Quantitative imaging methods in combined pulmonary fibrosis and emphysema.

TOPIC IMPORTANCE: Combined pulmonary fibrosis and emphysema (CPFE) is an underdiagnosed syndrome in which individuals have variable degrees of pulmonary fibrosis and emphysema. Patients with CPFE have high morbidity, including poor exercise tolerance and increased development of co-morbidities. CPFE mortality also appears to outpace lone emphysema and pulmonary fibrosis. A major limitation to rigorous, large-scale studies of CPFE has been the lack of a precise definition for this syndrome. A 2022 ATS/ERJ/JRS/ALAT Research Statement called attention to fundamental gaps in our understanding of CPFE and highlighted the potential use of quantitative imaging techniques to better define CPFE. REVIEW FINDINGS: Broadly, CPFE has been defined using visual interpretation of chest computed tomography (CT) documenting the presence of both emphysema and fibrosis, with varying distributions. When quantitative approaches were employed, varying thresholds of emphysema and fibrosis on imaging have been used across different studies. SUMMARY: This review is structured into three primary themes, starting with early imaging studies, then evaluating the use of quantitative methods and imaging-based thresholds both in large population studies and single center cohorts to define CPFE and assess patient outcomes, and concludes by discussing current challenges and how to focus our efforts so quantitative imaging methods can effectively address the most pressing clinical dilemmas in CPFE.

Anesthetic management of a case of a lip mass with paraseptal emphysema and multiple bilateral giant bullae for surgical resection under mental nerve block.

Anesthesia in patients with emphysematous giant bulla undergoing non-thoracic surgery is challenging and can cause serious complications. We report a successful case of lip mass resection in a 65-year-old male with paraseptal emphysema and giant bullae under regional anesthesia using a mental nerve block. The patient presented with a slow-growing ulcerative mass on his lower lip and had a history of non-compliant COPD management. An excisional biopsy was planned. Preoperative workup revealed extensive lung pathology with giant bullae. General anesthesia with positive pressure ventilation in patients with emphysematous giant bullae can cause compression of lung parenchyma, vena cava kinking, circulatory collapse, and even death. To circumvent such risks, regional anesthesia was preferred and surgery was successfully done under ultrasound-guided bilateral mental nerve block. The procedure was uneventful, with stable hemodynamics throughout.

Pneumomastia following subdermal upper arm helium contouring treatment.

A case is presented of extensive pneumomastia seen on a screening mammogram of an asymptomatic patient who had helium plasma treatment 2 weeks earlier for flabby upper arms. Contribution: Rare complications of subcutaneous emphysema, following helium plasma treatment, have been discussed to highlight that such emphysema is usually self-limiting.

Occlusive Tight Strapping for Tracheostomy Decannulation; Is it Safe?

Decannulation following tracheostomy is an important transition. Subcutaneous emphysema (SE) following decannulation has been rarely reported. We, herein, report a case of massive subcutaneous emphysema following decannulation of a short-term tracheostomy, discuss the various decannulation methods and causes of SE. We report and hypothesize the tight occlusive dressing method for tracheostomy decannulation to be the possible cause of SE in the present case.

The Use of Bronchial Rheoplasty in Emphysema Patients Previously Treated with Endoscopic Lung Volume Reduction: A Case Series.

Endoscopic lung volume reduction (ELVR) is an established treatment option for patients with severe emphysema. Not all patients are candidates for this type of intervention, and in the context of significant airway secretions, they may be excluded from treatment. Bronchial Rheoplasty (BR) was developed to treat mucus hypersecretion by delivering nonthermal pulsed electric fields to the airway epithelium and submucosa. The literature to date demonstrates that patients treated with BR in clinical studies have a reduction in airway goblet cell hyperplasia as well as substantive clinical improvement in the setting of chronic bronchitis (CB). In this case series, we present four patients treated at three different institutions who had previously undergone ELVR with beneficial outcome. However, over time, these patients subsequently developed worsening clinical issues, including complaints of increased and thickened mucus, along with exacerbations in the setting of a loss of some ELVR-associated benefits. These patients then underwent exploratory treatment with BR with the intent of reducing their secretion burden and potentially restoring the efficacy associated with the initial placement of the airway valves. All BR procedures were well tolerated, and three of the four patients showed substantial improvement in their symptom burden. Airway examinations during the second of the two BR procedures also revealed what appeared to be less airway mucosal inflammation and a decrease in the quantity of airway secretions. Therefore, treatment with BR may have the potential to improve and restore the initial benefits associated with ELVR, thus enhancing long-term outcomes. Further clinical studies with sufficient follow-up are warranted to assess this in a larger cohort of patients, and to determine whether treatment with BR prior to ELVR may make more patients eligible for this treatment through reduction in their secretions and/or symptoms.

A Multicenter Study of COPD and Cognitive Impairment: Unraveling the Interplay of Quantitative CT, Lung Function, HIF-1α, and Clinical Variables.

Purpose: The exact link between cognitive impairment (CI) and chronic obstructive pulmonary disease (COPD) is still limited. Thus, we aim to find the relationship and interaction of quantitative CT (QCT), lung function, HIF-1α, and clinical factors with the development of CI among COPD patients. Patients and Methods: A cross-sectional multicentre study was conducted from January 2022 to December 2023. We collected clinical data, spirometry, CT images, and venous blood samples from 114 COPD participants. Cognitive impairment assessment using the Montreal Cognitive Assessment Indonesian version (MoCA-Ina) with a cutoff value 26. The QCT analysis consists of lung density, airway wall thickness, pulmonary artery-to-aorta ratio (PA:A), and pectoralis muscles using 3D Slicer software. Serum HIF-1α analysis was performed using ELISA. Results: We found significant differences between %LAA-950, age, COPD duration, BMI, FEV1 pp, and FEV1/FVC among GOLD grades I-IV. Only education duration was found to correlate with CI (r = 0.40; p < 0.001). We found no significant difference in HIF-1α among GOLD grades (p = 0.149) and no correlation between HIF-1α and CI (p = 0.105). From multiple linear regression, we observed that the MoCA-Ina score was influenced mainly by %LAA-950 (p = 0.02) and education duration (p = 0.01). The path analysis model showed both %LAA and education duration directly and indirectly through FEV1 pp contributing to CI. Conclusion: We conclude that the utilization of QCT parameters is beneficial as it can identify abnormalities and contribute to the development of CI, indicating its potential utility in clinical decision-making. The MoCA-Ina score in COPD is mainly affected by %LAA-950 and education duration. Contrary to expectations, this study concludes that HIF-1α does not affect CI among COPD patients.

Efficacy and safety of simultaneous combined Zephyr and Spiration valve therapy in patients with advanced pulmonary emphysema.

BACKGROUND: Endoscopic lung volume reduction with valves is a minimally invasive treatment strategy for patients with severe pulmonary emphysema. Two valve systems are currently available: Zephyr and Spiration valves. As these can be implanted simultaneously in the same procedure, the question arose as to the effect on lung function, exercise capacity and subjective disease perception after combined valve treatment. METHODS: We conducted a retrospective analysis of 108 patients with combined, simultaneous treatment of Zephyr and Spiration valves. The decision on which and how many valves to implant was based on the individual patient anatomy. Effects on lung function, exercise capacity and atelectasis formation as well as complications were evaluated 90- and 180-days post-treatment (90d-FU and 180d-FU). RESULTS: At 90d-FU (n=90), the mean change was 86.7±183.7mL for FEV1 and -645.3±1276.5mL for RV, with responder rates of 39.8% and 46.5%, respectively. Complete atelectasis occurred in 16.7% and partial atelectasis in 25.5% of patients. Six-minute walking distance increased by 27.00 m [-1.50 - 68.50m]. The rates of pneumothorax (10.2%) 6 months after treatment were not higher than in randomized controlled trials (RCTs). Likely due to the inclusion of high-risk patients, there was a higher incidence of severe COPD exacerbation (21.3%) and pneumonia (12.0%) compared to RCTs. CONCLUSIONS: The combined implantation of Zephyr and Spiration valves resulted in significant clinical and functional improvements with an acceptable risk profile. Therefore, the ability to combine both valve types in severe emphysema could be a promising option in endoscopic lung volume reduction.

Effect of decreased expression of latent TGF-ß binding proteins 4 on the pathogenesis of emphysema as an age-related disease.

PURPOSE: Latent TGF-ß binding protein 4 (LTBP4) is involved in the production of elastin fibers and has been implicated in LTBP4-related cutis laxa and its complication, emphysema-like changes. Various factors have been implicated in the pathogenesis of emphysema, including elastic degeneration, inflammation, cellular senescence, mitochondrial dysfunction, and decreased angiogenesis in the lungs. We investigated the association between LTBP4 and emphysema using human lung fibroblasts with silenced LTBP4 genes. METHODS: Cell contraction, elastin expression, cellular senescence, inflammation, anti-inflammatory factors, and mitochondrial function were compared between the LTBP4 small interfering RNA (siRNA) and control siRNA. RESULTS: Under the suppression of LTBP4, significant changes were observed in the following: decreased cell contractility, decreased elastin expression, increased expression of the p16 gene involved in cellular senescence, increased TNFα, decreased GSTM3 and SOD, decreased mitochondrial membrane potential, and decreased VEGF expression. Furthermore, the decreased cell contractility and increased GSTM3 expression observed under LTBP4 suppression were restored by the addition of N-acetyl-L-cysteine or recombinant LTBP4. CONCLUSION: The decreased elastin expression, cellular senescence, inflammation, decreased antioxidant activity, mitochondrial dysfunction, and decreased VEGF expression under reduced LTBP4 expression may all be involved in the destruction of the alveolar wall in emphysema. Smoking is the most common cause of emphysema; however, genetic factors related to LTBP4 expression and other factors may also contribute to its pathogenesis.

Causal inference analysis of the radiologic progression in the chronic obstructive pulmonary disease.

There is limited evidence regarding the causal inference of emphysema and functional small airway disease in the subsequent progression of chronic obstructive pulmonary disease (COPD). Patients consisting of two independent cohorts diagnosed with COPD and underwent two serial chest CT scans were included. Total percent emphysema (PRMEmph) and fSAD (PRMfSAD) was quantified via PRM. To investigate the progression of emphysema, we divided COPD patients with PRMEmph < 10% into low and high PRMfSADgroup, matched with similar baseline characteristics, and conducted nonparametric hypothesis tests based on randomization inference using Wilcoxon signed rank test and Huber's M statistics. In patients with baseline PRMEmph < 10%, there were 26 and 16 patients in the low PRMfSA group and 52 and 64 patients in the high PRMfSA in the derivation and validation cohorts, respectively. In the both low and high PRMfSAD groups, there were 0.11 and 1.43 percentage point increases (Huber's M statistic p = 0.016) and 0.58 and 2.09 percentage point increases (p = 0.038) in the proportion of emphysema in the derivation and validation cohorts, respectively. On the contrary, among patients with baseline PRMfSAD < 20%, there was no significant differences in the interval changes of PRMfSAD between the low and high PRMEmph groups in both cohorts. In COPD patients with low emphysema, group with baseline high PRMfSAD showed greater change of PRMEmph than those with low PRMfSAD in both the derivation and validation cohorts. Imaging-based longitudinal quantitative analysis may provide important evidence that small airway disease precedes emphysema in CT-based early COPD patients.

Efficacy and safety of bronchoscopic lung volume reduction for chronic obstructive pulmonary disease: a systematic review and network meta-analysis.

BACKGROUND: Various bronchoscopic lung volume reduction (BLVR) methods have been developed to treat chronic obstructive pulmonary disease (COPD). The efficacy and safety of these interventions remain unclear. This study assessed the efficacy and safety of various BLVR interventions in COPD patients. METHODS: PubMed and Embase were searched from inception to 21 October 2023. The primary outcomes assessed included the 6-min walking distance (6MWD), St. George Respiratory Questionnaire (SGRQ) score, lung function, and adverse events (AE). A frequentist approach with a random-effects model was used for a network meta-analysis. RESULTS: Twelve randomized controlled trials (RCTs) with 1646 patients were included in this meta-analysis. Patients treated with an endobronchial valve (EBV) achieved a minimum clinically important difference (MCID) in 6MWD and SGRQ at 6 months. Patients treated with coils achieved MCID in the SGRQ score at 12 months. Patients with aspiration valve system and bronchoscopic thermal vapor ablation (BTVA) achieved MCID in the SGRQ score at 6 months. CONCLUSIONS: In COPD patients, EBV should be considered first, while being wary of pneumothorax. Coil and BTVA are potential therapeutic alternatives. Although BTVA demonstrates a safer procedural profile than coils, additional studies are imperative to clarify its efficacy.

Improved diagnostic yield of peripheral pulmonary malignant lesions with emphysema using a combination of radial endobronchial ultrasonography and rapid on-site evaluation.

BACKGROUND: This is a retrospective cohort study from a single center of Chest Medical District of Nanjing Brain Hospital Affiliated to Nanjing Medical University, Jiangsu Province, China. It was aim to evaluate the diagnostic value of radial endobronchial ultrasound (R-EBUS) combination with rapid on-site evaluation (ROSE) guided transbronchial lung biopsy (TBLB) for peripheral pulmonary lesions in patients with emphysema. METHODS: All 170 patients who underwent PPLs with emphysema received an R-EBUS examination with or without the ROSE procedure, and the diagnostic yield, safety, and possible factors influencing diagnosis were analyzed between the two groups by the SPSS 25.0 software. RESULTS: The pooled and benign diagnostic yields were not different in the two groups (P = 0.224, 0.924), but the diagnostic yield of malignant PPLs was significantly higher in the group with ROSE than the group without ROSE (P = 0.042). The sensitivity of ROSE was 79.10%, the specificity, 91.67%, the positive predictive value, 98.15%, and the negative predictive value, 84.62%. The diagnostic accuracy, was 95.52%. In the group of R-EBUS + ROSE, the procedural time and the number of times of biopsy or brushing were both significantly reduced (all P<0.05). The incidence of pneumothorax (1.20%) and bleeding (10.84%) in the group of R-EBUS + ROSE were also less than those in the group of R-EBUS (P<0.05). The lesion's diameter ≥ 2 cm, the distance between the pleura and the lesion ≥ 2 cm, the positive air bronchograms sign, the location of the ultrasound probe within the lesion, and the even echo with clear margin feature of lesion ultrasonic image, these factors are possibly relevant to a higher diagnostic yield. The diagnostic yield of PPLs those were adjacent to emphysema were lower than those PPLs which were away from emphysema (P = 0.048) in the group without ROSE, however, in the group of R-EBUS + ROSE, there was no such difference whether the lesion is adjacent to emphysema or not (P = 0.236). CONCLUSION: Our study found that the combination of R-EBUS and ROSE during bronchoscopy procedure was a safe and effective modality to improve diagnostic yield of PPLs with emphysema, especially for malignant PPLs. The distance between the pleura and the lesion ≥ 2 cm, the positive air bronchograms sign, the location of the ultrasound probe within the lesion, and the even echo with clear margin feature of lesion ultrasonic image, these factors possibly indicated a higher diagnostic yield. Those lesions' position is adjacent to emphysema may reduce diagnostic yield but ROSE may make up for this deficiency.

A rare AAT variant presenting in a COPD patient: Q0 amersfoort mutation.

Introduction: Alpha-1 antitrypsin (AAT) deficiency, characterized by reduced synthesis of a serine protease inhibitor in liver cells, has been recognized to contribute to the development of emphysema and liver disease. Additional clinical manifestations encompassing respiratory disorders and dermatological issues have also been documented. Case: A 56-year-old male patient presented with dyspnea. Despite being a non-smoker, he had a diagnosis of chronic obstructive pulmonary disease (COPD) five years ago. Utilizing inhaled corticosteroids (ICSs) - long-acting ß2-agonists (LABAs)- long-acting muscarinic antagonists (LAMAs) inhalers, the patient's medical treatment had ceased for the past four months due to inhaler depletion. High-resolution thoracic computed tomography unveiled bilateral emphysematous regions, predominantly located in the lower pulmonary lobes. In light of the absence of smoking history, the suspicion of AAT deficiency was raised, prompting the assessment of serum AAT levels. Subsequent analysis indicated diminished AAT levels, prompting the collection of a dried blood sample for genetic evaluation. Genomic DNA amplification was performed using polymerase chain reaction (PCR), succeeded by allele-specific hybridization via Luminex XMAP Technology. This analysis disclosed a Q0amersfoort (Exon 2 Y160TAC > Ter TAG) (+/+) variant linked with AAT deficiency, originating from a frame-shift mutation that triggers a null (Q0amersfoort) stop codon. Conclusion: The presentation of COPD-related emphysema in a non-smoker underscores the necessity to consider AAT deficiency in the differential diagnosis.

Anticancer Effects of Spiperone in C57BL/6 Mice with Emphysema and Lung Carcinoma.

The antitumor and antimetastatic activity of dopamine D2 receptor antagonists spiperone was studied in C57BL/6 mice in a model of combined pathology (emphysema and lung cancer). Emphysema was induced by administration of LPS and cigarette smoke extract. Lung cancer was induced by injection of Lewis lung carcinoma cells into the lung. It has been shown that under conditions of combined lung pathology, spiperone prevents inflammatory infiltration and emphysematous expansion of the lungs and reduces the size of the primary tumor node, the number of metastases, and the area of the lungs affected by metastases. Spiperone reduces the number of cancer stem cells (CSCs) in the lungs and blood of mice with combined pathology. CSCs isolated from the lungs and blood of mice with combined pathology treated with spiperone had a significantly lower potential to form a tumorosphere in vitro than CSCs from untreated mice with emphysema and lung carcinoma. Thus, blockade of dopamine D2 receptors is a promising approach for correcting combined lung pathology and can be used in the development of a method for treating lung cancer in patients with emphysema.

Sex-biased Regulation of Extracellular Matrix Genes in COPD.

Compared to men, women often develop COPD at an earlier age with worse respiratory symptoms despite lower smoking exposure. However, most preventive, and therapeutic strategies ignore biological sex differences in COPD. Our goal was to better understand sex-specific gene regulatory processes in lung tissue and the molecular basis for sex differences in COPD onset and severity. We analyzed lung tissue gene expression and DNA methylation data from 747 individuals in the Lung Tissue Research Consortium (LTRC), and 85 individuals in an independent dataset. We identified sex differences in COPD-associated gene regulation using gene regulatory networks. We used linear regression to test for sex-biased associations of methylation with lung function, emphysema, smoking, and age. Analyzing gene regulatory networks in the control group, we identified that genes involved in the extracellular matrix (ECM) have higher transcriptional factor targeting in females than in males. However, this pattern is reversed in COPD, with males showing stronger regulatory targeting of ECM-related genes than females. Smoking exposure, age, lung function, and emphysema were all associated with sex-specific differential methylation of ECM-related genes. We identified sex-based gene regulatory patterns of ECM-related genes associated with lung function and emphysema. Multiple factors including epigenetics, smoking, aging, and cell heterogeneity influence sex-specific gene regulation in COPD. Our findings underscore the importance of considering sex as a key factor in disease susceptibility and severity.

Successful Bronchoscopic Lung Volume Reduction with New Lung Tensioning Device Coil: A Case Report.

INTRODUCTION: Bronchoscopic lung volume reduction (BLVR) using endobronchial coil treatment is a widely studied therapeutic option in patients with end-stage chronic obstructive pulmonary disease (COPD) and pulmonary emphysema. However, patient responses were inconsistent, and, from 2020, production discontinuation rendered the treatment unavailable. In the meantime, a next-generation lung tensioning coil (FreeFlow Coil 4; FreeFlow Medical, Inc., Fremont, CA, USA) has been developed by the inventor of the lung volume reduction coil implant technology. This case study presents the first documented successful BLVR using FreeFlow Coils 4. CASE PRESENTATION: A 68-year-old male patient with COPD, classified as Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage 3, and homogenous emphysema with incomplete interlobar fissures was treated using the new developed FreeFlow Coil 4 in both upper lobes. Apart from a suspected coil-associated opacity, no adverse events occurred. At the 18-week follow-up, a significant improvement in lung function and quality of life was observed, as measured by forced expiratory volume in 1 s (+150 mL), residual volume (-0.50 L), 6-min walking distance (+75 m), and the total score of the St. George's Respiratory Questionnaire (SGRQ) (-35 points). CONCLUSION: BLVR with FreeFlow Coils 4 has shown promising outcomes, significantly improving both pulmonary function and quality of life in 1 patient. However, larger studies and randomized controlled trials are imperative to investigate the efficacy and safety profile of the new coil system.

COPD is associated with increased cardiovascular disease risk independent of phenotype.

BACKGROUND AND OBJECTIVE: Chronic obstructive pulmonary disease (COPD) is a leading cause of death worldwide that frequently presents with concomitant cardiovascular diseases. Despite the pathological distinction between individual COPD phenotypes such as emphysema and chronic bronchitis, there is a lack of knowledge about the impact of COPD phenotype on cardiovascular disease risk. Thus, this study aimed to utilize a nationally representative sample to investigate cardiovascular disease prevalence in patients with COPD with emphysema and chronic bronchitis phenotypes. METHODS: Data from 31,560 adults including 2504 individuals with COPD, collected as part of the National Health and Nutrition Examination Survey (1999-2018), were examined. RESULTS: A significantly increased cardiovascular disease risk, including coronary heart disease, heart failure, myocardial infarction and stroke, was identified in patients with COPD among all disease phenotypes. Particularly, compared to those without COPD, individuals with chronic bronchitis presented with 1.76 (95% CI: 1.41-2.20) times greater odds, individuals with emphysema with 2.31 (95% CI: 1.80-2.96) times greater odds, while those with a concurrent phenotype (combined chronic bronchitis and emphysema) exhibited 2.98 (95% CI: 2.11-4.21) times greater odds of reporting cardiovascular diseases. CONCLUSION: Our data confirms that patients with COPD present an elevated risk of developing cardiovascular disease among all phenotypes, with the most marked increase being in those with concurrent chronic bronchitis and emphysema phenotypes. These findings emphasize the need for awareness and appropriate cardiovascular screening in COPD.

Association of the Healthy Dietary Index 2020 and its components with chronic respiratory disease among U.S. adults.

Background: Chronic respiratory disease is an important public health problem in the United States and globally. Diet, an important part of a healthy lifestyle, is also relevant to chronic respiratory health. We aimed to explore the relationship between overall dietary quality and the risk of chronic respiratory disease (CRD), include chronic bronchitis (CB), emphysema and asthma. Method: A total of 4,499 United States adults were extracted from the National Health and Nutrition Examination Survey (NHANES) in 2017-2018. Diet quality was assessed using 2 day, 24 h dietary recall data and quantified as the Healthy Diet Index (HEI)-2020 score. Binary logistic regression models, restricted cubic splines (RCS) and generalized additive modeling (GAM), the weighted quartile sum (WQS) and qgcom models were used to assess the relationship between HEI-2020 scores and risk of CB, emphysema and asthma. Results: High HEI-2020 scores are associated with low risk of chronic respiratory disease (CB: 0.98, 0.97-0.99; emphysema: 0.98, 0.97-0.99; asthma: 0.98, 0.97-0.99) and consistent results across different dietary variable categorization (Tertile: CB: 0.58, 0.42-0.81; asthma: 0.51, 0.35-0.74; Quartile: CB: 0.57, 0.34-0.97; asthma: 0.56, 0.36-0.86) and different weighting models. Negative dose-response relationship between dietary quality and risk of chronic respiratory disease also shown in RCS and GAM models. The WQS and qgcom models also showed a healthy mixing effect of dietary components on respiratory disease, with high-quality proteins, vegetables, and fruits making the heaviest contributions. Conclusion: Higher HEI-2020 scores were associated with lower risk of CB, emphysema, and asthma. Following Dietary Guidelines for Americans 2020-2025 could support enhanced respiratory health.

Computed tomography (CT) quantitative assessment of single lobe emphysema correlates with chronic obstructive pulmonary disease (COPD) severity: a cross-sectional study with retrospective data collection.

Background: In the past, many researchers have studied the correlation between quantitative parameters of computed tomography (CT) and parameters of pulmonary function test (PFT) in patients with chronic obstructive pulmonary disease (COPD) with good results. Most of these studies have focused on the whole-lung level. In this study, we analyzed the biphasic CT lung volume parameters and the percentage of emphysema volume in different lobes of the lungs of patients with different grades of COPD and assessed their relationship with different lung function indices. Methods: We retrospectively collected patients who underwent PFTs at The First Affiliated Hospital of Guangzhou Medical University from 1 July 2019 to 27 January 2020, and underwent chest respiratory dual-phase CT scans within 1 week, including 112 non-COPD patients and 297 COPD patients. We quantified the biphasic CT lung volume parameters and the percentage of emphysema volume in different lobes using a pulmonary image analysis tool. One-way analysis of variance (ANOVA) and Kruskal-Wallis H method were used to compare the quantitative CT parameters of each lung lobe in different groups. The correlation between quantitative CT parameters of different lung lobes and lung function indices was assessed using multiple linear regression. Results: Among the 3 biphasic CT lung volume parameters, only volume change/inspiratory lung volume (∆LV/LVin) in the non-COPD control, mildly to moderately severe, and severe to extremely severe groups had statistical differences in each lobe level (all P<0.05). Correlation was significant between LVin and different lung function indices and between low attenuation areas percent below the threshold of -950 in the inspiratory phase [low attenuation area below -950 in the inspiratory phase (%LAA-950in)] and lung function indices in the left lower lobe (all P<0.05). There was statistically significant correlation between expiratory lung volume and ∆LV/LVin and lung function indices in the right lower lung (all P≤0.001). In the remaining lobes, LVin, expiratory lung volume, ∆LV/LVin, and %LAA-950in correlated with only some of the lung function indices. Conclusions: The percentage of emphysema volume did not differ between lobes in the non-COPD control and severe to extremely severe COPD populations. LVin and %LAA-950in in the left upper lobe, expiratory lung volume and ∆LV/LVin in the right lower lobe were more reflective of the changes in lung function indices of the patients, whereas the correlation of the 3 biphasic CT lung volume parameters and the percentage of emphysema volume in the upper lobes of both lungs and the right middle lung with lung function indices was unclear.

Investigation of Inspiratory Muscle Training Efficiency Before Bronchoscopic Lung Volume Reduction: A Randomized Controlled Trial.

INTRODUCTION: Pulmonary rehabilitation (PR) is recommended prior to bronchoscopic lung volume reduction (BLVR) procedures to optimize patient outcomes. However, there's a lack of clear guidance on PR content. The aim of our study is to examine the effect of adding inspiratory muscle training (IMT) to standard PR before BLVR on exercise capacity, dyspnea, fatigue level and quality of life. METHODS: Sixty-four patients were randomly assigned to either the PR Group (PRGr) or the PR with IMT group (IMTGr). Both groups underwent an 8-week standard PR program, including breathing exercises, muscle strengthening, and walking. Additionally, IMTGr received IMT sessions. Outcome measures comprised six-minute walking distance (6MWD), maximal inspiratory and expiratory pressures (MIP, MEP), peripheral muscle strength, modified Medical Research Council dyspnea score, fatigue symptom scale, spirometric parameters, Saint George Quality of Life Questionnaire (SGRQ), International Physical Activity Questionnaire Short Form (IPAQ-SF), and Hospital Anxiety and Depression Scale. RESULTS: Our study found no significant difference in exercise capacity improvement between IMTGr and PRGr. However, IMTGr showed significant improvement in MIP compared to PRGr. Both groups experienced improvements in dyspnea, fatigue, and depression scores, as well as enhancements in 6MWD, MEP, peripheral muscle strength, IPAQ-SF and SGRQ scores. CONCLUSION: Adding IMT to PR did not show a significant difference between groups among BLVR-eligible patients. However, improved respiratory muscle strength may have positive clinical implications. Further research is needed to explore short and long-term effects.