Standardisation of the measurement of lung volumes

Quantitative CT in mortality prediction in pulmonary fibrosis with or without emphysema

Aim:

We aimed to evaluate the quantitative CT analysis of patients with CPFE in comparison with IPF and emphysema.

Methods:

Patients with CPFE(n:36), IPF(n:38) and emphysema(n:32) were retrospectively included in the study with the approval of the ethics committee.

Results:

There was a positive correlation between total lung volume and FVC%, TLCO% and 6 MWT, and negative correlation between mMRC and mortality. Negative correlation was found between right, left lung density and FVC%, TLCO% and 6 MWT, and positive correlation between mortality. Also, total lung volume, right and left lung densities were significant in predicting mortality and cut-off values are ≤3831,> -778 and> -775, respectively (p = 0.040, 0.020, 0.013).

Conclusion:

Quantitative CT are guiding in predicting mortality of the disease.

Lung Tissue Microbiome Is Associated With Clinical Outcomes of Idiopathic Pulmonary Fibrosis

Background: Several studies using bronchoalveolar lavage fluid (BALF) reported that lung microbial communities were associated with the development and clinical outcome of idiopathic pulmonary fibrosis (IPF). However, the microbial communities in IPF lung tissues are not well known. This study is aimed to investigate bacterial microbial communities in lung tissues and determine their impact on the clinical outcomes of patients with IPF. Methods: Genomic DNA extracted from lung tissues of patients with IPF (n = 20; 10 non-survivors) and age- and sex-matched controls (n = 20) was amplified using fusion primers targeting the V3 and V4 regions of the 16S RNA genes with indexing barcodes. Results: Mean age of IPF subjects was 63.3 yr, and 65% were male. Alpha diversity indices did not significantly differ between IPF patients and controls, or between IPF non-survivors and survivors. The relative abundance of Lactobacillus, Paracoccus, and Akkermansia was increased, whereas that of Caulobacter, Azonexus, and Undibacterium decreased in patients with IPF compared with that in the controls. A decreased relative abundance of Pelomonas (odds ratio [OR], 0.352, p = 0.027) and Azonexus (OR, 0.013, p = 0.046) was associated with a diagnosis of IPF in the multivariable logistic analysis adjusted by age and gender. Multivariable Cox analysis adjusted for age and forced vital capacity (FVC) revealed that higher relative abundance of Streptococcus (hazard ratio [HR], 1.993, p = 0.044), Sphingomonas (HR, 57.590, p = 0.024), and Clostridium (HR, 37.189, p = 0.038) was independently associated with IPF mortality. The relative abundance of Curvibacter (r = 0.590) and Thioprofundum (r = 0.373) was correlated positively, whereas that of Anoxybacillus (r = -0.509) and Enterococcus (r = -0.593) was correlated inversely with FVC. In addition, the relative abundance of the Aquabacterium (r = 0.616) and Peptoniphilus (r = 0.606) genera was positively correlated, whereas that of the Fusobacterium (r = -0.464) and Phycicoccus (r = -0.495) genera was inversely correlated with distance during the 6-min walking test. Conclusions: The composition of the microbiome in lung tissues differed between patients with IPF and controls and was associated with the diagnosis, mortality, and disease severity of IPF.

Measurement of chest wall motion using a motion capture system with the one-pitch phase analysis method

Spirometry is a standard method for assessing lung function. However, its use is challenging in some patients, and it has limitations such as risk of infection and inability to assess regional chest wall motion. A three-dimensional motion capture system using the one-pitch phase analysis (MCO) method can facilitate high precision measurement of moving objects in real-time in a non-contacting manner. In this study, the MCO method was applied to examine thoraco-abdominal (TA) wall motion for assessing pulmonary function. We recruited 48 male participants, and all underwent spirometry and chest wall motion measurement with the MCO method. A significant positive correlation was observed between the vital capacity (Spearman’s ρ = 0.68, p < 0.0001), forced vital capacity (Spearman’s ρ = 0.62, p < 0.0001), and tidal volume (Spearman’s ρ = 0.61, p < 0.0001) of spirometry and the counterpart parameters of MCO method. Moreover, the MCO method could detect regional rib cage and abdomen compartment contributions and could assess TA asynchrony, indicating almost complete synchronous movement (phase angle for each compartment: − 5.05° to 3.86°). These findings suggest that this technique could examine chest wall motion, and may be effective in analyzing chest wall volume changes and pulmonary function.

X-ray dark-field chest imaging for detection and quantification of emphysema in patients with chronic obstructive pulmonary disease: a diagnostic accuracy study

BACKGROUND

Although advanced medical imaging technologies give detailed diagnostic information, a low-dose, fast, and inexpensive option for early detection of respiratory diseases and follow-ups is still lacking. The novel method of x-ray dark-field chest imaging might fill this gap but has not yet been studied in living humans. Enabling the assessment of microstructural changes in lung parenchyma, this technique presents a more sensitive alternative to conventional chest x-rays, and yet requires only a fraction of the dose applied in CT. We studied the application of this technique to assess pulmonary emphysema in patients with chronic obstructive pulmonary disease (COPD).

METHODS

In this diagnostic accuracy study, we designed and built a novel dark-field chest x-ray system (Technical University of Munich, Munich, Germany)-which is also capable of simultaneously acquiring a conventional thorax radiograph (7 s, 0·035 mSv effective dose). Patients who had undergone a medically indicated chest CT were recruited from the department of Radiology and Pneumology of our site (Klinikum rechts der Isar, Technical University of Munich, Munich, Germany). Patients with pulmonary pathologies, or conditions other than COPD, that might influence lung parenchyma were excluded. For patients with different disease stages of pulmonary emphysema, x-ray dark-field images and CT images were acquired and visually assessed by five readers. Pulmonary function tests (spirometry and body plethysmography) were performed for every patient and for a subgroup of patients the measurement of diffusion capacity was performed. Individual patient datasets were statistically evaluated using correlation testing, rank-based analysis of variance, and pair-wise post-hoc comparison.

FINDINGS

Between October, 2018 and December, 2019 we enrolled 77 patients. Compared with CT-based parameters (quantitative emphysema ρ=-0·27, p=0·089 and visual emphysema ρ=-0·45, p=0·0028), the dark-field signal (ρ=0·62, p<0·0001) yields a stronger correlation with lung diffusion capacity in the evaluated cohort. Emphysema assessment based on dark-field chest x-ray features yields consistent conclusions with findings from visual CT image interpretation and shows improved diagnostic performance than conventional clinical tests characterising emphysema. Pair-wise comparison of corresponding test parameters between adjacent visual emphysema severity groups (CT-based, reference standard) showed higher effect sizes. The mean effect size over the group comparisons (absent-trace, trace-mild, mild-moderate, and moderate-confluent or advanced destructive visual emphysema grades) for the COPD assessment test score is 0·21, for forced expiratory volume in 1 s (FEV1)/functional vital capacity is 0·25, for FEV1% of predicted is 0·23, for residual volume % of predicted is 0·24, for CT emphysema index is 0·35, for dark-field signal homogeneity within lungs is 0·38, for dark-field signal texture within lungs is 0·38, and for dark-field-based emphysema severity is 0·42.

INTERPRETATION

X-ray dark-field chest imaging allows the diagnosis of pulmonary emphysema in patients with COPD because this technique provides relevant information representing the structural condition of lung parenchyma. This technique might offer a low radiation dose alternative to CT in COPD and potentially other lung disorders.

FUNDING

European Research Council, Deutsche Forschungsgemeinschaft, Royal Philips, and Karlsruhe Nano Micro Facility.

Progressive fibrosing interstitial lung disease: prevalence and clinical outcome

Background

The progressive fibrosing (PF) phenotype of interstitial lung disease (ILD) is characterised by worsening respiratory symptoms, lung function, and extent of fibrosis on high-resolution computed tomography. We aimed to investigate the prevalence and clinical outcomes of PF-ILD in a real-world cohort and assess the prognostic significance of the PF-ILD diagnostic criteria.

Methods

Clinical data of patients with fibrosing ILD other than idiopathic pulmonary fibrosis (IPF) consecutively diagnosed at a single centre were retrospectively reviewed. A PF phenotype was defined based on the criteria used in the INBUILD trial.

Results

The median follow-up duration was 62.7 months. Of the total of 396 patients, the mean age was 58.1 years, 39.9% were men, and rheumatoid arthritis-ILD was the most common (42.4%). A PF phenotype was identified in 135 patients (34.1%). The PF-ILD group showed lower forced vital capacity and total lung capacity (TLC) than the non-PF-ILD group. The PF-ILD group also showed poorer survival (median survival, 91.2 months vs. not reached; P < 0.001) than the non-PF-ILD group. In multivariable Cox analysis adjusted for age, DL_CO, HRCT pattern, and specific diagnosis, PF phenotype was independent prognostic factor (hazard ratio, 3.053; P < 0.001) in patients with fibrosing ILD. Each criterion of PF-ILD showed similar survival outcomes.

Conclusions

Our results showed that approximately 34% of patients with non-IPF fibrosing ILD showed a progressive phenotype and a poor outcome similar to that of IPF, regardless of the diagnostic criteria used.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-021-01879-6.

Telemonitoring Techniques for Lung Volume Measurement: Accuracy, Artifacts and Effort

Telemonitoring becomes more important in pulmonary research. It can be used to decrease the pressure on the health care system, to lower the costs of health care and to increase quality of life of patients. Previous studies show contradictory results regarding the effectiveness of telemonitoring. According to multiple researchers, inefficiency can be a result of poor study design, low data quality and usability issues. To counteract these issues, this review proves for an in-depth explanation of four (potential) telemonitoring systems in terms of work principle, accuracy, disturbing factors and usability. The evaluated systems are portable spirometry/breath-by-breath analyzers, respiratory inductance and magnetic plethysmography and electrical impedance tomography. These insights can be used to select the optimal technique for a specific purpose in future studies.

Computed tomography total airway count predicts progression to COPD in at-risk smokers

There is limited understanding of how to identify people at high risk of developing COPD. Our objective was to investigate the association between computed tomography (CT) total airway count (TAC) and incident COPD over 3 years among ever-smokers from the population-based Canadian Cohort Obstructive Lung Disease (CanCOLD) study.

CT and spirometry were acquired in ever-smokers at baseline; spirometry was repeated at 3-year follow-up. CT TAC was generated by summing all airway segments in the segmented airway tree (VIDA Diagnostics, Inc.). CT airway wall area, wall thickness for a theoretical airway with 10 mm perimeter (Pi10), and low attenuation areas below −856 HU (LAA₈₅₆) were also measured. Logistic and mixed effects regression models were constructed to determine the association for CT measurements with development of COPD and forced expiratory volume in 1 s/forced vital capacity (FEV₁/FVC) decline, respectively.

Among 316 at-risk participants evaluated at baseline (65±9 years, 40% female, 18±19 pack-years), incident COPD was detected in 56 participants (18%) over a median 3.1±0.6 years of follow-up. Among CT measurements, only TAC was associated with incident COPD (p=0.03), where a 1-sd decrement in TAC increased the odds ratio for incident COPD by a factor of two. In a multivariable linear regression model, reduced TAC was significantly associated with greater longitudinal FEV₁/FVC decline (p=0.03), but no other measurements were significant.

CT TAC predicts incident COPD in at-risk smokers, indicating that smokers exhibit early structural changes associated with COPD prior to abnormal spirometry.

Computed tomography (CT) total airway count (TAC) predicts incident COPD in at-risk smokers, indicating that smokers exhibit early airway remodelling prior to abnormal spirometry and that CT TAC is a potential tool to help identify smokers at increased risk of COPDhttps://bit.ly/2UTw3I4

Effects of a 12-Week Recreational Skiing Program on Cardio-Pulmonary Fitness in the Elderly: Results from the Salzburg Skiing in the Elderly Study (SASES)

OBJECTIVES

To investigate whether recreational alpine skiing in the elderly can improve cardio-pulmonary fitness.

DESIGN

Randomized controlled study with pre-post repeated measurements.

METHODS

A total of 48 elderly participants (60-76 years) were randomly assigned to either participate in a 12-week guided recreational skiing program (intervention group, IG, average of 28.5 ± 2.6 skiing days) or to continue a sedentary ski-free lifestyle (control group, CG). Cardio-pulmonary exercise testing (CPET) and pulmonary function testing were performed in both groups before (PRE) and after (POST) the intervention/control period to compare parameters PRE vs. POST CPET.

RESULTS

At baseline, IG and CG did not differ significantly with respect to CPET and pulmonary function parameters. At POST, several measures of maximal exercise capacity and breathing economy were significantly improved in IG as compared to CG: maximal oxygen capacity (IG: 33.8 ± 7.9; CG: 28.7 ± 5.9 mL/min/kg; p = 0.030), maximal carbon dioxide production (IG: 36.2 ± 7.7; CG: 31.8 ± 6.5 mL/min/kg; p = 0.05), maximal oxygen pulse (IG: 16.8 ± 4.2; CG: 13.2 ± 4 mL/heart beat; p = 0.010), maximal minute ventilation (IG: 96.8 ± 17.8; CG: 81.3 ± 21.9 l/min; p = 0.025), and maximal metabolic equivalent of task (METs, IG: 9.65 ± 2.26; CG: 8.19 ± 1.68 METs; p = 0.029). Except for oxygen pulse, these significant changes could also be observed at the anaerobic threshold. Maximal heart rate and pulmonary function parameters remained essentially unchanged.

CONCLUSION

Regular recreational skiing improves cardio-pulmonary fitness along with breathing economy and thus can contribute to a heart-healthy lifestyle for the elderly.

The Value of 18F-FDG PET/CT in Evaluating Disease Severity and Prognosis in Idiopathic Pulmonary Fibrosis Patients

BACKGROUND

Several parameters are useful for assessing disease severity in idiopathic pulmonary fibrosis (IPF); however, the role of ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) is not well-defined. We aimed to evaluate the value of ¹⁸F-FDG PET/CT for assessing disease severity and prognosis in IPF patients.

METHODS

Clinical data of 89 IPF patients (mean age: 68.1 years, male: 94%) who underwent ¹⁸F-FDG PET/CT for evaluation of lung nodules or cancer staging were retrospectively reviewed. Mean and maximal standardized uptake values (SUV_mean, SUV_max, respectively) were measured in the fibrotic area. Adjusted SUV, including SUV ratio (SUVR, defined as SUV_max-to-liver SUV_mean ratio), tissue fraction-corrected SUV_mean (SUV_meanTF), and SUVR (SUVR_TF), and tissue-to-blood ratio (SUV_max/SUV_mean venous; TBR_blood) were obtained. Death was defined as the primary outcome, and associations between other clinical parameters (lung function, exercise capacity, C-reactive protein [CRP] level) were also investigated.

RESULTS

All SUV parameters were inversely correlated with the forced vital capacity, diffusing capacity for carbon monoxide, and positively correlated with CRP level and the gender-age-physiology index. The SUV_mean, SUV_max, and SUV_meanTF were associated with changes in lung function at six months. The SUVR (hazard ratio [HR], 1.738; 95% confidence interval [CI], 1.011-2.991), SUVR_TF (HR, 1.441; 95% CI, 1.000-2.098), and TBR_blood (HR, 1.377; 95% CI, 1.038-1.827) were significant predictors for mortality in patients with IPF in the univariate analysis, but not in the multivariate analysis.

CONCLUSION

¹⁸F-FDG PET/CT may provide additional information on the disease severity and prognosis in IPF patients, and the SUVR may be superior to other SUV parameters.

The role of ventilatory support for long-term outcomes after critical infection with COVID-19: A prospective cohort study

Objectives

The full range of long‐term health consequences in intensive care unit (ICU) survivors with COVID‐19 is unclear. This study aims to investigate the role of ventilatory support for long‐term pulmonary impairment in critically ill patients and further to identify risk factors for prolonged radiological recovery.

Methods

A prospective observational study from a single general hospital, including all with COVID‐19 admitted to ICU between March and August 2020, investigating the association between ventilatory support and the extent of residual parenchymal changes on chest computed tomography (CT) scan and measurement of lung volumes at follow‐up comparing high‐flow nasal oxygen (HFNO) or non‐invasive ventilation (NIV) with invasive ventilation. A semi‐quantitative score (CT involvement score) based on lobar involvement and a total score for all five lobes was used to estimate residual parenchymal changes. The association was calculated with logistic regression and adjusted for age, sex, smoking, and severity of illness.

Results

Among the 187 eligible, 86 had a chest CT scan and 76 a pulmonary function test at the follow‐up with a median time of 6 months after ICU discharge. Residual lung changes were seen in 74%. The extent of pulmonary changes was similar regardless of ventilatory support, but patients with invasive ventilation had a lower total lung capacity 84% versus 92% of predicted (p < 0.001).

Conclusions

The majority of ICU‐treated patients with COVID‐19 had residual lung changes at 6 months of follow‐up regardless of ventilator support or not, but the total lung capacity was lower in those treated with invasive ventilation.

Body composition parameters and functional status test in predicting future acute exacerbation risk among hospitalized patients with chronic obstructive pulmonary disease

BACKGROUND & AIMS

Chronic obstructive pulmonary disease (COPD) is a leading cause of morbidity and mortality worldwide. Nutritional and functional status derangement is a commonly seen in COPD patients, and this is associated with a higher disease severity and mortality. To assess body composition analysis - measured by segmental multi-frequency bioelectrical impedance analysis (BIA)- and functional status and investigate their relationship with the COPD acute exacerbation risk.

METHODS

Eighty COPD patients admitted to hospital for COPD acute exacerbation were prospectively followed-up for one year after discharge, focusing on a new incidence of COPD acute exacerbation. Following discharge, participants' body composition was assessed with the use of segmental multi-frequency BIA, whereas physical function by performing 5-repetitions and 30 s sit-to-stand (STS) tests. Unadjusted and multivariate logistic regression analyses were performed to evaluate the ability of the various measures to predict incidence of future COPD acute exacerbation in one-year period.

RESULTS

Seventy-six out of 80 participants completed the study and were analyzed. Fifty-one [24 male (47.1%)] out of 76 participants (67.1%), mean aged of 69.3 ± 8.9 years, developed at least one new COPD acute exacerbation during the one year follow-up. The probability of COPD acute exacerbation in one year was significantly related to BMI (OR = 0.75, 95% CI; 0.61-0.91, p = 0.004) and Fat Free Mass (OR = 0.88, 95% CI; 0.79-0.97, p = 0.012) after adjustment for sex, age and smoking index (pack × years). Both 5-repetitions and 30 s STS tests had a good predictive ability for the incidence of COPD acute exacerbation in one year (AUC = 0.80, 95% CI; 0.65-0.95, p = 0.009 and AUC = 0.83, 95% CI; 0.70-0.96, p = 0.004, respectively).

CONCLUSION

In an observational study among patients admitted with COPD acute exacerbation, body composition analysis parameters and functional status are related to acute exacerbation risk incidence.

Positive Expiratory Pressure: A Potential Therapy to Mitigate Acute Bronchoconstriction in the Asthma of Obesity

Late-onset non-allergic (LONA) asthma in obesity is characterized by increased peripheral airway closure secondary to abnormally collapsible airways. We hypothesized that positive expiratory pressure (PEP) would mitigate the tendency to airway closure during bronchoconstriction, potentially serving as rescue therapy for LONA asthma of obesity. The PC₂₀ dose of methacholine was determined in 18 obese participants with LONA asthma. At each of 4 subsequent visits, we used oscillometry to measure input respiratory impedance (Z_rs) over 8 minutes; participants received their PC₂₀ concentration of methacholine aerosol during the first 4.5 minutes. PEP combinations of either 0 or 10 cmH₂O either during and/or after the methacholine delivery were applied, randomized between visits. Parameters characterizing respiratory system mechanics were extracted from the Z_rs spectra. In 18 LONA asthma patients (14 females, BMI: 39.6±3.4 kg/m²), 10 cmH₂O PEP during methacholine reduced elevations in the central airway resistance, peripheral airway resistance and elastance, and breathing frequency was also reduced. During the 3.5 min following methacholine delivery, PEP of 10 cmH₂O reduced A_x and peripheral elastance compared to no PEP. PEP mitigates the onset of airway narrowing brought on by methacholine challenge, and airway closure once it is established. PEP thus might serve as a non-pharmacologic therapy to manage acute airway narrowing for obese LONA asthma.

Effect of nocturnal oxygen therapy on exercise performance of COPD patients at 2048 m: data from a randomized clinical trial

This trial evaluates whether nocturnal oxygen therapy (NOT) during a stay at 2048 m improves altitude-induced exercise intolerance in lowlanders with chronic obstructive pulmonary disease (COPD). 32 lowlanders with moderate to severe COPD, mean ± SD forced expiratory volume in the first second of expiration (FEV₁) 54 ± 13% predicted, stayed for 2 days at 2048 m twice, once with NOT, once with placebo according to a randomized, crossover trial with a 2-week washout period at < 800 m in-between. Semi-supine, constant-load cycle exercise to exhaustion at 60% of maximal work-rate was performed at 490 m and after the first night at 2048 m. Endurance time was the primary outcome. Additional outcomes were cerebral tissue oxygenation (CTO), arterial blood gases and breath-by-breath measurements (http://www.ClinicalTrials.gov NCT02150590). Mean ± SE endurance time at 490 m was 602 ± 65 s, at 2048 m after placebo 345 ± 62 s and at 2048 m after NOT 293 ± 60 s, respectively (P < 0.001 vs. 490 m). Mean difference (95%CI) NOT versus placebo was − 52 s (− 174 to 70), P = 0.401. End-exercise pulse oximetry (SpO₂), CTO and minute ventilation (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\dot{\text{V}}}_{{\text{E}}}$$\end{document}V˙E) at 490 m were: SpO₂ 92 ± 1%, CTO 65 ± 1%, \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\dot{\text{V}}}_{{\text{E}}}$$\end{document}V˙E 37.7 ± 2.0 L/min; at 2048 m with placebo: SpO₂ 85 ± 1%, CTO 61 ± 1%, \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\dot{\text{V}}}_{{\text{E}}}$$\end{document}V˙E 40.6 ± 2.0 L/min and with NOT: SpO₂ 84 ± 1%; CTO 61 ± 1%; \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\dot{\text{V}}}_{{\text{E}}}$$\end{document}V˙E 40.6 ± 2.0 L/min (P < 0.05, SpO₂, CTO at 2048 m with placebo vs. 490 m; P = NS, NOT vs. placebo). Altitude-related hypoxemia and cerebral hypoxia impaired exercise endurance in patients with moderate to severe COPD and were not prevented by NOT.

Predictors of methacholine challenge testing results in subjects without airflow obstruction

OBJECTIVE

Methacholine challenge testing (MCT) is considered when asthma remains clinically suspected despite normal spirometry. Few studies have attempted to determine the predictive factors of MCT results. We aimed to establish which demographic data, clinical symptoms, pulmonary function testing results, and laboratory values were associated with abnormal MCT (provocation concentration causing a 20% decrease in FEV₁ (PC20) ≤ 16 mg/mL) in subjects without airflow obstruction on spirometry.

METHODS

All patients who completed MCT at Montfort Hospital between January 1^st, 2016 and December 31^st, 2018 were identified. Subjects with a reduced FEV₁/FVC ratio were excluded. We used Pearson's chi-squared test and point-biserial correlation method to determine which variables had a significant relationship (p < 0.05) with MCT results.

RESULTS

23.3% of patients who underwent MCT had airflow limitation. In the 1126 subjects with a normal FEV₁/FVC ratio, PC20 ≤ 16 mg/mL was found in 13.0%. Younger age, female gender, body mass index ≥ 40, and reported wheezing were factors associated with increased probability of airway hyper responsiveness. Lower FEV₁, significant improvement of the FEV₁ post-bronchodilator, reduced FEF25%-75%, greater FEF25%-75% reversibility, airway resistance measurements above the upper limit of normal, and increased blood eosinophil counts were predictive of abnormal MCT.

CONCLUSIONS

Only 13.0% of patients referred for MCT had a PC20 ≤ 16 mg/mL when the FEV₁/FVC ratio was normal, highlighting the need to further define in which individuals this test is truly warranted. Further investigation is required to develop an easy-to-use and validated prediction model in order to better understand patients' pretest probability of abnormal MCT.

Long-term consequences in critically ill COVID-19 patients: A prospective cohort study

BACKGROUND

COVID-19 can cause severe disease with need of treatment in the intensive care unit (ICU) for several weeks. Increased knowledge is needed about the long-term consequences.

METHODS

This is a single-center prospective follow-up study of COVID-19 patients admitted to the ICU for respiratory organ support between March and July 2020. Patients with invasive ventilation were compared with those with high-flow nasal oxygen (HFNO) or non-invasive ventilation (NIV) regarding functional outcome and health-related qualify of life. The mean follow-up time was 5 months after ICU discharge and included clinical history, three well-validated questionnaires about health-related quality of life and psychological health, pulmonary function test, 6-minute walk test (6MWT) and work ability. Data were analyzed with multivariable general linear and logistic regression models with 95% confidence intervals.

RESULTS

Among 248 ICU patients, 200 patients survived. Of these, 113 patients came for follow-up. Seventy patients (62%) had received invasive ventilation. Most patients reported impaired health-related quality of life. Approximately one-third suffered from post-traumatic stress, anxiety and depression. Twenty-six percent had reduced total lung capacity, 34% had reduced 6MWT and 50% worked fulltime. The outcomes were similar regardless of ventilatory support, but invasive ventilation was associated with more bodily pain (MSD -19, 95% CI: -32 to -5) and <80% total lung capacity (OR 4.1, 95% CI: 1.3-16.5).

CONCLUSION

Among survivors of COVID-19 who required respiratory organ support, outcomes 5 months after discharge from ICU were largely similar among those requiring invasive compared to non-invasive ventilation.

Effects of High and Moderate-Intensity Interval Training on Pulmonary and Performance Parameters in Miners Suffering From Chronic Obstructive Pulmonary Diseases

OBJECTIVE

To characterize the effect of 12 weeks of high and moderate-intensity interval training on pulmonary and functional parameters in miners with chronic obstructive pulmonary disease working in the polluted environment.

METHODS

Forty-five miners with COPD (average degree: 60 > FEV1 < 70), were randomly divided into HIIT (with 100%-125% ISWT); MIIT (with 60%-85% ISWT), and control. The study period was 12 weeks (3 sessions per week). At the beginning and end of the study, pulmonary and functional indices was evaluated.

RESULTS

Based on results, HIIT and MIIT significantly increased FVC, FEV1, and mean traveled distance in ISWT compared with control. Comparison of training intensities showed that HIIT led to a significant change in FVC, FEV1, and ISWT record compared to MIIT.

CONCLUSION

It is suggested that miners suffering from COPD, consider HIIT as part of their treatment plan.

Oates K, J. Fletcher A, P. Sylvester K. The association of six-minute walk work and other clinical measures to cardiopulmonary exercise test parameters in pulmonary vascular disease

INTRODUCTION

In pulmonary vascular disease exercise, abnormalities can include reduced exercise capacity, reduced oxygen pulse and elevated VE/VCO2. The association of clinical measures such as six-minute walk work, haemodynamics, lung function and echocardiogram to peak VO2, O2 pulse and VE/VCO2 has not been fully investigated in pulmonary vascular disease.

AIMS

To determine the relationship of six-minute walk work and other clinical measures to peak VO2, peak O2 pulse and VE/VCO2. Additionally, to investigate the ability to predict peak VO2 from six-minute walk work and other clinical parameters.

METHODS

Clinical data was retrospectively analysed from 63 chronic thromboembolic pulmonary hypertension (CTEPH) and 54 chronic thromboembolic disease (CTED) patients. Six-minute walk test measures, haemodynamics, lung function and echocardiographic measures were correlated with peak VO2, peak O2 pulse and VE/VCO2. Predictive equations were developed to predict peak V̇O2 in both CTEPH and CTED cohorts and subsequently validated.

RESULTS

A number of clinical parameters correlated to peak VO2, peak O2 pulse and VE/VCO2. Six-minute walk work and transfer factor for carbon monoxide demonstrated the strongest correlation to peak VO2 and peak O2 pulse. The validation of the predictive equations showed a variable level of agreement between measured peak VO2 and calculated peak VO2 from the predictive equations.

CONCLUSION

Six-minute walk work and additionally a number of clinical test parameters were associated to peak VO2, peak O2 pulse and VE/VCO2. Six-minute walk work and transfer factor for carbon monoxide were particularly highly correlated to peak VO2 and similarly to peak oxygen pulse. The validation of the predictive equations showed a variable level of agreement and therefore may have limited clinical applicability.

Measurement of the Total Lung Volume Using an Adjusted Single-Breath Helium Dilution Method in Patients With Obstructive Lung Disease

Background: Whole-body plethysmography (WBP) is the gold standard for measuring lung volume, but its clinical application is limited as it requires expensive equipment and is not simple to use. Studies have shown that the single-breath helium dilution (SBHD) method, which is commonly used in clinical practice, significantly underestimates lung volume in patients with obstructive lung disease (OLD). By comparing the differences in lung volume measured using SBHD and WBP, we aimed to establish a correction equation for the SBHD method to determine the total lung volume in patients with OLD of different severities.

Methods: From 628 patients with OLD simultaneously subjected to SBHD and WBP, 407 patients enrolled between January 2018 and November 2019 were in the training group and 221 enrolled between December 2019 and December 2020 were in the prospective verification cohort. The multiple linear regression equation was used for data in the training group to establish a correction equation for SBHD to determine the total lung volume, and this was validated in the prospective validation cohort.

Results: There was a moderate positive correlation between total lung capacity (TLC) determined using the SBHD [TLC (SBHD)] and WBP methods [TLC (WBP)] (r = 0.701; P < 0.05), and the differences between TLC (SBHD) and TLC (WBP) (ΔTLC) were related to the severity of obstruction. As the severity of obstruction increased, the TLC was underestimated by the SBHD method. We established the following correction equation: TLC (adjusted SBHD) (L) = −0.669 + 0.756*TLC(SBHD)(L) – 0.047*FEV1FVC+0.039*height (cm)–0.009*weight(kg)(r2 = 0.753 and adjusted r2 = 0.751). Next, we validated this equation in the validation cohort. With the correction equation, no statistical difference was observed between TLC (adjusted SBHD) and TLC (WBP) among the obstruction degree groups (P > 0.05).

Conclusions: The SBHD method is correlated with WBP to measure the total lung volume, but the SBHD method presents limitations in determining the total lung volume in patients with obstructive lung disease. Here, we established an effective and reliable correction equation in order to accurately assess the total lung volume of patients with OLD using the SBHD method.

Total Lung and Lobar Quantitative Assessment Based on Paired Inspiratory-Expiratory Chest CT in Healthy Adults: Correlation with Pulmonary Ventilatory Function

Objective: To provide the quantitative volumetric data of the total lung and lobes in inspiration and expiration from healthy adults, and to explore the value of paired inspiratory–expiratory chest CT scan in pulmonary ventilatory function and further explore the influence of each lobe on ventilation. Methods: A total of 65 adults (29 males and 36 females) with normal clinical pulmonary function test (PFT) and paired inspiratory–expiratory chest CT scan were retrospectively enrolled. The inspiratory and expiratory volumetric indexes of the total lung (TL) and 5 lobes (left upper lobe [LUL], left lower lobe [LLL], right upper lobe [RUL], right middle lobe [RML], and right lower lobe [RLL]) were obtained by Philips IntelliSpace Portal image postprocessing workstation, including inspiratory lung volume (LV_in), expiratory lung volume (LV_ex), volume change (∆LV), and well-aerated lung volume (WAL, lung tissue with CT threshold between −950 and −750 HU in inspiratory scan). Spearman correlation analysis was used to explore the correlation between CT quantitative indexes of the total lung and ventilatory function indexes (including total lung capacity [TLC], residual volume [RV], and force vital capacity [FVC]). Multiple stepwise regression analysis was used to explore the influence of each lobe on ventilation. Results: At end-inspiratory phase, the LV_in-TL was 4664.6 (4282.7, 5916.2) mL, the WAL_TL was 4173 (3639.6, 5250.9) mL; both showed excellent correlation with TLC (LV_in-TL: r = 0.890, p < 0.001; WAL_TL: r = 0.879, p < 0.001). From multiple linear regression analysis with lobar CT indexes as variables, the LV_in and WAL of these two lobes, LLL and RUL, showed a significant relationship with TLC. At end-expiratory phase, the LV_ex-TL was 2325.2 (1969.7, 2722.5) mL with good correlation with RV (r = 0.811, p < 0.001), of which the LV_ex of RUL and RML had a significant relationship with RV. For the volumetric change within breathing, the ∆LV_TL was 2485.6 (2169.8, 3078.1) mL with good correlation with FVC (r = 0.719, p < 0.001), moreover, WAL_TL showed a better correlation with FVC (r = 0.817, p < 0.001) than that of ∆LV_TL. Likewise, there was also a strong association between ∆LV, WAL of these two lobes (LLL and RUL), and FVC. Conclusions: The quantitative indexes derived from paired inspiratory–expiratory chest CT could reflect the clinical pulmonary ventilatory function, LLL, and RUL give greater impact on ventilation. Thus, the pulmonary functional evaluation needs to be more precise and not limited to the total lung level.

Lung function and breathing patterns in hospitalised COVID-19 survivors: a review of post-COVID-19 Clinics

INTRODUCTION

There is relatively little published on the effects of COVID-19 on respiratory physiology, particularly breathing patterns. We sought to determine if there were lasting detrimental effect following hospital discharge and if these related to the severity of COVID-19.

METHODS

We reviewed lung function and breathing patterns in COVID-19 survivors > 3 months after discharge, comparing patients who had been admitted to the intensive therapy unit (ITU) (n = 47) to those who just received ward treatments (n = 45). Lung function included spirometry and gas transfer and breathing patterns were measured with structured light plethysmography. Continuous data were compared with an independent t-test or Mann Whitney-U test (depending on distribution) and nominal data were compared using a Fisher's exact test (for 2 categories in 2 groups) or a chi-squared test (for > 2 categories in 2 groups). A p-value of < 0.05 was taken to be statistically significant.

RESULTS

We found evidence of pulmonary restriction (reduced vital capacity and/or alveolar volume) in 65.4% of all patients. 36.1% of all patients has a reduced transfer factor (TLCO) but the majority of these (78.1%) had a preserved/increased transfer coefficient (KCO), suggesting an extrapulmonary cause. There were no major differences between ITU and ward lung function, although KCO alone was higher in the ITU patients (p = 0.03). This could be explained partly by obesity, respiratory muscle fatigue, localised microvascular changes, or haemosiderosis from lung damage. Abnormal breathing patterns were observed in 18.8% of subjects, although no consistent pattern of breathing pattern abnormalities was evident.

CONCLUSIONS

An "extrapulmonary restrictive" like pattern appears to be a common phenomenon in previously admitted COVID-19 survivors. Whilst the cause of this is not clear, the effects seem to be similar on patients whether or not they received mechanical ventilation or had ward based respiratory support/supplemental oxygen.

Computed Tomography and Spirometry Can Predict Unresectability in Malignant Pleural Mesothelioma

Preoperative identification of unresectable pleural mesothelioma could spare unnecessary surgical intervention and accelerate the initiation of medical treatments. The aim of this study is to determine predictors of unresectability, testing our impression that the contraction of the ipsilateral hemithorax is often associated with exploratory thoracotomy. Between 1994 and 2020, 291 patients undergoing intended macroscopic complete resection for mesothelioma after chemotherapy were retrospectively investigated. Eligible patients (n = 58) presented a preoperative 3 mm slice-thickness chest computed tomography without pleural effusion or hydropneumothorax. Lung volumes (segmented using a semi-automated method), modified-Response Evaluation Criteria in Solid Tumors (RECIST) measurements, and spirometries were collected after chemotherapy. Multivariable analysis was performed to determine the predictors of unresectability. An unresectable disease was found at the time of operation in 25.9% cases. By multivariable analysis, the total lung capacity (p = 0.03) and the disease burden (p = 0.02) were found to be predictors of unresectability; cut-off values were <77.5% and >120.5 mm, respectively. Lung volumes were not confirmed to be associated with unresectability at multivariable analysis, probably due to the correlation with the disease burden (p < 0.001; r = −0.4). Our study suggests that disease burden and total lung capacity could predict MPM unresectability, helping surgeons in recommending surgery or not in a multimodality setting.

Pulmonary rehabilitation for idiopathic pleuroparenchymal fibroelastosis: A retrospective study on its efficacy, feasibility, and safety

BACKGROUND

The beneficial effects of pulmonary rehabilitation (PR) for patients with idiopathic pleuroparenchymal fibroelastosis (IPPFE) remain unknown. This study aimed to examine the efficacy, feasibility, and safety of PR for IPPFE.

METHODS

We retrospectively investigated 25 patients with IPPFE referred for PR between April 2007 and March 2017. The PR mainly consisted of a 10-week exercise training program. The primary outcome was a change in 6-min walk distance (6MWD). Secondary outcomes included changes in dyspnea (transition dyspnea index [TDI]), anxiety and depression (hospital anxiety and depression scale [HADS]), and health-related quality of life (HRQoL) (St George's respiratory questionnaire [SGRQ]).

RESULTS

Thirteen patients participated in the PR program (PRP). Recurrent pneumothorax was the most common reason for patients not participating in the PRP. Four patients discontinued the PRP due to the recurrence of pneumothorax, new onset of pneumomediastinum, stroke, and another reason, respectively. Nine patients completed the PRP. Significant improvement was observed in 6MWD (median [interquartile range], 90 m [55-116 m]; P = 0.033). Clinically important improvements in the 6MWD, and TDI, HADS-anxiety, HADS-depression, and SGRQ total domain scores were observed in seven (78%), five (56%), four (44%), four (44%), and five (56%) of the nine patients, respectively.

CONCLUSIONS

Patients with IPPFE benefited from PR in terms of exercise capacity, dyspnea, anxiety, depression, and HRQoL. Pneumothorax and pneumomediastinum may impede the implementation of a PRP for patients with IPPFE. While careful patient selection is required, PR may be an efficacious non-pharmacological approach for managing disabilities in patients with IPPFE.

Residual Volume Responsiveness Testing May Improve the Detection of Reversible Airway Obstruction in Asthma

BACKGROUND

Residual volume responsiveness to bronchodilator administration has been observed in subjects with chronic obstructive pulmonary disease. However, the prevalence of residual volume (RV) responsiveness has not been formally studied in asthma.

OBJECTIVE

To identify the prevalence and magnitude of RV responsiveness in asthma.

METHODS

Physician-diagnosed adult subjects with asthma on treatment for >12 months were prospectively recruited to perform spirometry and measurement of lung volumes using body plethysmography before and after administration of 360 μg of albuterol.

RESULTS

Among 120 subjects, 76% were women. The ethnic composition was 64% Caucasian, 32% Hispanic, and 13% African American. The mean age was 52 ± 15 years. The mean duration of asthma was 16 ± 15 years. The mean RV% responsiveness was -7.74 ± 14. Whereas patients with the lowest baseline forced expiratory volume in 1 second (FEV1) value showed the highest mean responsiveness (P = .001), the baseline RV value had minimal influence on RV responsiveness. Using -7.74% to define significant RV responsiveness, and ≥12% and ≥200 mL to define significant FEV1 responsiveness, more subjects showed isolated RV responsiveness (37%) compared with 6% with isolated FEV1 responsiveness and 14% with both FEV1 and RV responsiveness (P = .04). There was a minimal correlation between FEV1 responsiveness and RV responsiveness (r = 0.17, P = .06). The RV responsiveness was significantly associated with the wheeze score (P = .006) and dyspnea score (P = .029).

CONCLUSION

The addition of RV responsiveness testing to spirometry based responsiveness testing can improve the identification of reversible airway obstruction in asthma. RV responsiveness may be useful in monitoring symptoms associated with air trapping in asthma.

18F-FDG PET/CT predicts acute exacerbation in idiopathic pulmonary fibrosis after thoracic surgery

Background

Acute exacerbation (AE) is the most lethal postoperative complication in idiopathic pulmonary fibrosis (IPF); however, prediction before surgery is difficult. We investigated the role of ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) in predicting postoperative AE in IPF.

Method

Clinical data of 48 IPF patients who underwent 18F-FDG PET/CT before thoracic surgery were retrospectively analyzed. Mean and maximal standardized uptake values (SUV_mean and SUV_max, respectively) were measured in the fibrotic area. Additionally, adjusted values-SUV ratio (SUVR, defined as SUV_max-to-liver SUV_mean ratio), tissue fraction-corrected SUV_mean (SUV_meanTF), and SUVR (SUVR_TF)-were calculated.

Results

The mean age of the subjects was 67.8 years and 91.7% were male. After thoracic surgery, 21 (43.8%) patients experienced postoperative complications including prolonged air leakage (29.2%), death (14.6%), and AE (12.5%) within 30 days. Patients who experienced AE showed higher SUV_max, SUVR, SUV_meanTF, and SUVR_TF than those who did not, but other clinical parameters were not different between patients with and without AE. The SUV parameters did not differ for other complications. The SUVR (odds ratio [OR] 29.262; P = 0.030), SUV_meanTF (OR 3.709; P = 0.041) and SUVR_TF (OR 20.592; P = 0.017) were significant predicting factors for postoperative AE following a multivariate logistic regression analysis. On receiver operating characteristics curve analysis, SUVR_TF had the largest area under the curve (0.806, P = 0.007) for predicting postoperative AE among SUV parameters.

Conclusions

Our findings suggest that ¹⁸F-FDG PET/CT may be useful in predicting postoperative AE in IPF patients and among SUVs, SUVR_TF is the best parameter for predicting postoperative AE in IPF patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-021-01659-4.

Changes in pulmonary function and patient-reported outcomes during COVID-19 recovery: a longitudinal, prospective cohort study

Objectives

The aim of this study was to compare respiratory and patient-reported outcome measures (PROMs) between 3 and 6 months after symptom onset and to identify features that predict these changes.

Methods

This was a consecutive prospective cohort of 73 patients who were hospitalised with coronavirus disease 2019 (COVID-19). We evaluated the changes in pulmonary function tests and PROMs between 3 and 6 months and then investigated the associations between outcomes (change in diffusing capacity of the lung for carbon monoxide (D _LCO), dyspnoea and quality of life (QoL)) and clinical and radiological features.

Results

There was improvement in forced vital capacity, total lung capacity and D _LCO between 3 and 6 months by 3.25%, 3.82% and 5.69%, respectively; however, there was no difference in PROMs. Reticulation and total computed tomography (CT) scores were associated with lower D _LCO % predicted at 6 months (coefficients; -8.7 and -5.3, respectively). The association between radiological scores and D _LCO were modified by time, with the degree of association between ground glass and D _LCO having decreased markedly over time. There was no association between other predictors and change in dyspnoea or QoL over time.

Conclusions

There is improvement in pulmonary function measurements between 3 and 6 months after COVID-19 symptom onset; however, PROMs did not improve. A higher reticulation and total CT score are negatively associated with D _LCO, but this association is attenuated over time. Lastly, there is a considerable proportion of patients with unexplained dyspnoea at 6 months, motivating further research to identify the underlying mechanisms.

Prognostic Implication of Diagnostic Confidence Level in Patients with Fibrotic Hypersensitivity Pneumonitis

BACKGROUND

Hypersensitivity pneumonitis (HP) has various clinical courses and outcomes, but the prognostic factors are not well-defined. Vasakova et al. [Am J Respir Crit Care Med. 2017 Sep;196(6):680-9] have proposed a diagnostic algorithm that categorized suspected patients according to the level of confidence in the diagnosis. This study aimed to investigate whether the confidence level of clinical diagnosis has prognostic implication in patients with fibrotic HP.

METHODS

This study included 101 biopsy-proven fibrotic HP patients diagnosed between 2002 and 2017. The patients were retrospectively classified into confident, probable, possible, and unlikely chronic HP, according to the confidence level in the diagnostic criteria/algorithm. The survival and forced vital capacity (FVC) changes were compared between the groups. Risk factors for mortality were analysed using a Cox proportional hazard model.

RESULTS

The median follow-up duration was 67.6 months. The mean age was 60.4 years, and percentages of women were 60.4%. When classified based on the diagnostic criteria/algorithm, possible HP was the most common (51.5%), followed by probable (26.7%), confident (9.9%), and unlikely HP (6.9%). Distinctive survival curves were found according to the diagnostic confidence level, showing the worst outcome in unlikely chronic HP (median survival, 30.2 months). In a multivariable Cox analysis, unlikely HP was a significant predictor of poor survival (hazard ratio, 4.652; 95% confidence interval, 1.231-17.586; p = 0.023), after adjustment for age, body mass index, FVC, and diffusing capacity.

CONCLUSIONS

The diagnostic confidence level may predict clinical outcomes in patients with HP. Unlikely HP was shown to have a significantly poorer survival than other diagnostic confidence levels.

Spatial Dependence of CT Emphysema in Chronic Obstructive Pulmonary Disease Quantified by Using Join-Count Statistics

Background Existing CT emphysema measurements quantify the extent or clustering of emphysema voxels in chronic obstructive pulmonary disease (COPD); however, these measurements do not quantify how those voxels are clustered. Purpose To develop a CT measurement to quantify the "compactness" of emphysema voxels, called the normalized join count (NJC), and to determine whether the NJC measurement differentiates COPD disease severity and correlates with lung function and visual emphysema scores. Materials and Methods In this secondary analysis of a prospective study, lung function and CT images were obtained from the Canadian Cohort Obstructive Lung Disease study visit 1 from 2009 to 2013. Participants were categorized as never-smokers, at risk, mild COPD, or moderate-severe COPD. Diffusion capacity for carbon monoxide/alveolar volume was measured. CT emphysema was scored visually by radiologists. CT measurements included the percentage low-attenuation area with attenuation less than -950 HU (%LAA_-950insp), low-attenuation cluster (LAC), and lowest 15th percentile point of the CT lung density histogram. NJC was developed to measure compactness of CT emphysema voxels. An analysis of variance determined differences between groups. Multivariable ridge regression determined association between CT measurements with lung function and radiologist scores. Results A total of 1294 participants (750 men; mean age, 67 years ± 10) were analyzed (277 never-smokers, 306 at risk, 427 mild COPD, and 284 moderate-severe COPD). NJC, %LAA_-950insp, and LAC measurements were higher in moderate-severe COPD than in never-smokers and at-risk participants (P < .05 for all comparisons), but only NJC was different between mild and ;moderate-severe COPD (mean, 1.98% ± 3.61 vs 1.44% ± 2.14; P < .05). In multivariable regression analysis, among all CT measurements NJC had the greatest relative contribution to diffusion capacity for carbon monoxide/alveolar volume (P = .002) and visual emphysema score (P < .001). Conclusion The relationship of normalized join count with severity of chronic obstructive pulmonary disease may indicate that the assessment of this disease is dependent on the number of low attenuating voxels or the size of clusters and the spatial arrangement of such voxels. © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Grenier in this issue.

Non-Invasive Respiratory Assessment in Duchenne Muscular Dystrophy: From Clinical Research to Outcome Measures

Ventilatory failure, due to the progressive wasting of respiratory muscles, is the main cause of death in patients with Duchenne muscular dystrophy (DMD). Reliable measures of lung function and respiratory muscle action are important to monitor disease progression, to identify early signs of ventilatory insufficiency and to plan individual respiratory management. Moreover, the current development of novel gene-modifying and pharmacological therapies highlighted the urgent need of respiratory outcomes to quantify the effects of these therapies. Pulmonary function tests represent the standard of care for lung function evaluation in DMD, but provide a global evaluation of respiratory involvement, which results from the interaction between different respiratory muscles. Currently, research studies have focused on finding novel outcome measures able to describe the behavior of individual respiratory muscles. This review overviews the measures currently identified in clinical research to follow the progressive respiratory decline in patients with DMD, from a global assessment to an individual structure–function muscle characterization. We aim to discuss their strengths and limitations, in relation to their current development and suitability as outcome measures for use in a clinical setting and as in upcoming drug trials in DMD.

Mechanisms of Exertional Dyspnea in Patients with Mild COPD and a Low Resting DLCO

Patients with mild chronic obstructive pulmonary disease (COPD) and lower resting diffusing capacity for carbon monoxide (DL_CO) often report troublesome dyspnea during exercise although the mechanisms are not clear. We postulated that in such individuals, exertional dyspnea is linked to relatively high inspiratory neural drive (IND) due, in part, to the effects of reduced ventilatory efficiency. This cross-sectional study included 28 patients with GOLD I COPD stratified into two groups with (n = 15) and without (n = 13) DL_CO less than the lower limit of normal (<LLN; Global Lung Function Initiative criteria) and 16 healthy controls. We compared dyspnea (Borg scale), IND (by diaphragm electromyography), ventilatory equivalent for CO₂ (V̇_E/V̇CO₂), and respiratory mechanics during incremental cycle exercise in the three groups. Spirometry and resting lung volumes were similar between COPD groups. During exercise, dyspnea, IND and V̇_E/V̇CO₂ were higher at equivalent work rates (WR) in the DL_CO<LLN group compared with the other two groups (all p < 0.05). In patients with DL_CO<LLN, severe respiratory mechanical constraints, indicated by end-inspiratory lung volume of approximately 90% of total lung capacity, occurred at a lower WR than the other two groups (p < 0.05). The dyspnea/IND relationship was similar across groups; therefore, the increased dyspnea at a standardized WR in the low DL_CO<LLN group reflected the higher corresponding IND. Higher dyspnea ratings in patients with mild COPD and DL_CO<LLN were associated with higher IND and V̇_E/V̇CO₂ at a given work rate. Higher ventilatory requirements in the DL_CO<LLN group accelerated dynamic mechanical abnormalities earlier in exercise, further increasing IND and dyspnea.

Dynapenia is highly prevalent in older patients with advanced idiopathic pulmonary fibrosis

Body composition and muscle strength are emerging aspects in idiopathic pulmonary fibrosis (IPF) clinical assessment. We aimed to study the relationships of handgrip strength (HGS) with anthropometric variables, body composition, and disease staging, and to evaluate the prevalence of dynapenia in 102 clinically stable IPF patients (70 M; mean age: 69.4 years). Fat-free mass (FFM), skeletal muscle (SM) were estimated with bioimpedance analysis. HGS was measured with a digital handle dynamometer for both dominant and non-dominant body sides. Dynapenia was identified according to six recognized criteria sets. Mean body mass index (BMI) was 28.2 ± 4.7 kg/m², with a prevalence of overweight (BMI > 25 and < 30 kg/m²) and obesity (BMI ≥ 30 kg/m²) of 35% and 37%, respectively. FFM and SM were greater in males, whereas percentage body fat was higher in women. HGS was higher and declined with age slightly more rapidly in men, showing a stronger correlation with FFM and SM. Dynapenia prevalence ranged from 20.6 to 56.9%, depending on the criteria used, and was more frequent in older patients and advanced disease. Dynapenia is highly prevalent in IPF. HGS is a promising proxy marker of muscle function to be used in clinical evaluation and follow-up programs.

Effect of sildenafil added to antifibrotic treatment in idiopathic pulmonary fibrosis

Sildenafil is a phosphodiesterase-5 inhibitor used to treat idiopathic pulmonary arterial hypertension; however, its benefits are unclear in patients with advanced idiopathic pulmonary fibrosis (IPF). We aimed to evaluate its effect as an add-on to antifibrotic agents on clinical outcomes of real-world IPF patients. Among a total of 607 IPF patients treated with antifibrotic agent, 66 concurrently received sildenafil. Propensity score matching was performed to adjust for differences in age, sex, body mass index, forced vital capacity (FVC), and diffusing capacity (DL_CO) between the sildenafil and no-sildenafil groups. The outcomes of these groups in terms of FVC decline rate, all-cause mortality, hospitalization, and acute exacerbation were compared. Propensity score matching identified 51 matched pairs. The mean age of the patients was 69.5 years and 80.4% were male. Mean FVC and DL_CO were 51.7% and 29.5% of the predicted values, respectively. The FVC decline rates did not differ significantly (p = 0.714) between the sildenafil (− 101 mL/year) and no-sildenafil (− 117 mL/year) groups. In multivariable analyses adjusted for comorbidities and presence of pulmonary hypertension, sildenafil had no significant impact on all-cause mortality, hospitalization, or acute exacerbation. Sildenafil add-on to antifibrotic treatment had no significant effects on the clinical outcomes of IPF patients.

Quantitative 18F-fluorodeoxyglucose positron emission tomography/computed tomography to assess pulmonary inflammation in COPD

Rationale

COPD and smoking are characterised by pulmonary inflammation. ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) imaging may improve knowledge of pulmonary inflammation in COPD patients and aid early development of novel therapies as an imaging biomarker.

Objectives

To evaluate pulmonary inflammation, assessed by FDG uptake, in whole and regional lung in “usual” (smoking-related) COPD patients, alpha-1 antitrypsin deficiency (α₁ATD) COPD patients, smokers without COPD and never-smokers using FDG PET/CT. Secondly, to explore cross-sectional associations between FDG PET/CT and systemic inflammatory markers in COPD patients and repeatability of the technique in COPD patients.

Methods

Data from two imaging studies were evaluated. Pulmonary FDG uptake (normalised K_i; nK_i) was measured by Patlak graphical analysis in four subject groups: 84 COPD patients, 11 α₁ATD-COPD patients, 12 smokers and 10 never-smokers. Within the COPD group, associations between nK_i and systemic markers of inflammation were assessed. Repeatability was evaluated in 32 COPD patients comparing nK_i values at baseline and at 4-month follow-up.

Results

COPD patients, α₁ATD-COPD patients and smokers had increased whole lung FDG uptake (nK_i) compared with never-smokers (0.0037±0.001, 0.0040±0.001, 0.0040±0.001 versus 0.0028±0.001 mL·cm⁻³·min⁻¹, respectively, p<0.05 for all). Similar results were observed in upper and middle lung regions. In COPD participants, plasma fibrinogen was associated with whole lung nK_i (β=0.30, p=0.02) in multivariate analysis adjusted for current smoking, forced expiratory volume in 1 s % predicted, systemic neutrophils and C-reactive protein levels. Mean percentage difference in nK_i between the baseline and follow-up was 3.2%, and the within subject coefficient of variability was 7.7%.

Conclusions

FDG PET/CT has potential as a noninvasive tool to enable whole lung and regional quantification of FDG uptake to assess smoking- and COPD-related pulmonary inflammation.

FDG PET/CT has potential utility to noninvasively evaluate pulmonary inflammation in COPD. Pulmonary FDG uptake is increased in COPD patients, positively associated with systemic inflammatory markers and shows low inter-occasion variability.https://bit.ly/3dELYAW

Ventilatory limitations are not associated with dyspnea on exertion or reduced aerobic fitness in pectus excavatum

Exercise intolerance and chest pain are common symptoms in patients with pectus excavatum. To assess if the anatomic extent of pectus deformities determined by the correction index (CI) is associated with a pulmonary impairment at rest and during exercise we performed a retrospective review on pectus patients in our center who completed a symptom questionnaire, cardiopulmonary exercise test (CPET), pulmonary function tests (PFT), and chest magnetic resonance imaging. Of 259 patients studied, dyspnea on exertion and chest pain was reported in 64% and 41%, respectively. Peak oxygen uptake (VO₂ ) was reduced in 30% and classified as mild in two-thirds. A pulmonary limitation during exercise was identified in less than 3%. Ventilatory limitations on PFT was found in 26% and classified as mild in 85%. Obstruction was the most common abnormal pattern (11%). There were no differences between patients with normal or abnormal PFT patterns for the CI, VO_2, or percentage reporting dyspnea or chest pain. Scatter plots demonstrated significant but weak inverse relationships between the CI and lung volumes at rest and during exercise. Multivariable linear regression modeling evaluating predictors of VO₂ demonstrated positive associations with the forced expiratory volume at one second and a negative association with the CI. We conclude that resting PFT patterns have poor correlation with the anatomic extent of the pectus defect, symptomatology or aerobic fitness. Pulmonary limitations on CPET are uncommon and lung volumes during exercise are only minimally associated with the CI.

Stable to improved cardiac and pulmonary function in children with high-risk sickle cell disease following haploidentical stem cell transplantation

Children with sickle cell disease (SCD) are at high-risk of progressive, chronic pulmonary and cardiac dysfunction. In this prospective multicenter Phase II trial of myeloimmunoablative conditioning followed by haploidentical stem cell transplantation in children with high-risk SCD, 19 patients, 2.0-21.0 years of age, were enrolled with one or more of the following: history of (1) overt stroke; (2) silent stroke; (3) elevated transcranial Doppler velocity; (4) multiple vaso-occlusive crises; and/or (5) two or more acute chest syndromes and received haploidentical transplants from 18 parental donors. Cardiac and pulmonary centralized cores were established. Pulmonary function results were expressed as percent of the median of healthy reference cohorts, matched for age, sex, height and race. At 2 years, pulmonary functions including forced expiratory volume (FEV), FEV₁/ forced vital capacity (FVC), total lung capacity (TLC), diffusing capacity of lung for carbon monoxide (DLCO) were stable to improved compared to baseline values. Importantly, specific airway conductance was significantly improved at 2 years (p < 0.004). Left ventricular systolic function (fractional shortening) and tricuspid regurgitant velocity were stable at 2 years. These results demonstrate that haploidentical stem cell transplantation can stabilize or improve cardiopulmonary function in patients with SCD.

Posttraumatic Stress Disorder Is Associated With a Decrease in Anaerobic Threshold, Oxygen Pulse, and Maximal Oxygen Uptake

BACKGROUND

Posttraumatic stress disorder (PTSD) has been linked to respiratory symptoms and functional limitations, but the mechanisms leading to this association are poorly defined.

RESEARCH QUESTION

What is the relationship between PTSD, lung function, and the cardiopulmonary response to exercise in combat veterans presenting with chronic respiratory symptoms?

STUDY DESIGN AND METHODS

This study prospectively enrolled military service members with respiratory symptoms following deployment to southwest Asia. All participants underwent a comprehensive evaluation that included pulmonary function testing and cardiopulmonary exercise testing. Pulmonary function test variables and cardiopulmonary response to exercise were compared in subjects with and without PTSD by using multivariable linear regression to adjust for confounders.

RESULTS

A total of 303 participants were included (PTSD, n = 70; non-PTSD, n = 233). Those with PTSD had a greater frequency of current respiratory symptoms. There were no differences in measures for airway disease or lung volumes, but patients with PTSD had a reduction in diffusing capacity that was eliminated following adjustment for differences in hemoglobin levels. Participants with PTSD had a lower anaerobic threshold (23.9 vs 26.4 cc/kg per minute; P = .004), peak oxygen pulse (19.7 vs 18.5 cc/beat; P = .03), and peak oxygen uptake (34.5 vs 38.8 cc/kg per minute; P < .001). No significant difference was observed in gas exchange, respiratory reserve, or effort at peak exercise between participants with and without PTSD.

INTERPRETATION

A diagnosis of PTSD was associated with a reduced anaerobic threshold, oxygen pulse, and peak oxygen uptake. This objective reduction in cardiopulmonary work is independent of baseline lung function, was not associated with abnormalities in gas exchange or respiratory reserve, and may be related to deconditioning.

Health-related quality of life in patients with chronic obstructive pulmonary disease: A hospital-based study

Background & objectives:

Chronic obstructive pulmonary disease (COPD) adversely affects various functional and structural domains of the lungs, in addition to having an array of extra-pulmonary effects which affect overall well-being of a patient. This study was aimed at measuring the health-related quality of life (HRQOL) in COPD patients and relating the severity of disease and other factors with the degree of impairment of HRQOL.

Methods:

This cross-sectional study was conducted on 100 individuals with established COPD aged 45 yr or above. COPD severity was graded based on the Global Initiative for Obstructive Lung Disease (GOLD) staging system. Pulmonary function test was carried out as per the American Thoracic Society and European Respiratory Society task force standardised lung function testing guidelines. The quality of life was measured using the COPD-specific version of the St. George's Respiratory Questionnaire (SGRQ). The three component scores (activity, impact and symptoms) and the total score were compared across the various categories of age, gender and COPD grades. Using multivariable linear regression analysis, the relationship between COPD grades and various component scores, adjusting for age and gender, was determined.

Results:

The mean total SGRQ Classification score was found to be 48.5±17.1. There was a significant increase in the symptom, activity and impact component scores and the total scores of the participants with worsening of COPD grade. The activity, impact component scores and total score showed an increasing trend with age. However, the values of these three scores were lower in participants in the age group of 56-65 yr in comparison to those in the 45-55 yr age group. There was a significant increase in the symptom component score with increasing age across the study population. The difference in the various scores between males and females was not significant.

Interpretation & conclusions:

HRQOL is impaired in patients with COPD, and it deteriorates with increasing severity of the disease. The onset of COPD at a younger age has a much more significant deterioration of HRQOL, due to the early onset of symptoms and complications. These findings call for better early care and integration of pulmonary rehabilitation programmes into current health policies.

The Severity of Pectus Excavatum Defect Is Associated With Impaired Cardiopulmonary Function

BACKGROUND

Repair of pectus excavatum has cosmetic benefits, but the physiologic impact remains controversial. The aim of this study was to characterize the relationship between the degree of pectus excavatum and cardiopulmonary dysfunction seen on cardiac magnetic resonance (CMR) imaging, cardiopulmonary exercise testing (CPET), and pulmonary function testing (PFT).

METHODS

A single-center analysis of CMR, CPET, and PFT was conducted. Regression models evaluated relationships between pectus indices and the clinical end points of cardiopulmonary function.

RESULTS

Data from 345 CMRs, 261 CPETs, and 281 PFTs were analyzed. Patients were a mean age of 15.2 ± 4 years, and 81% were aged <18 years. The right ventricular ejection fraction (RVEF) was <0.50 in 16% of patients, left ventricular ejection fraction (LVEF) was <0.55 in 22%, RVEF Z-score was < -2 in 32%, and the LVEF Z-score was < -2 in 18%. CPET revealed 33% of patients had reduced aerobic fitness. PFT results were abnormal in 23.1% of patients. Adjusted analyses revealed the Haller index had significant (P < .05) inverse associations with RVEF and LVEF.

CONCLUSIONS

The severity of pectus excavatum is associated with ventricular systolic dysfunction. Pectus excavatum impacts right and left ventricular systolic function and can also impact exercise tolerance. The Haller index and correction index may be the most useful predictors of impairment.

Ultrasound Evaluation of Diaphragm Force Reserve in Patients with Chronic Obstructive Pulmonary Disease

Rationale: Diaphragm function is a key determinant of dyspnea in chronic obstructive pulmonary disease (COPD); however, it is rarely assessed in clinical practice. Lung hyperinflation can also impair diaphragm function. Ultrasound can assess the activity, function, and force reserve of the diaphragm.Objectives: To compare diaphragm activity, function, and force reserve among patients with COPD and healthy control subjects.Methods: Patients with stable COPD (n = 80) and healthy control subjects (n = 20) were enrolled (97% of them were men). Ultrasound was used to measure the thickening fraction of the diaphragm during tidal breathing and maximum volitional effort. Outcome measures were as follows: 1) the difference in diaphragm force reserve, activity, and function between patients with COPD and control subjects; 2) the correlation between lung volumes and diaphragm force reserve, activity, and function; and 3) the relationship between diaphragm force reserve and the rate of moderate to severe exacerbation of COPD.Results: The tidal thickening fraction of the diaphragm during resting breathing (TFdi-tidal) was higher in patients with COPD than in control subjects (P = 0.002); it was approximately twice as high in patients with severe COPD than in control subjects. Patients with COPD had poorer diaphragm function than control subjects as assessed by the maximal thickening fraction of the diaphragm during Muller maneuver (P < 0.01). Diaphragm force reserve ratio assessed by 1-(tidal thickening fraction of the diagphragm during resting breathing/maximal thickening fraction of the diaphragm) was lower in patients with COPD than in control subjects, and it fell with increasing Global Initiative for Chronic Obstructive Lung Disease stages (P < 0.001); it correlated with inspiratory capacity (r = 0.46) and the body mass index, airflow obstruction, dyspnea, exercise capacity (BODE) index, a multidimensional scoring system (r = -0.49). Patients who developed exacerbation during the following 2 years had less force reserve than patients without exacerbation (P = 0.024).Conclusions: Male patients with COPD have increased diaphragm workload, impaired diaphragm function, and reduced force reserve compared with healthy subjects. Ultrasound assessment of the diaphragm in COPD provides important functional information.Clinical trial registered with the Thai Clinical Trials Registry (TCTR20160411001). Registered 31 April 5, 2016.

Longitudinal Lung Volume Changes by Ultrastructure and Genotype in Primary Ciliary Dyskinesia

Rationale: Genotype-phenotype relationships are emerging in primary ciliary dyskinesia (PCD), but little is known about lung volume changes over time. Objectives: To investigate the evolution of static lung volumes with ultrastructural defects, gene mutations, body mass index, and specific infections in PCD. Methods: Prospective, longitudinal, single-center study in children and adults evaluated twice yearly for up to 10 years. Linear mixed-effects models were used to assess associations between ciliary morphology, genetic mutations, and clinical features. Results: A total of 122 patients had 1,096 visits. At enrollment, almost all spirometric and, especially in adults, plethysmographic parameters were significantly worse in absent inner dynein arms (IDAs), central apparatus (CA) defects, and microtubular disorganization (MTD) (IDA/CA/MTD) compared with patients with normal electron microscopy (EM) results. The mean trend increase with time for residual volume (RV) was significantly higher in IDA/CA/MTD group compared with groups with outer dynein arm defect and normal EM results. The mean trend of RV/total lung capacity in the IDA/CA/MTD group was significantly worse than in all other groups. The steepest rise in lung volumes was in CCDC39 and CCDC40, whereas hyperinflation increased less in DNAH5 and DNAH11 groups. RV/total lung capacity showed a significantly steeper rise in patients with Pseudomonas aeruginosa compared with patients with other infections or patients without infection. Conclusions: Patients with IDA/CA/MTD defects or CCDC39 and CCDC40 mutations had the greatest increase in hyperinflation, whereas those with outer dynein arm defect and normal EM results or DNAH11 and DNAH5 mutations had less severe changes. We have robustly confirmed the worse prognosis for some genetic and ultrastructural defects, which association hitherto rested solely on spirometry.

Diaphragm Morphology Assessed by Computed Tomography in Chronic Obstructive Pulmonary Disease

Rationale: Chronic obstructive pulmonary disease (COPD) is associated with abnormal skeletal muscle morphology and function. Objectives: To test the hypothesis that in vivo diaphragm muscle morphology assessed by computed tomography (CT) imaging would be associated with COPD severity, exacerbations, health status, and exercise capacity. Methods: The COPD Morphometry Study is a cross-sectional study that enrolled a clinical sample of smokers with COPD. Spirometry was performed and COPD severity was defined according to guidelines. Three-dimensional left hemidiaphragm morphology was segmented from contiguous axial CT images acquired at maximal inspiration, yielding quantitative measures of diaphragm CT density in Hounsfield units, dome height, and muscle volume. Exacerbations prompting pharmacotherapy or hospitalization in the preceding 12 months and St. George's Respiratory Questionnaire for COPD were assessed. Incremental symptom-limited cycle ergometry quantified peak oxygen uptake ([Formula: see text]o_2Peak). Associations were adjusted for age, sex, body height, body mass index, and smoking status. Results: Among 65 smokers with COPD (75% male; [mean ± standard deviation (SD)] 56 ± 26 pack-years; forced expiratory volume in 1 second [FEV₁] percentage predicted 55 ± 23%), mean diaphragm CT density was 3.1 ± 10 Hounsfield units, dome height was 5.2 ± 1.3 cm, and muscle volume was 57 ± 24 cm³. A 1-SD decrement in the diaphragm CT density was associated with 8.3% lower FEV₁, 3.27-fold higher odds of exacerbation history, 9.7-point higher score on the St. George's Respiratory Questionnaire for COPD, and 2.5 ml/kg/min lower [Formula: see text]o_2Peak. A 1-SD decrement in dome height was associated with 11% lower FEV₁ and 1.3 ml/kg/min lower [Formula: see text]o_2Peak. There were no associations with diaphragm volume observed. Conclusions: CT-assessed diaphragm morphology was associated with COPD severity, exacerbations, impaired health status, and exercise intolerance. The mechanisms and functional impact of lower diaphragm CT density merit investigation.

Static and dynamic balance impairment and relationship with disease-related factors in patients with chronic obstructive pulmonary disease : A cross-sectional study

BACKGROUND

Disease and aging-related factors may predispose chronic obstructive pulmonary disease (COPD) patients to impaired balance, although the underlying determinants of impaired balance in COPD patients are still unknown. The purpose of this study was to identify the determinants of impaired balance in COPD patients. Also, we aimed to determine which balance measures (clinical or laboratory tests) are more indicative in determining balance impairment in these patients.

METHODS

This cross-sectional study recruited 24 patients with moderate to severe COPD and 24 age-matched healthy subjects. Participants were evaluated regarding demographic and clinical data, previous falls history, lower limb muscle strength, exercise capacity, physical activity and balance level.

RESULTS

COPD patients exhibited significantly a longer test duration on timed up and go test, a higher sway index on the postural stability and lower directional control score on the limit of stability of Biodex balance system (all, p < 0.001) compared to healthy controls, whereas there was no difference in Berg balance scale score between groups (p > 0.05). Balance impairment of the patient group was significantly associated with nonpulmonary conditions, such as physical activity level, exercise capacity, lower limb muscle strength, and with fall history. Also, COPD patients represented significantly lower physical activity level and exercise capacity, weaker lower limb muscle strength than healthy controls (all, p < 0.001).

CONCLUSIONS

Patients with moderate to severe COPD exhibit apparently important reductions in balance control that is directly associated with nonpulmonary consequences and fall history. These results may be extremely important to fall prevention and to guide the development of interventions for this population.

Persistent Endothelial Dysfunction in Post-Acute COVID-19 Syndrome: A Case-Control Study

Background: Endothelial dysfunction has a key role in the pathogenesis of coronavirus disease 2019 (COVID-19) and its disabling complications. We designed a case-control study to assess the alterations of endothelium-dependent flow-mediated dilation (FMD) among convalescent COVID-19 patients. Methods: COVID-19 patients referred to a Pulmonary Rehabilitation Unit within 2 months from swab test negativization were consecutively evaluated for inclusion and compared to controls matched for age, gender, and cardiovascular risk factors. Results: A total of 133 convalescent COVID-19 patients (81.2% males, mean age 61.6 years) and 133 matched controls (80.5% males, mean age 60.4 years) were included. A significantly lower FMD was documented in convalescent COVID-19 patients as compared to controls (3.2% ± 2.6 vs. 6.4% ± 4.1 p < 0.001), confirmed when stratifying the study population according to age and major clinical variables. Among cases, females exhibited significantly higher FMD values as compared to males (6.1% ± 2.9 vs. 2.5% ± 1.9, p < 0.001). Thus, no significant difference was observed between cases and controls in the subgroup analysis on females (6.1% ± 2.9 vs. 5.3% ± 3.4, p = 0.362). Among convalescent COVID-19 patients, FMD showed a direct correlation with arterial oxygen tension (rho = 0.247, p = 0.004), forced expiratory volume in 1 s (rho = 0.436, p < 0.001), forced vital capacity (rho = 0.406, p < 0.001), and diffusing capacity for carbon monoxide (rho = 0.280, p = 0.008). Overall, after adjusting for major confounders, a recent COVID-19 was a major and independent predictor of FMD values (β = −0.427, p < 0.001). Conclusions: Post-acute COVID-19 syndrome is associated with a persistent and sex-biased endothelial dysfunction, directly correlated with the severity of pulmonary impairment.

Effect of Dynamic Hyperinflation on Cardiac Response to Exercise of Patients With Chronic Obstructive Pulmonary Disease

INTRODUCTION

Although the major limitation to exercise performance in patients with COPD is dynamic hyperinflation (DH), little is known about its relation with cardiac response to exercise. Our objectives were to compare the exercise response of stroke volume (SV) and cardiac output (CO) between COPD patients with or without DH and control subjects, and to assess the main determinants.

METHODS

Fifty-seven stable COPD patients without cardiac comorbidity and 25 healthy subjects were recruited. Clinical evaluation, baseline function tests, computed tomography and echocardiography were conducted in all subjects. Patients performed consecutive incremental exercise tests with measurement of operating lung volumes and non-invasive measurement of SV, CO and oxygen uptake (VO₂) by an inert gas rebreathing method. Biomarkers of systemic inflammation and oxidative stress, tissue damage/repair, cardiac involvement and airway inflammation were measured.

RESULTS

COPD patients showed a lower SV/VO₂ slope than control subjects, while CO response was compensated by a higher heart rate increase. COPD patients with DH experienced a reduction of SV/VO₂ and CO/VO₂ compared to those without DH. In COPD patients, the end-expiratory lung volume (EELV) increase was related to SV/VO₂ and CO/VO₂ slopes, and it was the only independent predictor of cardiac response to exercise. However, in the regression models without EELV, plasma IL-1β and high-sensitivity cardiac troponin T were also retained as independent predictors of SV/VO₂ slope.

CONCLUSION

Dynamic hyperinflation decreases the cardiac response to exercise of COPD patients. This effect is related to systemic inflammation and myocardial stress but not with left ventricle diastolic dysfunction.

Association between frailty index, lung function, and major clinical determinants in chronic obstructive pulmonary disease

BACKGROUND

Airflow limitation alone is unable to capture the complexity of chronic obstructive pulmonary disease (COPD), better explained by comprehensive disease-specific indexes. Frailty is a clinical condition characterized by high vulnerability to internal and external stressors and represents a strong predictor of adverse outcomes.

AIMS

Primary objective was to test the association between indexes of lung function and COPD severity with frailty index (FI), and secondary to evaluate the association between FI and comorbidities, cognitive and physical function, BODE index, and mortality.

METHODS

150 stable COPD outpatients were enrolled and followed up to 4 years. At baseline, participants performed a geriatric multidimensional assessment, pulmonary function tests, arterial blood gas analysis, 6-min walking test, and bioimpedance analysis. BODE and FI were calculated. Spearman's ρ was used to assess correlations. Mortality was assessed using Kaplan-Meier curves.

RESULTS

Participants were followed up for a median of 39 months. Mean age was 73 years and median frailty index 0.15 (IQR 0.11-0.19). FI was higher in frequent exacerbators (≥ 2/year) (mean 0.18 vs 0.15, p 0.01) and dyspnoeic patients (mMRC ≥ 2) (mean 0.21 vs 0.14, p < 0.01) and correlated with lung volumes, expiratory flows, and pressure of arterial oxygen. FI was positively correlated with the number of comorbidities, depressive symptoms, cognitive decline, and BODE index. Mortality was higher in patients with BODE higher than 3 (HR 3.6, 95% CI 1.2-10.9), and not associated with FI.

DISCUSSION

FI positively correlates with all clinical drivers orienting the choice of treatment in COPD.

CONCLUSIONS

FI associates with lung function and COPD severity, but does not associate with mortality.

Respiratory and Perceptual Responses to High-Intensity Interval Exercise in Obese Adults

PURPOSE

Although high-intensity interval exercise (HIIE) has emerged as an attractive alternative to continuous exercise (CE), the effects of HIIE on ventilatory constraints and dyspnea on exertion have not been studied in obese adults, and thus, tolerability of HIIE in obese adults is unknown. The purpose of this study was to examine differences in respiratory and perceptual responses between HIIE and CE in nonobese and obese adults.

METHODS

Ten nonobese (5 men; 24.1 ± 6.2 yr; body mass index, 23.0 ± 1.3 kg·m-2) and 10 obese (5 men; 24.2 ± 3.8 yr; body mass index, 37 ± 4.6 kg·m-2) adults participated in this study. Respiratory and perceptual responses were assessed during HIIE (eight 30-s intervals at 80% maximal work rate, with 45-s recovery periods) and two 6-min sessions of CE, completed below and above ventilatory threshold (Vth).

RESULTS

Despite similar work rate, HIIE was completed at a higher relative intensity in obese when compared with nonobese participants (68.8% ± 9.4% vs 58.9% ± 5.6% maximal oxygen uptake, respectively; P = 0.01). Expiratory flow limitation and/or dynamic hyperinflation was present during HIIE in 50% of the obese but in none of the nonobese participants. Ratings of perceived breathlessness were highest during HIIE (5.3 ± 2.4), followed by CEaboveVth (2.5 ± 1.6), and CEbelowVth (0.9 ± 0.7; P < 0.05) in obese participants. Unpleasantness associated with breathlessness was higher in obese (4.2 ± 3.0) when compared with nonobese participants (0.6 ± 1.3; P = 0.005) during HIIE.

CONCLUSIONS

HIIE, when prescribed relative to maximal work rate, is associated with greater ventilatory constraints and dyspnea on exertion when compared with CE in obese adults. CE may be more tolerable when compared with HIIE for obese adults.

Patient Satisfaction and Attainment of Patient-Specific Goals after Endobronchial Valve Treatment

Rationale: Bronchoscopic lung volume reduction with endobronchial valves (EBVs) significantly improves clinical outcomes in patients with severe emphysema. However, patient-reported outcomes like patient satisfaction and patient-specific treatment goals were never investigated.Objectives: To investigate the patient-satisfaction level 1 year after treatment and patient-specific goals before and 1 year after EBV treatment. Furthermore, the study aimed to investigate whether the level of patient satisfaction or change in goals was associated with change in the clinical outcome.Methods: We prospectively included patients who underwent EBV treatment as part of regular care in our hospital and asked patients to report and score their personal treatment goals on the patient-specific complaint (PSC) questionnaire at baseline and after 1 year of follow-up and to complete a patient-satisfaction questionnaire at 1 year of follow-up.Results: Of the 134 patients who were treated with EBV, 109 filled out the patient-satisfaction questionnaire and 88 filled out the PSC questionnaire at baseline and 1 year after treatment. When adjusting for the patients who were lost to follow-up, 91% of the patients in total would recommend the EBV treatment to other patients. Seventy-five percent of the patients were (very) satisfied with the treatment and 11% were (very) unsatisfied. The three most frequently reported patient-specific goals to improve were walking (reported by 77% of the patients), taking a shower/washing/getting dressed (35%), and completing household chores (32%). Both the total PSC questionnaire sum score (mean change, -6.01 ± 6.0) and all individual reported goals significantly improved 1 year after treatment (P < 0.001). Furthermore, a higher patient-satisfaction level and larger improvement in goals was significantly associated with an improvement in forced expiratory volume in 1 second, residual volume, dyspnea severity, and quality of life.Conclusions: We found that the patient-satisfaction level is high and patient-specific goals significantly improve 1 year after EBV treatment. We believe that the individual patient's goals are important in the process of shared decision-making before treatment, as they can be used to identify unrealistic expectations beforehand and prevent disappointment afterward.Clinical trial registered at clinicaltrials.gov (NCT02815683).

Electronic Health Records and Pulmonary Function Data: Developing an Interoperability Roadmap. An Official American Thoracic Society Workshop Report

A workshop "Electronic Health Records and Pulmonary Function Data: Developing an Interoperability Roadmap" was held at the American Thoracic Society 2019 International Conference. "Interoperability" is defined as is the ability of different information-technology systems and software applications to directly communicate, exchange data, and use the information that has been exchanged. At present, pulmonary function test (PFT) equipment is not required to be interoperable with other clinical data systems, including electronic health records (EHRs). For this workshop, we assembled a diverse group of experts and stakeholders, including representatives from patient-advocacy groups, adult and pediatric general and pulmonary medicine, informatics, government and healthcare organizations, pulmonary function laboratories, and EHR and PFT equipment and software companies. The participants were tasked with two overarching Aobjectives: 1) identifying the key obstacles to achieving interoperability of PFT systems and the EHR and 2) recommending solutions to the identified obstacles. Successful interoperability of PFT data with the EHR impacts the full scope of individual patient health and clinical care, population health, and research. The existing EHR-PFT device platforms lack sufficient data standardization to promote interoperability. Cost is a major obstacle to PFT-EHR interoperability, and incentives are insufficient to justify the needed investment. The current vendor-EHR system lacks sufficient flexibility, thereby impeding interoperability. To advance the goal of achieving interoperability, next steps include identifying and standardizing priority PFT data elements. To increase the motivation of stakeholders to invest in this effort, it is necessary to demonstrate the benefits of PFT interoperability across patient care and population health.

Neuropsychobiological Fingerprints of Chronic Fatigue in Sarcoidosis

Background

Chronic fatigue is a prominent symptom in many sarcoidosis patients, affecting quality of life and interfering with treatment. This study investigated neuropsychobiological mechanisms and markers of chronic fatigue in sarcoidosis.

Methods

Thirty patients with a histological diagnosis of sarcoidosis were included. The Multidimensional Fatigue Inventory was used to define patients with and without chronic fatigue. All patients were then characterised using several depression, quality of life questionnaires, and executive functioning. Cognitive functioning and underlying neural correlates were assessed using an n-back task measuring working memory and (sustained) attention during functional magnetic resonance imaging. Sarcoidosis disease activity was determined using lung function, laboratory parameters, and exercise capacity.

Results

Nineteen patients had chronic fatigue and 11 did not; both groups had similar demographic and disease activity characteristics. Chronic fatigue patients showed more symptoms of depression and anxiety, and lower quality of life. During the n-back task, chronic fatigue was associated with a smaller increase in brain activation with increasing task difficulty versus the group without fatigue, especially in the angular gyrus.

Conclusion

Inadequate adjustment of brain activation with increasing demands appears to be a potential neurobiological marker of chronic fatigue in sarcoidosis patients. The angular gyrus, which plays an important role in the working memory system, was the major area in which fatigue patients showed smaller increase of brain activation compared to those without fatigue. These findings might be relevant for a deeper understanding of chronic fatigue mechanisms in sarcoidosis and future clinical treatment of this disabling syndrome.

Trial Registration

ClinicalTrials.gov, Trial registration number: NCT04178239

Date of registration: November 26, 2019, retrospectively registered

URL: https://clinicaltrials.gov/ct2/show/NCT04178239.

Lung physiology and controlled exposure study design

Controlled human inhalation exposure ( CHIE) studies provide a unique opportunity to conduct formal experiments to examine the human health effects of airborne pollutants. Lung function, easily measured using spirometry, is a common physiological variable often utilized in these studies. By design, CHIE studies only induce mild and reversible acute effects, which may or may not predict adverse effects that may develop under chronic exposure conditions. There is substantial inter- and intra-individual variability in functional capacity and symptoms such as chest tightness and dyspnea, which are complex variables that are affected by individual perception, physiological lung impairment, and other variables (e.g., concomitant health conditions, and level of conditioning/fitness). Thus, the design of the CHIE study and physiological and environmental factors of study participants can affect each CHIE study's results. Researchers can address many of these critical issues in the problem formulation phase of CHIE studies, utilizing existing information on the expected effects of the substance of interest and possible modes of action. Thoughtful design and interpretation of CHIE studies will increase their utility for evaluating and setting environmental health policy.