Effect of pursed-lip breathing and forward trunk lean positions on regional chest wall volume and ventilatory pattern in older adults: An observational study.

ABSTRACT: Pursed-lip breathing (PLB) and forward trunk lean posture (FTLP) are commonly used to relieve dyspnea and improve ventilation in a rehabilitation program. However, their effect on chest wall volumes and movements in older adults without chronic obstructive pulmonary disease has never been investigated. This observational study aimed to identify the effect of combined PLB and FTLP on total and regional chest wall volumes, ventilatory pattern, and thoracoabdominal movement using in older adults. It was hypothesized that the combined PLB with FTLP would result in the highest chest wall volumes among the experimental tasks. Twenty older adults performed 2 breathing patterns of quiet breathing (QB) and PLB during a seated upright (UP) position and FTLP. An optoelectronic plethysmography system was used to capture the chest wall movements during the 4 experimental tasks. Tidal volume (VT) was separated into pulmonary ribcage, abdominal ribcage, and abdomen volume. The changes in anterior-posterior (AP) and medial-lateral (ML) chest wall diameters at 3 levels were measured and used to identify chest wall mechanics to improve chest wall volumes. The PLB significantly improved ventilation and chest wall volumes than the QB (P < .05). VT of pulmonary ribcage, VT of abdominal ribcage, and VT were significantly higher during the PLB + UP (P < .05) and during the PLB + FTLP (P < .01) as compared to those of QB performed in similar body positions. However, there was no significant in total and regional lung volumes between the PLB + UP and the PLB + FTLP. The AP diameter changes at the angle of Louis and xiphoid levels were greater during the PLB + UP than the QB + UP and the QB + FTLP (P < .01). The AP diameter changes at the umbilical level and the ML diameter changes at the xiphoid level were significantly larger during the PLB + FTLP than the QB + FTLP and the QB + UP (P < .05). The ML diameter changes at the umbilical level were significantly greater during the PLB + FTLP than the QB + UP (P < .05). However, no significant difference in the relative regional chest wall volumes and phase angle among the experimental tasks (P > .05). In conclusion, a combined PLB performed in an FTLP or UP sitting could be used as a strategy to improve chest wall volumes and ventilation in older adults.

Severity of respiratory failure and computed chest tomography in acute COVID-19 correlates with pulmonary function and respiratory symptoms after infection with SARS-CoV-2: An observational longitudinal study over 12 months.

INTRODUCTION: Prospective and longitudinal data on pulmonary injury over one year after acute coronavirus disease 2019 (COVID-19) are sparse. We aim to determine reductions in pulmonary function and respiratory related quality of life up to 12 months after acute COVID-19. METHODS: Patients with acute COVID-19 were enrolled into an ongoing single-centre, prospective observational study and prospectively examined 6 weeks, 3, 6 and 12 months after onset of COVID-19 symptoms. Chest CT-scans, pulmonary function and symptoms assessed by St. Georges Respiratory Questionnaire were used to evaluate respiratory limitations. Patients were stratified according to severity of acute COVID-19. RESULTS: Median age of all patients was 57 years, 37.8% were female. Higher age, male sex and higher BMI were associated with acute-COVID-19 severity (p < 0.0001, 0.001 and 0.004 respectively). Also, pulmonary restriction and reduced carbon monoxide diffusion capacity was associated with disease severity. In patients with restriction and impaired diffusion capacity, FVC improved over 12 months from 61.32 to 71.82, TLC from 68.92 to 76.95, DLCO from 60.18 to 68.98 and KCO from 81.28 to 87.80 (percent predicted values; p = 0.002, 0.045, 0.0002 and 0.0005). The CT-score of lung involvement in the acute phase was associated with restriction and reduction in diffusion capacity in follow-up. Respiratory symptoms improved for patients in higher severity groups during follow-up, but not for patients with initially mild disease. CONCLUSION: Severity of respiratory failure during COVID-19 correlates with the degree of pulmonary function impairment and respiratory quality of life in the year after acute infection.

Interventional bronchoscopy for chronic obstructive pulmonary disease: more than a pipe dream.

Endoscopic lung volume reduction (ELVR) is recognised in both national and international expert guidelines as one of the few additive treatments to benefit patients with advanced chronic obstructive pulmonary disease (COPD) who are otherwise receiving optimal medical and supportive care. Despite these recommendations and a growing evidence base, these procedures are not widely offered across Australia and New Zealand, and general practitioner and physician awareness of this therapy can be improved. ELVR aims to mitigate the impact of hyperinflation and gas trapping on dyspnoea and exercise intolerance in COPD. Effective ELVR is of proven benefit in improving symptoms, quality of life, lung function and survival. Several endoscopic techniques to achieve ELVR have been developed, with endobronchial valve placement to collapse a single lobe being the most widely studied and commonly practised. This review describes the physiological rationale underpinning lung volume reduction, highlights the challenges of patient selection, and provides an overview of the evidence for current and investigational endoscopic interventions for COPD.

A simplified strategy for donor-recipient size-matching in lung transplant for interstitial lung disease.

BACKGROUND: Donor-recipient size-matching has been repeatedly reported to improve outcomes following lung transplantation (LTx). However, there is significant variability in practice and the optimal strategy for size-matching is yet to be defined. For recipients with ILD, size-matching decisions are complicated by concerns regarding the potential impact of pre-LTx pulmonary restriction. We evaluate whether a specific donor-to-recipient size-matching strategy, based on predicted total lung capacity, benefits this patient group. METHODS: This retrospective, single-centre, cohort study describes the post-LTx outcomes of adults who underwent LTx for ILD between 1983 and 2020. Only patients with restrictive physiology, based on pre-LTx pulmonary function testing were included. Post-LTx outcomes were compared based on donor-recipient predicted TLC (D-R pTLC) ratio. A D-R pTLC ratio of ≥0.8 or <1.2 for DLTx, and a D-R pTLC ratio of ≥0.8 or <1.0 for SLTx were classified as 'size-matched'. RESULTS: Five-hundred and fifty LTx recipients met inclusion criteria. Of these, 404 underwent DLTx and 146 underwent SLTx. Size-matching was achieved in 78% of DLTx and 47% of SLTx. Overall survival (p = 0.007) and CLAD-free survival (p < 0.001) was significantly improved following a size-matched DLTx, compared to those with D-R pTLC ratios <0.8 or ≥1.2. Size-matching based on a D-R pTLC ratio 0.8≥ <1.0 for SLTX did not significantly improve survival. CONCLUSIONS: D-R pTLC size-matching, based on a ratio of 0.8≥ <1.2 improved post-DLTx outcomes for patients with restrictive lung disease. This is simple to do, and if applied clinically, could improve overall outcomes in lung transplantation.

Validation of a Novel Compact System for the Measurement of Lung Volumes.

BACKGROUND: Current techniques for measuring absolute lung volumes rely on bulky and expensive equipment and are complicated to use for the operator and the patient. A novel method for measurement of absolute lung volumes, the MiniBox method, is presented. RESEARCH QUESTION: Across a population of patients and healthy participants, do values for total lung capacity (TLC) determined by the novel compact device (MiniBox, PulmOne Advanced Medical Devices, Ltd.) compare favorably with measurements determined by traditional whole body plethysmography? STUDY DESIGN AND METHODS: A total of 266 participants (130 men) and respiratory patients were recruited from five global centers (three in Europe and two in the United States). The study population comprised individuals with obstructive (n = 197) and restrictive (n = 33) disorders as well as healthy participants (n = 36). TLC measured by conventional plethysmography (TLCPleth) was compared with TLC measured by the MiniBox (TLCMB). RESULTS: TLC values ranged between 2.7 and 10.9 L. The normalized root mean square difference (NSD) between TLCPleth and TLCMB was 7.0% in healthy participants. In obstructed patients, the NSD was 7.9% in mild obstruction and 9.1% in severe obstruction. In restricted patients, the NSD was 7.8% in mild restriction and 13.9% in moderate and severe restriction. No significant differences were found between TLC values obtained by the two measurement techniques. Also no significant differences were found in results obtained among the five centers. INTERPRETATION: TLC as measured by the novel MiniBox system is not significantly different from TLC measured by conventional whole body plethysmography, thus validating the MiniBox method as a reliable method to measure absolute lung volumes.

Respiratory function in patients post-infection by COVID-19: a systematic review and meta-analysis.

BACKGROUND: Evidence suggests lungs as the organ most affected by coronavirus disease 2019 (COVID-19). The literature on previous coronavirus infections reports that patients may experience persistent impairment in respiratory function after being discharged. Our objective was to determine the prevalence of restrictive pattern, obstructive pattern and altered diffusion in patients post-COVID-19 infection and to describe the different evaluations of respiratory function used with these patients. METHODS: A systematic review was conducted in five databases. Studies that used lung function testing to assess post-infection COVID-19 patients were included for review. Two independent reviewers analysed the studies, extracted the data and assessed the quality of evidence. RESULTS: Of the 1973 reports returned by the initial search, seven articles reporting on 380 patients were included in the data synthesis. In the sensitivity analysis, we found a prevalence of 0.39 (CI 0.24-0.56, p < 0.01, I2 = 86%), 0.15 (CI 0.09-0.22, p = 0.03, I2 = 59%), and 0.07 (CI 0.04-0.11, p = 0.31, I2 = 16%) for altered diffusion capacity of the lungs for carbon monoxide (DLCO), restrictive pattern and obstructive pattern, respectively. CONCLUSION: Post-infection COVID-19 patients showed impaired lung function; the most important of the pulmonary function tests affected was the diffusion capacity.

Changes in pulmonary restrictive parameters by intensive home hemodialysis: a case report.

BACKGROUND: Patients with End-Stage Renal Disease (ESRD) are at an increased risk for restrictive lung disease due to accumulation of uremic toxins and volume overload. Hemodialysis is the preferred treatment for improving lung function in dialysis patients. However, the effects of fluid removal and solute clearance by hemodialysis on lung function remain unclear. CASE PRESENTATION: We report a case of restrictive lung disorder in a hemodialysis patient, who showed improvement in both clinical and spirometric lung function after initiation of intensive home hemodialysis (32 h per week). CONCLUSION: Intensive hemodialysis augments fluid removal and solute clearance, which in turn may improve restrictive lung function.

[A study on the end criteria of forced vital capacity curve in adults].

Objective: To explore the end criteria of forced vital capacity(FVC) curve in adults. Methods: A multicenter cross-sectional study was performed in Zhongshan Hospital Affiliated to Fudan University, the First Affiliated Hospital of Fujian Medical University, and the Third Affiliated Hospital of Inner Mongolia Medical University from January 2017 to August 2017. A consecutive sample of subjects who completed the spirometry test and FVC curves met end criteria of no volume change (<0.025 L) for ≥ 1 s were qualified in this study. Subjects were divided into a normal group (n=610), an obstructive group (n=536), and a restrictive group(n=306) according to pulmonary function test results. The FET values in different groups were compared. The side effects in the 3 groups and the diagnostic accuracy, specificity and security of different FET in the obstructive group were assessed. Results: The FET values of the normal group, the obstructive group, and the restricted group were (4.00±1.07) s, (8.08±1.56) s and (2.97±0.76) s respectively, and the 95% CI of FET in the 3 groups were between 3.88-4.12 s, 7.02-10.14 and 2.21- 3.73 s (F=2 263.80, P<0.01). When the exhalation platform was used as the standard of FVC curve, the adverse reaction rate in the normal group and the restricted group were 1.1% and 1.3% respectively, lower than the rate of 17.2% in the obstructive group (χ(2)=92.73, χ(2)=48.49 respectively; all P<0.05). In the obstructive group, 7 s as the ending criterion had similar incidence of adverse reactions to 6 s (χ(2)=0.01, P=0.93). With further extension of expiration time, the incidence of adverse reactions increased significantly. In the obstructive group, the sensitivity of FEV(1)/FEV(7) was 99.25%, higher than that at FEV(1)/FEV(6) (χ(2)=4.06, P=0.04), and the specificity of diagnosis was very similar and 100%. Conclusions: FET was variable in subjects with different lung function status. It is not appropriate to use a fixed FET≥ 6 s as the end criterion of spirometry for adults. For patients with normal lung function or restrictive lung function defect, exhalation platform should be used as the end of exhalation standard. For patients with obstructive lung function defect, an FET of up to 7 s is appropriate.

Quantitative CT-based structural alterations of segmental airways in cement dust-exposed subjects.

BACKGROUND: Dust exposure has been reported as a risk factor of pulmonary disease, leading to alterations of segmental airways and parenchymal lungs. This study aims to investigate alterations of quantitative computed tomography (QCT)-based airway structural and functional metrics due to cement-dust exposure. METHODS: To reduce confounding factors, subjects with normal spirometry without fibrosis, asthma and pneumonia histories were only selected, and a propensity score matching was applied to match age, sex, height, smoking status, and pack-years. Thus, from a larger data set (N = 609), only 41 cement dust-exposed subjects were compared with 164 non-cement dust-exposed subjects. QCT imaging metrics of airway hydraulic diameter (Dh), wall thickness (WT), and bifurcation angle (θ) were extracted at total lung capacity (TLC) and functional residual capacity (FRC), along with their deformation ratios between TLC and FRC. RESULTS: In TLC scan, dust-exposed subjects showed a decrease of Dh (airway narrowing) especially at lower-lobes (p < 0.05), an increase of WT (wall thickening) at all segmental airways (p < 0.05), and an alteration of θ at most of the central airways (p < 0.001) compared with non-dust-exposed subjects. Furthermore, dust-exposed subjects had smaller deformation ratios of WT at the segmental airways (p < 0.05) and θ at the right main bronchi and left main bronchi (p < 0.01), indicating airway stiffness. CONCLUSIONS: Dust-exposed subjects with normal spirometry demonstrated airway narrowing at lower-lobes, wall thickening at all segmental airways, a different bifurcation angle at central airways, and a loss of airway wall elasticity at lower-lobes. The airway structural alterations may indicate different airway pathophysiology due to cement dusts.

Low FVC/TLC in Preserved Ratio Impaired Spirometry (PRISm) is associated with features of and progression to obstructive lung disease.

One quarter of individuals with Preserved Ratio Impaired Spirometry (PRISm) will develop airflow obstruction, but there are no established methods to identify these individuals. We examined the utility of FVC/TLC in identifying features of obstructive lung disease. The ratio of post-bronchodilator FVC and TLCCT from chest CT (FVC/TLCCT) among current and former smokers with PRISm (FEV1/FVC ≥ 0.7 and FEV1 < 80%) in COPDGene was used to stratify subjects into quartiles: very high, high, low, and very low. We examined the associations between FVC/TLCCT quartiles and (1) baseline characteristics, (2) respiratory exacerbations, (3) progression to COPD at 5 years, and (4) all-cause mortality. Among participants with PRISm at baseline (n = 1,131), the very low FVC/TLCCT quartile was associated with increased gas trapping and emphysema, and higher rates of progression to COPD at 5 years (36% versus 17%; p < 0.001) relative to the very high quartile. The very low FVC/TLCCT quartile was associated with increased total (IRR = 1.65; 95% CI [1.07-2.54]) and severe (IRR = 2.24; 95% CI [1.29-3.89]) respiratory exacerbations. Mortality was lower in the very high FVC/TLCCT quartile relative to the other quartiles combined. Reduced FVC/TLCCT ratio in PRISm is associated with increased symptoms, radiographic emphysema and gas trapping, exacerbations, and progression to COPD.

Diaphragm thickening assessed by ultrasonography is lower than healthy adults in patients with chronic obstructive pulmonary disease.

BACKGROUND: Ultrasound imaging has been widely used for imaging of the diaphragm thickness (Tdi) and thickening. Few studies assessed the Tdi using ultrasonography in patients with chronic obstructive pulmonary disease (COPD). We measured the Tdi and thickening in patients with COPD compared with healthy younger and healthy older adults to reveal the influence of ageing and/or COPD. METHODS: Thirty-eight male patients with COPD (age 72 ± 8 years), 15 healthy younger (age 22 ± 1 years) and 15 healthy older (age 72 ± 5 years) male volunteers were recruited. We measured Tdi at total lung capacity (TdiTLC ), functional residual capacity (TdiFRC ) and residual volume (TdiRV ) using B-mode ultrasonography. We calculated the change ratio of TdiTLC and TdiRV (ΔTdi%). We used a one-way analysis of variance and multiple comparison test for the comparison analysis. RESULTS: The TdiTLC and the ΔTdi% were significantly lower in patients with COPD compared to the healthy adults. There was no significant difference in these values with age. There was no between group difference in the TdiFRC or TdiRV . CONCLUSIONS: Our results indicate significant differences in TdiTLC and ΔTdi% between patients with COPD and healthy adults. Therefore, diaphragm ultrasonography can assess diaphragm dysfunction associated with COPD. We suggest that it is better to use TdiTLC and ΔTdi% (not only Tdi at rest) to assess diaphragm function.

Diaphragmatic dysfunction associates with dyspnoea, fatigue, and hiccup in haemodialysis patients: a cross-sectional study.

Muscle wasting is associated with increased mortality and morbidity in chronic kidney disease (CKD) patients, especially in the haemodialysis (HD) population. Nevertheless, little is known regarding diaphragm dysfunction in HD patients. We conducted a cross-sectional study at the Institute of Nephrology, Southeast University, involving 103 HD patients and 103 healthy volunteers as normal control. Ultrasonography was used to evaluate diaphragmatic function, including diaphragm thickness and excursion during quiet and deep breathing. HD patients showed lower end-inspiration thickness of the diaphragm at total lung capacity (0.386 ± 0.144 cm vs. 0.439 ± 0.134 cm, p < 0.01) and thickening fraction (TF) (0.838 ± 0.618 vs. 1.127 ± 0.757; p < 0.01) compared to controls. The velocity and excursion of the diaphragm were significantly lower in the HD patients during deep breathing (3.686 ± 1.567 cm/s vs. 4.410 ± 1.720 cm/s, p < 0.01; 5.290 ± 2.048 cm vs. 7.232 ± 2.365 cm; p < 0.05). Changes in diaphragm displacement from quiet breathing to deep breathing (△m) were lower in HD patients than in controls (2.608 ± 1.630 vs. 4.628 ± 2.110 cm; p < 0.01). After multivariate adjustment, diaphragmatic excursion during deep breathing was associated with haemoglobin level (regression coefficient = 0.022; p < 0.01). We also found that the incidence of dyspnoea and hiccup and the fatigue scores, all of which were related to diaphragmatic dysfunction, were significantly higher in HD patients than in controls (all p < 0.01). Improving diaphragm function through targeted therapies may positively impact clinical outcomes in HD patients.

Reference values for pulmonary volumes by plethysmography in a Brazilian sample of white adults.

OBJECTIVE: To derive reference values for healthy white Brazilian adults who have never smoked and to compare the obtained values with reference values derived by Crapo and by Neder. METHODS: Reference equations by quantile regressions were derived in 122 men and 122 women, non-obese, living in seven cities in Brazil. Age ranged from 21 to 92 years in women and from 25 to 88 years in men. Lung function tests were performed using SensorMedics automated body plethysmographies according ATS/ERS recommendations. Lower and upper limits were derived by specific equations for 5 and 95 percentiles. The results were compared to those suggested by Crapo in 1982, and Neder in 1999. RESULTS: Median values for total lung capacity (TLC) were influenced only by stature in men, and by stature and age in women. Residual volume was influenced by age and stature in both genders. Weight was directly related to inspiratory capacity and inversely with functional residual capacity and expiratory reserve volume in both genders. A comparison of observed TLC data with values predicted by Neder equations showed significant lower values by the present data. Mean values were similar between data from present study and those derived by Crapo. CONCLUSION: New predicted values for lung volumes were obtained in a sample of white Brazilians. The values differ from those derived by Neder, but are similar to those derived by Crapo.

Clinical significance of lower-lobe interstitial lung disease on high-resolution computed tomography in patients with idiopathic pleuroparenchymal fibroelastosis.

BACKGROUND: Idiopathic pleuroparenchymal fibroelastosis (IPPFE) is a rare form of idiopathic interstitial pneumonias (IIP) and may have other patterns of interstitial lung disease (ILD) in the lower lobe, such as usual interstitial pneumonia (UIP). However, the clinical significance of lower-lobe ILD in patients with IPPFE is unclear. METHODS: A retrospective review of 40 consecutive patients with clinically diagnosed IPPFE in our institution from 2005 to 2016 was conducted. The presence of lower-lobe ILD on high-resolution computed tomography (HRCT) was assessed and classified into UIP or non-UIP pattern according to a modification of diagnostic criteria for idiopathic pulmonary fibrosis. Clinical characteristics and prognostic factors were evaluated. RESULTS: Among the 40 patients with IPPFE, 21 (53%) had lower-lobe ILD, including 13 with UIP pattern and 8 with non-UIP pattern. Patients with IPPFE who had lower-lobe ILD had significantly older age, higher frequency of fine crackles, higher serum KL-6 level, lower residual volume (RV), and lower total lung capacity (TLC) than those without lower-lobe ILD. In addition, those with lower-lobe ILD, especially UIP pattern, had a significantly poorer survival than those without lower-lobe ILD (log-rank test; p = 0.014, p < 0.001, respectively). Multivariate Cox proportional hazards regression analysis revealed that low %forced vital capacity (%FVC) at baseline and coexistence of UIP pattern were significantly associated with poor prognosis in patients with IPPFE. CONCLUSIONS: The coexistence of lower-lobe ILD on HRCT, especially the UIP pattern, may predict poor survival in patients with IPPFE.

Functional state of the small airways in patients with bronchial asthma associated with obesity.

AIM: To assess the functional status of the small Airways in patients with bronchial asthma associated with obesity, by body plethysmography. MATERIALS AND METHODS: 65 patients with bronchial asthma of mild severity, partially controlled course, including 30 patients with normal body weight and 35 patients with obesity of I degree were examined. Control group-30 healthy volunteers. Examined forced vital capacity (FVC), forced expiratory volume in first second (FEV1) ratio of FEV1 to FVC (FEV1/FVC), maximum volumetric exhalation rate after 25.50 and 75% FVC (MEF75, MEF50, MEF25), average flow velocity in the exhalation interval 25-75% of FVC (MMEF25-75). Method bodyplethysmography was evaluated in bronchial resistance, functional residual capacity (FRC), residual volume of the lungs (RV), total lung capacity (TLC), the percentage of RV/TLC. RESULTS: Patients with bronchial asthma with obesity showed a reduction of indicators of bronchial obstruction: FEV1 of 14% (p=0.02), FEV1/FVC by 14% (p=0.001), MEF75 30% (p=0.001), MEF50 by 35% (p=0.001), MEF25 by 44% (p=0.003), MMEF25-75 by 38% (p=0.001). The increase of bronchial resistance on inhalation in 2 times (p=0.001), on exhalation in 3.3 times (p=0.003) was found, which is typical for generalized bronchial obstruction at the proximal level. An increase in RV by 24% (p=0.03), TLC - by 9% (p=0.03), RV/TLC - by 18% (p=0.03), indicating the presence of "air traps" and dysfunction of the small respiratory tract. CONCLUSION: In patients with asthma of mild severity associated with obesity, both the central bronchis and the distal lung are affected, which are manifested by generalized bronchial obstruction, the formation of "air traps" and dysfunction of the small respiratory tract.

Developing a New Marker of Dynamic Hyperinflation in Patients with Obstructive Airway Disease - an observational study.

Tidal volume at peak exercise and vital capacity ratio (VTpeak/VC) and VTpeak/inspiratory capacity (IC) were used to differentiate lung expansion in subjects with normal health and chronic obstructive pulmonary disease (COPD) from that in subjects with restrictive ventilation. However, VC and IC variably change due to pseudorestriction of lung volumes. Thus, these variables are currently not recommended. In contrast, total lung capacity (TLC) does little change during exercise. The aims of the study investigated whether VTpeak/TLC is more significantly correlated with static air trapping and lung hyperinflation in patients with COPD than VTpeak/IC, VTpeak/FVC, and VTpeak/SVC (study 1), and developed a marker to replace dynamic IC maneuvers by evaluation of the relationship between end-expiratory lung volume (EELV) and VTpeak/TLC and identification of a cutoff value for VTpeak/TLC (study 2). One hundred adults with COPD (study 1) and 23 with COPD and 19 controls (study 2) were analyzed. Spirometry, lung volume, diffusing capacity, incremental cardiopulmonary exercise tests with dynamic IC maneuvers were compared between groups. An ROC curve was generated to identify a cut off value for VTpeak/TLC. In study 1, VTpeak/TLC was more significantly associated with airflow obstruction, static air trapping and hyperinflation. In study 2, VTpeak/TLC was highly correlated with EELV in the patients (r = -0.83), and VTpeak/TLC ≥ 0.27 predicted that 18% of the patients with static air trapping and hyperinflation can expand their VT equivalent to the controls. In conclusions, VTpeak/TLC was superior to other VTpeak/capacities. VTpeak/TLC may be a marker of dynamic hyperinflation in subjects with COPD, thereby avoiding the need for dynamic IC maneuvers. VTpeak/TLC < 0.27 identified approximately 82% of subjects with COPD who could not adequately expand their tidal volume. As most of our participants were male, further studies are required to elucidate whether the results of this study can be applied to female patients with COPD.

Respiratory Phase and Lung Volume Patterns During Swallowing in Healthy Adults: A Systematic Review and Meta-Analysis.

Purpose The coordination of respiration with swallowing is critical for facilitation of airway protection and the efficiency of movements that propel ingested material through the upper aerodigestive tract. Confirmation of a predominant pattern in healthy adults provides a platform for comparison to aberrant patterns observed in the population with swallowing impairment (dysphagia). Method A comprehensive search of published research in MEDLINE via PubMed 1946-2018, Embase 1947-2018, and Proquest Dissertations & Theses Global 1861-2018 was completed. Results Thirty-seven articles meeting inclusion criteria were selected for data extraction, and the findings were reviewed. In addition, a meta-analysis of the data was completed. A significantly higher occurrence ( p < .001) of expiration prior to and following the swallow was found when compared to 3 other patterns. The predominance of the pattern was influenced by increases in bolus volume when controlling for participant sample size. Conclusion Determination of this predominant pattern provides a normative framework for evaluating respiratory-swallow coordination in adults across the age span and highlights the relevance for assessing and incorporating respiratory swallowing coordination during assessment and interventions.

Inspiratory muscle training improves pulmonary functions and respiratory muscle strength in healthy male smokers.

The aim of the present study is to investigate the effects of inspiratory muscle training (IMT) on pulmonary function and respiratory muscle strength of both healthy smokers and nonsmokers. Forty-two healthy males (16 in the IMT smokers group [IMTS], 16 in the IMT nonsmokers group [IMTN], and 10 in the placebo group) participated in the present study. Using a randomized, double-blind, placebo-controlled design, IMTS and IMTN underwent 4 weeks of 30 breaths twice daily at 50% (+5% increase each week) of maximum inspiratory pressure (MIP), while the placebo group maintained 30 breaths twice daily at 15% MIP using an IMT device. The data were analyzed with repeated measures for one-way analysis of variance, 3 × 2 mixed factor analysis of variance, and least significant difference tests. Respiratory muscle strength (MIP and maximal expiratory pressure [MEP]) and pulmonary functions significantly improved after a 4-week period (between the pre and posttests) in the IMTN and IMTS groups (p < 0.05). The mean difference and percentage differences showed significant alterations in the respiratory muscle strength, forced and slow pulmonary capacities, and pulmonary volume between the IMTN and IMTS groups (p < 0.05). There were significant changes in the expiratory muscle strength (MEP), slow vital capacity (SVC), and forced pulmonary measurements (forced expiratory volume after 1 s and maximal voluntary ventilation) between IMTN and IMTS groups in favor of smokers (p < 0.05). These results show that greater improvements occurred in smokers after IMT. Increased respiratory muscle strength may be the underlying mechanism responsible for this improvement. Additionally, the benefits of IMT were greater in smokers than nonsmokers. This difference between smokers and nonsmokers may potentially be explained by higher influence of exercise on smokers' lung microbiome, resulting in greater reversal of negative effects.

Clinical characteristics and outcomes of hypersensitivity pneumonitis: a population-based study in China.

BACKGROUNDS: Hypersensitivity pneumonitis (HP) is an immune-mediated interstitial lung disease (ILD) that develops in response to the inhalation of various antigens. The clinical pathologies are very complex and undetermined. The clinical features and outcomes of HP have not been fully elucidated. The aim of this study was to analyze the incidence, clinical features, and outcomes of HP patients and construct a simple clinical model for diagnosing chronic HP (CHP). METHODS: The cohort study included 101 patients with HP admitted to the Nanjing Drum Tower Hospital from January 2009 to December 2017. The patients were categorized into acute HP (AHP, n = 72) and CHP (n = 29) groups according to the updated international criteria. The clinical, imaging, treatment, and follow-up data were retrospectively reviewed. All patients were followed up until December 31, 2017. Statistical analysis was performed, and a clinical scoring system for CHP was constructed by SPSS 20.0 software. RESULTS: The incidence of HP was 2.4% in ILD inpatients in our center. Patients in the CHP group were older (t = -2.212, P = 0.029), had more smokers (χ = 8.428, P = 0.004), and longer duration of symptoms (t = -4.852, P < 0.001) than those in the AHP group. Weight loss, crackles, digital clubbing, and cyanosis were more common in the CHP group than those in the AHP group (χ = 5.862, P < 0.001; χ = 8.997, P = 0.003; χ = 11.939, P = 0.001; and χ = 4.025, P = 0.045, respectively). On chest high-resolution computed tomography (HRCT), reticular patterns, traction bronchiectasis, and accompanying honeycombing were more common in CHP cases than those in AHP cases (χ = 101.000, P < 0.001; χ = 32.048, P < 0.001; and χ = 36.568, P < 0.001, respectively). The clinical scoring system for CHP was established based on the clinical variables (age [A], duration of symptoms [D], smoking history [S], unidentified exposure [U], and chest HRCT [C]; ADSUC) (area under the curve 0.935, 95% confidence interval: 0.883-0.987, P < 0.001). Eleven patients (15.3%) in the AHP group developed CHP, and unidentified exposure was an independent risk factor for the progression of disease (P = 0.038). The survival of patients with CHP, smoking history, unidentified antigens and fibrosis on Chest HRCT were significantly worse (P = 0.011, P = 0.001, P = 0.005, and P = 0.011, respectively) by Kaplan-Meier analysis. Cox multivariate regression analysis revealed that unidentified exposure and total lung volume (TLC pred%) were independent prognostic predictors for HP patients (P = 0.017 and P = 0.017, respectively). CONCLUSIONS: The clinical features and outcomes of the CHP patients differ from those of the AHP patients. ADSUC is a simple and feasible clinical model for CHP. Unidentified exposure is an independent risk factor for the progression of AHP to CHP. Unidentified exposure and a low baseline TLC pred% are independent predictors for survival in HP patients.

Early onset of airway derecruitment assessed using the forced oscillation technique in subjects with asthma.

Derecruitment of air spaces in the lung occurs when airways close during exhalation and is related to ventilation heterogeneity and symptoms in asthma. The forced oscillation technique has been used to identify surrogate measures of airway closure via the reactance (Xrs) versus lung volume relationship. This study used a new algorithm to identify derecruitment from the Xrs versus lung volume relationship from a slow vital capacity maneuver. We aimed to compare two derecruitment markers on the Xrs versus volume curve, the onset reduction of Xrs (DR1vol) and the onset of more rapid reduction of Xrs (DR2vol), between control and asthmatic subjects. We hypothesized that the onset of DR1vol and DR2vol occurred at higher lung volume in asthmatic subjects. DR1vol and DR2vol were measured in 18 subjects with asthma and 18 healthy controls, and their relationships with age and height were examined using linear regression. In the control group, DR1vol and DR2vol increased with age (r2 = 0.68, P < 0.001 and r2 = 0.71, P < 0.001, respectively). DR1vol and DR2vol in subjects with asthma [76.58% of total lung capacity (TLC) and 56.79%TLC, respectively] were at higher lung volume compared with control subjects (46.1 and 37.69%TLC, respectively) (P < 0.001). DR2vol correlated with predicted values of closing capacity (r = 0.94, P < 0.001). This study demonstrates that derecruitment occurs at two points along the Xrs-volume relationship. Both derecruitment points occurred at significantly higher lung volumes in subjects with asthma compared with healthy control subjects. This technique offers a novel way to measure the effects of changes in airways/lung mechanics. NEW & NOTEWORTHY This study demonstrates that the forced oscillation technique can be used to identify two lung volume points where lung derecruitment occurs: 1) where derecruitment is initiated and 2) where onset of rapid derecruitment commences. Measurements of derecruitment increase with age. The onset of rapid derecruitment was highly correlated with predicted closing capacity. Also, the initiation and rate of derecruitment are significantly altered in subjects with asthma.