"Horses for courses" computed tomography or predicted total lung capacity for size matching in lung transplantation.

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.

Lung Volumes in a Mouse Model of Pulmonary Allergic Inflammation.

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.

Assessment of respiratory function and exercise tolerance at 4-6 months after COVID-19 infection in patients with pneumonia of different severity.

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.

Air pollution enhance the progression of restrictive lung function impairment and diffusion capacity reduction: an elderly cohort study.

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.

Tidal volume expandability affected by flow, dynamic hyperinflation, and quasi-fixed inspiratory time in patients with COPD and healthy individuals.

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 (VTpeak). As VTpeak is the product of inspiratory time (TIpeak) and flow (VT/TIpeak), it was hypothesized that VTpeak and VTpeak/total lung capacity (VTpeak/TLC) may be affected by TIpeak and VT/TIpeak. Hence, the study investigated the (1) effect of TIpeak and VT/TIpeak on VTpeak expansion, (2) factors associated with TIpeak, expiratory time (TEpeak), VT/TIpeak, and VTpeak/TLC, and (3) relationships between VT/TIpeak and VTpeak/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, TIpeak 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 VT/TIpeak (1.71 ± 0.49 L/s versus 2.58 ± 0.69 L/s, p < .0001) and thus the COPD group had smaller VTpeak (1.31 ± 0.34 L versus 2.01 ± 0.45 L,p < .0001) and VTpeak/TLC (0.22 ± 0.06 vs 0.33 ± 0.05, p < .0001). TIpeak, TEpeak, and VT/TIpeak were mainly affected by exercise effort, whereas VTpeak/TLC was not. TEpeak, VT/TIpeak, and VTpeak/TLC were inversely changed by impaired lung function. TIpeak was not affected by lung function. Dynamic hyperinflation did not occur in the controls, however, VTpeak/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 VTpeak/TLC with ED and EP than VT/TIpeak in the COPD group (|r| = 0.55-0.56 vs 0.38-0.43). In summary, TIpeak 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.

In vivo measurement of lung volume in ringed seals: insights from biomedical imaging.

Marine mammals rely on oxygen stored in blood, muscle and lungs to support breath-hold diving and foraging at sea. Here, we used biomedical imaging to examine lung oxygen stores and other key respiratory parameters in living ringed seals (Pusa hispida). Three-dimensional models created from computed tomography (CT) images were used to quantify total lung capacity (TLC), respiratory dead space, minimum air volume and total body volume to improve assessment of lung oxygen storage capacity, scaling relationships and buoyant force estimates. The results suggest that lung oxygen stores determined in vivo are smaller than those derived from postmortem measurements. We also demonstrate that, whereas established allometric relationships hold well for most pinnipeds, these relationships consistently overestimate TLC for the smallest phocid seal. Finally, measures of total body volume reveal differences in body density and net vertical forces in the water column that influence costs associated with diving and foraging in free-ranging seals.

In Vivo Measurements of Lung Volumes in Ringed Seals: Insights from Biomedical Imaging.

Marine mammals rely on oxygen stored in blood, muscle, and lungs to support breath-hold diving and foraging at sea. Here, we used biomedical imaging to examine lung oxygen stores and other key respiratory parameters in living ringed seals (Pusa hispida). Three-dimensional models created from computed tomography (CT) images were used to quantify total lung capacity (TLC), respiratory dead space, minimum air volume, and total body volume to improve assessments of lung oxygen storage capacity, scaling relationships, and buoyant force estimates. Results suggest that lung oxygen stores determined in vivo are smaller than those derived from postmortem measurements. We also demonstrate that-while established allometric relationships hold well for most pinnipeds-these relationships consistently overestimate TLC for the smallest phocid seal. Finally, measures of total body volume reveal differences in body density and net vertical forces in the water column that influence costs associated with diving and foraging in free-ranging seals.

Can a New Scoring System Improve Prediction of Pulmonary Hypertension in Newly Recognised Interstitial Lung Diseases?

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.

Computed tomography findings as determinants of pulmonary function tests in fibrotic interstitial lung diseases-Network-analyses and multivariate models.

The aim was to evaluate the impact of multiple high-resolution computed tomography (HRCT) features on pulmonary function test (PFT) biomarkers in fibrotic interstitial lung disease (FILD) patients. HRCT of subsequently ILD-board-discussed FILD patients were semi-quantitatively evaluated in a standardized approach: 18 distinct lung regions were scored for noduli, reticulation, honeycombing, consolidations, ground glass opacities (GGO), traction bronchiectasis (BRK) and emphysema. Total lung capacity (TLC), forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), FEV1/FVC, diffusion capacity for carbon monoxide (DLCO) and transfer coefficient (KCO) were assessed. Interactions between each PFT biomarker and all HRCT scores were visualized by network analyses, modeled according to the Schwarz Bayesian Information Criterion and incorporated in uni- and multivariate stepwise regression analyses. Among 108 FILD patients (mean age 67 years, 77% male), BRK extent was a major significant uni- or multivariate determinant of all PFT analyzed. Besides that, diffusion-based variables DLCO and KCO showed a larger dependency on reticulation, emphysema and GGO, while forced expiratory volume-based measures FEV1, FVC and FEV1/FVC were more closely associated with consolidations. For TLC, the only significant multivariate determinant was reticulation. In conclusion, PFT biomarkers derived from spirometry, body plethysmography and diffusion capacity in FILD patients are differentially influenced by semi-quantified HRCT findings.

Magnetic resonance elastography of the lungs: A repeatability and reproducibility study.

Lung diseases are one of the leading causes of death worldwide, from which four million people die annually. Lung diseases are associated with changes in the mechanical properties of the lungs. Several studies have shown the feasibility of using magnetic resonance elastography (MRE) to quantify the lungs' shear stiffness. The aim of this study is to investigate the reproducibility and repeatability of lung MRE, and its shear stiffness measurements, obtained using a modified spin echo-echo planar imaging (SE-EPI) MRE sequence. In this study, 21 healthy volunteers were scanned twice by repositioning the volunteers to image right lung both at residual volume (RV) and total lung capacity (TLC) to assess the reproducibility of lung shear stiffness measurements. Additionally, 19 out of the 21 volunteers were scanned immediately without moving the volunteers to test the repeatability of the modified SE-EPI MRE sequence. A paired t-test was performed to determine the significant difference between stiffness measurements obtained at RV and TLC. Concordance correlation and Bland-Altman's analysis were performed to determine the reproducibility and repeatability of the SE-EPI MRE-derived shear stiffness measurements. The SE-EPI MRE sequence is highly repeatable with a concordance correlation coefficient (CCC) of 0.95 at RV and 0.96 at TLC. Similarly, the stiffness measurements obtained across all volunteers were highly reproducible with a CCC of 0.95 at RV and 0.92 at TLC. The mean shear stiffness of the lung at RV was 0.93 ± 0.22 kPa and at TLC was 1.41 ± 0.41 kPa. TLC showed a significantly higher mean shear stiffness (P = 0.0004) compared with RV. Lung MRE stiffness measurements obtained using the SE-EPI sequence were reproducible and repeatable, both at RV and TLC. Lung shear stiffness changes across respiratory cycle with significantly higher stiffness at TLC than RV.

Difference Between Slow and Forced Vital Capacity and Its Relationship with Dynamic Hyperinflation in Patients with Chronic Obstructive Pulmonary Disease.

The aim of the study was to investigate the relationship between slow and forced vital capacity (SVC-FVC) difference with dynamic lung hyperinflation (DH) during the 6-min walking test (6MWT) in subjects with chronic obstructive pulmonary disease (COPD). Twenty-four subjects with COPD (12 males; 67 ± 6 years; forced expiratory volume in first second [FEV1] 56 ± 18% predicted) performed lung function tests by spirometry and plethysmography. DH was assessed by serial measurements of inspiratory capacity (IC) performed during the 6MWT and defined as ∆IC ≥ 150 mL or 10%. IC decrease significantly during the 6MWT (ΔCI: - 0.48 ± - 0.40 L; P < 0.0001), and 18 individuals (75%) presented DH. There was significant difference when comparing IC measured at rest with the other serial IC measurements (P < 0.0001). Correlation between the SVC-FVC difference and DH during the 6MWT was r = - 0.38; P = 0.06. The SVC-FVC difference presented only weak correlation with the development of DH during the 6MWT in patients with COPD.

A single-nucleotide polymorphism in a gene modulating glucocorticoid sensitivity is associated with the decline in total lung capacity after lung transplantation.

PURPOSE: Glucocorticoids are used to prevent chronic lung allograft dysfunction (CLAD) after lung transplantation (LT). Our study was aimed at assessing the association between the glucocorticoid-induced transcript 1 gene (GLCCI1) variant, which modulates glucocorticoid sensitivity, and the postoperative lung function and development of CLAD after LT. METHODS: A total of 71 recipients of LT were genotyped for the GLCCI1 variant (rs37972) and divided into three groups: the homozygous mutant allele (TT) group, the heterozygous mutant allele (CT) group, and the wild-type allele (CC) group. The results of pulmonary function tests were compared with the postoperative baseline values. RESULTS: The total lung capacity (TLC) in the TT group was significantly lower than that in the CC group at 3 years after LT (P = 0.029). In the recipients of cadaveric LT, the TLC and forced expiratory volume in 1 s in the TT group were significantly lower than those in the CC groups, resulting in a significant worse CLAD-free survival at 3 years after LT (P = 0.016). CONCLUSION: The GLCCI1 variant was associated with a significant decrease of the TLC at 3 years after LT and the development of CLAD at 3 years, especially in patients undergoing cadaveric LT.

Identifying a Deletion Affecting Total Lung Capacity Among Subjects in the COPDGene Study Cohort.

Chronic obstructive pulmonary disease (COPD) is a progressive disease with both environmental and genetic risk factors. Genome-wide association studies (GWAS) have identified multiple genomic regions influencing risk of COPD. To thoroughly investigate the genetic etiology of COPD, however, it is also important to explore the role of copy number variants (CNVs) because the presence of structural variants can alter gene expression and can be causal for some diseases. Here, we investigated effects of polymorphic CNVs on quantitative measures of pulmonary function and chest computed tomography (CT) phenotypes among subjects enrolled in COPDGene, a multisite study. COPDGene subjects consist of roughly one-third African American (AA) and two-thirds non-Hispanic white adult smokers (with or without COPD). We estimated CNVs using PennCNV on 9,076 COPDGene subjects using Illumina's Omni-Express genome-wide marker array. We tested for association between polymorphic CNV components (defined as disjoint intervals of copy number regions) for several quantitative phenotypes associated with COPD within each racial group. Among the AAs, we identified a polymorphic CNV on chromosome 5q35.2 located between two genes (FAM153B and SIMK1, but also harboring several pseudo-genes) giving genome-wide significance in tests of association with total lung capacity (TLCCT ) as measured by chest CT scans. This is the first study of genome-wide association tests of polymorphic CNVs and TLCCT . Although the ARIC cohort did not have the phenotype of TLCCT , we found similar counts of CNV deletions and amplifications among AA and European subjects in this second cohort.

Respiratory function and mechanics in pinnipeds and cetaceans.

In this Review, we focus on the functional properties of the respiratory system of pinnipeds and cetaceans, and briefly summarize the underlying anatomy; in doing so, we provide an overview of what is currently known about their respiratory physiology and mechanics. While exposure to high pressure is a common challenge among breath-hold divers, there is a large variation in respiratory anatomy, function and capacity between species - how are these traits adapted to allow the animals to withstand the physiological challenges faced during dives? The ultra-deep diving feats of some marine mammals defy our current understanding of respiratory physiology and lung mechanics. These animals cope daily with lung compression, alveolar collapse, transient hyperoxia and extreme hypoxia. By improving our understanding of respiratory physiology under these conditions, we will be better able to define the physiological constraints imposed on these animals, and how these limitations may affect the survival of marine mammals in a changing environment. Many of the respiratory traits to survive exposure to an extreme environment may inspire novel treatments for a variety of respiratory problems in humans.

Lung mechanics and pulmonary function testing in cetaceans.

We measured esophageal pressures, respiratory flow rates, and expired O2 and CO2 in six adult bottlenose dolphins (Tursiops truncatus) during voluntary breaths and maximal (chuff) respiratory efforts. The data were used to estimate the dynamic specific lung compliance (sCL), the O2 consumption rate (V̇O2 ) and CO2 production rates (V̇CO2 ) during rest. Our results indicate that bottlenose dolphins have the capacity to generate respiratory flow rates that exceed 130 l s(-1) and 30 l s(-1) during expiration and inspiration, respectively. The esophageal pressures indicated that expiration is passive during voluntary breaths, but active during maximal efforts, whereas inspiration is active for all breaths. The average sCL of dolphins was 0.31±0.04 cmH2O(-1), which is considerably higher than that of humans (0.08 cmH2O(-1)) and that previously measured in a pilot whale (0.13 cmH2O(-1)). The average estimated V̇O2  and V̇CO2  using our breath-by-breath respirometry system ranged from 0.857 to 1.185 l O2 min(-1) and 0.589 to 0.851 l CO2 min(-1), respectively, which is similar to previously published metabolic measurements from the same animals using conventional flow-through respirometry. In addition, our custom-made system allows us to approximate end tidal gas composition. Our measurements provide novel data for respiratory physiology in cetaceans, which may be important for clinical medicine and conservation efforts.

The Prognostic Value of Residual Volume/Total Lung Capacity in Patients with Chronic Obstructive Pulmonary Disease.

The prognostic role of resting pulmonary hyperinflation as measured by residual volume (RV)/total lung capacity (TLC) in chronic obstructive pulmonary disease (COPD) remains poorly understood. Therefore, this study aimed to identify the factors related to resting pulmonary hyperinflation in COPD and to determine whether resting pulmonary hyperinflation is a prognostic factor in COPD. In total, 353 patients with COPD in the Korean Obstructive Lung Disease cohort recruited from 16 hospitals were enrolled. Resting pulmonary hyperinflation was defined as RV/TLC ≥ 40%. Multivariate logistic regression analysis demonstrated that older age (P = 0.001), lower forced expiratory volume in 1 second (FEV1) (P < 0.001), higher St. George Respiratory Questionnaire (SGRQ) score (P = 0.019), and higher emphysema index (P = 0.010) were associated independently with resting hyperinflation. Multivariate Cox regression model that included age, gender, dyspnea scale, SGRQ, RV/TLC, and 6-min walking distance revealed that an older age (HR = 1.07, P = 0.027), a higher RV/TLC (HR = 1.04, P = 0.025), and a shorter 6-min walking distance (HR = 0.99, P < 0.001) were independent predictors of all-cause mortality. Our data showed that older age, higher emphysema index, higher SGRQ score, and lower FEV1 were associated independently with resting pulmonary hyperinflation in COPD. RV/TLC is an independent risk factor for all-cause mortality in COPD.

Pulmonary outcome in former preterm, very low birth weight children with bronchopulmonary dysplasia: a case-control follow-up at school age.

OBJECTIVE: To assess and compare long-term pulmonary outcomes in former preterm-born, very low birth weight (VLBW) children with and without bronchopulmonary dysplasia (BPD) born in the surfactant era. STUDY DESIGN: Pulmonary function tests (ie, spirometry, body plethysmography, and gas transfer testing) were performed in children with a history of VLBW and BPD (n = 28) and compared with a matched preterm-born VLBW control group (n = 28). Medical history was evaluated by questionnaire. RESULTS: At time of follow-up (mean age, 9.5 years), respiratory symptoms (36% vs 8%) and receipt of asthma medication (21% vs 0%) were significantly more frequent in the preterm-born children with previous BPD than in those with no history of BPD. The children with a history of BPD had significantly lower values for forced expiratory volume in 1 second (z-score -1.27 vs -0.4; P = .008), forced vital capacity (z-score -1.39 vs -0.71 z-score; P = .022), and forced expiratory flow rate at 50% of forced vital capacity (z-score -2.21 vs -1.04; P = .048) compared with the preterm control group. CONCLUSION: Preterm-born children with a history of BPD are significantly more likely to have lung function abnormalities, such as airway obstruction and respiratory symptoms, at school age compared with preterm-born children without BPD.

A reference equation for lung volume on computed tomography in Japanese middle-aged and elderly adults.

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 (R2) 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.

Lung function at three months after hospitalization due to COVID­19 pneumonia: Comparison of alpha, delta and omicron variant predominance periods.

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.

Size-matching in lung transplantation by computed tomography for end-stage interstitial disease: a retrospective analysis.

Background: Size matching between donors and recipients is a major issue in lung transplantation (LTx), especially in patients with restrictive lung disease (RLD). This study aims to evaluate computed tomography (CT) as an additional method for defining the total lung capacity (TLC) in patients with end-stage interstitial disease awaiting LTx. Methods: Clinical data and CT scans from patients who underwent a first LTx from January 2014 to July 2018 in Bichat Hospital, Paris, were prospectively included in a database. CT TLC (ctTLC) was retrospectively calculated after semi-automatic contouring of the parenchyma and compared with measured TLC (mTLC) and predicted TLC (pTLC) values. Results: The study group included 89 patients (male:female =68:21; mean age, 59.5±10.0 years). The time between pulmonary function tests (PFTs) and CT scan was 162±270 days [median, 67 days; interquartile range (IQR), 0-233 days]. ctTLC was inferior to mTLC and pTLC (respectively 2,979±1,001 mL, 3,530±1,077 and 6,381±955 mL, P<0.001). The relative difference between CT lung volume (ctLV) and measured lung volume (mLV) was higher on the left than on the right side (25.4% vs. 16.3%, respectively, P=0.11). After exclusion of two outliers, we found a significant correlation between ctTLC and mTLC (r=0.762, P<0.001). Conclusions: CT volume is a feasible method to assess TLC in patients with end-stage interstitial disease awaiting LTx. This study highlights potential size-mismatch for graft selection before LTx and opens the perspective of a prospective trial evaluating impact of size-matching by donor-recipient (D-R) ctTLC ratio on postoperative outcomes.