restriction. Two authors independently applied eligibility criteria and assessed the risk of bias of included studies using the Cochrane risk-of-bias tool. Outcomes were lung hyperinflation measures detected through changes in inspiratory capacity (IC), functional residual capacity (FRC), total lung capacity (TLC), and residual volume (RV), as well as FEV 1 , FVC, dyspnea, and physical capacity. Pooled standardized mean differences (SMDs) or mean differences (MDs) and 95% CI were calculated using a random-effects model., Results: Seven trials, all with a high risk of bias, were included. Compared to control group, RV significantly decreased (4 studies, n = 231; SMD -0.42 [95% CI -0.77 to -0.08], P = .02), dyspnea improved ( n = 321, SMD -1.17 [95% CI -1.68 to -0.66], P < .001), and physical capacity increased (5 studies, n = 311; MD 30.1 [95% CI 19.2-41.0] m, P < .001) with PEP therapy. There was no significant difference between PEP therapy and the control group in TLC, FVC, or FEV 1 . Only one study reported changes in inspiratory capacity as well as FRC., Conclusions: In patients with COPD, the effect of PEP therapy on lung hyperinflation is unclear owing to the non-consistent change in lung hyperinflation outcomes, insufficient data, and lack of high-quality trials. Dyspnea and physical capacity might improve with PEP therapy., Competing Interests: The authors have disclosed no conflicts of interest., (Copyright © 2024 by Daedalus Enterprises.)

Background: Previous studies have shown that the ratio between alveolar volume (V A ) and total lung capacity (TLC) reflects ventilation heterogeneity in subjects with chronic obstructive pulmonary disease (COPD). However, the ratio and its correlation to respiratory symptoms had to our knowledge not previously been investigated in subjects with mild chronic airflow obstruction or without airflow obstruction (normal ratio FEV 1 /VC). The purpose of this study was to investigate potential connection between V A /TLC and respiratory symptoms, smoking habits and lung function parameters in subjects with normal spirometry and with mild chronic airflow obstruction., Methods: We examined 450 subjects (82 non-smokers with normal spirometry, 298 subjects who smoked or had smoked earlier but had a normal spirometry and 70 subjects with chronical airflow obstruction) with routine lung function tests and a questionnaire regarding respiratory symptoms., Results: This study showed 31 out of 54 subjects with a low V A /TLC had a normal ratio FEV 1 /VC. Of these subjects, 58.1 % had respiratory symptoms, compared to the group with normal ratio for both V A /TLC and FEV 1/ VC where 35.8 % had respiratory symptoms (p-value 0.02)., Conclusion: This study has shown that within the group of subjects with a normal ratio FEV 1 /VC, those with a decreased ratio V A /TLC had a higher prevalence of respiratory symptoms compared to subjects with a normal V A /TLC ratio. These findings indicate that including the ratio V A /TLC in the evaluation of a pulmonary function test assessment might increase the possibility to identify subjects with early or at risk of lung disease., Competing Interests: Declaration of competing interest The authors declare the following financial interests/ personal relationships which may be considered as potential competing interests: P Wollmer reports a relationship with Chiesi Pharma that includes consulting or advisory. P Wollmer has patent issued to Method and device for pulmonary function measurement., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Purpose: To evaluate the degree of lung hyperinflation (LH) in patients with stable chronic obstructive pulmonary disease (COPD) by lung ultrasound score (LUS) and assess its value., Patients and Methods: We conducted a study of 149 patients with stable COPD and 100 healthy controls recruited by the Second Affiliated Hospital of Fujian Medical University. The pleural sliding displacement (PSD) was measured, the sliding of the pleura in different areas was observed, and LUS was calculated from both of them. The diaphragm excursion (DE), residual capacity (RV), total lung capacity (TLC), inspiratory capacity (IC) and functional residual capacity (FRC) were measured. We described the correlation between ultrasound indicators and pulmonary function indicators reflecting LH. Multiple linear regression analysis was used. The ROC curves of LUS and DE were drawn to evaluate their diagnostic efficacy, and De Long method was used for comparison., Results: (1) The LUS of patients with stable COPD were positively correlated with RV, TLC, RV/TLC and FRC and negatively correlated with IC and IC/TLC ( r 1 =0.72, r 2 =0.41, r 3 =0.72, r 4 =0.70, r 5 =-0.56, r 6 =-0.65, P < 0.001). The correlation was stronger than that between DE at maximal deep inspiration and the corresponding pulmonary function indices ( r 1 =-0.41, r 2 =-0.26, r 3 =-0.40, r 4 =-0.43, r 5 =0.30, r 6 =0.37, P < 0.001). (2) Multiple linear regression analysis showed that LUS were significantly correlated with IC/TLC and RV/TLC. (3) With IC/TLC<25% and RV/TLC>60% as the diagnostic criterion of severe LH, the areas under the ROC curves of LUS and DE at maximal deep inspiration for diagnosing severe LH were 0.914 and 0.385, 0.845 and 0.543, respectively ( P < 0.001)., Conclusion: The lung ultrasound score is an important parameter for evaluating LH. LUS is better than DE at maximal deep inspiration for diagnosing severe LH and is expected to become an effective auxiliary tool for evaluating LH., Competing Interests: The authors declare that they have no competing interests in this work., (© 2024 Chen et al.)

The coronavirus disease (COVID-19) pandemic has already affected millions of individuals, with increasing numbers of survivors. These data suggest that the pulmonary sequelae of the infection may have an effect on a wide range of individuals. The aim of the present study was to evaluate pulmonary function in patients hospitalized due to COVID-19 three months after hospital discharge. A total of 116 patients, 34 females and 82 males, with a mean age of 57.77±11.45 years, who were hospitalized due to COVID-19, underwent pulmonary function testing three months after their hospital discharge. Of these, 83 (71.6%) patients were hospitalized in the period of alpha variant predominance, 16 (13.8%) in the period of delta variant predominance and 17 (14.6%) in the omicron variant predominance period. The mean value of diffusion capacity for carbon monoxide (DLCO)% predicted (pred) was statistically higher in patients affected by the omicron variant (P=0.028). Abnormal values (<80% pred) of DLCO and total lung capacity (TLC) were observed in 28.4 and 20.7% of the patients, respectively. Active smoking was an independent predictor of abnormal values of forced expiratory volume in 1 sec % pred and TLC% pred [P=0.038; odds ratio (OR): 8.574, confidence interval (CI) 1.124-65.424 and P=0.004, OR: 14.733, CI 2.323-93.429, respectively], age was an independent predictor of abnormal values of forced vital capacity % pred and DLCO% pred (P=0.027, OR: 1.124, CI 1.014-1.246 and P=0.011, OR:1.054, CI 1.012-1.098, respectively); and female sex was an independent predictor of abnormal values of DLCO% pred (P=0.009, OR: 1.124, CI 1.014-1.246). Α significant percentage of hospitalized patients due to COVID-19 pneumonia will develop abnormal pulmonary function, regardless of the SARS-CoV-2 variant., Competing Interests: DAS is the Editor-in-Chief for the journal, but had no personal involvement in the reviewing process, or any influence in terms of adjudicating on the final decision, for this article. The other authors declare that they have no competing interests., (Copyright: © Georgakopoulou et al.)

Background: Effective use of lung volume data measured on computed tomography (CT) requires reference values for specific populations. This study examined whether an equation previously generated for multiple ethnic groups in the United States, including Asians predominantly composed of Chinese people, in the Multi-Ethnic Study of Atherosclerosis (MESA) could be used for Japanese people and, if necessary, to optimize this equation. Moreover, the equation was used to characterize patients with chronic obstructive pulmonary disease (COPD) and lung hyperexpansion., Methods: This study included a lung cancer screening CT cohort of asymptomatic never smokers aged ≥40 years from two institutions (n = 364 and 419) to validate and optimize the MESA equation and a COPD cohort (n = 199) to test its applicability., Results: In all asymptomatic never smokers, the variance explained by the predicted values (R 2 ) based on the original MESA equation was 0.60. The original equation was optimized to minimize the root mean squared error (RMSE) by adjusting the scaling factor but not the age, sex, height, or body mass index terms of the equation. The RMSE changed from 714 ml in the original equation to 637 ml in the optimized equation. In the COPD cohort, lung hyperexpansion, defined based on the 95th percentile of the ratio of measured lung volume to predicted lung volume in never smokers (122 %), was observed in 60 (30 %) patients and was associated with centrilobular emphysema and air trapping on inspiratory/expiratory CT., Conclusions: The MESA equation was optimized for Japanese middle-aged and elderly adults., Competing Interests: Declaration of competing interest N.T. and T.H. received research grants from Daiichi Sankyo and FUJIFILM Co., Ltd., outside of the submitted work. S.S. received grants from Nippon Boehringer Ingelheim, Philips-Respironics, Fukuda Denshi, Fukuda Lifetec Keiji, and ResMed outside of the submitted work. None of these companies played a role in the design or analysis of the study or the writing of the manuscript. The other authors have no conflicts of interest., (Copyright © 2023. Published by Elsevier B.V.)

Background: Current measures of tidal volume/forced vital capacity (VT/FVC) and VT/inspiratory capacity (VT/IC) at peak exercise cannot differentiate restrictive from obstructive ventilation patterns. This study aimed to investigate the utility of VT/total lung capacity (VT/TLC) as a marker for dynamic lung hyperinflation (DH) in patients with chronic obstructive pulmonary disease (COPD) and interstitial lung disease (ILD)., Methods: 267 subjects were screened: 23 ILD, 126 COPD, and 33 healthy individuals were enrolled. Lung function tests and cardiopulmonary exercise tests with repeated IC maneuver were conducted and compared at three exercise efforts: unloaded, middle of exercise, and peak exercise., Results: During exercise, ILD patients demonstrated normal end-expiratory lung volume/TLC (EELV/TLC) ratios, but elevated end-inspiratory lung volume/TLC (EILV/TLC) ratios, except for peak exercise. COPD patients exhibited elevated ratios for both EELV/TLC and EILV/TLC during exercise with a larger EELV/TLC ratio compared to ILD patients at peak exercise (p < 0.05). The VT/TLC ratio distinguished ILD, COPD, and healthy controls at peak exercise (p < 0.05). A VT/TLC ratio of ≤ 0.22 or ≥ 0.30 indicated airflow obstruction with hyperinflation or normal lung expansion, respectively (AUC: 0.74 or 0.88). Furthermore, VT/TLC outperformed VT/FVC and VT/IC in differentiating lung expansion between ILD and COPD during exercise (all p < 0.05)., Conclusion: Exercise-induced DH was absent in ILD patients but observed in COPD patients. Excessive lung expansion occurred in all patients during exercise, except for limited expansion in ILD at peak exercise probably due to specific lung properties. VT/TLC can distinguish between restrictive, obstructive, and normal ventilatory patterns., Competing Interests: Declaration of Competing Interest The authors declare no competing interests., (Copyright © 2023. Published by Elsevier B.V.)

Sliding between lung lobes along lobar fissures is a poorly understood aspect of lung mechanics. The objective of this study was to test the hypothesis that lobar sliding helps reduce distortion in the lung parenchyma during breathing. Finite element models of left lungs with geometries and boundary conditions derived from medical images of human subjects were developed. Effect of lobar sliding was studied by comparing nonlinear finite elastic contact mechanics simulations that allowed and disallowed lobar sliding. Lung parenchymal distortion during simulated breath-holds and tidal breathing was quantified with the model's spatial mean anisotropic deformation index (ADI), a measure of directional preference in volume change that varies spatially in the lung. Models that allowed lobar sliding had significantly lower mean ADI (i.e., lesser parenchymal distortion) than models that disallowed lobar sliding under simulations of both tidal breathing (5.3% median difference, P = 0.008, n = 8) and lung deformation between breath-holds at total lung capacity and functional residual capacity (3.2% median difference, P = 0.03, n = 6). This effect was most pronounced in the lower lobe where lobar sliding reduced parenchymal distortion with statistical significance, but not in the upper lobe. In addition, more lobar sliding was correlated with greater reduction in distortion between sliding and nonsliding models in our study cohorts (Pearson's correlation coefficient of 0.95 for tidal breathing, 0.87 for breath-holds, and 0.91 for the combined dataset). These findings are consistent with the hypothesis that lung lobar sliding reduces parenchymal distortion during breathing. NEW & NOTEWORTHY The role of lobar sliding in lung mechanics is poorly understood. Delineating this role could help explain how breathing is affected by anatomical differences between subjects such as incomplete and missing lobar fissures. We used computational contact mechanics models of lungs from human subjects to delineate the effect of lobar sliding by comparing simulations that allowed and disallowed sliding. We found evidence consistent with the hypothesis that lung lobar sliding reduces parenchymal distortion during breathing.

Predicted lung volumes based on the Global Lung Function Initiative (GLI) model are used in pulmonary disease detection and monitoring. It is unknown how well the predicted lung volume corresponds with computed tomography (CT) derived total lung volume (TLV). The aim of this study was to compare the GLI-2021 model predictions of total lung capacity (TLC) with CT-derived TLV. 151 female and 139 male healthy participants (age 45-65 years) were consecutively selected from a Dutch general population cohort, the Imaging in Lifelines (ImaLife) cohort. In ImaLife, all participants underwent low-dose, inspiratory chest CT. TLV was measured by an automated analysis, and compared to predicted TLC based on the GLI-2021 model. Bland-Altman analysis was performed for analysis of systematic bias and range between limits of agreement. To further mimic the GLI-cohort all analyses were repeated in a subset of never-smokers (51% of the cohort). Mean±SD of TLV was 4.7±0.9 L in women and 6.2±1.2 L in men. TLC overestimated TLV, with systematic bias of 1.0 L in women and 1.6 L in men. Range between limits of agreement was 3.2 L for women and 4.2 L for men, indicating high variability. Performing the analysis with never-smokers yielded similar results. In conclusion, in a healthy cohort, predicted TLC substantially overestimates CT-derived TLV, with low precision and accuracy. In a clinical context where an accurate or precise lung volume is required, measurement of lung volume should be considered., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Wisselink et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Background and Objective: Spirometry 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., Methods: We 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., Results: The 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., Conclusion: A 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., Competing Interests: MT, AH, and PD were employed by the ArtiQ NV. MV has received consultancy fees from ArtiQ NV. WJ was a shareholder at ArtiQ NV. The remaining author declares that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Beverin, Topalovic, Halilovic, Desbordes, Janssens and De Vos.)

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 (DL CO ) 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 DL CO 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., (© 2022 The Authors. Internal Medicine Journal published by John Wiley & Sons Australia, Ltd on behalf of Royal Australasian College of Physicians.)

Background: Preserved ratio impaired spirometry (PRISm) refers to decreased forced expiratory volume in 1 s (FEV 1 ) in the setting of preserved ratio. Little is known about the role of PRISm and its complex relation with small airway dysfunction (SAD) and lung volume. Therefore, we aimed to investigate the associations between PRISm and SAD and lung volume., Methods: We conducted a cross-sectional community-dwelling study in China. Demographic data, standard respiratory epidemiology questionnaire, spirometry, impulse oscillometry (IOS) and computed tomography (CT) data were collected. PRISm was defined as post-bronchodilator FEV 1 /FVC ≥ 0.70 and FEV 1  < 80% predicted. Spirometry-defined SAD was defined as at least two of three of the post-bronchodilator maximal mid-expiratory flow (MMEF), forced expiratory flow 50% (FEF50), and forced expiratory flow 75% (FEF75) less than 65% of predicted. IOS-defined SAD and CT-defined gas trapping were defined by the fact that the cutoff value of peripheral airway resistance R5-R20 > 0.07 kPa/L/s and LAA - 856 >20%, respectively. Analysis of covariance and logistic regression were used to determine associations between PRISm and SAD and lung volume. We then repeated the analysis with a lower limit of normal definition of spirometry criteria and FVC definition of PRISm. Moreover, we also performed subgroup analyses in ever smoker, never smoker, subjects without airway reversibility or self-reported diagnosed asthma, and subjects with CT-measured total lung capacity ≥70% of predicted., Results: The final analysis included 1439 subjects. PRISm had higher odds and more severity in spirometry-defined SAD (pre-bronchodilator: odds ratio [OR]: 5.99, 95% confidence interval [95%CI]: 3.87-9.27, P < 0.001; post-bronchodilator: OR: 14.05, 95%CI: 8.88-22.24, P < 0.001), IOS-defined SAD (OR: 2.89, 95%CI: 1.82-4.58, P < 0.001), and CT-air trapping (OR: 2.01, 95%CI: 1.08-3.72, P = 0.027) compared with healthy control after adjustment for confounding factors. CT-measured total lung capacity in PRISm was lower than that in healthy controls (4.15 ± 0.98 vs. 4.78 ± 1.05 L, P < 0.05), after adjustment. These results were robust in repeating analyses and subgroup analyses., Conclusion: Our finding revealed that PRISm was associated with SAD and reduced total lung capacity. Future studies to identify the underlying mechanisms and longitudinal progression of PRISm are warranted., (© 2022. The Author(s).)

Cement dust exposure (CDE) can be a risk factor for pulmonary disease, causing changes in segmental airways and parenchymal lungs. This study investigates longitudinal alterations in quantitative computed tomography (CT)-based metrics due to CDE. We obtained CT-based airway structural and lung functional metrics from CDE subjects with baseline CT and follow-up CT scans performed three years later. From the CT, we extracted wall thickness (WT) and bifurcation angle (θ) at total lung capacity (TLC) and functional residual capacity (FRC), respectively. We also computed air volume (V air ), tissue volume (V tissue ), global lung shape, percentage of emphysema (Emph%), and more. Clinical measures were used to associate with CT-based metrics. Three years after their baseline, the pulmonary function tests of CDE subjects were similar or improved, but there were significant alterations in the CT-based structural and functional metrics. The follow-up CT scans showed changes in θ at most of the central airways; increased WT at the subgroup bronchi; smaller V air at TLC at all except the right upper and lower lobes; smaller V tissue at all lobes in TLC and FRC except for the upper lobes in FRC; smaller global lung shape; and greater Emph% at the right upper and lower lobes. CT-based structural and functional variables are more sensitive to the early identification of CDE subjects, while most clinical lung function changes were not noticeable. We speculate that the significant long-term changes in CT are uniquely observed in CDE subjects, different from smoking-induced structural changes., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

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 (PM 2.5 ) and nitric dioxide (NO 2 ) 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 NO 2 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 NO 2 remained robust after adjustment for PM 2.5 exposure., Conclusions: Long-term exposure to ambient NO 2 is associated with an accelerated decline in static lung volume and diffusion capacity in the elderly. NO 2 related air pollution may be a risk factor for restrictive lung disorders., (© 2022. The Author(s).)

Body plethysmography is a fundamental method for the assessment of static lung volumes. Although equipment is provided by several manufacturers, there are no established cross-vendor tools for quality control. In the process of quality control and analysis of data on hyperinflation from the large COPD cohort COSYCONET, hints appeared that plethysmographs of different vendors might yield different values for static lung volumes. Functional residual capacity (FRC) differed about 0.67 litres between plethysmographs of the manufacturer Vyaire and Ganshorn. Absolute differences of residual lung volume (RV) and total lung capacity (TLC) were similar. It appears undeniable that differences of this magnitude have an impact on clinical interpretation. Thus, device harmonization seems to be required., Competing Interests: Peter Alter declares no relevant competing interests. Jan Orszag declares no relevant competing interests. Emiel F. M. Wouters declares no relevant competing interests. Claus F. Vogelmeier declares grants or contracts to his institution from the German Ministry of Education and Science (BMBF), AstraZeneca, Boehringer Ingelheim, GlaxoSmithKline, Grifols, and Novartis, consulting fees from AstraZeneca, Boehringer Ingelheim, CSL Behring, Chiesi, GlaxoSmithKline, Menarini, Novartis, and Nuvaira, MedUpdate, payment or honoraria for lectures, presentations, speakers bureaus, manuscript writing or educational events from Aerogen, AstraZeneca, Boehringer Ingelheim, CSL Behring, Chiesi, GlaxoSmithKline, Menarini, and Novartis, all of which are outside the scope of the submitted work. Rudolf A. Jörres declares no relevant competing interests., (© 2022 Alter et al.)

The best available evidence and the predictive value of computed tomography (CT) findings for prognosis in patients with acute respiratory distress syndrome (ARDS) are unknown. We systematically searched three electronic databases (MEDLINE, CENTRAL, and ClinicalTrials.gov). A total of 410 patients from six observational studies were included in this systematic review. Of these, 143 patients (34.9%) died due to ARDS in short-term. As for CT grade, the CTs used ranged from 4- to 320-row. The index test included diffuse attenuations in one study, affected lung in one study, well-aerated lung region/predicted total lung capacity in one study, CT score in one study and high-resolution CT score in two studies. Considering the CT findings, pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio were 62% (95% confidence interval [CI] 30-88%), 76% (95% CI 57-89%), 2.58 (95% CI 2.05-2.73), 0.50 (95% CI 0.21-0.79), and 5.16 (95% CI 2.59-3.46), respectively. This systematic review revealed that there were major differences in the definitions of CT findings, and that the integration of CT findings might not be adequate for predicting short-term mortality in ARDS. Standardisation of CT findings and accumulation of further studies by CT with unified standards are warranted., (© 2022. The Author(s).)

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 FEV 1 /FVC ≥ 0.7 and definition 2: FVC < LLN and FEV 1 /FVC ≥ LLN) and RSPs defined by Youden's method (definition 3: FVC < 85.5% of predicted and FEV 1 /FVC ≥ LLN and definition 4: FVC Z-score < -1.0 and FEV 1 /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 FEV 1 /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 FEV 1 /FVC ≥ LLN, may serve as an alternative with higher sensitivity for screening., (© 2022 The Authors. Clinical Physiology and Functional Imaging published by John Wiley & Sons Ltd on behalf of Scandinavian Society of Clinical Physiology and Nuclear Medicine.)

Background and Aims: Air 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 Methods: To 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., Results: Of 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)., Conclusions: In 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., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Kim, Kim, Rhee, Lee, Lee, Kim, Shin, Jung, Yoo and Park.)

Background: To clarify the differences in diaphragm thickness between male and female participants in healthy young adults with ultrasonography using the mean intima media thickness (IMT) method and to investigate the relationship between diaphragm thickness and respiratory pressure., Methods: Twenty-nine healthy individuals (16 females and 13 males) participated in the study. Diaphragm thickness was measured at total lung capacity (TLC) and at functional residual capacity (FRC) in each participant. We measured the diaphragm thickness using a method for mean intima media thickness. Moreover, change ratio of diaphragm thickness was calculated with the diaphragm thickness at TLC and FRC., Results: Mean diaphragm thicknesses at FRC in males were significantly narrower than those in females (p < 0.001). The change ratio of diaphragm thickness was significantly augmented in males compared with that in females (p < 0.001). There was a positive correlation between the change ratio of diaphragm thickness and pulmonary function data and respiratory muscle strength in healthy young adults., Conclusions: The change ratio of diaphragm thickness using the IMT method can be accurately performed with a high degree of reproducibility by clinical laboratory technicians and may be a useful indicator for evaluating diaphragm muscle strength., (© 2022. The Author(s).)

Abstract: A high dead space (VD) to tidal volume (VT) ratio during peak exercise (VD/VTpeak) is a sensitive and consistent marker of gas exchange abnormalities; therefore, it is important in patients with chronic obstructive pulmonary disease (COPD). However, it is necessary to use invasive methods to obtain VD/VTpeak, as noninvasive methods, such as end-tidal PCO2 (PETCO2peak) and PETCO2 adjusted with Jones' equation (PJCO2peak) at peak exercise, have been reported to be inconsistent with arterial PCO2 at peak exercise (PaCO2peak). Hence, this study aimed to generate prediction equations for VD/VTpeak using statistical techniques, and to use PETCO2peak and PJCO2peak to calculate the corresponding VD/VTpeaks (i.e., VD/VTpeakETVD/VTpeakJ).A total of 46 male subjects diagnosed with COPD who underwent incremental cardiopulmonary exercise tests with PaCO2 measured via arterial catheterization were enrolled. Demographic data, blood laboratory tests, functional daily activities, chest radiography, two-dimensional echocardiography, and lung function tests were assessed.In multivariate analysis, diffusing capacity, vital capacity, mean inspiratory tidal flow, heart rate, and oxygen pulse at peak exercise were selected with a predictive power of 0.74. There were no significant differences in the PCO2peak values and the corresponding VD/VTpeak values across the three types (both p = NS).In subjects with COPD, VD/VTpeak can be estimated using statistical methods and the PETCO2peak and PJCO2peak. These methods may have similar predictive power and thus can be used in clinical practice., Competing Interests: The authors have no conflicts of interests to disclose., (Copyright © 2022 the Author(s). Published by Wolters Kluwer Health, Inc.)

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 one 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., (© 2022 Revista Medica del Instituto Mexicano del Seguro Social.)

Navy divers tend to have large lungs and low expiratory flow rates in the terminal portion of a spirogram. We examined Finnish Navy divers for the presence of air trapping, airway obstruction, and functional airway compression, and their association with lung volumes. Divers (n = 57) and non-diving men (n = 10) underwent a variety of pulmonary function tests. The amount of trapped air was calculated as the subtraction of the total lung capacity (TLC) measured in a single-breath helium dilution test from the TLC in body plethysmography (TLCb). Mean vital capacity (VC) was 6.4 L in the divers versus 5.8 L in the controls (p = 0.006) and TLCb 8.9 L in the divers versus 8.1 L in the controls (p = 0.002). No difference existed between them in the amount of trapped air. However, we found break points in a linear regression model (Davies test) between trapped air and several pulmonary parameters. Those individuals above the break points had lower ratio of forced expiratory volume in first second to forced vital capacity, lower resistance of airways, and higher reactance than those below the break points. In conclusion, navy divers had larger lungs than controls. Large lung volumes (VC >7.31 L or >122% of predicted value) were associated with air trapping. Furthermore, large volumes of air trapping (>1.1 L) were associated with increased residual volume (RV) and RV/TLCb. Despite no concurrent obstruction, functional airway compression, or reduced diffusing capacity, this slowly ventilated trapped air might remain disadvantageous for divers., (© 2021 The Authors. Physiological Reports published by Wiley Periodicals LLC on behalf of The Physiological Society and the American Physiological Society.)

Case Presentation: A 21-year-old male college student presented for a second opinion with low alpha-1 antitrypsin (AAT) levels and complaints of episodic dyspnea with wheezing and cough. He was a never smoker with a medical history of frequent respiratory tract infections in early childhood and allergy to dander, dust mites, peanuts, and eggs. There was no travel history outside of the continental United States. His mother had asthma. His symptoms were not controlled on inhaled corticosteroids and bronchodilators. His AAT genotype was found to be PI∗SZ, and augmentation therapy (with pooled human-plasma derived AAT) was recommended locally., (Copyright © 2021 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.)

Exertional dyspnea (ED) and impaired exercise performance (EP) are mainly caused by dynamic hyperinflation (DH) in chronic obstructive pulmonary disease (COPD) patients by constraining tidal volume expansion at peak exercise (V Tpeak ). As V Tpeak is the product of inspiratory time (T Ipeak ) and flow (V T /T Ipeak ), it was hypothesized that V Tpeak and V Tpeak /total lung capacity (V Tpeak /TLC) may be affected by T Ipeak and V T /T Ipeak . Hence, the study investigated the (1) effect of T Ipeak and V T /T Ipeak on V Tpeak expansion, (2) factors associated with T Ipeak , expiratory time (T Epeak ), V T /T Ipeak , and V Tpeak /TLC, and (3) relationships between V T /T Ipeak and V Tpeak /TLC with ED and EP in COPD patients and controls. The study enrolled 126 male stable COPD patients and 33 sex-matched controls. At peak exercise, T Ipeak was similar in all subjects (COPD versus controls, mean ± SD: 0.78 ± 0.17 s versus 0.81 ± 0.20 s, p = NS), whereas the COPD group had lower V T /T Ipeak (1.71 ± 0.49 L/s versus 2.58 ± 0.69 L/s, p < .0001) and thus the COPD group had smaller V Tpeak (1.31 ± 0.34 L versus 2.01 ± 0.45 L, p < .0001) and V Tpeak /TLC (0.22 ± 0.06 vs 0.33 ± 0.05, p < .0001). T Ipeak , T Epeak, and V T /T Ipeak were mainly affected by exercise effort, whereas V Tpeak /TLC was not. T Epeak, V T /T Ipeak , and V Tpeak /TLC were inversely changed by impaired lung function. T Ipeak was not affected by lung function. Dynamic hyperinflation did not occur in the controls, however, V Tpeak /TLC was strongly inversely related to DH (r = -0.79) and moderately to strongly related to lung function, ED, and EP in the COPD group. There was a slightly stronger correlation between V Tpeak /TLC with ED and EP than V T /T Ipeak in the COPD group (|r| = 0.55-0.56 vs 0.38-0.43). In summary, T Ipeak was similar in both groups and the key to understanding how flow affects lung expansion. However, the DH volume effect was more important than the flow effect on ED and EP in the COPD group.

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.

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 cross-sectional 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 cm 2 , 0.5 mm, and 46.4 mm 3 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., Competing Interests: Conflicts of Interest: The authors have no potential conflicts of interest to disclose., (Copyrights © 2021 The Korean Society of Radiology.)

Background: Infant pulmonary function tests (iPFTs) in subjects with neuroendocrine cell hyperplasia of infancy (NEHI) have demonstrated substantial expiratory airflow obstruction and air trapping., Research Question: Can indices from iPFTs be used in the diagnosis of NEHI?, Study Design and Methods: This is an observational case-control study evaluating iPFT results from a registry of patients assessed at the Hadassah Hebrew University Medical Center between 2008 and 2018. iPFTs results in infants with NEHI were compared to two disease control infant groups (infants evaluated for recurrent wheezing and infants evaluated due to prematurity) and a spirometry control group of infants with normal expiratory airflow, using the Kruskal-Wallis test. Receiver operating characteristic (ROC) curves were used to assess the diagnostic accuracy of iPFT indices., Results: We evaluated iPFT data in 481 infants (15, NEHI; 292, wheezing; 128, premature; and 46, spirometry control group). Infants with NEHI had significantly increased trapped air volumes (median functional residual capacity measured with infant whole-body plethysmography [FRC pleth ] was 199% predicted; median ratio of residual volume to total lung capacity was 59% predicted) when compared with results in all evaluated groups of infants (P < .001), including multiple pairwise comparisons. Airflow limitation was demonstrated in infants with NEHI when compared with the infants in the spirometry control group but was similar to the two disease control groups. FRC pleth had the best discriminatory ability for NEHI diagnosis, with an FRC pleth  ≥ 150% predicted demonstrating a ROC of 0.91 (95% CI, 0.82-1.00), sensitivity of 86.7% (95% CI, 59.5%-98.3%), and specificity of 95.5% (95% CI, 93.2%-97.3%)., Interpretation: Findings on iPFTs of markedly increased air trapping, out of proportion to the degree of airflow limitation, are characteristic of infants with NEHI. iPFT results demonstrating an FRC pleth  ≥ 150% predicted are highly specific for NEHI and may aid in early diagnosis. Further research is required to confirm these findings in a prospective cohort and to understand the pathophysiologic explanation for these findings., (Copyright © 2021 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.)

Background: Mechanical ventilation immediately after lung transplantation may impact the development of primary graft dysfunction (PGD), particularly in cases of donor-recipient size mismatch as ventilation is typically based on recipient rather than donor size., Methods: We conducted a retrospective cohort study of adult bilateral lung transplant recipients at our center between January 2010 and January 2017. We defined donor-based lung protective ventilation (dLPV) as 6 to 8 ml/kg of donor ideal body weight and plateau pressure <30 cm H 2 O. We calculated the donor-recipient predicted total lung capacity (pTLC) ratio and used logistic regression to examine relationships between pTLC ratio, dLPV and PGD grade 3 at 48 to 72 hours. We used Cox proportional hazards modelling to examine the relationship between pTLC ratio, dLPV and 1-year survival., Results: The cohort included 373 recipients; 24 (6.4%) developed PGD grade 3 at 48 to 72 hours, and 213 (57.3%) received dLPV. Mean pTLC ratio was 1.04 ± 0.18. dLPV was associated with significantly lower risks of PGD grade 3 (OR = 0.44; 95% CI: 0.29-0.68, p < 0.001) and 1-year mortality (HR = 0.49; 95% CI: 0.29-0.8, p = 0.018). There was a significant association between pTLC ratio and the risk of PGD grade 3, but this was attenuated by the use of dLPV., Conclusions: dLPV is associated with decreased risk of PGD grade 3 at 48 to 72 hours and decreased 1-year mortality. Additionally, dLPV attenuates the association between pTLC and both PGD grade 3 and 1-year mortality. Donor-based ventilation strategies may help to mitigate the risk of PGD and other adverse outcomes associated with size mismatch after lung transplantation., (Copyright © 2021 International Society for Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.)

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* F E V 1 F V C +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., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Liu, Zhou, Feng, Liu, Shen, Huang, Wang, Zou, Xia and Huang.)

Objective: This study investigated the consequences of Coronavirus Disease 2019 (COVID-19) pneumonia on lung function in the first 6 months after hospital discharge., Methods: A prospective lung function assessment in SARS-CoV2 patients with COVID-19 pneumonia, hospitalized between March and April 2020, was conducted with spirometry measurements including lung volumes, mainly total lung capacity (TLC), lung diffusion capacity for carbon monoxide (DL CO ) collected at 3 months after hospital discharge. Patients with restrictive ventilatory defect or impaired DL CO or both were re-evaluated at 6 months with global spirometry and chest HRCT scan., Results: Among 40 consecutive patients, 19 (48%) had normal pulmonary functional tests (group A), and 21 (52%) showed residual lung function abnormalities at 3 months after hospital discharge (group B). In group B, 4 patients (19%) had only loss of lung volume as shown by TLC reduction (group 1), 13 patients (62%) had decreased both TLC and DL CO (group 2), and 4 patients (19%) had isolated reduction in DL CO (group 3). At 6-month follow-up in group 1, although all patients improved, only one normalized total lung capacity (TLC). In group 2, TLC and DL CO increased significantly (p < 0.01), but only 3 patients reached normal values. In group 3, DL CO improved for most patients, normalizing in 50% of them. At 6-months significant correlations between an internal-built chest HRCT scan severity score and TLC (r 2  = 0.33; p < 0.01) and DL CO (r 2  = 0.32; p < 0.01) were found., Conclusions: Nearly 50% of patients recovered in the post-critical phase. Most of those with abnormal pulmonary function tests at 3 months improved subsequently, but only another 29% (6 out of 21) reached normal values at 6 months. These results indicate that lung function spontaneous recovery is faster at first and occurs more slowly thereafter, leaving more than one third (15 out of 40) of patients with abnormal lung function tests at 6 months., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

An object-tracking algorithm was used on computed tomography (CT) images of the thorax from six healthy participants and nine participants with chronic obstructive pulmonary disease (COPD) to describe the movement of the ribs between the static lung volumes of functional residual capacity (FRC) and total lung capacity (TLC). The continuous motion of the ribs during tidal breathing was also described using four-dimensional CT datasets from seven participants with thoracic esophageal malignancies. Rib motion was defined relative to a local joint coordinate system where rotations about the axes that predominantly affected the anteroposterior and transverse diameters of the rib cage were referred to as pump-handle and bucket-handle movements, respectively. Between TLC and FRC, pump-handle movements were 1.8 times larger in healthy participants than in participants with COPD, in line with their 1.6 times larger inspiratory capacities. However, when rib motion was normalized to the change in lung volume, pump-handle movements were similar for healthy participants and participants with COPD. We found no differences in bucket-handle movements between participant groups before and after normalization. Pump-handle movement was the dominant rib motion between FRC and TLC, on average four times greater than bucket-handle movement in healthy participants. For expiratory tidal volume, pump-handle movements were 20% smaller than bucket-handle movements. When normalized to tidal volume and compared with inspiratory capacity, pump-handle movements were smaller and bucket-handle movements were larger during tidal breathing. The findings suggest that the pump-handle and bucket-handle components of rib motion vary for small and large changes in lung volume. NEW & NOTEWORTHY Rib movements over inspiratory capacity are comparable for healthy participants and participants with chronic obstructive pulmonary disease when normalized to the change in lung volume. The kinematics of the ribs during tidal breathing were described from four-dimensional computed tomography images. For large changes in lung volume with inspiratory capacity, pump-handle movements of the ribs are four times greater than bucket-handle movements, whereas at tidal volume, pump-handle movements are 20% smaller than bucket-handle movements.

Background: Lung volume reduction (LVR) surgery has traditionally been performed as a 1-stage bilateral procedure or staged at a predetermined interval. However to maximize the overall benefit we have allowed the patient to determine the timing of further interventions and have added endobronchial LVR into the protocol. We have reviewed the long-term outcome., Methods: Three hundred thirty-one LVR procedures were performed on 254 patients (median age, 61 years [range, 23-79]) with baseline predicted lung function of (mean ± SD) forced expiratory volume in 1 second 28% ± 11% and residual volume 253% ± 53%. The initial procedure was by video-assisted thoracoscopic surgery in 236 patients (unilateral, 227; bilateral, 9), by open surgery in 5, and by endobronchial valve insertion in 13. Sixty-four patients received a second and 13 a third LVR procedure. The median time interval between first and third stage was 5.8 years (range, 1.9-10) RESULTS: In the subgroup of patients who underwent staged procedures there was a significant improvement in predicted forced expiratory volume in 1 second from 28% at baseline to 34% up to 6 years. There was sustained reduction in static lung volumes up to 8 years: Predicted residual volume remained reduced from 259% to 189%. There were sustained improvements over baseline in health status: EuroQol-5D improved from 50 ± 26 to 62 ± 23 (P < .01) for up to 5 years and the Short Form 36-item questionnaire for up to 9 years. Overall 30-day mortality was 3%. Median survival was 5.6 years (95% confidence interval, 4.7-6.9)., Conclusions: A program of staged unilateral procedures of LVR has resulted in sustained benefits for up to 9 years in physiology and health status., (Copyright © 2021 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

Objective . Total lung capacity (TLC) assessment outside of a research laboratory is challenging. We describe a novel method for measuring TLC that is both simple and based only on portable equipment, and report preliminary data in healthy subjects. Approach . We developed an open circuit system to administer a known amount of oxygen to a subject in a single maximal inspiratory maneuver. Oxygen fraction, expired and inspired flows were continuously monitored to allow a precise computation of the mass balance. Values of TLC and functional residual capacity (FRC) were compared with standard methods (body plethysmography and multiple-breath helium dilution). Twenty healthy subjects participated to the study, eleven of which performed the maneuver twice to assess test-retest reliability. Main results. There was high agreement in TLC between the proposed method and the two standard methods ( R 2  > 0.98, bias not different from 0, and 95% limits of agreements <± 0.4 l for both). Test-retest reliability was high (intraclass correlation coefficient >0.99 and no bias). Results were similar for FRC, with a slightly higher variability due its sensitivity to changes in posture or breathing pattern. Significance. Single-breath oxygen dilution is accurate and reliable in assessing TLC and FRC in healthy subjects. The technique is appealing for time- or resource-limited settings, such as field physiological research expeditions or mass screenings., (© 2021 Institute of Physics and Engineering in Medicine.)

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 (TLC Pleth ) was compared with TLC measured by the MiniBox (TLC MB )., Results: TLC values ranged between 2.7 and 10.9 L. The normalized root mean square difference (NSD) between TLC Pleth and TLC MB 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., (Copyright © 2021 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.)