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Objective The digital age has made children more dependent on digital sources for study and entertainment, which leads to increased physical inactivity that contributes to reduced work breathing and attention. Yoga Sana can be a promising form of physical activity that improves a child’s lung function and attention span if, started at a young age. To find out the effect of yoga exercises on lung volumes, vital capacity, and attention span in school-going children. Methods A total of 56 children between the ages of 10–15 years were included using the chit method. The children were randomly divided into 2 groups: group A (yoga group, n = 27) and group B (control group, n = 29). The students of both groups were assessed for chest expansion, lung volumes, and attention span. Group A (yoga group) was trained to perform yoga exercises 3 days a week for 4 weeks. Group B (control group) children were asked to perform daily activities. At the end of the 4 weeks, post-assessment of both the groups was assessed, documented, and statistically analysed using Wilcoxon signed rank and Mann–Whitney U -tests. Results Respiratory parameters (FEV1, FVC/FEV1, and PEFR), chest expansion, and the attention span of group A were statistically significant compared to group B with a p -value < 0.05. Conclusions Yoga exercises led to improvement in lung volumes, vital capacity, and attention in school-going students.

Background: The 6-minute walk test is a common clinical instrument for assessing patient's functional capacity. The 6MWT should be performed preferably indoors, on a flat, straight, hard surfaced corridor usually at least 30 meter long. The test is also used for assessing the effect of therapies such as pulmonary rehabilitation, oxygen therapy, long‐term use of inhaled corticosteroids, and lung volume reduction surgery. The 6MWD in healthy adults has been reported to range from 400 to 700 metres. Method: A total of 300 subjects were included in the study. All the healthy volunteers presenting during the study period were included in the study, provided they met the inclusion and exclusion criteria as above. A written informed consent was taken from all the subjects who were to be included in the study. They were assured about the maintenance of confidentiality and the nature of voluntary participation. Once consent was given, they were included in the study. Result: In the present study, there were 150 males and 150 females. They were comparable in terms of age. The height and weight of males was more than females. It can be concluded from the present study that there is an increase in the hemodynamic parameters immediately after the test. However, the levels return to normal/baseline when measured 4 minutes after the test. Conclusion: The prediction equation developed from distance walked is: 6MWD (females) = 83.76 – (1.42*Age in years) – (3.98*Weight in kgs)+ (426.60*Height in metres). 6MWD (males) = 553.46 – (2.62*Age in years) + (1.82*Weight in kgs) - (38.98*Height in metres. [ABSTRACT FROM AUTHOR]

Introduction. The digital age has made children more dependent on digital sources for study and entertainment, which leads to increased physical inactivity that contributes to reduced work breathing and attention. Yogasana can be a promising form of physical activity that improves a child's lung function and attention span if, started at a young age. To find out the effect of yoga exercises on lung volumes, vital capacity, and attention span in school-going children. Methods. A total of 56 children between the ages of 10-15 years were included using the chit method. The children were randomly divided into 2 groups: group A (yoga group, n = 27) and group B (control group, n = 29). The students of both groups were assessed for chest expansion, lung volumes, and attention span. Group A (yoga group) was trained to perform yoga exercises 3 days a week for 4 weeks. Group B (control group) children were asked to perform daily activities. At the end of the 4 weeks, post-assessment of both the groups was assessed, documented, and statistically analysed using Wilcoxon signed rank and Mann-Whitney U-tests. Results. Respiratory parameters (FEV1, FVC/FEV1, and PEFR), chest expansion, and the attention span of group A were statistically significant compared to group B with a p-value < 0.05. Conclusions. Yoga exercises led to improvement in lung volumes, vital capacity, and attention in school-going students. [ABSTRACT FROM AUTHOR]

BACKGROUND: Abnormal lung volumes representing air trapping identify the subset of smokers with preserved spirometry who develop spirometric chronic obstructive pulmonary disease (COPD) and adverse outcomes. However, how lung volumes evolve in early COPD as airflow obstruction develops remains unclear. METHODS: To establish how lung volumes change with the development of spirometric COPD, we examined lung volumes from the pulmonary function data (seated posture) available in the U.S. Department of Veterans Affairs electronic health records (n=71,356) and lung volumes measured by computed tomography (supine posture) available from the COPD Genetic Epidemiology (COPDGene®) study (n=7969) and the SubPopulations and InterMediate Outcome Measures In COPD Study (SPIROMICS) (n=2552) cohorts, and studied their cross-sectional distributions and longitudinal changes across the airflow obstruction spectrum. Patients with preserved ratio-impaired spirometry (PRISm) were excluded from this analysis. RESULTS: Lung volumes from all 3 cohorts showed similar patterns of distributions and longitudinal changes with worsening airflow obstruction. The distributions for total lung capacity (TLC), vital capacity (VC), and inspiratory capacity (IC) and their patterns of change were nonlinear and included different phases. When stratified by airflow obstruction using Global initiative for chronic Obstructive Lung Disease (GOLD) stages, patients with GOLD 1 (mild) COPD had larger lung volumes (TLC, VC, IC) compared to patients with GOLD 0 (smokers with preserved spirometry) or GOLD 2 (moderate) disease. In longitudinal follow-up of baseline GOLD 0 patients who progressed to spirometric COPD, those with an initially higher TLC and VC developed mild obstruction (GOLD 1) while those with an initially lower TLC and VC developed moderate obstruction (GOLD 2). CONCLUSIONS: In COPD, TLC, and VC have biphasic distributions, change in nonlinear fashions as obstruction worsens, and could differentiate those GOLD 0 patients at risk for more rapid spirometric disease progression.

Introduction: Fetal magnetic resonance imaging (MRI) lung volume nomograms are increasingly used to prognosticate neonatal outcomes in fetuses with suspected pulmonary hypoplasia. However, pregnancies complicated by fetal anomalies associated with pulmonary hypoplasia may also be complicated by fetal growth restriction (FGR). If a small lung volume is suspected in such cases, it is often unclear whether the lungs are "small" because of underlying lung pathology, or small fetal size. Existing MRI lung volume nomograms have mostly been stratified by gestational age (GA), rather than estimated fetal weight (EFW). Therefore, we aimed to develop a novel fetal lung volume nomogram stratified by EFW. Methods: Consecutive fetal MRIs performed at a quaternary medical center from 2019 to 2021 were analyzed. MRIs performed due to fetal lung anomalies and cases with FGR were excluded. All MRIs were performed without IV contrast on GE 3 or 1.5 Tesla scanners (GE Healthcare). Images were reviewed by three experienced fetal radiologists. Freehand ROI in square centimeter was drawn around the contours of the lungs on consecutive slices from the apex to the base. The volume of the right, left and total lungs were calculated in mL. Lung volumes were plotted by both EFW and GA. Results: Among 301 MRI studies performed during the study period, 170 cases met inclusion criteria and were analyzed. MRIs were performed between 19- and 38-week gestation, and a sonographic EFW was obtained within a mean of 2.9 days (SD ± 5.5 days, range 0–14 days) of each MRI. Nomograms stratified by both EFW and GA were created using 200 g. and weekly intervals respectively. A formula using EFW to predict total lung volume was calculated: LV = 0.07497804 EFW0.88276 (R2 = 0.87). Conclusions: We developed a novel fetal lung volume nomogram stratified by EFW. If validated, this nomogram may assist clinicians predict outcomes in cases of fetal pulmonary hypoplasia with concomitant FGR. [ABSTRACT FROM AUTHOR]

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

Rationale: The term "pre–chronic obstructive pulmonary disease" ("pre-COPD") refers to individuals at high risk of developing COPD who do not meet conventional spirometric criteria for airflow obstruction. New approaches to identifying these individuals are needed, particularly in younger populations. Objectives: To determine whether lung function thresholds and respiratory symptoms can be used to identify individuals at risk of developing COPD. Methods: The Tasmanian Longitudinal Health Study comprises a population-based cohort first studied in 1968 (at age 7 yr). Respiratory symptoms, pre- and post-bronchodilator (BD) spirometry, diffusing capacity, and static lung volumes were measured in a subgroup at age 45, and the incidence of COPD was assessed at age 53. For each lung function measure, z-scores were calculated using Global Lung Function Initiative references. The optimal threshold for best discrimination of COPD incidence was determined by the unweighted Youden index. Measurements and Main Results: Among 801 participants who did not have COPD at age 45, the optimal threshold for COPD incidence by age 53 was pre-BD FEV1/FVC z-score less than −1.264, corresponding to the lowest 10th percentile. Those below this threshold had a 36-fold increased risk of developing COPD over an 8-year follow-up period (risk ratio, 35.8; 95% confidence interval, 8.88 to 144), corresponding to a risk difference of 16.4% (95% confidence interval, 3.7 to 67.4). The sensitivity was 88%, and the specificity was 87%. Positive and negative likelihood ratios were 6.79 and 0.14, respectively. Respiratory symptoms, post-BD spirometry, diffusing capacity, and static lung volumes did not improve on the classification achieved by pre-BD FEV1/FVC alone. Conclusions: This is the first study, to our knowledge, to evaluate the discriminatory accuracy of spirometry, diffusing capacity, and static lung volume thresholds for COPD incidence in middle-aged adults. Our findings support the inclusion of pre-BD spirometry in the physiological definition of pre-COPD and indicate that pre-BD FEV1/FVC at the 10th percentile accurately identifies individuals at high risk of developing COPD in community-based settings. [ABSTRACT FROM AUTHOR]

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

The prevalence and incidence of asthma continue to rise globally. Obesity has been identified as a potential risk factor for asthma exacerbations. The association between body mass index (BMI) and asthma is not well studied in some regions. This study aims to investigate the impact of BMI on pediatric asthmatic patients. This retrospective study was conducted at the Aga Khan University Hospital from 2019 to 2022. Children and adolescents with asthma exacerbations were included. The patients were classified into four groups based on their BMI: underweight, healthy weight, overweight, and obese. The demographic characteristics, medications used, predicted forced expiratory volume in 1 second (FEV1) measurements, asthma exacerbations per year, length of stay per admission, and the number of patients requiring high dependency unit (HDU) care were recorded and analyzed. Our results demonstrated that patients in the healthy weight category had the highest percentage of FEV1 (91.46±8.58) and FEV1/forced vital capacity (FVC) (85.75±9.23) (p<0.001). The study found a significant difference in the average number of asthma exacerbations per year between the four groups. Obese patients had the highest number of episodes (3.22±0.94), followed by the underweight group (2.42±0.59) (p<0.01). The length of stay per admission was significantly shorter for patients with a healthy weight (2.0±0.81), and there was a statistically significant difference observed in the number of patients requiring HDU care among the four groups, as well as in the average length of stay at the HDU (p<0.001). Elevated BMI is related to an increased number of annual asthma exacerbations, a low FEV1 and FEV1/FVC, an increased length of stay at admission, and an increased stay in the HDU. [ABSTRACT FROM AUTHOR]

OBJECTIVE: Hypersensitivity pneumonitis (HP) is an inflammatory and/or fibrotic lung disease. The restrictive lung function with low diffusing capacity of carbon monoxide (DLCO) is common in interstitial lung diseases (ILD). There are limited data on pulmonary function test (PFT) in HP and its role for diagnosis is questionable. We analyzed the data of 152 HP patients for type of defect, lung volume, and DLCO. MATERIAL AND METHODS: The present study is a retrospective analysis of 152 patients at one of the tertiary chest institutes in India. All diagnosed cases with at least spirometry were included. PFT findings were classified and graded as obstructive, restrictive, and mixed patterns. The correlation of PFT was calculated with disease duration and 6MWT distance. RESULTS: The majority were female [106 (70%)], with a mean age of 47.8 ± 12.3 years. Spirometry with lung volume data were available for 97% patients. PFT was abnormal in 118 (80%) cases. Among the patterns of abnormality, the most common type was restrictive (74%) followed by mixed (15%) and obstructive (11%) with the majority in the severe to very severe grade. The mean total lung capacity (TLC) and residual volume (RV) were reduced, with the grade more severe when the pattern of abnormality was restrictive while the RV/TLC was higher suggestive of air tapping. DLCO data were available for 132 (87%) cases, with levels decreased in 67%. The severity of DLCO was highest when the pattern of abnormality was restrictive. One of the PFT parameters was abnormal in 137 (90%) cases, with isolated decreased DLCO levels seen in 16 (10%) cases. Forced vital capacity (FVC), TLC, and DLCO showed positive correlation with 6MWT distance (FVC r = .22, P = .02; TLC r = .28, P = .003; DLCO r = .30, P = .002). CONCLUSION: The PFT abnormality is seen in >80% of HP patients. All types of abnormality were seen, with the restrictive pattern being the most common. Isolated decreased DLCO levels were seen in 10% of cases. We advised to do full PFT for diagnosis and followup of HP. [ABSTRACT FROM AUTHOR]

The use of wet spirometers, although once common, has greatly declined because these devices measure only static lung volumes and students often face technical issues in their use. In this study, the wet spirometer has been modified to investigate the fundamental laws of flow and different types of lung disease. This modification was achieved by changing the dimensions of the device, printing a scale on the bell, and attaching an airflow control system (ACS) between the corrugated tube and hollow tube of the inner cylinder. The ACS allowed for flow control during the exercises. Two exercises were performed: exercise I compared the parameters measured by the wet spirometer, modified spirometer, and computerized spirometer to determine the suitability of the modification, while exercise II tested the variables affecting flow. These exercises introduce students to data collection, analysis, and the use of statistical tests as they compare various spirometers. Additionally, students gain valuable experience in experimental design by conducting diverse experiments that investigate factors influencing flow dynamics. By plotting the results and participating in small group discussions, students can apply flow principles in respiratory and circulatory systems, offering a hands-on experience that integrates physics and physiology. The modified spirometer facilitated multifaceted topic exploration, surpassing the traditional wet spirometer's capabilities. [ABSTRACT FROM AUTHOR]

Rationale: Epidemiological studies have reported on the detrimental effects on lung function after natural, and thus limited, weight gain in unselected populations. Studies on bariatric surgery, on the contrary, have indicated large improvements in lung function after substantial weight loss. Objectives: To study the associations between profound weight loss or gain and pulmonary function within the same population. A second objective was to investigate the effect of weight cycling on pulmonary function. Methods: From our lung function database, we selected the records of subjects in follow-up for continuous positive airway pressure therapy for sleep apnea with a weight change of >20 kg within 5 years. Lung function (N= 255) at baseline was normal except for a tendency toward mild restriction in morbid obesity. Within this sample, 73 subjects were identified with significant "weight cycling", defined as a >10-kg opposite change in body weight before or after the >20-kg weight change. Results: Weight change affected pulmonary function more in men than in women (P,0.001). In men, forced vital capacity (FVC) increased an average of 1.4% predicted per unit of body mass index after weight loss and the reverse after weight gain, whereas women exhibited a smaller change of 0.9% predicted per unit of body mass index. Weight loss slightly increased the ratio of forced expiratory volume in 1 second to FVC and decreased the specific airway resistance, whereas the opposite occurred with weight gain. Greater effects of weight change on lung function were observed in leaner subjects (P = 0.02) and in older subjects (P,0.002). Changes in total lung capacity followed the changes in FVC, with no change in residual volume, and the greatest change was observed in functional residual capacity. In subjects with weight cycling, the improvement in lung function due to weight loss was reversed by subsequent weight gain and vice versa. Conclusions: This study provides evidence that the detrimental effect of obesity on lung function is a passive and reversible process. [ABSTRACT FROM AUTHOR]

The BodPod® (COSMED, Concord, CA) uses predicted (pTGV) or measured thoracic gas volume (mTGV) during estimations of percentage body fat (%BF). In young adults, there is inconsistent evidence on the variation between pTGV and mTGV, and the effect of sex as a potential covariate on this relationship is unknown. This study examined the difference between TGV assessments and its effect on %BF and potential sex differences that may impact this relationship. A retrospective analysis of BodPod® pTGV and mTGV for 95 men and 86 women ages 18–30 years was performed. Predicted TGV was lower than mTGV for men (−0.49 ± 0.7 L; p <.0001). For men, %BF derived by pTGV was lower than that by mTGV (−1.3 ± 1.8%; p <.0001). For women, no differences were found between pTGV and mTGV (−0.08 ± 0.6 L; p >.05) or %BF (−0.03 ± 0.2%; p >.05). The two-predictor model of sex and height was able to account for 57.9% of the variance in mTGV, F(2, 178) = 122.5, p <.0001. Sex corrected for the effect of height was a significant predictor of mTGV (β = 0.483 L, p <.0001). There is bias for pTGV to underestimate mTGV in individuals with a large mTGV, which can lead to significant underestimations of %BF in young adults; this was especially evident for men in this study. Sex is an important covariate that should be considered when deciding to use pTGV. The results indicate that TGV should be measured whenever possible for both men and women ages 18–30 years. [ABSTRACT FROM AUTHOR]

Recently an international multidisciplinary task force of the ERS/ATS has produced a report that updates the previous 2005 documents for the execution and for the interpretation of the respiratory function tests. This document arises from the need for a change from previous interpretative models in which an absolute level of ideal lung function (i.e. the predicted value) is replaced in favor of a range of values that are observed in the majority of individuals without disease respiratory (i.e., z-scores or percentiles). The main changes in the report are described below. [ABSTRACT FROM AUTHOR]

Objectives: The aims of the study are to determine the cardiovascular risk burden rehabilitation discharge and to explore the association between recovery during rehabilitation and cardiovascular disease risk profile. Methods: We included adults without cardiovascular disease admitted for rehabilitation. We evaluated rehabilitation outcomes on admission and discharge. Cardiovascular disease risk profile was assessed by Framingham risk score, high-density lipoprotein, and fasting glucose level. Results: We analyzed data from 706 participants (69.6% men) with a median age of 53.5 yrs. The median time since injury was 14 days, and the admission length was 5.2 months. Majority had paraplegia (53.3%) and motor incomplete injury (53.7%). One third of the cohort had high cardiovascular risk profile before discharge. At discharge, poorer anthropometric measures were associated with higher Framingham risk score and lower high-density lipoprotein levels. Individuals with higher forced vital capacity (>2.72 l) and peak expiratory flow (>3.4 l/min) had 0.16 mmol/l and 0.14 mmol/l higher high-density lipoprotein compared with those with lower respiratory function, respectively. Individuals with higher mobility score (>12.5) and functional independence score (>74) had 0.21 and 0.18 mmol/l higher high-density lipoprotein compared with those with lower scores. Conclusions: There is high cardiometabolic syndrome burden and cardiovascular disease risk profile upon rehabilitation discharge. Higher respiratory function, mobility, and overall independence were associated with better cardiovascular disease risk profile, although with study design limitations and short follow-up. Future studies should explore whether rehabilitation outcomes could be used to prioritize screening. [ABSTRACT FROM AUTHOR]

Background and Study Aim. In modern sports, the research and study of the functional capabilities of athletes' breathing is relevant. The analysis of individual results made it possible to form an idea about the respiratory functions of athletes. Among elite athletes, parameters of respiratory functions are significantly higher than the norm, so their interpretation relative to the general healthy population is inadequate. The purpose of the study is to determine lung volumes and dynamic parameters of the respiratory act and their difference in height and weight categories, respectively. Material and methods. The study involved 22 elite athletes aged 19-24 took part in the study. Testing of all athletes was carried out during the period of preparation for the competition The following research methods were used: method of anthropometry; method of computer Spirometry (was used to assess the functional state of reserve possibilities of the external breathing of athletes by absolute indicators). The studied material was processed by the methods of mathematical statistics using the "Statistica 6.0" software and MS Excel. Athletes were divided into three groups of height categories: group-A (190 cm and above), group-B (180-189 cm), group-C (170-179 cm) and three weight categories: group-D (90 kg and above), group-E (80-89 kg), group-F (70-79 kg). Results. Studies have shown that the absolute values of respiratory functions in athletes with significant hight and significant body weight are higher than in athletes with short height and insignificant weight. Real indicators of respiratory functions in most athletes are within the normal range. The highest actual indicators of respiratory functions are observed in the group of athletes with average height and average body weight. Also, in elite athletes with average height and average body weight, individual actual indicators are practically the same. Conclusion. Planning and construction of the training process requires knowledge of absolute and actual indicators of respiratory functions. The conducted research made it possible to establish the level of functional reserves of power and mobilization functions of breathing in elite-level rowers. The results allow effective planning of physical activity during training.

Objectives: To find correlation between single breath counting (SBC) and spirometry in acute exacerbation of asthma in children. Methods: A cross-sectional observational study including all children aged 6–12 y age, who presented in outpatient department or emergency room with acute exacerbation of asthma, not fitting in exclusion criteria were enrolled. SBC and spirometry parameters were obtained before treatment and 1 h after initiating treatment (GINA 2017 Guidelines). Results: Significant correlation was observed in SBC and FVC (r = 0.349), FEV1 (r = 0.439), FEF25-75 (r = 0.424), and PEF (r = 0.593). Cutoff value of SBC of 23 was found to be suggestive of severe/life-threatening asthma with sensitivity of 83.3% and specificity of 84.4%. No significant association was found between percent change in SBC and spirometry parameters in response to treatment. Conclusions: SBC can be used to predict PEF, FEV1, FVC, and FEF25-75 of a patient aged between 6 and 12 y during acute asthma exacerbation. The observed cutoff value of 23 of SBC score has a good sensitivity and specificity to identify life-threatening/severe exacerbation. SBC score significantly increases in response to therapy. [ABSTRACT FROM AUTHOR]

Background: Exposure to high altitude causes significant stress in the functioning of cardiovascular and respiratory systems. Aim: The aim of this study was to investigate the changes in systolic and diastolic blood pressure (BP), heart rate (HR) and pulmonary volumes during the classic ascent of Damavand 5671 m peak. Materials and Methods: 14 healthy male climbers (age = 23.85±5.93 years, height = 175.5±5.91 cm, weight =71.35±8.20 kg) participated voluntarily in this study. BP, HR and lung volumes were measured in basic (2000 M), BC (3100 m) the first day, C1 (3650 m) the first day, BC (3100 m) the second day after the one-night stopover, C1 (3650 m) the second day, C2 (4100 m) the second day, C2 (4100 M) third day after the one-night stopover, C3 (5000 m) and, peak (5671 m). Data were compared by repeated measures test at the significant level of P≤0.05 and Bonferroni post hoc test. Results: The results of repeated measures analysis were significant for HR, systolic BP, diastolic BP and MVV (P<0.05), but not significant for FVC and FEV1 (P≥0.05). BP was high in the base camp and the first camp and gradually decreased. HR continued to increase significantly with increasing altitude. MVV increased with increasing altitude and is reduced after the one-night stopover in each height. Conclusion: It can be concluded that climbing with classic method increased the HR and decreased systolic and diastolic BP of climbers. It was able to induce adaptation in lung volumes of climbers. [ABSTRACT FROM AUTHOR]

Nocturnal worsening of asthma may be due to reduced lung volumes and fewer sigh breaths, which have been shown to increase airway resistance and bronchoreactivity. We hypothesized that mimicking deep inspiration using nocturnal mechanical support would improve symptoms in patients with asthma. Subjects with asthma underwent usual care and bilevel positive airway pressure (PAP) therapy for 4 weeks, separated by 4 weeks, and methacholine challenge (PC20) and subjective assessments. 13 patients with asthma alone and 8 with asthma + OSA completed the protocol. Change in bronchoreactivity (ratio of Post/Pre PC20) was not significantly different during usual care and bilevel PAP [0.86 (IQR 0.19, 1.82) vs 0.94 (IQR 0.56, 2.5), p = 0.88], nor was the change in Asthma Control Test different: 0.1 ± 2.2 vs. -0.2 ± 2.9, p = 0.79, respectively. Bilevel PAP therapy for four weeks did not improve subjective or objective measures of asthma severity in patients with asthma or those with asthma and OSA, although there was heterogeneity in response.

Introduction: Pulmonary function is lower after a severe burn injury, which could influence ventilatory responses during exercise. It is unclear whether exercise training improves pulmonary function or ventilatory responses during exercise in adults with well-healed burn injuries. Therefore, we tested the hypothesis that exercise training improves pulmonary function and ventilatory responses during exercise in adults with well-healed burn injuries. Methods: Thirty-nine adults (28 with well-healed burn injuries and 11 non–burn-injured controls) completed 6 months of unsupervised, progressive exercise training including endurance, resistance, and high-intensity interval components. Before and after exercise training, we performed comprehensive pulmonary function testing and measured ventilatory responses during cycling exercise. We compared variables using two-way ANOVA (group–time; i.e., preexercise/postexercise training (repeated factor)). Results: Exercise training did not increase percent predicted spirometry, lung diffusing capacity, or airway resistance measures (time: P ≥ 0.14 for all variables). However, exercise training reduced minute ventilation (V̇ E; time: P ≤ 0.05 for 50 and 75 W) and the ventilatory equivalent for oxygen (V̇ E/V̇O2; time: P < 0.001 for 75 W) during fixed-load exercise for both groups. The ventilatory equivalent for carbon dioxide (V̇ E/V̇CO2) during exercise at 75 W was reduced after exercise training (time: P = 0.04). The percentage of age-predicted maximum heart rate at the ventilatory threshold was lower in adults with well-healed burn injuries before (P = 0.002), but not after (P = 0.22), exercise training. Lastly, exercise training increased V̇ E and reduced V̇ E/V̇O2 during maximal exercise (time: P = 0.005 for both variables). Conclusions: These novel findings demonstrate that exercise training can improve ventilatory responses during exercise in adults with well-healed burn injuries. [ABSTRACT FROM AUTHOR]

The prevalence and incidence of asthma continue to rise globally. Obesity has been identified as a potential risk factor for asthma exacerbations. The association between body mass index (BMI) and asthma is not well studied in some regions. This study aims to investigate the impact of BMI in pediatric asthmatic patients. This retrospective study was conducted at the Aga Khan University Hospital from 2019 to 2022. Children and adolescents with asthma exacerbation were included. The patients were classified into four groups based on their BMI: underweight, healthy weight, overweight, and obese. The demographic characteristics, medications used, predicted FEV1 measurements, asthma exacerbations per year, length of stay per admission, and the number of patients requiring High Dependency Unit (HDU) care were recorded and analyzed. Our results demonstrated that patients in the healthy weight category had the highest percentage of FEV1 (91.46±8.58) and FEV1/FVC (85.75±9.23) (p

Dual-energy computed tomography (DECT) has been used for detecting pulmonary embolism, but the role of lung perfusion DECT as a predictor of prognosis of coronavirus disease 2019 (COVID-19) has not been defined yet. The aim of our study was to explore whether the enhancement pattern in COVID-19+ patients relates to the disease outcome. A secondary aim was to compare the lung volumes in two subgroups of patients. In this observational study, we considered all consecutive COVID-19+ patients who presented to the emergency room between January 2021 and December 2021 with respiratory symptoms (with mild to absent lung consolidation) and were studied by chest contrast-enhanced DECT to be eligible. Two experienced radiologists post-processed the images using the "lung-analysis" software (SyngoVia). Absolute and relative enhancement lung volumes were assessed. Patients were stratified in two subgroups depending on clinical outcome at 30 days: (i) good outcome (i.e., discharge, absence of clinical or imaging signs of disease); (ii) bad outcome (i.e., hospitalization, death). Patient sub-groups were compared using chi-square test or Fisher test for qualitative parameters, chi-square test or Spearman's Rho test for quantitative parameters, Students' t-test for parametric variables and Wilcoxon test for non-parametric variables. We enrolled 78 patients (45M), of whom, 16.7% had good outcomes. We did not observe any significant differences between the two groups, both in terms of the total enhancement evaluation (p = 0.679) and of the relative enhancement (p = 0.918). In contrast, the average lung volume of good outcome patients (mean value of 4262 mL) was significantly larger than that of bad outcome patients (mean value of 3577.8 mL), p = 0.0116. All COVID-19+ patients, with either good or bad outcomes, presented similar enhancement parameters and relative enhancements, underlining no differences in lung perfusion. Conversely, a significant drop in lung volume was identified in the bad outcome subgroup eligible compared to the good outcome subgroup. [ABSTRACT FROM AUTHOR]

The longer-term effects of COVID-19 on lung physiology remain poorly understood. Here, a new technique, computed cardiopulmonography (CCP), was used to study two COVID-19 cohorts (MCOVID and C-MORE-LP) at both ~6 and ~12 mo after infection. CCP is comprised of two components. The first is collection of highly precise, highly time-resolved measurements of gas exchange with a purpose-built molecular flow sensor based around laser absorption spectroscopy. The second component is estimation of physiological parameters by fitting a cardiopulmonary model to the data set. The measurement protocol involved 7 min of breathing air followed by 5 min of breathing pure O2. One hundred seventy-eight participants were studied, with 97 returning for a repeat assessment. One hundred twenty-six arterial blood gas samples were drawn from MCOVID participants. For participants who had required intensive care and/or invasive mechanical ventilation, there was a significant increase in anatomical dead space of ~30 mL and a significant increase in alveolar-to-arterial PO2 gradient of ~0.9 kPa relative to control participants. Those who had been hospitalized had reductions in functional residual capacity of ~15%. Irrespectively of COVID-19 severity, participants who had had COVID-19 demonstrated a modest increase in ventilation inhomogeneity, broadly equivalent to that associated with 15 yr of aging. This study illustrates the capability of CCP to study aspects of lung function not so easily addressed through standard clinical lung function tests. However, without measurements before infection, it is not possible to conclude whether the findings relate to the effects of COVID-19 or whether they constitute risk factors for more serious disease. NEW & NOTEWORTHY This study used a novel technique, computed cardiopulmonography, to study the lungs of patients who have had COVID-19. Depending on severity of infection, there were increases in anatomical dead space, reductions in absolute lung volumes, and increases in ventilation inhomogeneity broadly equivalent to those associated with 15 yr of aging. However, without measurements taken before infection, it is unclear whether the changes result from COVID-19 infection or are risk factors for more severe disease. [ABSTRACT FROM AUTHOR]

Background: Yoga is an ancient Indian system and largest surviving philosophical system in the world. It is a novel and emerging discipline in broad category of mind-body medicine. Yoga, a spiritual discipline, induces positive health and its effect on lung function test can be used clinically as a therapeutic intervention in lung diseases like asthma. Objective: The study was conducted to assess the effect of yoga on dynamic lung volumes. Results: The lung function tests were conducted on 50 healthy male and female controls not practicing yoga in the age group of 30-50 years and sex and age-matched 50 healthy subjects practicing yoga for 5 years. The lung volumes recorded on electronic Medspiror were forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), maximum voluntary ventilation (MVV), peak expiratory flow rate (PEFR), forced expiratory volume in 3 seconds (FEV3) respiratory rate (RR) and breath holding time (BHT). The study demonstrates increase in FVC, FEV1, MVV, PEFR, FEV3 and breath holding time and decrease of respiratory rate in yoga performers. Conclusion: Yoga has a therapeutic value and doctor with yogic attitude is likely to transmit to the patient a positive attitude and calm disposition to achieve better results in healing various diseases with less medication. [ABSTRACT FROM AUTHOR]

Abstract Background Intra-abdominal hypertension (IAH) is common in critically ill patients and is associated with increased morbidity and mortality. High positive end-expiratory pressures (PEEP) can reverse lung volume and oxygenation decline caused by IAH, but its impact on alveolar overdistension is less clear. We aimed to find a PEEP range that would be high enough to reduce atelectasis, while low enough to minimize alveolar overdistention in the presence of IAH and lung injury. Methods Five anesthetized pigs received standardized anesthesia and mechanical ventilation. Peritoneal insufflation of air was used to generate intra-abdominal pressure of 27 cmH2O. Lung injury was created by intravenous oleic acid. PEEP levels of 5, 12, 17, 22, and 27 cmH2O were applied. We performed computed tomography and measured arterial oxygen levels, respiratory mechanics, and cardiac output 5 min after each new PEEP level. The proportion of overdistended, normally aerated, poorly aerated, and non-aerated atelectatic lung tissue was calculated based on Hounsfield units. Results PEEP decreased the proportion of poorly aerated and atelectatic lung, while increasing normally aerated lung. Overdistension increased with each incremental increase in applied PEEP. “Best PEEP” (respiratory mechanics or oxygenation) was higher than the “optimal CT inflation PEEP range” (difference between lower inflection points of atelectatic and overdistended lung) in healthy and injured lungs. Conclusions Our findings in a large animal model suggest that titrating a PEEP to respiratory mechanics or oxygenation in the presence of IAH is associated with increased alveolar overdistension.

Background: Yoga is an ancient Indian system and largest surviving philosophical system in the world. It is a novel and emerging discipline in broad category of mind-body medicine. Yoga, a spiritual discipline, induces positive health and its effect on lung function test can be used clinically as a therapeutic intervention in lung diseases like asthma. Objective: The study was conducted to assess the effect of yoga on dynamic lung volumes. Results: The lung function tests were conducted on 50 healthy male and female controls not practicing yoga in the age group of 30-50 years and sex and age-matched 50 healthy subjects practicing yoga for 5 years. The lung volumes recorded on electronic Medspiror were forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), maximum voluntary ventilation (MVV), peak expiratory flow rate (PEFR), forced expiratory volume in 3 seconds (FEV3) respiratory rate (RR) and breath holding time (BHT). The study demonstrates increase in FVC, FEV1, MVV, PEFR, FEV3 and breath holding time and decrease of respiratory rate in yoga performers. Conclusion: Yoga has a therapeutic value and doctor with yogic attitude is likely to transmit to the patient a positive attitude and calm disposition to achieve better results in healing various diseases with less medication.

Roberto W Dal Negro,1 Paola Turco,2 Massimiliano Povero3 1National Centre for Respiratory Pharmacoeconomics and Pharmacoepidemiology, Verona, Italy; 2Research & Clinical Governance, Verona, Italy; 3AdRes Health Economics and Outcome Research, Torino, ItalyCorrespondence: Massimiliano PoveroAdRes Health Economics and Outcome Research, Torino, ItalyEmail m.povero@adreshe.comBackground: The MiniBox+™ is an innovative technique for assessing lung volumes (LVs) and the diffusing capacity of the lung for carbon monoxide (DLco). Differently from the equipment needed for whole body plethysmography (WBP), the MiniBox+ is a small, transportable instrument, which derives total lung capacity (TLC) during tidal breathing by analyzing gas pressures and airflows immediately preceding and immediately following airway occlusions.Aim: To compare the consistency and the feasibility of LV and DLco measurements between the two instruments in different lung function disorders, and their cost of execution.Methods: Consecutive patients of both genders with obstructive and restrictive respiratory disorders were randomly recruited. LVs and DLco were measured by a randomized sequence. The failure risk, number of attempts to achieve the first reliable measurement, corresponding time spent, and costs per patient were compared.Results: A total of 134 patients were enrolled: 42 asthmatics (32.1%), and 47 patients with obstructive (35.1%) and 44 with restrictive respiratory disorders (32.8%). The overall failure risk was 19.4% for WBP and 8.2% for the MiniBox+ (risk ratio=0.417, 95% CI 0.242 to 0.72). LVs and DLco values proved equal with both techniques, regardless of the patients’ age, sex, schooling level, and initial lung disorder. Number of attempts and total time spent in achieving the first reliable measurement were significantly lower with the MiniBox+. Mean cost per patient was € 87.58 with WBP and € 75.11 with the MiniBox+, with a mean saving of € 12.33 (95% CI 5.93 to 18.73), mainly due to the saving in productivity loss.Conclusion: LV and DLco measurements with the MiniBox+ were highly consistent with those obtained with WBP. The MiniBox+ proved easier to use (lower failure risk) and more convenient (lower execution costs) than WBP.Keywords: economic impact, lung volumes, CO diffusing capacity, failure risk, whole body plethysmography, MiniBox+&#x2122

At altitude, factors such as decreased barometric pressure, low temperatures, and acclimatization might affect lung function. The effects of exposure and acclimatization to high-altitude on lung function were assessed in 39 subjects by repetitive spirometry up to 6022 m during a high-altitude expedition. Subjects were classified depending on the occurrence of acute mountain sickness (AMS) and summit success to evaluate whether lung function relates to successful climb and risk of developing AMS. Peak expiratory flow (PEF), forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV1) increased with progressive altitude (max. +20.2 %pred, +9.3 %pred, and +6.7 %pred, all p<0.05). Only PEF improved with acclimatization (BC1 vs. BC2, +7.2 %pred, p=0.044). At altitude FEV1 (p=0.008) and PEF (p<0.001) were lower in the AMS group. The risk of developing AMS was associated with lower baseline PEF (p<0.001) and longitudinal changes in PEF (p=0.008) and FEV1 (p<0.001). Lung function was not related to summit success (7126 m). Improvement in PEF after acclimatization might indicate respiratory muscle adaptation. • Dynamic lung volumes increase with altitude. • Improved peak expiratory flow (PEF) after acclimatization might indicate respiratory muscle adaptation. • Lower PEF and FEV1 at baseline and during the expedition are associated with an increased risk of moderate to severe AMS. [ABSTRACT FROM AUTHOR]

Despite decades of research, studies investigating the physiological alterations caused by an acute bout of inflammation induced by exposing the lung to lipopolysaccharide have yielded inconsistent results. This can be attributed to small effects and/or a lack of fitted physiological testing. Herein, a comprehensive investigation of lung mechanics was conducted on 270 male C57BL/6 mice at 24, 48, or 96 h after an intranasal exposure to saline or lipopolysaccharide at either 1 or 3 mg/kg (30 mice per group). Traditional techniques that probe the lung using small-amplitude perturbations (i.e., oscillometry) were used, together with less conventional and new techniques that probe the lung using maneuvers of large amplitudes. The latter include a partial and a full-range pressure-volume maneuvers to measure quasi-static elastance, compliance, total lung volume, vital capacity, and residual volume. The results demonstrate that lung mechanics assessed by oscillometry was only slightly affected by lipopolysaccharide, confirming previous findings. In contradistinction, lipopolysaccharide markedly altered mechanics when the lung was probed with maneuvers of large amplitudes. With the dose of 3 mg/kg at the peak of inflammation (48 h postexposure), lipopolysaccharide increased quasi-static elastance by 26.7% (P < 0.0001) and decreased compliance by 34.5% (P < 0.0001). It also decreased lung volumes, including total lung capacity, vital capacity, and residual volume by 33.3%, 30.5%, and 43.3%, respectively (all P < 0.0001). These newly reported physiological alterations represent sensitive outcomes to efficiently evaluate countermeasures (e.g., drugs) in the context of several lung diseases. [ABSTRACT FROM AUTHOR]

Abstract Background Reversibility measured by spirometry in chronic obstructive pulmonary disease (COPD) is defined as an increase in forced expiratory volume in first second (FEV1) that is both more than 12% and 200 mL above the pre-bronchodilator value in response to inhaled bronchodilators. FEV1 only may not fully reverberate the changes caused by reduction in air trapping or hyperinflation. To date, the studies that examined the effect of inhaled bronchodilators (BD) on residual volume (RV) and total lung capacity (TLC) are limited. This study was carried out to assess the differences between flow and volume responses after bronchodilator reversibility testing in patients with different COPD GOLD stages (GOLD stage I to stage IV). Spirometry and whole body plethysmography were done before and 15 min after inhalation of 400 μg salbutamol. Results Majority (53.3%) of cases were volume responders, 18.7% were flow responders, 20% were flow and volume responders, and 8% were non responders. Significant increase in Δ FEV1% was found in 15% of cases while 55% showed a significant increase in Δ FVC (P= < 0.001). Mean difference of Δ FVC (L) post BD was significantly increased with advancing GOLD stage (P= 0.03). A cutoff point > 20% for Δ RV% had 70% sensitivity and 60% specificity and > 12% for Δ TLC% showed 90% sensitivity and 45% specificity for prediction of clinically significant response to BD based on FEV1. A cutoff point > 18% for Δ RV% had 78% sensitivity and 29% specificity and > 14% for Δ TLC% had 50% sensitivity and 70% specificity for prediction of clinically significant response to BD based on FVC. Conclusion ΔFEV1 underestimates the true effect of bronchodilators with advancing GOLD stage. Measurement of lung volumes in addition to the standard spirometric indices is recommended when determining bronchodilator response in COPD patients.

Background: Polyacrylate (PA) powder dust formed in PA manufacturing units is fine sized, i.e., in nanosize. Although several previous studies reported possible significant adverse effects of nanomaterials, studies on the harmful effect of small-sized PA particles on the respiratory health of the workers are scarce. The present study was carried out to assess the effect of PA on respiratory health and lung volumes/rates among the workers of PA manufacturing unit. Materials and Methods: The present cross-sectional study included 84 workers of PA manufacturing unit. Using interview technique as a tool for data collection, demographic, occupational, and clinical details of the workers were recorded on the predesigned pro forma. This was followed by detailed clinical examination, spirometry, chest X-ray ( posteroanterior [PA] view), and high-resolution computed tomography (HRCT) examination of each worker. Results: On the basis of clinical examination, chest radiography, and HRCT, 17.9% of the workers were found to have fibrotic and cavitary changes in lung parenchyma. The production department workers had a higher proportion of respiratory morbidities as compared to supervisory or office staff. Age, gender, smoking habit, and duration of exposure were nonsignificant risk factors for respiratory morbidity. The overall mean forced vital capacity, forced expiratory volume in 1st s, Peak Expiratory Flow Rate (PEFR), (Maximal Mid Expiratory Flow Rate) MMEFR0.2–1.2, and MMEFR25%–75% were 3.19 ± 0.77 L, 2.72 ± 0.67 L, 6.82 ± 1.86 L/s, 5.79 ± 2.03 L/s, and 3.16 ± 1.19 L/s, respectively. Females and those having respiratory morbidity had significantly lower values of all spirometric parameters as compared to their counterparts. Conclusions: The workers exposed to engineered fine dust of PA may be at risk of respiratory ill-health.

Sub‐acute (e.g., inhalation injury) and/or acute insults sustained during a severe burn injury impairs pulmonary function. However, previous work has not fully characterized pulmonary function in adults with well‐healed burn injuries decades after an injury. Therefore, we tested the hypothesis that adults with well‐healed burn injuries have lower pulmonary function years after recovery. Our cohort of adults with well‐healed burn‐injuries (n = 41) had a lower forced expiratory volume in one second (Burn: 93 ± 16 vs. Control: 103 ± 10%predicted, mean ± SD; d = 0.60, p = 0.04), lower maximal voluntary ventilation (Burn: 84 [71–97] vs. Control: 105 [94–122] %predicted, median [IQR]; d = 0.84, p < 0.01), and a higher specific airway resistance (Burn: 235 ± 80 vs. Control: 179 ± 40%predicted, mean ± SD; d = 0.66, p = 0.02) than non‐burned control participants (n = 12). No variables were meaningfully influenced by having a previous inhalation injury (d ≤ 0.44, p ≥ 0.19; 13 of 41 had an inhalation injury), the size of the body surface area burned (R2 ≤ 0.06, p ≥ 0.15; range of 15%–88% body surface area burned), or the time since the burn injury (R2 ≤ 0.04, p ≥ 0.22; range of 2–50 years post‐injury). These data suggest that adults with well‐healed burn injuries have lower pulmonary function decades after injury. Therefore, future research should examine rehabilitation strategies that could improve pulmonary function among adults with well‐healed burn injuries. [ABSTRACT FROM AUTHOR]

Andras Bikov,1,2 Peter Lange,3,4 Julie A Anderson,5 Robert D Brook,6 Peter MA Calverley,7 Bartolome R Celli,8 Nicholas J Cowans,9 Courtney Crim,10 Ian J Dixon,9 Fernando J Martinez,11 David E Newby,12 Julie C Yates,10 Jørgen Vestbo1,2 1Manchester University NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, UK; 2Division of Infection, Immunity & Respiratory Medicine, University of Manchester, Manchester, UK; 3Medical Department, Herlev and Gentofte Hospital, Herlev, Denmark; 4Section of Epidemiology, Department of Public Health, University of Copenhagen, Copenhagen, Denmark; 5Research & Development, GlaxoSmithKline, Middlesex, UK; 6University of Michigan Health System, Ann Arbor, MI, USA; 7University of Liverpool, Department of Medicine, Clinical Sciences Centre, University Hospital Aintree, Liverpool, UK; 8Pulmonary and Critical Care Division, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, USA; 9Statistics & Programming, Veramed Ltd., Twickenham, UK; 10Research & Development, GlaxoSmithKline, Research Triangle Park, NC, USA; 11Division of Pulmonary and Critical Care Medicine, Weill Cornell Medicine, New York, NY, USA; 12British Heart Foundation Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, UKCorrespondence: Andras Bikov 2nd Floor ERC Building, Wythenshawe Hospital, Southmoor Road, Manchester M23 9LT, UKTel +36203141599Fax +441612915730Email andras.bikov@gmail.comPurpose: Chronic obstructive pulmonary disease (COPD) is one of the leading causes of death worldwide. Impaired lung function is associated with heightened risk for death, cardiovascular events, and COPD exacerbations. However, it is unclear if forced expiratory volume in one second (FEV1) and forced vital capacity (FVC) differ in predictive value.Patients and Methods: Data from 16,485 participants in the Study to Understand Mortality and Morbidity (SUMMIT) in COPD were analyzed. Patients were grouped into quintiles for each lung function parameter (FEV1 %predicted, FVC %predicted, FEV1/FVC). The four highest quintiles (Q2–Q5) were compared to the lowest (Q1) to assess their relationship with all-cause mortality, cardiovascular events, and moderate-to-severe and severe exacerbations. Cox-regression was used, adjusted for age, sex, ethnicity, body-mass index, smoking status, previous exacerbations, cardiovascular disease, treatment, and modified Medical Research Council dyspnea score.Results: Compared to Q1 (< 53.5% FEV1 predicted), increasing FEV1 quintiles (Q2 53.5– 457.5% predicted, Q3 57.5– 461.6% predicted, Q4 61.6– 465.8% predicted, and Q5 ≥ 65.8%) were all associated with significantly decreased all-cause mortality (20% (4– 34%), 28% (13– 40%), 23% (7– 36%), and 30% (15– 42%) risk reduction, respectively). In contrast, a significant risk reduction (21% (4– 35%)) was seen only between Q1 and Q5 quintiles of FVC. Neither FEV1 nor FVC was associated with cardiovascular risk. Increased FEV1 and FEV1/FVC quintiles were also associated with the reduction of moderate-to-severe and severe exacerbations while, surprisingly, the highest FVC quintile was related to the heightened exacerbation risk (28% (8– 52%) risk increase).Conclusion: Our results suggest that FEV1 is a stronger predictor for all-cause mortality than FVC in moderate COPD patients with heightened cardiovascular risk and that subjects with moderate COPD have very different risks.Keywords: airflow limitation, cardiovascular risk, exacerbation, lung function, lung volumes, death rate

Inspiratory muscle training (IMT) has found its way into athletes' routine as a promising way of improving pulmonary function in combination with standard training. The objective of the study was to examine the effects of resistive IMT on the pulmonary function variables in athletes of two combat sports, i.e., mixed martial arts (MMA) and kickboxing. Fourteen kickboxing and 12 MMA male athletes qualified for the study. They were randomly assigned into experimental and control groups. While both groups participated in their standard training, the experimental group additionally participated in IMT which consisted of 30 breaths twice a day for 6 weeks. The pulmonary functions were measured at baseline and after 6 weeks of IMT. The addition of IMT to standard training increased significantly the forced expiratory volume in the first second to vital capacity ratio (FEV1/VC), and the maximum voluntary ventilation (MVV) (p < 0.05) with changes of 5.7%, and 28.6%, respectively, in MMA athletes. The kickboxing group showed no significant changes. The interaction of the sport discipline and IMT intervention yielded a strong significant change in the MVV (F(1, 11) = 14.53, p < 0.01), and FEV1/VC (F(1, 11) = 20.67, p < 0.01) to the benefit of MMA athletes in comparison with kickboxing athletes. Combining resistive IMT for 6 weeks with standard training was effective to improve some pulmonary functions in MMA athletes, but did not lead to additional gains in kickboxing athletes. [ABSTRACT FROM AUTHOR]

BACKGROUND: The role of end-expiratory lung volume (EELV) during a spontaneous breathing trial (SBT) in patients who were tracheostomized and on prolonged mechanical ventilation is unclear. This study aimed to assess EELV during a 60-min SBT and its correlation with weaning success. METHODS: Enrolled subjects admitted to a weaning unit were measured for EELV and relevant parameters before and after the SBT. RESULTS: Of the 44 enrolled subjects, 29 (66%) were successfully liberated, defined as not needing mechanical ventilation for 5 d. The success group had fewer subjects with chronic kidney disease (41% vs 73%, P = .044), stronger mean ± SD maximum inspiratory pressure (41.6 ± 10.4 vs 34.1 ± 7.1 cm H2O; P = .02) and mean ± SD maximum expiratory pressure (46.9 ± 11.7 vs 35.3 ± 16.9 cm H2O; P = .01) versus the failure group. Toward the end of the SBT, the success group had a significant increase in the mean ± SD EELV (before vs after: 1,278 ± 744 vs 1,493 ± 867 mL; P = .040) and a decrease in the mean ± SD rapid shallow breathing index (83.8 ± 39.4 vs 66.3 ± 29.4; P = .02), whereas there were no significant changes in these 2 parameters in the failure group. The Cox regression analysis showed that, at the beginning of SBT, a greater difference between EELV with a PEEP of 0 cm H2O and with a PEEP of 5 cm H2O was significantly correlated to a higher likelihood of weaning success. Toward the end of the SBT, a greater EELV level at a PEEP of 0 cm H2O was also correlated with weaning success. Also, the greater difference of EELV at a PEEP of 0 cm H2O between the beginning and the end of the SBT was also correlated with a shorter duration to weaning success. CONCLUSIONS: The change in EELV during a 60-min SBT may be of prognostic value for liberation from prolonged mechanical ventilation in patients who had a tracheostomy. Our findings suggest a model to understand the underlying mechanism of failure of liberation from mechanical ventilation in these patients. [ABSTRACT FROM AUTHOR]

Background: Intra-abdominal hypertension (IAH) is common in critically ill patients and is associated with increased morbidity and mortality. High positive end-expiratory pressures (PEEP) can reverse lung volume and oxygenation decline caused by IAH, but its impact on alveolar overdistension is less clear. We aimed to find a PEEP range that would be high enough to reduce atelectasis, while low enough to minimize alveolar overdistention in the presence of IAH and lung injury. Methods: Five anesthetized pigs received standardized anesthesia and mechanical ventilation. Peritoneal insufflation of air was used to generate intra-abdominal pressure of 27 cmH2O. Lung injury was created by intravenous oleic acid. PEEP levels of 5, 12, 17, 22, and 27 cmH2O were applied. We performed computed tomography and measured arterial oxygen levels, respiratory mechanics, and cardiac output 5 min after each new PEEP level. The proportion of overdistended, normally aerated, poorly aerated, and non-aerated atelectatic lung tissue was calculated based on Hounsfield units. Results: PEEP decreased the proportion of poorly aerated and atelectatic lung, while increasing normally aerated lung. Overdistension increased with each incremental increase in applied PEEP. "Best PEEP" (respiratory mechanics or oxygenation) was higher than the "optimal CT inflation PEEP range" (difference between lower inflection points of atelectatic and overdistended lung) in healthy and injured lungs. Conclusions: Our findings in a large animal model suggest that titrating a PEEP to respiratory mechanics or oxygenation in the presence of IAH is associated with increased alveolar overdistension. [ABSTRACT FROM AUTHOR]