Low Lung Volumes Research Articles

Back to basics: lung volumes on pediatric chest X-rays-pitfalls and diagnostic implications.

Evaluating lung "volumes" when interpreting pediatric chest radiographs is useful for supporting the diagnosis of lung pathology in children. Lung volumes can be estimated using semi-objective criteria such as anterior rib counting. Estimating lung volumes is one advantage plain radiographs have over other imaging modalities such as ultrasound or even cross-sectional imaging (Computed Tomography and Magnetic Resonance Imaging, where volumes can be calculated, but remain difficult to quickly be appreciated subjectively or semi-objectively in clinical practice). Lung hyperinflation is often a surrogate of air-trapping and may be suggestive of diseases such as bronchiolitis. Identifying under-inspired chest radiographs is also important to avoid misinterpreting findings related to low lung volumes as pathology, which is a significant diagnostic pitfall in children. This pictorial review will demonstrate the method for evaluating lung volumes, specifically for identifying lung hyperinflation as a surrogate of air-trapping and under-inspiration for avoiding false positive diagnoses.

Relationship between symptoms and results on spirometry in adults seen in non-tertiary public health facilities presenting with preserved ratio impaired spirometry.

Preserved ratio impaired spirometry (PRISm), defined by reduced forced expiratory volume in 1 second (FEV1) without meeting criteria for airway obstruction, is often encountered in clinical practice. The management of this heterogeneous condition in individuals with chronic respiratory symptoms is challenging, especially under limited diagnostic resources. Since 2020, all consecutive patients referred for spirometry at our institution have been invited to participate in our registry. Other than spirometry, no other physiological lung function testing is available in this public health service. Therefore, we reviewed our databank with the aim of assessing: i) the proportion of symptomatic patients aged 18 years or older referred for spirometry presenting with PRISm; ii) the rate of inhaled medication used in this group, suggesting a referral diagnosis of obstructive airway disease (OAD); and iii) the relationship between symptoms and results on spirometry in PRISM compared to a group with obstruction matched by FEV1. To this end, the COPD Assessment Test (CAT) and the Asthma Control Test (ACT) were conjointly responded to by 1032 participants, irrespective of the clinical suspicion. We found that 22% had PRISM, of whom 200 were paired with obstruction by FEV1 (68±10% of predicted). The CAT and ACT results were well-correlated in both groups (r=-0.727 and -0,698, respectively; p<0.001) and used to measure symptoms. Participants in the final sample (n=400) were aged 62±13 years; 70% were ever smokers; and 55% reported household exposure to biomass smoke (at least 5 years). The CAT responses were in the range of moderate symptoms (17±9) and ACT borderline for uncontrolled symptoms (19±5). The main differences were higher body mass index (33±7 versus 29±7 kg/m2; p<0.001) and proportion of females (72 versus 49%; p<0.001) in PRISm compared to obstruction. This group had lower exposure to tobacco (65 versus 76% of ever-smokers) but greater exposure to biomass smoke (61 versus 49%) (p<0.05 for all). The rate of inhaled medication use was as high in PRISm as in obstruction (80%). Notwithstanding matched FEV1, we found less prominent signs of airway disease in PRISM: marginally reduced FEV1/forced vital capacity (FVC) ratio (94±8% of predicted); higher expiratory flow between 25% and 75% of vital capacity, despite presumed lower lung volumes (lower FVC); and lower rate of bronchial hyperresponsiveness. In an identical multivariate model, FEV1 predicted symptoms of obstruction only. In conclusion, these data raise suspicion of a substantial rate of misclassification of individuals with PRISM as having OAD in healthcare facilities with constraints on diagnostic resources.

Cardiorespiratory and muscle oxygenation responses to voluntary hypoventilation at low lung volume in upper body repeated sprints

PurposeTo investigate the impact of voluntary hypoventilation at low lung volumes (VHL) during upper body repeated sprints (RS) on performance, metabolic markers and muscle oxygenation in Brazilian Jiu-Jitsu (BJJ) athletes.MethodsEighteen male well-trained athletes performed two randomized RS sessions, one with normal breathing (RSN) and another with VHL (RS-VHL), on an arm cycle ergometer, consisting of two sets of eight all-out 6-s sprints performed every 30 s. Peak (PPO), mean power output (MPO), and RS percentage decrement score were calculated. Arterial oxygen saturation (SpO2), heart rate (HR), gas exchange, and muscle oxygenation of the long head of the triceps brachii were continuously recorded. Blood lactate concentration ([La]) was measured at the end of each set. Bench press throw peak power (BPPP) was recorded before and after the RS protocol.ResultsAlthough SpO2 was not different between conditions, PPO and MPO were significantly lower in RS-VHL. V˙\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\\dot{\ ext{V}}}$$\\end{document}E, HR, [La], and RER were lower in RS-VHL, and VO2 was higher in RS-VLH than in RSN. Muscle oxygenation was not different between conditions nor was its pattern of change across the RS protocol influenced by condition. [La] was lower in RS-VHL than in RSN after both sets.ConclusionPerformance was significantly lower in RS-VHL, even though SPO2 was not consistent with hypoxemia. However, the fatigue index was not significantly affected by VHL, nor was the neuromuscular upper body power after the RS-VHL protocol. Additionally, [La] was lower, and oxygen consumption was higher in RS-VHL, suggesting a higher aerobic contribution in this condition.

Prenatal Prognosis of Omphalocele Using Magnetic Resonance Imaging Measurement of Fetal Lung Volumes

BackgroundOmphalocele is a congenital midline abdominal wall defect resulting in herniation of viscera into a membrane-covered sac. Pulmonary complications, including pulmonary hypoplasia, pulmonary hypertension, and prolonged respiratory support are a leading cause of neonatal morbidity and mortality. Objective(s)This study aimed to assess the role of fetal MRI-derived lung volumes and omphalocele defect size as clinical tools to prognosticate postnatal pulmonary morbidity and neonatal mortality in those with a prenatally diagnosed omphalocele (PDO). Study DesignThis was a retrospective cohort study of all pregnancies with PDO at our fetal center from 2007–2023. Pregnancies with aneuploidy or concurrent life-limiting fetal anomalies were excluded. Using fetal MRI, observed-to-expected total fetal lung volume (O/E TLV) ratios were determined by a previously published method. The transverse diameter of the abdominal defect was also measured. The O/E TLV ratios and abdominal defect measurements were compared with postnatal outcomes. The primary outcome was death at any time. Secondary outcomes included death in the first 30 days of life or before discharge from birth hospitalization, the requirement of respiratory support with intubation and mechanical ventilation, or development of pulmonary hypertension. ResultsOf 101 pregnancies with a PDO, 54 pregnancies (53.5%) with prenatally diagnosed omphalocele met inclusion criteria. There was a significant increase in the rate of death when compared between the three O/E TLV classifications: 1/36 (2.8%) in the O/E≥50% group, 3/14 (21.4%) in the O/E 25%–49.9% group, and 4/4 (100%) in the O/E<25% group (P<.001). The rate of intubation increased with the severity of O/E TLV classification, with 27.8% in the O/E≥50% group, 64.3% in the O/E 25%–49.9% group, and 100% in the O/E<25% group (P=.003). The rate of pulmonary hypertension was also higher in the O/E 25%–49.9% (50.0%) and the O/E<25% (50.0%) groups compared to the O/E≥50% group (8.3%, P=.002). There was no association between the transverse diameter of the abdominal wall defect and the primary outcome of death (OR=1.08 95% CI=[0.65–1.78], P=.77). ConclusionsIn our cohort of patients with PDO, O/E TLV<50% is associated with death, need for intubation, prolonged intubation, and pulmonary hypertension. In contrast, omphalocele size demonstrated no prognostic value for these outcomes. The strong association between low fetal lung volume on MRI and poor neonatal outcomes highlights the utility of fetal MRI for estimating postnatal prognosis. Clinicians can utilize fetal lung volumes to direct perinatal counseling and optimize the plan of care.

Respiratory modulation of sympathetic transduction to blood pressure in health and type 2 diabetes.

Type 2 diabetes (T2D) is often accompanied by hypertension, exaggerated blood pressure (BP) responses to sympatho-excitatory stressors, and raised cardiovascular disease risk. Appropriate respiratory-sympathetic coupling and sympathetic transduction to BP are important for short- and longer-term BP control. We tested the hypotheses that respiratory modulation of muscle sympathetic nerve activity (MSNA) and its transduction to BP would be impaired in T2D and associated with higher BP and respiratory-coupled BP variability. Resting MSNA, respiration and beat-to-beat BP were recorded in 20 T2D (49.1 ± 7.4 years; mean ± SD) and 13 healthy control (46.3 ± 9.4 years) participants. MSNA and the transduction of sympathetic bursts (signal-averaging) to mean arterial pressure (MAP) were compared at low and high lung volume phases. The peak MAP response following a sympathetic burst was lower during the high lung volume than low lung volume phase in controls (P = 0.005), whereas it was unchanged with phase in T2D participants (P = 0.522). Respiratory modulation of MSNA was impaired in T2D participants, who had an attenuated reduction in burst incidence from low to the high lung volume phase, versus controls (27.8 ± 38.4% vs. 49.4 ± 24.6%, respectively; P = 0.043). The T2D participants were grouped into unimpaired respiratory modulators (burst incidence modulation median or above) or impaired respiratory modulators (below median). Impaired modulators had higher systolic BP (133 ± 14 vs. 121 ± 11mmHg, P = 0.046), greater Traube-Hering wave amplitudes (6.3 ± 2.4 vs. 4.6 ± 1.1mmHg; P = 0.028) and higher BP variability (MAP average real variability, 2.0 ± 0.7 vs. 1.4 ± 0.3, P = 0.033). Respiratory modulation of MSNA and sympathetic transduction to BP are altered in T2D patients and may contribute to their increased hypertension and cardiovascular risk. KEY POINTS: Respiratory-sympathetic coupling and sympathetic transduction to blood pressure (BP) contribute to short- and longer-term BP control. Our understanding of these processes in health and type 2 diabetes (T2D), a condition with high prevalence of hypertension and cardiovascular risk, is incomplete. We found that respiration and sympathetic transduction to BP are coupled in healthy individuals. The mean arterial pressure response to a sympathetic burst was reduced during the high lung volume compared to the low lung volume phase. This coupling was absent in T2D. Respiratory modulation of muscle sympathetic nerve activity (MSNA) is impaired in T2D, with a blunted reduction of MSNA observed during the high lung volume phase. T2D patients with impaired respiratory MSNA modulation had augmented systolic BP, respiratory-related BP excursions (Traube-Hering waves) and BP variability. Abnormal respiratory modulation of MSNA and sympathetic transduction to BP in T2D may contribute to altered blood pressure control and cardiovascular risk in this population.

Apnoea as a novel method to improve exercise performance: A current state of the literature.

Acute breath-holding (apnoea) induces a spleen contraction leading to a transient increase in haemoglobin concentration. Additionally, the apnoea-induced hypoxia has been shown to lead to an increase in erythropoietin concentration up to 5h after acute breath-holding, suggesting long-term haemoglobin enhancement. Given its potential to improve haemoglobin content, an important determinant for oxygen transport, apnoea has been suggested as a novel training method to improve aerobic performance. This review aims to provide an update on the current state of the literature on this topic. Although the apnoea-induced spleen contraction appears to be effective in improving oxygen uptake kinetics, this does not seem to transfer into immediately improved aerobic performance when apnoea is integrated into a warm-up. Furthermore, only long and intense apnoea protocols in individuals who are experienced in breath-holding show increased erythropoietin and reticulocytes. So far, studies on inexperienced individuals have failed to induce acute changes in erythropoietin concentration following apnoea. As such, apnoea training protocols fail to demonstrate longitudinal changes in haemoglobin mass and aerobic performance. The low hypoxic dose, as evidenced by minor oxygen desaturation, is likely insufficient to elicit a strong erythropoietic response. Apnoea therefore does not seem to be useful for improving aerobic performance. However, variations in apnoea, such as hypoventilation training at low lung volume and repeated-sprint training in hypoxia through short end-expiratory breath-holds, have been shown to induce metabolic adaptations and improve several physical qualities. This shows promise for application of dynamic apnoea in order to improve exercise performance. HIGHLIGHTS: What is the topic of this review? Apnoea is considered as an innovative method to improve performance. This review discusses the effectiveness of apnoea (training) on performance. What advances does it highlight? Although the apnoea-induced spleen contraction and the increase in EPO observed in freedivers seem promising to improve haematological variables both acutely and on the long term, they do not improve exercise performance in an athletic population. However, performing repeated sprints on end-expiratory breath-holds seems promising to improve repeated-sprint capacity.

Pulmonary Function, Computed Tomography Lung Abnormalities, and Small Airway Disease after COVID-19: 3-, 6-, and 9-Month Follow-Up.

Background/Objectives: Coronavirus disease 2019 (COVID-19) course may differ among individuals-in particular, those with comorbidities may have severe pneumonia, requiring oxygen supplementation or mechanical ventilation. Post-COVID-19 long-term structural changes in imaging studies can contribute to persistent respiratory disturbance. This study aimed to investigate COVID-19 sequels affecting the possibility of persistent structural lung tissue abnormalities and their influence on the respiratory function of peripheral airways and gas transfer. Methods: Patients were divided into two groups according to severity grades described by the World Health Organization. Among the 176 hospitalized patients were 154 patients with mask oxygen supplementation and 22 patients with high-flow nasal cannula (HFNC) or mechanical ventilation. All tests were performed at 3, 6, and 9 months post-hospitalization. Results: Patients in the severe/critical group had lower lung volumes in FVC, FVC%, FEV1, FEV1%, LC, TLC%, and DLCO% at three months post-hospitalization. At 6 and 9 months, neither group had significant FVC and FEV1 value improvements. The MEF 25-75 values were not significantly higher in the mild/moderate group than in the severe/critical group at three months. There were weak significant correlations between FVC and FEV1, MEF50, MEF 75, plethysmography TLC, disturbances in DLCO, and total CT abnormalities in the severe/critical group at three months. In a mild/moderate group, there was a significant negative correlation between the spirometry, plethysmography parameters, and CT lesions in all periods. Conclusions: Persistent respiratory symptoms post-COVID-19 can result from fibrotic lung parenchyma and post-infectious stenotic small airway changes not visible in CT, probably due to persistent inflammation.

Effects of a 6-Week Repeated-Sprint Training With Voluntary Hypoventilation at Low and High Lung Volume on Repeated-Sprint Ability in Female Soccer Players.

To investigate the effects of repeated-sprint training with voluntary hypoventilation at low (RSH-VHL) and high (RS-VHH) lung volume on repeated-sprint ability (RSA) in female athletes. Over a 6-week period, 24 female soccer players completed 12 sessions of repeated 30-m running sprints with end-expiratory breath holding (RSH-VHL, n = 8), end-inspiratory breath holding (RS-VHH, n = 8), or unrestricted breathing (RS-URB, n = 8). Before and after training, a running RSA test consisting of performing 30-m all-out sprints until exhaustion was implemented. From before to after training, the number of sprints completed during the RSA test was increased in both RSH-VHL (19.3 [0.9] vs 22.6 [0.9]; P < .01) and RS-VHH (19.3 [1.5] vs 20.5 [1.7]; P < .01) but not in RS-URB (19.4 [1.3] vs 19.5 [1.7]; P = .67). The mean velocity and the percentage decrement score calculated over sprints 1 to 17 were, respectively, higher (82.2% [1.8%] vs 84.6% [2.1%] of maximal velocity) and lower (23.7% [3.1%] vs 19.4% [3.2%]) in RSH-VHL (P < .01), whereas they remained unchanged in RS-VHH and RS-URB. The mean arterial oxygen saturation recorded during training at the end of the sprints was lower in RSH-VHL (92.1% [0.4%]) than in RS-VHH (97.3% [0.1%]) and RS-URB (97.8% [0.1%]). This study shows that female athletes can benefit from the RSH-VHL intervention to improve RSA. The performance gains may have been limited by the short sprinting distance with end-expiratory breath holding, which provoked only moderate hypoxemia. The increase in the number of sprints in RS-VHH seems to show that factors other than hypoxia may have played a role in RSA improvement.

Respiratory Modulation of Muscle Sympathetic Nerve Activity in Type 2 Diabetes Mellitus

Dysfunctional sympathetic neural regulation is present in patients with type 2 diabetes (T2D) with augmented muscle sympathetic nerve activity (MSNA) responses to handgrip exercise, cold pressor testing, and augmented sympathetic-blood pressure transduction identified. MSNA is modulated by respiration such that it is inhibited at higher lung volumes and increased at lower lung volumes. Herein we aimed to determine whether T2D affects the respiratory modulation of MSNA. Resting MSNA (microneurography) and respiration pattern (strain-gauge pneumobelt) were measured simultaneously in 20 patients with T2D (age 49.1±7.4 years, body mass index [BMI] 31.9±4.1 kg∙m−2, mean ± SD) and 13 age- and BMI-matched, healthy controls (46.3±9.4 years; 32.1±4.6 kg∙m−2). MSNA was stratified by the phase of respiration. Further comparisons were made between low lung volume (defined as 60-100% expiration + 0-60% inspiration) and high lung volume states (60-100% inspiration + 0-60% expiration). Resting MSNA burst frequency, burst incidence and total activity were similar between T2D and controls (p=0.953, p=0.624, and p=0.884, respectively). Both groups exhibited peak MSNA in late expiration to early inspiration, whilst inhibition of MSNA occurred during late inspiration to early expiration (respiratory phase p&lt;0.001 for burst frequency, incidence and total activity), though no group x respiratory phase interaction was observed (p&gt;0.05 for all MSNA measures). When MSNA responses were compared between lung volume states, percent reduction of MSNA burst incidence from low lung volume to high lung volume was less in T2D than controls (26.1±33.9 vs 50.1±25.6%, p=0.025). Furthermore, in T2D, there was a shift in the distribution of MSNA bursts with a greater proportion of bursts occurring at high lung volumes (i.e., burst count during high lung volume divided by total burst count) compared to controls (43.8±10.5 vs. 37.8±12.5% respectively, group x volume interaction p=0.04). Notably, the normal pattern of respiratory modulation of MSNA was absent in 5 T2D patients (non-modulators), whilst this did not occur in any control participants. Non-modulators had higher systolic blood pressure compared to modulators (138.7±16.6 vs. 123.2±10.6 mmHg respectively, p=0.024), with no differences in age, BMI, HbA1c, duration of T2D, or overall MSNA parameters (all p&lt;0.05). These results suggest that whilst respiratory modulation of MSNA occurs in T2D, its effect appears blunted compared to healthy controls. Notably, the usual pattern of respiratory-sympathetic coupling is absent in some T2D patients, which may be associated with higher resting systolic blood pressure. MP is supported by the Greenlane Research and Educational Fund (21/01/4153). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Pulmonary Function Abnormalities in Heart Failure Subtypes: Impact of Upper Body Adiposity

Study objective: Heart failure (HF) syndrome is associated with pulmonary system abnormalities that have a direct impact on mortality. Heart failure with preserved ejection fraction (HFpEF) and heart failure with reduced ejection fraction (HFrEF) are distinct subtypes of HF with different pathophysiologies, clinical presentations, and treatment approaches. Obesity is highly prevalent in HFpEF and significantly contributes to its development. Importantly, obesity and high abdominal adiposity can have significant effects on pulmonary function. Therefore, HFpEF patients may have more pronounced pulmonary function impairment than HFrEF patients in part due to higher prevalence of upper body adiposity. Hypothesis: We hypothesized that lung volumes would be lower in patients with HFpEF compared to those with HFrEF and CTL. Further, we hypothesized that higher upper body adiposity (measured as trunk fat by dual-energy X-ray absorptiometry) would be associated with lower lung volumes in patients with HFpEF. Methods: HFpEF patients (n=26), HFrEF patients (n=26) and CTL (n=36) performed pulmonary function tests according to ATS/ERS guidelines. Total lung capacity (TLC), residual volume (RV), forced vital capacity (FVC), and forced expiratory volume in one second (FEV1) were measured and absolute and % predicted values are reported. Dual-energy X-ray absorptiometry scans quantified % trunk fat. Absolute lung volumes were compared across groups using ANCOVA with age as a covariate and % predicted lung volumes were compared using one-way ANOVA. Results: HFpEF patients were older than HFrEF patients and CTL (HFpEF: 71±9 vs. HFrEF: 65±9 vs. CTL: 63±11 yrs, both p&lt;0.05) while no differences were present among groups for sex, height, or BMI (all, p&gt;0.05). HFpEF patients had higher % trunk fat than CTL (p&lt;0.01), while no differences were present between HFrEF and HFpEF or CTL (p&gt;0.05) (HFpEF: 46±11 vs. HFrEF: 42±8 vs. CTL: 38±11%). HFpEF patients had lower FVC (HFpEF: 3.0±0.7 vs. HFrEF: 3.7±1.0 vs. CTL: 3.8±0.8 L), FEV1 (HFpEF: 2.3±0.5 vs. HFrEF: 2.8±0.8 vs. CTL: 2.9±0.6 L), TLC (HFpEF: 5.5±1.3 vs. HFrEF: 6.3±1.4 vs. CTL: 6.4±1.1 L), and % predicted TLC than CTL (all, p&lt;0.05). HFpEF and HFrEF patients had lower % predicted FVC and % predicted FEV1 than CTL (p&lt;0.05). All other pulmonary function parameters were not different among groups (p&gt;0.05). There was a negative relationship between % trunk fat and TLC for HFpEF patients (r= -0.51, p&lt;0.05). There were negative relationships between % trunk fat and FVC for CTL (r= -0.37) and HFpEF patients (r= -0.50) (both, p&lt;0.05), with statistically different y-intercepts (p&lt;0.01). There were no other significant relationships (all, p&gt;0.05). Conclusion: These findings demonstrate that patients with HF have smaller lung volumes than CTL. Further, our findings suggest that upper body adiposity may be an important contributing factor to these pulmonary system abnormalities in HFpEF. None. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

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...

Deep Learning-based Segmentation of Computed Tomography Scans Predicts Disease Progression and Mortality in Idiopathic Pulmonary Fibrosis.

Rationale: Despite evidence demonstrating a prognostic role for computed tomography (CT) scans in idiopathic pulmonary fibrosis (IPF), image-based biomarkers are not routinely used in clinical practice or trials. Objectives: To develop automated imaging biomarkers using deep learning-based segmentation of CT scans. Methods: We developed segmentation processes for four anatomical biomarkers, which were applied to a unique cohort of treatment-naive patients with IPF enrolled in the PROFILE (Prospective Observation of Fibrosis in the Lung Clinical Endpoints) study and tested against a further United Kingdom cohort. The relationships among CT biomarkers, lung function, disease progression, and mortality were assessed. Measurements and Main Results: Data from 446 PROFILE patients were analyzed. Median follow-up duration was 39.1 months (interquartile range, 18.1-66.4 mo), with a cumulative incidence of death of 277 (62.1%) over 5 years. Segmentation was successful on 97.8% of all scans, across multiple imaging vendors, at slice thicknesses of 0.5-5 mm. Of four segmentations, lung volume showed the strongest correlation with FVC (r = 0.82; P < 0.001). Lung, vascular, and fibrosis volumes were consistently associated across cohorts with differential 5-year survival, which persisted after adjustment for baseline gender, age, and physiology score. Lower lung volume (hazard ratio [HR], 0.98 [95% confidence interval (CI), 0.96-0.99]; P = 0.001), increased vascular volume (HR, 1.30 [95% CI, 1.12-1.51]; P = 0.001), and increased fibrosis volume (HR, 1.17 [95% CI, 1.12-1.22]; P < 0.001) were associated with reduced 2-year progression-free survival in the pooled PROFILE cohort. Longitudinally, decreasing lung volume (HR, 3.41 [95% CI, 1.36-8.54]; P = 0.009) and increasing fibrosis volume (HR, 2.23 [95% CI, 1.22-4.08]; P = 0.009) were associated with differential survival. Conclusions: Automated models can rapidly segment IPF CT scans, providing prognostic near and long-term information, which could be used in routine clinical practice or as key trial endpoints.

Prevalence of respiratory morbidities and lung function outcome in Traffic Police in eastern Nepal

Introduction: Outdoor air pollution is a cause for occupational lung disease. A community vulnerable to lung health hazards of outdoor air pollutants from vehicle emissions is traffic police, whose long duration of outdoor work, with no proper protective equipment, predisposes them to respiratory symptoms such as cough, dryness of nose, throat irritation and wheezing due to the air pollutants causing inflammation of the airways. The risks to lung function and development of respiratory disease are not known in traffic police in eastern Nepal. Objectives: To determine respiratory morbidities and lung function values of traffic police working in eastern Nepal. Methodology: This cross-sectional study was conducted for 6 months, from 1st January to 30th June 2022, in traffic police using a structured questionnaire adapted from American Thoracic Society and National Heart &amp; Lung Institute and portable spirometry, at the duty posts or office. Data were represented using descriptive statistics. Results: The study enrolled 129 traffic police in eastern Nepal, 109 (84.50%) were male and 20 (15.50%) females, mean age 34.50 (±8). Mean duration of active duty was 9.76 years (±6.19). Cough was present in 33 (25.58%), 50 (38.76%) phlegm, 37 (28.68%) dyspnea, and 28 (21.71%) noisy breathing. Mean FEV1% in ≤ 5 years exposure was 76.75 (±17.28), and 65.26 (±18.88) in &gt; 15 years. Mean FVC% in ≤ 5 years exposure was 81.81 (±20.56) and 76.18 (±19.77) in those working &gt;15 years. Mean FEF25-75% in ≤ 5 years was 73.69 (±23.73), which was 62.04 (±33.97) in those &gt; 15 years. The spirometry analysis suggested obstructive airways disease in 90 personnel (69.8%), restrictive disease in 80 (62%), mixed airways disease in 72 (55.8%), and small airways disease in 52 (40.3%). Conclusion: There was increased burden of respiratory problems such as cough with sputum production, noisy breathing, and dyspnea and lower lung volumes and flows among traffic police working in different parts of eastern Nepal. Long duration of exposure to traffic environments resulted in spirometry analyses suggestive of obstructive and restrictive airways diseases.

A Comparative Analysis of Implant-sparing Plan Versus Conventional Plans Utilizing Helical Tomotherapy in Breast Cancer Patients Undergoing Breast Reconstruction.

To compare implant sparing irradiation with conventional radiotherapy (RT) using helical (H) and TomoDirect (TD) techniques in breast cancer patients undergoing immediate breast reconstruction (IBR). The dosimetric parameters of 40 patients with retropectoral implants receiving 50.4 Gy delivered in 28 fractions were analyzed. Three plans were created: H plan using conventional planning target volume (PTV) that included the chest wall, skin, and implant; TD plan using conventional PTV; and Hs plan using implant-sparing PTV. The H, TD, and Hs plans were compared for PTV doses, organ-at-risk (OAR) doses, and treatment times. Dose distribution in the Hs plan was less homogeneous and uniform than that in the H and TD plans. The TD plan had lower lung, heart, contralateral breast, spinal cord, liver, and esophagus doses than the Hs plan. Compared to the Hs plan, the H plan had lower lung volume receiving 5Gy (V5) (39.1±3.9 vs. 41.2±3.9 Gy; p<0.001), higher V20 (12.3±1.3 vs. 11.5±2.6 Gy; p=0.02), and higher V30 (7.5±1.6 vs. 4.4±1.7 Gy; p<0.001). H plan outperformed Hs plan in heart dosimetric parameters except V20. The Hs plan had significantly lower mean implant doses (43.4±2.1 Gy) than the H plan (51.4±0.5 Gy; p<0.001) and the TD plan (51.9±0.6 Gy; p<0.001). Implementing an implant sparing technique for silicone dose reduction decreases lung doses. Conventional H and TD plans outperform the implant sparing helical plan dosimetrically. Because capsular contracture during RT is unpredictable, long-term clinical outcomes are required to determine whether silicon should be spared.

Lung function and cardiovascular risk at age 45 in a cohort of the general population

BackgroundImpaired lung function is associated with cardiovascular mortality, but the origins of this association are poorly understood. We investigated associations between lung function and cardiovascular risk scores in a general population cohort of men and women aged 45 years. MethodsParticipants are members of an unselected birth cohort followed to adulthood. Lung function determined at ages 32 and 45 by spirometry, body plethysmography, gas diffusion, and airway conductance were the main predictors. Future cardiovascular risk was estimated at age 45 using a multivariable cardiovascular risk algorithm – PREDICT. Risk scores were log-transformed and used as the dependent variable in linear regression analyses. We investigated cross-sectional associations with lung function at age 45 and longitudinal associations using changes in lung function between ages 32–45 as the predictors. Results863 of 1037 original cohort participants had data for analysis. Low lung volumes (FEV1, FVC, VA, TLC, and FRC) were associated with greater cardiovascular risk scores in the cross-sectional analyses at age 45 and the longitudinal analyses. These associations were stronger in women than in men, were independent of smoking history, and present in never smokers, even after adjusting for body mass index. Associations were not found for measures of airway function (FEV1/FVC ratio and sGaw) or gas transfer (TLco/VA). ConclusionsLow lung volumes at age 45 and accelerated pulmonary function decline are associated with a higher estimated cardiovascular risk scores in mid-adulthood. This association is stronger in women and is not explained by smoking or obesity.

Abstract 12847: The Heart Bus: A Mobile Patient-Centered Approach to Improve Early Diagnosis of Heart Failure in the Community

Introduction: Heart failure with preserved ejection fraction (HFpEF) is associated with poor quality of life and considerable morbidity and mortality risk. Early diagnosis is expected to improve clinical outcomes, but requires imaging and laboratory analyses with frequent hospital visits. We developed a mobile care unit, the Heart Bus, to improve early diagnosis of HF. Methods: The Heart Bus was a 70 m 2 trailer with examination rooms, cardiac ultrasound, exercise testing equipment, a clinical laboratory, and 4 staff. During 2020-2022, the Heart Bus team reached out to the population in local newspapers, via HF patient digital platforms, and visited locations in the West Coast of Sweden. Eligible participants had suspected signs or symptoms of HF. Participants underwent echocardiography and tests for cardiopulmonary exercise, vascular function, adenosine-stress coronary flow reserve, and routine biochemistry and haematology. Molecular and physiological deep phenotyping were also performed in the Heart Bus to facilitate future patient stratification and precision medicine (data to be presented Nov 2023). Results: Of 218 participants screened over 18 months (12/month), 200 were included. Most participants actively reached out to take part. Twenty three participants (11.5%) had HFrEF, 54 (27.0%) had HFmrEF, and 62 (31.0%) had HFpEF; 70 (35.0%) had a previous HF diagnosis. Of the remaining patients, 60 (30.0%) had intermediate risk of HFpEF. The phenotypes of the EF-stratified HF subgroups were similar. However, participants in the HFpEF cohort had more women ( p &lt; 0.001), lower lung volume ( p &lt; 0.01), higher pulse wave velocity ( p &lt; 0.01) and poorer kidney function ( p &lt; 0.05) than those with HFrEF. Conclusions: The Heart Bus mobile clinic identified large numbers of patients with HF and may represent a cost-effective way to early HF diagnosis also for underserved communities, those located remotely, or have other thresholds for admittance to HF clinics.

Comparison of Hybrid Techniques with 3D-Conformal Radiotherapy in Patients with Lung Cancer

Purpose: It’s postulated that hybrid techniques (HT) with lower weighting of IMRT/VMAT component would improve lung dose-volume parameters despite some disadvantage in PTV homogeneity index (HI) and target coverage (TC). &#x0D; Material and Methods: Conformal plans were prepared using 6-10-15 MV-X photon energies while IMRT/VMAT plans of HTs were prepared using 6MV-X. Four HTs were developed having two different ratios (10% and 50%) of IMRT/VMAT component (h-IMRT1, h-IMRT2 and h-VMAT1, h-VMAT2, respectively). HTs were compared with 3D-CRT in terms of HI and TC for PTV, and total lung (TL) and contralateral lung (CL) V5Gy, V10Gy, V20Gy and mean lung dose (MLD). &#x0D; Results: All HTs were advantageous for HI and TC, while disadvantageous for TL and CL-V5Gy. H-IMRT2 provided better TC than h-IMRT1, and so did h-VMAT2 compared to h-VMAT1. Lower weighting of IMRT/VMAT decreased TL and CL-V5Gy in HTs. In addition, h-IMRT1 decreased TL and CL-MLD and CL-V20Gy compared to h-IMRT2, while h-VMAT2 decreased TL-V20Gy and CL-MLD compared to h-VMAT2. &#x0D; Conclusion: In the RT of lung tumors close to vertebra, it may be appropriate to suggest a ratio of IMRT/VMAT component about 10% in order to decrease the low and intermediate dose-wash lung volume, if HI and TC values are acceptable.

The impact of nintedanib and pirfenidone on lung function and survival in patients with idiopathic pulmonary fibrosis in real-life setting

BackgroundIdiopathic pulmonary fibrosis (IPF) is a chronic, fibrosing interstitial pneumonia of unknown cause that is associated with radiological and/or histological features of usual interstitial pneumonia (UIP). A mean survival of 2–5 years was reported previously to the advent of antifibrotics. According to clinical trials, nintedanib and pirfenidone induce a significant delay in functional decline, with a favorable impact on survival. MethodsA real-life retrospective and longitudinal study was conducted to assess the efficacy and tolerability of antifibrotics in IPF patients, between January 2014 and December 2020. Two groups (under nintedanib or pirfenidone) were analyzed at diagnosis through their clinical features and radiological patterns. Lung function was assessed at diagnosis (time 0) and after 6, 12 and 24 months of treatment. We also compared this antifibrotic cohort with an older naïve antifibrotic cohort, mainly treated with immunosuppressive drugs and/or N- acetylcysteine. Survival was analyzed and prognostic features were also studied. Statistical analysis was performed with IBM® SPSS®. ResultsA cohort of 108 patients under antifibrotics (nintedanib n = 54; pirfenidone n = 54) was assessed. Lung function analysis showed an overall stabilization in FVC and DLCO mean predicted percentages at 6, 12 and 24 months of treatment. The mean decline in FVC and DLCO, at 12 months, was −40.95 ± 438.26 mL and −0.626 ± 1.31 mL/min/mmHg, respectively. However, during this period, 34.2% of the patients died mostly due to acute exacerbation associated with a poorer lung function at diagnosis. Mean survival in the naïve antifibrotic cohort was significantly lower than in the antifibrotic cohort (39.9 months versus 58.2 months; p < 0.005). Regarding lung function evolution and survival, we found no differences between definitive or probable UIP radiological patterns, both on patients under nintedanib and pirfenidone (p = 0.656). ConclusionsIn this real-life observational study, the positive impact of antifibrotic therapy on the IPF clinical course and on survival was corroborated. Regarding efficacy, there was no difference between patients taking nintedanib or pirfenidone. The need for an early treatment was also demonstrated, since a worse outcome is clearly associated with lower lung volumes and lower diffusing capacity at diagnosis.

The effect of abdominal bracing on respiration during a lifting task: a cross-sectional study

BackgroundAbdominal bracing is a maneuver widely used by rehabilitation specialists and sports trainers to improve spinal stability. This study aimed to investigate how lifting tasks with and without abdominal bracing affect the respiratory function of the diaphragm.MethodsM-mode ultrasonographic assessment of diaphragmatic motion combined with spirometry was performed on 31 healthy adults. Participants were asked to breathe continuously whilst lifting a load with spontaneous abdominal muscle contraction (natural loaded breathing) and abdominal bracing (AB loaded breathing).ResultsPearson’s correlations revealed strong correlations between ultrasonography and spirometry measures (p < 0.001) for all types of breathing: tidal breathing (r = 0.709, r2 = 0.503), natural loaded breathing (r = 0.731, r2 = 0.534) and AB loaded breathing (r = 0.795, r2 = 0.632). Using paired-samples t-tests, the natural loaded breathing ultrasonography revealed more caudal diaphragm positions during inspiration (p < 0.001) but not during expiration (p = .101). Spirometry demonstrated lower lung volumes (L) at the end of inspiration and expiration (p < 0.001), with no changes in total lung volume (p = 0.06). The AB loaded breathing ultrasonography revealed more caudal diaphragm positions during inspiration (p = 0.002) but not during expiration (p = 0.05). Spirometry demonstrated lower lung volumes at the end of inspiration (p < 0.001), expiration (p = 0.002), and total lung volumes (p = 0.019).ConclusionThis study demonstrated that abdominal bracing performed during a lifting task reduces lung volume despite an increase in diaphragmatic motion. Diaphragm excursions strongly correlate with lung volumes even under postural loading.Trial registrationThe study was prospectively registered on 8 April 2021 at ClinicalTrials.gov with identification number NCT04841109.

Sleep from Infancy Through Adolescence.

This article describes the changes in normal sleep regulation, structure, and organization and sleep-related changes in respiration from infancy to adolescence. The first 2years of age are striking, with more time asleep than awake. With development, the electroencephalogram architecture has a marked reduction in rapid eye movement sleep and the acquisition of K-complexes, sleep spindles, and slow-wave sleep. During adolescence there is a reduction in slow-wave sleep and a delay in the circadian phase. Infants have a more collapsible upper airway and lower lung volumes than older children, which predisposes them to obstructive sleep apnea and sleep-related hypoxemia.