Lung Residual Volume Research Articles

Subclinical impairment of the left atrium is associated with MRI-based lung volume but not with parameters from pulmonary function testing

Left atrial (LA) physiology and hemodynamics are intimately connected to cardiac and lung function in health and disease. This study examined the relationship between MRI-based left atrial (LA) size and function with MRI-based lung volume and pulmonary function testing (PFT) parameters in the population-based KORA study cohort of 400 participants without overt cardiovascular disease. MRI quantification assessed LA size/function in sequences with and without ECG synchronization, alongside lung volume. Regression analysis explored the relationship of LA with MRI lung volume and PFT parameters. Among 378 participants (average age 56.3 ± 9.2 years; 42.3% women), non-gated LA size averaged 16.8 cm2, while maximal and minimal LA size from gated measurements were 19.6 cm2 and 11.9 cm2 respectively. The average MRI-derived lung volume was 4.0 L, with PFT showing a total lung capacity of 6.2 L, residual lung volume of 2.1 L, and forced vital capacity of 4.1 L. Multivariate regression analysis, adjusted for age, gender, and cardiovascular risk factors, revealed an inverse association between maximum LA size, non-gated LA, and LA area fraction with lung volume (ß = − 0.03, p = 0.006; ß = − 0.03, p = 0.021; ß = − 0.01, p = 0.012), with no significant association with PFT parameters. This suggests that MRI-based assessment may offer greater sensitivity in detecting subclinical LA impairment than PFT.

ASO Visual Abstract: Effect of Resected Lung Volume on Pulmonary Function and Residual Lung Volume in Patients Undergoing Segmentectomy-A Retrospective Study.

ASO Visual Abstract: Effect of Resected Lung Volume on Pulmonary Function and Residual Lung Volume in Patients Undergoing Segmentectomy-A Retrospective Study.

An analysis of residual lung volume changes after segmentectomy based on three-dimensional computed tomography.

Based on the results of JCOG0802 and CALGB studies, segmentectomy has considered to be a standard procedure for early-stage non-small cell lung cancer (NSCLC). After lobectomy, the residual cavity is filled with mediastinal and diaphragmatic deviations, and compensatory volume changes are present in the residual lungs. In this study, we examined the efficacy of segmentectomy, a surgical procedure, by focusing on its impact on postoperative lung volume and function. We enrolled 77 patients who underwent segmentectomy as their initial surgical procedure, excluding those with additional lung resections and those who lacked postoperative computed tomography imaging. The predicted residual volume (mL) was defined as the total lung volume before surgery minus the volume of the resected area. Using the predicted residual volume (mL) and postoperative total lung volume (mL), we calculated the rate of postoperative lung volume increase [(postoperative total lung volume/predicted residual volume) × 100] (%). We also classified 52 cases with a rate of postoperative lung volume increase of ≥100% into a compensatory group, while those with a rate of <100% were classified into a non-compensatory group. The average postoperative lung volume increase was 104.6% among 77 cases. Age ≥65 years, pack year index ≥27.5, ≥3 resected segments, and use of electrocautery for intersegmental plane division were significantly associated with compensatory group classification. In 20 compensatory cases with preoperative and postoperative pulmonary function tests, postoperative vital capacity and forced expiratory volume in one second values exceeded the preoperative predictions. This study further examined the areas responsible for postoperative compensatory lung volume increase. In the compensatory group, significant expansion was observed in the ipsilateral lobes, excluding the resected segment and contralateral lung, while no significant changes were noted in the volume of the lobe, including the resected segment. Conversely, the non-compensatory group showed a significant volume decrease in the resected lobe, but no significant increase in other areas. This study emphasizes the importance of preserving lung segments in segmentectomy. The study demonstrates extensive compensatory volume changes in the ipsilateral lung and contralateral lung. There was no significant volume decrease in any residual segment. This underlines the potential of segmentectomy to maintain lung function and expand treatment options post-surgery. In addition, the compensated group included patients with a lower pack-year index and younger patients. These results suggest that postoperative compensatory lung expansion includes not only hyperinflation of the remaining lung, but also an increase in the functional lung parenchyma.

Effect of Resected Lung Volume on Pulmonary Function and Residual Lung Volume in Patients Undergoing Segmentectomy: A Retrospective Study.

We elucidated the effects of planned resection volume on postoperative pulmonary function and changes in residual lung volume during segmentectomy. This study included patients who underwent thoracoscopic segmentectomy between January 2017 and December 2022 and met eligibility criteria. Pre- and post-resection spirometry and computed tomography were performed. Three-dimensional reconstructions were performed by using computed tomography images to calculate the volumes of the resected, remaining, and nonoperative side regions. Based on the resected region volume, patients were divided into the higher and lower volume segmentectomy groups. Changes in lung volume and pulmonary function before and after the surgery were comparatively analyzed. The median percentage of resected lung volume was 10.9%, forming the basis for categorizing patients into the two groups. Postoperative forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) ratios to preoperative measurements in both groups did not differ significantly (FEV1, p = 0.254; FVC, p = 0.777). Postoperative FEV1 and FVC ratios to their predicted postoperative values were significantly higher in the higher volume segmentectomy group than in the lower volume segmentectomy group (FEV1, p = 0003; FVC, p < 0.001). The higher volume segmentectomy group showed significantly greater post-to-preoperative lung volume ratio in overall, contralateral, ipsilateral, residual lobe and residual segment than the lower volume segmentectomy group. Postoperative respiratory function did not differ significantly between the higher- and lower-volume segmentectomy groups, indicating improved respiratory function because of substantial postoperative residual lung expansion. Our findings would aid in determining the extent of resection during segmentectomy.

Buckling forces and the wavy folds between pleural epithelial cells

Cell shapes in tissues are affected by the biophysical interaction between cells. Tissue forces can influence specific cell features such as cell geometry and cell surface area. Here, we examined the 2-dimensional shape, size, and perimeter of pleural epithelial cells at various lung volumes. We demonstrated a 1.53-fold increase in 2-dimensional cell surface area and a 1.43-fold increase in cell perimeter at total lung capacity compared to residual lung volume. Consistent with previous results, close inspection of the pleura demonstrated wavy folds between pleural epithelial cells at all lung volumes. To investigate a potential explanation for the wavy folds, we developed a physical simulacrum suggested by D'Arcy Thompson in On Growth and Form. The simulacrum suggested that the wavy folds were the result of redundant cell membranes unable to contract. To test this hypothesis, we developed a numerical simulation to evaluate the impact of an increase in 2-dimensional cell surface area and cell perimeter on the shape of the cell-cell interface. Our simulation demonstrated that an increase in cell perimeter, rather than an increase in 2-dimensional cell surface area, had the most direct impact on the presence of wavy folds. We conclude that wavy folds between pleural epithelial cells reflects buckling forces arising from the excess cell perimeter necessary to accommodate visceral organ expansion.

Effects of aging on the biomechanical properties of the lung extracellular matrix: dependence on tissular stretch.

Introduction: Aging induces functional and structural changes in the lung, characterized by a decline in elasticity and diminished pulmonary remodeling and regenerative capacity. Emerging evidence suggests that most biomechanical alterations in the lung result from changes in the composition of the lung extracellular matrix (ECM), potentially modulating the behavior of pulmonary cells and increasing the susceptibility to chronic lung diseases. Therefore, it is crucial to investigate the mechanical properties of the aged lung. This study aims to assess the mechanical alterations in the lung ECM due to aging at both residual (RV) and functional (FV) lung volumes and to evaluate their effects on the survival and proliferation of mesenchymal stromal cells (MSCs). Methods: The lungs from young (4-6-month-old) and aged (20-24-month-old) mice were inflated with optimal cutting temperature compound to reach FV or non-inflated (RV). ECM proteins laminin, collagen I and fibronectin were quantified by immunofluorescence and the mechanical properties of the decellularized lung sections were assessed using atomic force microscopy. To investigate whether changes in ECM composition by aging and/or mechanical properties at RV and FV volumes affects MSCs, their viability and proliferation were evaluated after 72h. Results: Laminin presence was significantly reduced in aged mice compared to young mice, while fibronectin and collagen I were significantly increased in aged mice. In RV conditions, the acellular lungs from aged mice were significantly softer than from young mice. By contrast, in FV conditions, the aged lung ECM becomes stiffer than that of in young mice, revealing that strain hardening significantly depends on aging. Results after MSCs recellularization showed similar viability and proliferation rate in all conditions. Discussion: This data strongly suggests that biomechanical measurements, especially in aging models, should be carried out in physiomimetic conditions rather than following the conventional non-inflated lung (RV) approach. The use of decellularized lung scaffolds from aged and/or other lung disease murine/human models at physiomimetic conditions will help to better understand the potential role of mechanotransduction on the susceptibility and progression of chronic lung diseases, lung regeneration and cancer.

Right main pulmonary artery distensibility on dynamic ventilation CT and its association with respiratory function

BackgroundHeartbeat-based cross-sectional area (CSA) changes in the right main pulmonary artery (MPA), which reflects its distensibility associated with pulmonary hypertension, can be measured using dynamic ventilation computed tomography (DVCT) in patients with and without chronic obstructive pulmonary disease (COPD) during respiratory dynamics. We investigated the relationship between MPA distensibility (MPAD) and respiratory function and how heartbeat-based CSA is related to spirometry, mean lung density (MLD), and patient characteristics.MethodsWe retrospectively analyzed DVCT performed preoperatively in 37 patients (20 female and 17 males) with lung cancer aged 70.6 ± 7.9 years (mean ± standard deviation), 18 with COPD and 19 without. MPA-CSA was separated into respiratory and heartbeat waves by discrete Fourier transformation. For the cardiac pulse-derived waves, CSA change (CSAC) and CSA change ratio (CSACR) were calculated separately during inhalation and exhalation. Spearman rank correlation was computed.ResultIn the group without COPD as well as all cases, CSACR exhalation was inversely correlated with percent residual lung volume (%RV) and RV/total lung capacity (r = -0.68, p = 0.003 and r = -0.58, p = 0.014). In contrast, in the group with COPD, CSAC inhalation was correlated with MLDmax and MLD change rate (MLDmax/MLDmin) (r = 0.54, p = 0.020 and r = 0.64, p = 0.004) as well as CSAC exhalation and CSACR exhalation.ConclusionIn patients with insufficient exhalation, right MPAD during exhalation was decreased. Also, in COPD patients with insufficient exhalation, right MPAD was reduced during inhalation as well as exhalation, which implied that exhalation impairment is a contributing factor to pulmonary hypertension complicated with COPD.Relevance statementAssessment of MPAD in different respiratory phases on DVCT has the potential to be utilized as a non-invasive assessment for pulmonary hypertension due to lung disease and/or hypoxia and elucidation of its pathogenesis.Key points• There are no previous studies analyzing all respiratory phases of right main pulmonary artery distensibility (MPAD).• Patients with exhalation impairment decreased their right MPAD.• Analysis of MPAD on dynamic ventilation computed tomography contributes to understanding the pathogenesis of pulmonary hypertension due to lung disease and/or hypoxia in patients with expiratory impairment.Graphical

Lung volume measurement using chest CT in COVID-19 patients: a cohort study in Japan

ObjectiveThis study aimed to investigate the utility of CT quantification of lung volume for predicting critical outcomes in COVID-19 patients.MethodsThis retrospective cohort study included 1200 hospitalised patients with COVID-19 from...

МЕТОДИ ДОСЛІДЖЕННЯ ФУНКЦІЇ ЗОВНІШНЬОГО ДИХАННЯ В ДІАГНОСТИЦІ ТА МОНІТОРИНГУ ХРОНІЧНОГО ОБСТРУКТИВНОГО ЗАХВОРЮВАННЯ ЛЕГЕНЬ (СПІРОМЕТРІЯ, БОДИПЛЕТИЗМОГРАФІЯ, DLCO) З УРАХУВАННЯМ ЗМІН ДО GOLD-2024

Pulmonary function testing (PFT) is an integral component in the diagnosis of broncho-obstructive diseases. Spirometry is a mandatory method of pulmonary research, and chronic obstructive pulmonary disease (COPD) is the only respiratory nosology, the diagnosis of which is based on a change in functional indicators, which are measured precisely with the help of spirometry. With the help of spirometry, only the obstructive type of PFT violations can be clearly determined. But one can also suspect restrictive and mixed (presence of both restrictions and obstruction) types. To diagnose these disorders, an indicator of Total Lung Capacity (TLC) is required, which cannot be determined by spirometry, as it consists of TLC and Residual Lung Volume (RES), which is also not determined by spirometry. More complex and less widespread methods of investigation can determine these missing indicators: bodyplethysmography — it is a method of a wider study of lung volumes and capacities and makes it possible to measure general and specific bronchial resistance (Rtot, sRaw). It is not an indispensable condition for confirming obstructive disorders, but it can be useful for identifying underlying diseases and their functional consequences — an increase in TLC, RV or RV/TLC above the upper limit of normal variability allows to suspect the presence of emphysema, severe bronchial asthma, and also to assess the severity hyperinflation. Another important study for a more complete assessment of PFT — diffusion capacity of the lungs for carbon monoxide (DLCO); performed after forced spirometry (determination of FVC, VC) or bodyplethysmography (VC) and determination of the structure of static volumes. It is used in patients with restrictive and obstructive diseases, for the diagnosis of emphysema or pulmonary fibrosis. With the help of this study, the diffusion capacity of the lungs (DLCO) and the alveolar volume (Va) are determined. The article presents the results of research in which these methods were used and provides justification for their application. Conclusion. Different methods of PFT are important and complement each other in clinical practice Key words: chronic obstructive pulmonary disease, diagnosis, spirometry, bodyplethysmography, diffusion capacity of the lungs, Global initiative chronic obstructive pulmonary disease (GOLD).

EP07.02-05 A Three-Dimensional Computed Tomography Analysis of Residual Lung Volume Changes after Segmentectomy for Non-small-Cell Lung Cancer

EP07.02-05 A Three-Dimensional Computed Tomography Analysis of Residual Lung Volume Changes after Segmentectomy for Non-small-Cell Lung Cancer

Preservation vs. dissection of inferior pulmonary ligament for thoracoscopic upper lobectomy: a prospective randomized controlled trial

ObjectivesThe proper procedure for inferior pulmonary ligament (IPL) during upper lobectomy remains a topic of debate. To address this matter, we carried out a trial comparing the clinical outcomes of IPL preservation versus IPL dissection during thoracoscopic upper lobectomy (TUL).MethodsPatients undergoing thoracoscopic left/right upper lobectomy (TLUL/TRUL) were assigned to either the dissection group (Group D) or the preservation group (Group P). Our primary objective was to quantify and compare the alterations in postoperative residual bronchial angle and lung volume changes between the two groups. Our secondary objective encompassed the assessment of various other intraoperative and postoperative outcomes.ResultsFollowing adherence to the inclusion and exclusion criteria, we enrolled 100 patients (41 left and 59 right) in Group P and 108 patients (41 left and 67 right) in Group D for the study. Our findings revealed that in TLUL, Group P was able to reduce the degree of postoperative residual bronchial angle change (P < 0.05). Conversely, the situation was distinct for TRUL. We found no notable disparity between the two groups (P > 0.05) with regard to alterations in lung volume or the occurrence of postoperative complications—except for the duration of postoperative hospital stay (P < 0.05).ConclusionsOur study suggests IPL preservation especially for TLUL when compared to TRUL, which have important implications for the clinical management of patients undergoing upper lobectomy.

Arterial blood gases' analysis in elite breath-hold divers at extreme depths.

To showcase results of arterial blood gases' analysis in elite breath-hold divers sampled at depths where their total lung capacities are below their residual lung volume on surface. Three male elite breath-hold divers performed body plethysmographies to determine their lung volumes. Two dives were performed, one on normal inhalation to 60m of depth and the second on complete exhalation to 10m of depth. Blood samples were taken on five occasions; before the first dive, at 60 and 10m of depth and immediately after resurfacing after both dives. Arterial blood gases' analysis at 60m of depth showed an increase in partial pressures of oxygen and carbon dioxide, a consequent decrease in pH and an increase in concentration of HCO3-. After resurfacing, in two divers, values mostly returned to normal; hypoxemia was observed in one diver. At 10m of depth, all values showed similar variation, and hypoxemia was observed in the same diver but at depth. Upon resurfacing, all values returned to normal. This is the first study performed at depths where the total lung capacities of participants are below their residual lung volumes at the surface. Partial pressure of carbon dioxide increases at depth to higher than normal values causing pH to decrease thus exceeding the buffering potential of the blood. In addition, previous assumptions that maximum depth in breath-hold divers is where total lung capacity is reduced to their residual volume proved wrong as our group of divers had no symptoms after resurfacing.

A SINGLE ARM PILOT STUDY TO DETERMINE WHETHER AN EARLY CREATION OF PNEUMOTHORAX IN THE NON-VENTILATED LUNG IMPROVES THE QUALITY OF LUNG COLLAPSE DURING ONE LUNG VENTILATION.

<h3>Objective</h3> Rapid and complete collapse of the non-ventilated lung is desirable in minimally invasive thoracic surgery. Inadequate collapse leads to unsatisfactory surgical exposure resulting in excessive retraction of the lung and surrounding vascular structures causing haemodynamic disturbances, mechanical injury to the lung and longer procedure time. Despite good lung separation and application of various measures, in our practice, the incidence of complete collapse (atelectasis) at the time of insertion of the access port is low (around 15 - 20 %). We theorized that creation of pneumothorax in the non-ventilated lung would reduce the residual lung volume facilitating absorption atelectasis. We therefore conducted a pilot study to investigate if creating pneumothorax early in the non-ventilated lung improved the quality of lung collapse at the time of port insertion. <h3>Design and Method</h3> This single arm pilot study was conducted on a convenient sample size of twenty five patients after Institutional Ethics Committee approval. The study was registered in the national registry. All patients scheduled for minimally invasive video assisted thoracic surgery (VATS) and planned for a left sided double lumen tube (DLT) placement for lung isolation were recruited after written informed consent. After induction of anaesthesia and placement of DLT, lung collapse was confirmed by ultrasonography. Under aseptic precautions, a sterile 16 G cannula was used to puncture the pleura along the mid axillary line in the fourth intercostal space to enter the intrapleural space and create a pneumothorax in the operative hemithorax. The canula was then kept open to atmosphere for around 20 minutes till surgical site preparation. Immediately after insertion of thoracoscopy access port, a video of the collapsed lung was recorded. The time between creation of pneumothorax and insertion of thoracoscopy access port was noted. All video recordings were later assessed by two thoracic surgeons who independently scored the degree of lung collapse. The mean of the two scores was calculated. The lung collapse score was recorded on a numerical scale of 1-10 with 1 signifying complete collapse and 10 signifying a non-collapsed lung touching the chest wall. Cases with failed lung isolation or significant adhesions were excluded. <h3>Results</h3> Out of twenty five patients, one patient had an excellent collapse with a score of 3.5, twenty two patients had collapse scores between 4-7 while the other two had scores between 8-10. The mean score was 6.0 with a standard deviation of 1.24. The mean duration between creation of pneumothorax and port insertion was 29 minutes. <h3>Conclusion</h3> Creation of pneumothorax early during one lung ventilation did not result in high incidence of excellent lung collapse. Modifications to the technique could result in better results and should be explored.

New Equations for Hydrostatic Weighing without Head Submersion.

New equations were derived to predict the density of the body (DB) by hydrostatic weighing with the head above water (HWHAW). Hydrostatic weighing with the head below water (HWHBW) was the criterion for DB measurement in 90 subjects (44 M, 46 F). Head volume by immersion (HVIMM) was determined by subtracting the mass in water with the head below water (MWHBW) from the mass in water with the head above water (MWHAW), with subjects at residual lung volume. Equations were derived for head volume prediction (HVPRED) from head measurements and used to correct DB by HWHAW. Equations were also derived for HWHAW using direct regression of DB from uncorrected density (with MWHAW in place of MWHBW). Prediction equations were validated in 45 additional subjects (21 M, 24 F). Results were evaluated using equivalence testing, linear regression, Bland–Altman plots, and paired t-tests. Head girth, face girth, and body mass produced the smallest errors for HVPRED. In both M and F validation groups, equivalence (±2% fat by weight) was demonstrated between body fat percent (BF%) by HWHBW and BF% by HWHAW with HVPRED. Variance in computer-averaged samples of MWHAW was significantly less (p < 0.05) than MWHBW. Prediction error was smaller for BF% by HWHAW with HVPRED than for alternative methods. Conclusions: Equivalence between BF% by HWHBW and BF% by HWHAW with HVPRED was demonstrated and differences were not statistically significant. Weight fluctuations were smaller for HWHAW than HWHBW.

Comparison of Ultrasound Measurements for Diaphragmatic Mobility, Diaphragmatic Thickness, and Diaphragm Thickening Fraction with Each Other and with Lung Function in Patients with Chronic Obstructive Pulmonary Disease.

PurposeTo compare ultrasound measurements of diaphragmatic mobility, diaphragm thickness, and diaphragm thickening fraction with one another and also with lung function parameters in patients with chronic obstructive pulmonary disease (COPD).Patients and MethodsWe conducted a prospective, observational study from 2015 to 2018. A total of 140 patients were randomly selected for this study. Diaphragmatic thickness was measured at deep expiration and deep inspiration with a linear 10-MHz ultrasound probe. Diaphragm thickening fraction was calculated as the ratio between diaphragm thickness at deep inspiration and end expiratory diaphragm thickness. Diaphragmatic mobility was measured with a 3.5-MHz curved probe. Forced expiratory volume in one second (FEV1), residual lung volume, Pimax, and P0.1max were also measured. Sonographic results were compared to FEV1 and other lung function parameters.ResultsThere was a significant positive correlation between diaphragmatic mobility and the following measurements: FEV1 (P < 0.01), diaphragm thickening fraction (P = 0.013), and lung function parameters reflecting ventilatory muscle strength such as Pimax (P < 0.017) and P0.1/Pimax (P < 0.01). There was a significant negative correlation between diaphragmatic mobility and both residual volume (P < 0.01) and diaphragmatic thickness (P = 0.022). In contrast, there was no correlation between diaphragmatic thickness and FEV1, Pimax, and P0.1/Pimax. Diaphragm thickening fraction had a significant correlation with FEV1 (P = 0.041).ConclusionIn patients with COPD, diaphragm mobility measured sonographically correlates with different lung function parameters and also with sonographically measured diaphragm thickness (negative correlation) and diaphragm thickening fraction (positive correlation).

Application of whole body plethysmography for assessment of pulmonary function in patients with asthma and obesity

The incidence of asthma and obesity is constantly increasing. It is commonly acknowledged that obesity can make asthma more severe and poorly controlled. Conventional spirometry, despite of being a “gold standard” in diagnostics of lung diseases, cannot provide information on residual lung volume and bronchial resistance, which can be a key to understanding the mechanics of spirometric deviations found in asthma-obesity phenotype.The aim. To evaluate pulmonary function in patients with asthma and obesity by non-invasive and safe clinical method – body plethysmography.Methods. 46 women with asthma were enrolled into the study, of which 21 were obese and 25 had normal body weight. 18 women with obesity and 20 women with normal body weight were selected as controls. All the patients were postmenopausal. Body plethysmography was performed with MasterScreen Body device, CareFusion, Germany.Results. Asthma is associated with a decrease in forced vital lung capacity and an increase in residual volume. Also, Gensler index and peak expiration flows at 25, 50, and 75% expiration were decreased. Interestingly, specific effective resistance in patients with asthma without obesity was 30 – 40% higher than in the control group. In patients with asthma and obesity, specific effective resistance was 2,5 times higher than in the control group. Residual volume and bronchial resistance were found to have a strong positive correlation.Conclusion. despite of similar spirometric changes, only asthma in obesity was marked by an increase of specific bronchial resistance. This finding can be related to higher energy load of breathing process in obese asthma.

Imaging Severity COVID-19 Assessment in Vaccinated and Unvaccinated Patients: Comparison of the Different Variants in a High Volume Italian Reference Center.

Purpose: To analyze the vaccine effect by comparing five groups: unvaccinated patients with Alpha variant, unvaccinated patients with Delta variant, vaccinated patients with Delta variant, unvaccinated patients with Omicron variant, and vaccinated patients with Omicron variant, assessing the “gravity” of COVID-19 pulmonary involvement, based on CT findings in critically ill patients admitted to Intensive Care Unit (ICU). Methods: Patients were selected by ICU database considering the period from December 2021 to 23 March 2022, according to the following inclusion criteria: patients with proven Omicron variant COVID-19 infection with known COVID-19 vaccination with at least two doses and with chest Computed Tomography (CT) study during ICU hospitalization. Wee also evaluated the ICU database considering the period from March 2020 to December 2021, to select unvaccinated consecutive patients with Alpha variant, subjected to CT study, consecutive unvaccinated and vaccinated patients with Delta variant, subjected to CT study, and, consecutive unvaccinated patients with Omicron variant, subjected to CT study. CT images were evaluated qualitatively using a severity score scale of 5 levels (none involvement, mild: ≤25% of involvement, moderate: 26–50% of involvement, severe: 51–75% of involvement, and critical involvement: 76–100%) and quantitatively, using the Philips IntelliSpace Portal clinical application CT COPD computer tool. For each patient the lung volumetry was performed identifying the percentage value of aerated residual lung volume. Non-parametric tests for continuous and categorical variables were performed to assess statistically significant differences among groups. Results: The patient study group was composed of 13 vaccinated patients affected by the Omicron variant (Omicron V). As control groups we identified: 20 unvaccinated patients with Alpha variant (Alpha NV); 20 unvaccinated patients with Delta variant (Delta NV); 18 vaccinated patients with Delta variant (Delta V); and 20 unvaccinated patients affected by the Omicron variant (Omicron NV). No differences between the groups under examination were found (p value > 0.05 at Chi square test) in terms of risk factors (age, cardiovascular diseases, diabetes, immunosuppression, chronic kidney, cardiac, pulmonary, neurologic, and liver disease, etc.). A different median value of aerated residual lung volume was observed in the Delta variant groups: median value of aerated residual lung volume was 46.70% in unvaccinated patients compared to 67.10% in vaccinated patients. In addition, in patients with Delta variant every other extracted volume by automatic tool showed a statistically significant difference between vaccinated and unvaccinated group. Statistically significant differences were observed for each extracted volume by automatic tool between unvaccinated patients affected by Alpha variant and vaccinated patients affected by Delta variant of COVID-19. Good statistically significant correlations among volumes extracted by automatic tool for each lung lobe and overall radiological severity score were obtained (ICC range 0.71–0.86). GGO was the main sign of COVID-19 lesions on CT images found in 87 of the 91 (95.6%) patients. No statistically significant differences were observed in CT findings (ground glass opacities (GGO), consolidation or crazy paving sign) among patient groups. Conclusion: In our study, we showed that in critically ill patients no difference were observed in terms of severity of disease or exitus, between unvaccinated and vaccinated patients. The only statistically significant differences were observed, with regard to the severity of COVID-19 pulmonary parenchymal involvement, between unvaccinated patients affected by Alpha variant and vaccinated patients affected by Delta variant, and between unvaccinated patients with Delta variant and vaccinated patients with Delta variant.

Differences in the Measurement of Functional Residual Capacity Between Body Plethysmographs of Two Manufacturers.

Body plethysmography is a fundamental method for the assessment of static lung volumes. Although equipment is provided by several manufacturers, there are no established cross-vendor tools for quality control. In the process of quality control and analysis of data on hyperinflation from the large COPD cohort COSYCONET, hints appeared that plethysmographs of different vendors might yield different values for static lung volumes. Functional residual capacity (FRC) differed about 0.67 litres between plethysmographs of the manufacturer Vyaire and Ganshorn. Absolute differences of residual lung volume (RV) and total lung capacity (TLC) were similar. It appears undeniable that differences of this magnitude have an impact on clinical interpretation. Thus, device harmonization seems to be required.

Isolated Elevation in Lung Residual Volume Is Associated With Airway Diseases.

Residual volume (RV) is a derived lung compartment that correlates with air trapping in the context of air flow obstruction on spirometry. The significance of an isolated elevation in RV in the absence of other pulmonary function test (PFT) abnormalities is not well defined. We sought to assess the clinical and radiologic findings associated with isolated elevation in RV. We searched our out-patient PFT database at Mayo Clinic (Rochester, Minnesota) from 2016-2018 for adult patients with isolated elevation in RV. We defined isolated elevation in RV as RV ≥ upper limit of normal or ≥ 130% predicted with normal total lung capacity (TLC), spirometry, and diffusion capacity of the lung for carbon monoxide (DLCO). We then matched this high-RV group by age and sex to an equal number of individuals with normal RV, TLC, spirometry, and DLCO (normal-RV group). We identified 169 subjects with isolated elevation in RV on PFTs, with a median age of 73 y; 55.6% were female, and median body mass index was 26.8 (vs 29.8 in the normal-RV group). The median RV was 3.08 L (134% predicted, interquartile range [IQR] 130-141) in the high-RV group and 2.26 L (99% predicted, IQR 90-109) in the normal-RV group (P < .001). Subjects with high RV were more likely to have smoked (54% vs 40%, P = .01) and almost twice as likely to have a maximum voluntary ventilation < 30 times the FEV1 (21% vs 12%, P = .02). Clinically, asthma (21% vs 11%, P = .01) and non-tuberculous mycobacterial lung infections (12% vs 2%, P = .001) were more prevalent in the high-RV group. On chest computed tomography, bronchiectasis (31% vs 15%, P = .008), bronchial thickening or mucus plugging (46% vs 22%, P < .001), and emphysema (13% vs 5%, P = .046) were more common in the high-RV group. Isolated elevation in RV on PFTs is a clinically relevant abnormality associated with airway-centered diseases.

Функция аппарата внешнего дыхания при раке легкого, развившемся на фоне хронической обструктивной болезни легких

INTRODUCTION: Clinical observations ascertain a comorbid development of chronic obstructive pulmonary disease (COPD) and lung cancer (LC). Here, a more favorable prognosis for patients with LC depends on detection of the disease in early stages, when radical treatment is possible. This determines the importance of a detailed examination of the function of the external respiration using modern methods to identify predictors of lung cancer. AIM: To study the peculiarities of disorders in the apparatus of external respiration (AER) in patients with LC developed with the underlying COPD (LC + COPD). MATERIALS AND METHODS: A clinical and functional examination of 33 individuals was conducted — 10 healthy (control group), 12 patients with COPD and 11 patients with LC + COPD, using methods of spirography, pneumotachography and body plethysmography. RESULTS: In patients with COPD, as well as in those with LC + COPD, a statistically significant decrease in the median values of vital capacity of lungs (VCL), forced expiratory volume in 1 second (FEV1), flow-volume curve (PFER, MEF50, MEF75) and an increase in respiratory minute volume (RMV), residual lung volume (RLV), the ratio of residual lung volume to total lung capacity (RLV/TLC) and bronchial resistance (Raw) were revealed. It was found that in patients with LC + COPD, the median values of VСL, RLV/TLC, Raw did not differ, while the values of flow-volume curve were reduced as compared to patients with COPD. The observed decrease in the air flow rate parameters in the absence of differences in Raw indicates the extrapulmonary causes of these changes. CONCLUSION: In the course of the study, high reserve capacities of the apparatus of external respiration were found. The obtained parameters turned out to be of low informative value for diagnosis of development of LC with the underlying COPD. In patients with LC + COPD, the study of AER function, in addition to spirography and pneumotachography, should include body plethysmography, to avoid overdiagnosis of broncho-obstructive syndrome.