Mid-expiratory Flow Research Articles

Predictive Equations for Adult Pulmonary Function in Zhejiang Province, China.

Background Accurate interpretation of lung function tests requires appropriate spirometry reference values derived from large-scale population-specific epidemiological surveys. The aim of this cross-sectional study was to establish normal spirometric values for the population of healthy, nonsmoking Han Chinese adults residing in Zhejiang province, China. Methods We measured lung function parameters such as forced expiratory volume in 1 s, forced vital capacity, peak expiratory flow, maximal midexpiratory flow, and diffusion capacity for carbon monoxide and considered age, height, and weight as independent factors that may modify these parameters. The clinical data were divided into the study arm and validation group. The study arms were used to construct predictive equations using stepwise multiple linear regression, and data from the validation group were used to assess the robustness of the equations. Results The 3866 participants were randomized into a study arm (n = 1,949) and a validation arm (n = 1,917). Lung function parameters had a negative association with age and a positive association with height. Data from the two groups were similar. Predictive equations were constructed from the study arm, and the validation group was used to test the feasibility of the reference equations. Conclusions The reference values we derived can be used to evaluate lung function in this cohort in both epidemiological studies and clinical practice.

A study of pneumoproteins in crystalline silica exposed rock drillers

Objective: The objective was to assess serum concentrations of club cell protein 16 (CC-16) and the surfactant proteins A (SPs-A) and D (SP-D) in male rock drillers (N = 123) exposed to crystalline silica and in 48 occupationally non-exposed. Methods: The arithmetic mean (AM) duration of exposure was 10.7 years. The geometric mean (GM) crystalline silica exposure was 36 µg/m3 at the time of the study. The GM cumulative exposure was 239 µg/m3. Results: The concentrations of SP-D (GM 12.7 vs. 8.8 µg/L, p < 0.001) and SP-A (AM 1847 vs. 1378 ng/L, p = 0.051) were higher among rock drillers than among occupationally non-exposed. A positive significant association was observed between cumulative crystalline silica exposure and the SP-D concentrations (β = 0.07; p < 0.05). Rock drillers with small airway obstruction with maximal mid-expiratory flow % (MMEF%) <70% (N = 29) had higher SP-D concentrations than rock drillers with MMEF% ≥ 70% (N = 91) (GM 17.3 vs. 11.4 µg/L, p = 0.001). Rock drillers with MMEF% ≥70% (N = 91) had higher concentrations of SP-A (1957 vs. 1287 ng/L, p = 0.01) and SP-D (11.4 vs. 9.0 µg/L, p = 0.007) than non-exposed with MMEF% ≥70% (N = 39). Rock drillers with airway obstruction (FEV1/FVC < 0.70, N = 11) had significantly lower CC-16 concentrations than rock drillers with FEV1/FVC ≥0.70 (N = 109) after adjusting for relevant potential confounders (p = 0.02). Conclusion: The results indicate that pulmonary surfactant is a target for crystalline silica toxicity. The alterations appear to be driven by pulmonary alterations in the small airways and by exposure itself. Further studies on pneumoproteins and pulmonary function in other groups of workers exposed to crystalline silica are needed.

Genomic DNA hydroxymethylation reveals potential role in identification of lung injury in coal-burning arsenicosis populations.

Arsenic (As) is a toxic metalloid element that causes lung cancer and multiple non-malignant respiratory diseases. The toxicity of arsenic is mediated in part by epigenetic mechanisms, such as alterations in DNA methylation. While increasing studies have highlighted the potential importance of arsenic exposure to DNA methylation patterns and the subsequent risks for arsenic toxicity, there has been little focus on DNA hydroxymethylation-a negative regulation mechanism of DNA methylation. Therefore, this study aimed to investigate the relationship between genomic DNA methylation/hydroxymethylation and lung injury in arsenicosis populations. First, an increased risk of lung injury and exacerbation of lung function impairment in the arsenicosis population was confirmed. Levels of 5-methylcytosine/deoxycytidine (5mC/dC), 5-hydroxymethylcytosine/deoxycytidine (5hmC/dC) and 5hmC/5mC in genomic DNA of peripheral blood were decreased in the arsenicosis population compared to in the control. Additionally, multivariate logistic regression models showed an increased risk of chest digital radiography (DR) abnormalities when 5hmC/dC and 5hmC/5mC levels were lower (OR=3.12 and 3.96, all P< 0.001). For 3 years follow-up, regression analysis showed that a decline in 5hmC/dC was significantly associated with the decline of lung function parameters [forced vital capacity (FVC), forced expiratory volume in 1s (FEV1) and maximal mid-expiratory flow (MMEF); β=0.167, 0.122 and 0.073, respectively; all P< 0.05]. Using the receiver operating characteristic (ROC) curve, a combination of 5hmC/5dC and 5hmC/5mC obtained the highest value for distinguishing lung injury in all subjects (AUC=0.82, P< 0.01). In contrast, in arsenicosis subjects, 5hmC/dC was better at distinguishing lung injury (AUC=0.84, P< 0.01). Together, the results revealed that a decrease in genomic DNA hydroxymethylation markers was associated with lung injury in coal-burning arsenicosis populations. Genomic DNA hydroxymethylation could be a novel biomarker for identifying the risk of lung injury caused by coal-burning arsenicosis.

Expiratory Peak Flow and Minute Ventilation Are Significantly Increased at High Altitude versus Simulated Altitude in Normobaria.

Simulated altitude (normobaric hypoxia, NH) is used to study physiologic hypoxia responses of altitude. However, several publications show differences in physiological responses between NH and hypobaric conditions at altitude (hypobaric hypoxia, HH). The causality for these differences is controversially discussed. One theory is that the lower air density and environmental pressure in HH compared to NH lead to lower alveolar pressure and therefore lower oxygen diffusion in the lung. We hypothesized that, if this theory is correct, due to physical laws (Hagen-Poiseuille, Boyle), resistance respectively air compression (Boyle) at expiration should be lower, expiratory flow higher, and therefore peak flow and maximum expiratory flow (MEF) 75–50 increased in hypobaric hypoxia (HH) vs. normobaric hypoxia (NH). To prove the hypothesis of differences in respiratory flow as a result of lower alveolar pressure between HH and NH, we performed spirography in NH at different simulated altitudes and the corresponding altitudes in HH. In a cross over study, 6 healthy subjects (2 f/4 m, 28.3 ± 8.2 years, BMI: 23.2 ± 1.9) performed spirography as part of spiroergometry in a normobaric hypoxic room at a simulated altitude of 2800 m and after a seven-hour hike on a treadmill (average incline 14%, average walking speed 1.6 km/h) to the simulated summit of Mauna Kea at 4200 m. After a two-month washout, we repeated the spirometry in HH on the start and top of the Mauna Kea hiking trail, HI/USA. Comparison of NH (simulated 4200 m) and HH at 4200 m resulted in increased pulmonary ventilation during exercise (VE) (11.5%, p < 0.01), breathing-frequency (7.8%, p < 0.01), peak expiratory flow PEF (13.4%, p = 0.028), and MEF50 (15.9%, p = 0.028) in HH compared to NH, whereas VO2max decreased by 2%. At 2800 m, differences were only trendy, and at no altitude were differences in volume parameters. Spirography expresses higher mid expiratory flows and peak flows in HH vs. NH. This supports the theory of lower alveolar and small airway pressure due to a lower air density resulting in a lower resistance.

Differential Effects of Cannabis and Tobacco on Lung Function in Mid-Adult Life.

Rationale: Evidence suggests that the effects of smoking cannabis on lung function are different from tobacco. However, long-term follow-up data are scarce and mostly based on young adults. Objectives: To assess the effects of cannabis and tobacco on lung function in mid-adult life. Methods: Cannabis and tobacco use were reported at ages 18, 21, 26, 32, 38, and 45 years in a population-based cohort study of 1,037 participants. Spirometry, plethysmography, and carbon monoxide transfer factor were measured at age 45. Associations between lung function and cannabis use were adjusted for tobacco use. Measurements and Main Results: Data were available from 881 (88%) of 997 surviving participants. Cumulative cannabis use was associated with lower FEV1/FVC ratios, owing to a tendency toward higher FVCs. Cannabis use was also associated with higher TLC, FRC, residual volume, and Va along with lower midexpiratory flows, airway conductance, and transfer factor. Quitting regular cannabis use between assessments was not associated with changes in spirometry. Conclusions: Cannabis use is associated with higher lung volumes, suggesting hyperinflation. There is evidence of increased large-airway resistance and lower midexpiratory airflow, but impairment of FEV1/FVC ratio is because of higher FVC. This pattern of effects is different to those of tobacco. We provide the first evidence that lifetime cannabis use may be associated with impairment of gas transfer.

Baseline Spirometry as a Predictor of Positive Methacholine Challenge Testing for Exertional Dyspnea.

There are several tests recommended by the American Thoracic Society (ATS) to evaluate for airway hyper-responsiveness (AHR), one of which is methacholine challenge testing (MCT). Few studies have examined the correlation of baseline spirometry to predict AHR in MCT, especially in the younger, relatively healthy military population under clinical evaluation for symptoms of exertional dyspnea. The study aim was to retrospectively correlate baseline spirometry values with MCT responsiveness. This study is a retrospective review of all MCT performed at Brooke Army Medical Center/Wilford Hall Medical Center over a 12-y period; all completed studies were obtained from electronic databases. The following parameters were analyzed from the studies: baseline FEV1, FVC, FEV1/FVC, mid-expiratory flow (FEV25-75%), FEV25-75%/FVC. Studies were categorized based on baseline obstruction, restriction, FEF25-75% lower limit of normal, and response to bronchodilator testing (if completed); these values were compared based on methacholine reactivity and severity. Methacholine challenge studies (n = 1,933) were reviewed and categorized into reactive (n = 577) and nonreactive (n = 1,356) as determined by ATS guidelines. The mean baseline FEV1 (% predicted) with MCT reactivity was 88.0 ± 13.0% versus no MCT reactivity was 92.7 ± 13.0% (P < .001). The mean baseline FVC (% predicted) was 93.1 ± 13.7% versus 95.3 ± 13.5% (P < .001). The mean baseline FEV25-75% (% predicted) was 80.0 ± 22.1% versus 89.0 ± 23.4% (P < .001). Based on partition analysis, methacholine reactivity was most prevalent with baseline obstruction, n = 115 (43%), and in the absence of obstruction, when the FEF25-75% (% predicted) was below 0.70, n = 111 (40%). The negative predictive value with normal spirometry was 73%. The analysis of baseline spirometry prior to MCT proved useful in the evaluation of exertional dyspnea in a military population. The presence of airways obstruction (FEV1/FVC < lower limit of the normal range) followed by a reduction in FEV25-75% < 70% predicted showed a positive correlation with underlying AHR. In patients with exertional dyspnea and normal baseline spirometry, the use of the FEF25-75% may be a useful surrogate measurement to predict reactivity during MCT and consideration for additional testing or treatment.

The Investigation of Pulmonary Function Changes of COVID-19 Patients in Three Months.

Background Novel coronavirus disease 2019 (COVID-19) was discovered in December 2019 and has infected more than 80 million people worldwide, and more than 50 million people have achieved a clinical cure. In this study, the pulmonary function results of patients after clinical medicine for three months were reported. Objective To investigate the effect of COVID-19 on lung function in patients. Methods A retrospective analysis was performed on 56 COVID-19-infected patients who were cured after the clinical treatment at Taizhou Public Health Medical Center in Zhejiang Province from January 31, 2020, to March 10, 2020. At discharge and three months after discharge, lung function was measured, including inspiratory vital capacity (IVC), forced vital capacity (FVC), forced expiratory volume in first second (FEV1), forced expiratory volume in first second to inspiratory vital capacity (FEV1/IVC), maximum mid-expiratory flow rate (MEF), peak expiratory flow rate (PEF), and carbon monoxide dispersion (DLCO). Results At discharge, there were 37 patients (66.1%) with pulmonary dysfunction, 22 patients (39.3%) with ventilation dysfunction, 31 cases (55.4%) with small airway dysfunction, and 16 cases (28.6%) with restricted ventilation dysfunction combined with small airway dysfunction. At 3 months after discharge, 24 of the 56 patients still had pulmonary dysfunction and all of them had small airway dysfunction, of which 10 patients (17.9%) were restricted ventilation dysfunction combined with small airway dysfunction. DLCO was measured three months after discharge. Twenty-nine patients (51.8%) had mild to moderate diffuse dysfunction. All pulmonary function indexes of 56 patients recovered gradually after 3 months after release, except FEV1/IVC, and the difference was statistically significant (P < 0.05). There were 41 patients of normal type (73.2%) and 15 patients of severe type (26.8%). Among the 15 severe patients, 8 patients (53.3%) had ventilation dysfunction at discharge, 9 patients (60%) had small airway dysfunction, 4 patients (26.7%) still had ventilation dysfunction 3 months after discharge, 7 patients (46.7%) had small airway dysfunction, and 10 patients (66.7%) had diffuse dysfunction. Among the 41 common type patients, 14 patients (34.1%) had ventilation dysfunction at discharge, 22 patients (53.7%) had small airway dysfunction, 6 patients (14.6%) still had ventilation dysfunction 3 months after discharge, 17 patients (41.5%) had small airway dysfunction, and 19 patients (46.3%) had diffuse dysfunction. Patients with severe COVID-19 had more pulmonary impairment and improved pulmonary function than normal patients. Conclusion COVID-19 infection can cause lung function impairment, manifested as restricted ventilation dysfunction, small airway dysfunction, and diffuse dysfunction. The pulmonary function of most patients was improved 3 months after clinical cure and discharge, and some patients remained with mild to moderate diffuse dysfunction and small airway dysfunction.

Small Airway Dysfunction in Cough Variant Asthma: Prevalence, Clinical, and Pathophysiological Features.

Introduction: Small airway dysfunction (SAD) commonly presents in patients with classic asthma, which is associated with airway inflammation, disease severity, and asthma control. However, the prevalence of SAD, its relationship with cough severity and airway inflammation, and its development after antiasthmatic treatment in patients with cough variant asthma (CVA) need to be clarified. This study aimed to investigate the prevalence of SAD and its relationship with clinical and pathophysiological characteristics in patients with CVA and the change in small airway function after antiasthmatic treatment.Methods: We retrospectively analyzed 120 corticosteroid-naïve patients with CVA who had finished a standard questionnaire and relevant tests in a specialist cough clinic, such as cough visual analog scale (VAS), differential cells in induced sputum, fractional exhaled nitric oxide (FeNO) measurement, spirometry, and airway hyper-responsiveness. Information of 1-year follow-up was recorded in a part of patients who received complete cough relief after 2 months of treatment. SAD was defined as any two parameters of maximal mid-expiratory flow (MMEF)% pred, forced expiratory flow at 50% of forced vital capacity (FEF50%) pred, and forced expiratory flow at 75% of forced vital capacity (FEF75%) pred measuring <65%.Results: SAD occurred in 73 (60.8%) patients with CVA before treatment. The patients with SAD showed a significantly longer cough duration (24.0 vs. 6.0, p = 0.031), a higher proportion of women (78.1 vs. 59.6%, p = 0.029), older mean age (41.9 vs. 35.4, p = 0.005), and significantly lower forced expiratory volume in 1 s (FEV1%) pred, FEV1/FVC, MMEF% pred, FEF50% pred, FEF75% pred, PEF% pred, and PD20 (all p < 0.01) as compared with patients without SAD. There were no significant differences in cough VAS, sputum eosinophils count, FeNO, and TIgE level between patients with SAD and those without SAD. Among 105 patients who completed 2 months of antiasthmatic treatment and repeatedly experienced spirometry measurement, 57 (54.3%) patients still had SAD, despite a significant improvement in cough VAS, sputum eosinophils, FeNO, FEF50% pred, and PEF% pred (all p < 0.01). As compared with patients without SAD, patients with SAD showed no significant differences in the relapse rate (50.0 vs. 41.9%, p = 0.483) and wheeze development rate (10.4 vs. 0%, p = 0.063) during the follow-up.Conclusions: Small airway dysfunction occurred in over half of patients with CVA and persisted after short-term antiasthmatic treatment, which showed distinctive clinical and pathophysiological features.

Comparative pulmonary function test parameters in non-tribal and tribal women in singleton first, second, and the third trimester of pregnancy.

During pregnancy, women undergo adaptive changes in different organ systems including the respiratory system by hormonal changes and mechanical pressures. Several previous studies reported the change in pulmonary functions in pregnancy and tribal populations. However, trimester-wise, pulmonary functions in tribal women residing in Jharkhand, India, are not available. This study aimed to find and compare the pulmonary function test parameters in tribal and non-tribal women in singleton first, second, and third trimesters of pregnancy. We conducted this cross-sectional observational study in a tertiary care hospital in Jharkhand, India, with 58 tribal women and 116 age-matched controls. The pulmonary function tests, namely forced vital capacity (FVC), forced expiratory volume in the first second (FEV1), peak expiratory flow rate (PEFR), maximal mid expiratory flow (MMEF) were measured with a computerized spirometer (Spiro Excel, Medicaid, Punjab, India) and FEV1/FVC was calculated. A total of 58 tribal women with median age 22 (Q1-Q3: 21-25) years and 116 non-tribal women with median age 22 (20-25) (P=0.33) participated in the study. The tribal women showed higher respiratory rate (20 [18-24.5] vs. 16 [15-18] per minute, P<.0001), higher MMEF in the first trimester (1.46 [1.12-1.79] vs. 1.24 [1.04-1.5] L/s, P=0.047) and higher PEFR (4.02 [2.78-4.11] vs. 3.15 [2.58-3.87] L/s, P=.047) in the second trimester. There was no difference in the third trimester of pregnancy. In the overall sample, the tribal women showed higher PEFR (3.82 [2.96-4.33] vs. 3.3 [2.73-4.05] L/s, P=.02) and MMEF (1.43 [0.99-1.7] vs. 1.21 [1-1.47] L/s, P=.04). The respiratory rate was higher in the tribal women in the three trimesters of singleton pregnancy compared to the non-tribal women. There was a higher MMEF in the first trimester and PEFR in the second-trimester pregnancy in the tribal women. The finding of this pilot study should be enhanced by further study with a large number of tribal women from this region.

Novel imaging phenotypes of naïve asthma patients with distinctive clinical characteristics and T2 inflammation traits.

Objective:This study aims to describe the imaging features of naïve asthma patients, defined as not receiving corticosteroids or other asthma medications for at least 1 month, and their association with therapeutic response, and to discover novel unbiased imaging phenotypes.Methods:A total of 109 naïve asthma patients and 50 healthy controls were enrolled in this study. Clinical data and imaging indices of high-resolution computed tomography were collected. The correlation between imaging indices and clinical features was analyzed. Cluster analyses were adopted to determine three novel imaging phenotypes.Results:Compared with healthy controls, naïve asthma patients presented higher scores of airway remodeling, bronchiectasis, and mucus plugs. Mean airway wall area (WA)% was inversely correlated with mid-expiratory flow velocity% predicted. The extent score of bronchiectasis was positively correlated with smoking history and significantly increased in the high mucus group. Mucus plugs were related to improving lung function and type 2 (T2) inflammation, as assessed by sputum and blood eosinophils and fraction of exhaled nitric oxide. Cluster 1 patients had a high proportion of emphysema, the best lung function, and the lowest T2 inflammation; cluster 2 patients had severe airway remodeling, relatively good lung function, and moderate T2 inflammation; cluster 3 patients had severe airway remodeling, mucus plugs, and bronchiectasis, and showed the worst lung function and highest T2 inflammation.Conclusion:Naïve asthma patients had the imaging traits of airway remodeling, bronchiectasis, and mucus plugs. The unbiased imaging phenotypes had good consistency with clinical characteristics, therapeutic response, and T2 inflammation expression in naïve asthma patients.

Forced Expiratory Flow at 25%-75% Links COPD Physiology to Emphysema and Disease Severity in the SPIROMICS Cohort.

Forced expiratory volume in 1 second (FEV1) is central to the diagnosis of chronic obstructive pulmonary disease (COPD) but is imprecise in classifying disease burden. We examined the potential of the maximal mid-expiratory flow rate (forced expiratory flow rate between 25% and 75% [FEF25%-75%]) as an additional tool for characterizing pathophysiology in COPD. To determine whether FEF25%-75% helps predict clinical and radiographic abnormalities in COPD. The SubPopulations and InteRediate Outcome Measures In COPD Study (SPIROMICS) enrolled a prospective cohort of 2978 nonsmokers and ever-smokers, with and without COPD, to identify phenotypes and intermediate markers of disease progression. We used baseline data from 2771 ever-smokers from the SPIROMICS cohort to identify associations between percent predicted FEF25%-75% (%predFEF25%-75%) and both clinical markers and computed tomography (CT) findings of smoking-related lung disease. Lower %predFEF25-75% was associated with more severe disease, manifested radiographically by increased functional small airways disease, emphysema (most notably with homogeneous distribution), CT-measured residual volume, total lung capacity (TLC), and airway wall thickness, and clinically by increased symptoms, decreased 6-minute walk distance, and increased bronchodilator responsiveness (BDR). A lower %predFEF25-75% remained significantly associated with increased emphysema, functional small airways disease, TLC, and BDR after adjustment for FEV1 or forced vital capacity (FVC). The %predFEF25-75% provides additional information about disease manifestation beyond FEV1. These associations may reflect loss of elastic recoil and air trapping from emphysema and intrinsic small airways disease. Thus, %predFEF25-75% helps link the anatomic pathology and deranged physiology of COPD.

Diagnosis and Prognostic Analysis of Mycoplasma pneumoniae Pneumonia in Children Based on High-Resolution Computed Tomography.

Mycoplasma pneumoniae (MP) is defined as a common cause of pulmonary infections and accounts for up to four over ten of pneumonia in children over age 5. This study was aimed to explore the diagnosis and prognosis of mycoplasma pneumoniae pneumonia (MPP) in children using high-resolution computed tomography (CT) (HRCT). 71 children hospitalized with MPP were undertaken as the research objects to observe the incidence rate, occurrence time, and duration of the clinical symptoms and pathological signs. The chest HRCT and pulmonary ventilation function (PVF) were examined in the acute phase, the second phase re-examination period, and the third phase re-examination period. Relevant indicators were statistically analyzed to determine the change rules of chest HRCT and PVF and correlation between the two. Clinically, the children with MPP suffered from fever, cough, and sore throat. In addition to the above symptoms, children with MPP had different degrees of PVF impairment. Compared with the group with normal HRCT results, the forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), peak expiratory flow (PEF), forced expiratory flow at 25% forced expiratory volume (FEF25), forced expiratory flow at 50% forced expiratory volume (FEF50), forced expiratory flow at 75% forced expiratory volume (FEF75), and maximum mid-expiratory flow (MMEF75/25) of children in bronchopneumonia group, segmental pneumonia group, and lobar pneumonia group were obviously reduced, showing statistically great differences (P < 0.05). Compared with the case in acute phase, the PVF indicators of children in the re-examination phases were much higher, with greatly statistical differences (P < 0.05). In children with MPP, both the large and small airways were affected, but the recovery of the small airways was slow. Pulmonary HRCT and PVF can be undertaken as important indicators to judge the severity and prognosis of MPP in school-age children.

Autogenic drainage for airway clearance in cystic fibrosis.

Autogenic drainage is an airway clearance technique that was developed by Jean Chevaillier in 1967. The technique is characterised by breathing control using expiratory airflow to mobilise secretions from smaller to larger airways. Secretions are cleared independently by adjusting the depth and speed of respiration in a sequence of controlled breathing techniques during exhalation. The technique requires training, concentration and effort from the individual but it has previously been shown to be an effective treatment option for those who are seeking techniques to support and promote independence. However, at a time where the trajectory and demographics of the disease are changing, it is important to systematically review the evidence demonstrating that autogenic drainage is an effective intervention for people with cystic fibrosis. To compare the clinical effectiveness of autogenic drainage in people with cystic fibrosis with other physiotherapy airway clearance techniques. We searched the Cochrane Cystic Fibrosis Trials Register, compiled from electronic database searches and handsearching of journals and conference abstract books. We also searched the reference lists of relevant articles and reviews, as well as two ongoing trials registers (02 February 2021). Date of most recent search of the Cochrane Cystic Fibrosis Trials Register: 06 July 2021. We identified randomised and quasi-randomised controlled studies comparing autogenic drainage to another airway clearance technique or no therapy in people with cystic fibrosis for at least two treatment sessions. Data extraction and assessments of risk of bias were independently performed by three authors. The authors assessed the quality of the evidence using the GRADE system. The authors contacted seven teams of investigators for further information pertinent to their published studies. Searches retrieved 64 references to 37 individual studies, of which eight (n = 212) were eligible for inclusion. One study was of parallel design with the remaining seven being cross-over in design; participant numbers ranged from 4 to 75. The total study duration varied between four days and two years. The age of participants ranged between seven and 63 years with a wide range of disease severity reported. Six studies enrolled participants who were clinically stable, whilst participants in two studies received treatment whilst hospitalised with an infective exacerbation. All studies compared autogenic drainage to one (or more) other recognised airway clearance technique. Exercise is commonly used as an alternative therapy by people with cystic fibrosis; however, there were no studies identified comparing exercise with autogenic drainage. The certainty of the evidence was generally low or very low. The main reasons for downgrading the level of evidence were the frequent use of a cross-over design, outcome reporting bias and the inability to blind participants. The review's primary outcome, forced expiratory volume in one second, was the most common outcome measured and was reported by all eight studies; only three studies reported on quality of life (also a primary outcome of the review). One study reported on adverse events and described a decrease in oxygen saturation levels whilst performing active cycle of breathing techniques, but not with autogenic drainage. Seven of the eight included studies measured forced vital capacity and three of the studies used mid peak expiratory flow (per cent predicted) as an outcome. Six studies reported sputum weight. Less commonly used outcomes included oxygen saturation levels, personal preference, hospital admissions, intravenous antibiotics and pseudomonas gene expression. There were no statistically significant differences found between any of the techniques used with respect to the outcomes measured except when autogenic drainage was described as being the preferred technique of the participants in one study over postural drainage and percussion. Autogenic drainage is a challenging technique that requires commitment from the individual. As such, this intervention merits systematic review to ensure its effectiveness for people with cystic fibrosis, particularly in an era where treatment options are changing rapidly. From the studies assessed, autogenic drainage was not found to be superior to any other form of airway clearance technique. Larger studies are required to better evaluate autogenic drainage in comparison to other airway clearance techniques in view of the relatively small number of participants in this review and the complex study designs. The studies recruited a range of participants and were not powered to assess non-inferiority. The varied length and design of the studies made the analysis of pooled data challenging.

Maintenance of pulmonary rehabilitation benefits in patients with COPD: is a structured 5-year follow-up program helpful?

Pulmonary rehabilitation (PR) has proven useful in patients with chronic obstructive pulmonary disease (COPD), but the benefits decrease over time. We evaluated the effects of a structured follow-up program after PR on patient pulmonary function, dyspnea, body composition, exercise capacity, quality of life, psychological status, i-BODE index, hospitalization status, 5-year survival rate. We explored whether this follow-up program could serve as a maintenance program. COPD patients who completed PR attended follow-up visits over 5 years. We administered incremental (ISWT), endurance shuttle walk tests (ESWT), measured body (BMI), fat-free mass indices (FFMI), recorded modified Medical Research Council (mMRC), St. George’s respiratory questionnaire (SGRQ), anxiety-depression scores. We also noted the forced expiratory volume in 1 s (FEV1), the forced vital capacity (FVC), the forced midexpiratory flow (FEF25-75), hospitalization, survival rates before, after PR, and in years 1, 2, 3, 5. This was a retrospective observational study. Thirty-three COPD patients with a mean age of 58 ± 8 years were enrolled. Twenty-seven (82%) were male. The mean FEV1 was 47 ± 16% of the predicted. After PR, the mMRC scale, SGRQ, anxiety, depression scores; i-BODE index; ISWT, ESWT results improved (all p < 0.001), with the improvements persisting through the first year. Patient body composition, pulmonary function did not differ from the baseline over the 5 years (except for a decrease in the FEF25-75 value in year 5; p = 0.003). The hospitalization rate, i-BODE index did not change significantly over the 5 years, the improvements in the ISWT, ESWT outcomes were preserved for 3 years (p = 0.013/0.005, respectively). The quality-of-life, anxiety scores deteriorated in year 1 (both p < 0.001) and year 3 (p = 0.005/0.010, respectively). The dyspnea, depression scores increased progressively over the 5 years. Structured follow-up programs with visits at 6-month intervals may effectively maintain improvements in COPD. Long-term randomized controlled studies are needed to verify these results.

Acupoint thread-embedding as adjuvant therapy for bronchial asthma in children and its effect on pulmonary function, serum IgA and IgE levels

To observe the efficacy of acupoint thread-embedding combined with fluticasone propionate aerosol for chronic persistent bronchial asthma of lung-spleen qi deficiency and spleen-kidney yang deficiency in children and its effect on pulmonary function and serum levels of IgA and IgE. A total of 120 children with chronic persistent bronchial asthma were randomly divided into an observation group (60 cases, 9 cases dropped off) and a control group (60 cases, 7 cases dropped off). The control group was treated with fluticasone propionate aerosol (125 μg per inhalation), twice a day; based on the control group treatment, the observation group was treated with acupoint thread-embedding at Dingchuan (EX-B 1), Feishu (BL 13), Zusanli (ST 36) and Danzhong (CV 17), once half a month. Both groups were treated for 3 months. The pulmonary function, serum IgA, IgE levels and TCM symptom score were compared between the two groups before and after treatment, and the clinical efficacy was evaluated. After treatment, the large airway function (peak expiratory flow [PEF], forced expiratory volume at the first second [FEV1]) and small airway function (maximal expiratory flow at 25% of the forced capacity [MEF25%], maximal expiratory flow at 50% of the forced capacity [MEF50%], maximal expiratory flow at 75% of the forced capacity [MEF75%] and midexpiratory flow 25%-75% [MEF25%-75%]) were higher than those before treatment (P<0.05), and the pulmonary function in the observation group was higher than that in the control group (P<0.05). After treatment, the serum IgA levels in the two groups were higher than those before treatment (P<0.05), and the serum IgE levels and TCM symptom scores were lower than those before treatment (P<0.05); the serum IgA level in the observation group was higher than that in the control group (P<0.05), and the serum IgE level and TCM symptom score in the observation group were lower than those in the control group (P<0.05). The total effective rate was 94.1% (48/51) in the observation group, which was higher than 88.7% (47/53) in the control group (P<0.05). Acupoint thread-embedding combined with fluticasone propionate aerosol could improve the pulmonary function, TCM symptoms and serum IgA and IgE levels in children with chronic persistent bronchial asthma of lung-spleen qi deficiency and spleen-kidney yang deficiency. The curative effect is better than fluticasone propionate aerosol alone.

Longitudinal lung function in childhood cancer survivors after hematopoietic stem cell transplantation

Longitudinal data on pulmonary function after pediatric allogeneic or autologous hematopoietic stem cell transplantation (HSCT) are rare. We examined pulmonary function and associated risk factors in 5-year childhood cancer survivors (CCSs) longitudinally. We included 74 CCSs diagnosed between 1976 and 2010, treated with HSCT, and with at least two pulmonary function tests performed during follow-up. Median follow-up was 9 years (range 6–13). We described pulmonary function as z-scores for lung volumes (forced vital capacity [FVC], residual volume [RV], total lung capacity [TLC]), flows (forced expiratory volume in 1 s [FEV1], maximal mid-expiratory flow [MMEF]), and diffusion capacity for carbon monoxide (DLCO) and assessed associations with potential risk factors using multivariable regression analysis. The median z-scores for FEV1, FVC, and TLC were below the expected throughout the follow-up period. This was not the case for RV, MMEF and DLCO. Female gender, radiotherapy to the chest, and relapse were associated with lower z-scores of FEV1, FVC, MMEF, RV or DLCO. Childhood cancer survivors after HSCT are at risk of pulmonary dysfunction. The complex and multifactorial etiology of pulmonary dysfunction emphasizes the need for longitudinal prospective studies to better characterize the course and causes of pulmonary function impairment in CCSs.

Reduced ambient PM2.5, better lung function, and decreased risk of chronic obstructive pulmonary disease.

Several studies reported that long-term exposure to fine particulate matter (PM2.5) was associated with an increased risk of chronic obstructive pulmonary disease (COPD). It remains unclear whether reduced PM2.5 can decrease the risk of COPD development. To investigate the associations of dynamic changes (including deterioration and improvement) in long-term exposure to ambient PM2.5 with changes in lung function and the incidence of COPD. A total of 133,119 adults (aged 18years or older) were recruited in Taiwan between 2001 and 2014. All participants underwent at least two standard medical examinations including spirometry test. We estimated PM2.5 concentrations using a high-resolution (1km2) satellite-based spatio-temporal model. The change in PM2.5 (ΔPM2.5) was defined as the difference in concentration of PM2.5 between the respective visit and the previous visit. We used a multivariable mixed linear model and time-varying Cox model to investigate the associations of change in PM2.5 with annual change of lung function and the incidence of COPD, respectively. The PM2.5 concentration in Taiwan increased during 2002-2004 and began to decrease around 2005. Every 5-µg/m3/year decrease in the annual change of PM2.5 (i.e., ΔPM2.5/year of 5µg/m3/year) was associated with an average increase of 19.93mL/year (95%CI: 17.42,22.43) in forced expiratory volume in 1s (FEV1), 12.76mL/year (95%CI: 9.84,15.66) in forced vital capacity (FVC), 70.22mL/s/year (95%CI: 64.69,76.16) in midexpiratory flow between 25 and 75% of the forced vital capacity (MEF25-75), 0.27%/year (95%CI: 0.21%, 0.32%) in FEV1/FVC/year. Every 5µg/m3 decrease in PM2.5 (i.e., ΔPM2.5 of 5µg/m3) was associated with a 12% (95%CI: 7%, 17%) reduced risk of COPD development. The stratified and sensitivity analyses generally yielded similar results. An improvement in PM2.5 pollution exposure was associated with an attenuated decline in lung function parameters of FEV1, FVC, MEF25-75, and FEV1/FVC, and a decreased risk of COPD development. Our findings suggest that strategies aimed at reducing air pollution may effectively combat the risk of COPD development.

Deep Learning Algorithms-Based CT Images in Glucocorticoid Therapy in Asthma Children with Small Airway Obstruction.

CT image information data under deep learning algorithms was adopted to evaluate small airway function and analyze the clinical efficacy of different glucocorticoid administration ways in asthmatic children with small airway obstruction. The Res-NET in the deep learning algorithm was used to perform feature extraction, summary classification, and other reconstruction of CT images. A deep learning network model Mask-R-CNN was constructed to enhance the ability of image reconstruction. A total of 118 children hospitalized with acute exacerbation of asthma in the hospital were recruited. After acute exacerbation treatment, 96 children with asthma were screened out for small airway obstruction, which were divided into glucocorticoid aerosol inhalation group (group A, 32 cases), glucocorticoid combined with bronchodilator aerosol inhalation group (group B, 32 cases), and oral hormone therapy group (group C, 32 cases). Asthmatic children with small airway obstruction were screened after acute exacerbation treatment and were rolled into glucocorticoid aerosol inhalation group (group A), glucocorticoid combined with bronchodilators aerosol inhalation group (group B), and oral hormone therapy group (group C). Lung function indicators (maximal mid-expiratory flow (MMEF75 and 25), 50% forced expiratory flow (FEF50), and 75% forced expiratory flow (FEF75)), FeNO level, and airway inflammation indicators (IL-6, IL-35, and eosinophilic (EOS)) were compared before and one month after treatment. The ratio of airway wall thickness to outer diameter (T/D) and the percentage of airway wall area to total airway area (WA%) were measured by e-Health high-resolution CT (HRCT). The constructed network model was used to measure the patient's coronary artery plaque and blood vessel volume, and the image was reconstructed on the Res-Net network. It was found that the MSE value of the Res-Net network was the lowest, and the efficiency was very high during the training process. T/D and WA (%) of asthmatic children with small airway obstruction after treatment were significantly lower than those before treatment (P < 0.01). After treatment, MMEF75/25 and FEF75 were significantly higher than those before treatment (P < 0.05). Lung function-related indicator FEF50 was significantly higher than that before treatment (P < 0.01). FeNO level after treatment was remarkably lower than that before treatment (P < 0.01). In addition, lung function-related indicators, airway inflammation indicators, and FeNO level improved the most in group C, followed by group B, and those improvements in group A were the least obvious, with great differences among groups (P < 0.05). In summary, the Res-Net model proposed was of certain feasibility and effectiveness for CT image segmentation and can effectively improve the clinical evaluation of patient CT image information. Glucocorticoids could improve small airway function and airway inflammation in asthmatic children with small airway obstruction, and oral corticosteroids were more effective than aerosol inhalation therapy.

Role of the Emphysema Index Combined with the Chronic Obstructive Pulmonary Disease Assessment Test Score in the Evaluation of Chronic Obstructive Pulmonary Disease.

Background This study aimed to evaluate the efficacy of the emphysema index (EI) in distinguishing chronic bronchitis (CB) from chronic obstructive pulmonary disease (COPD) and its role, combined with the COPD Assessment Test (CAT) score, in the evaluation of COPD. Methods A total of 92 patients with CB and 277 patients with COPD were enrolled in this study. Receiver operating characteristic (ROC) curves were analyzed to evaluate whether the EI can preliminarily distinguish chronic bronchitis from COPD. Considering the heterogeneity of COPD, there might be missed diagnosis of some patients with bronchitis type when differentiating COPD patients only by EI. Therefore, patients with COPD were classified according to the CAT score and EI into four groups: Group 1 (EI < 16%, CAT < 10), Group 2 (EI < 16%, CAT ≥ 10), Group 3 (EI ≥ 16%, CAT < 10), and Group 4 (EI ≥ 16%, CAT ≥ 10). The records of pulmonary function and quantitative computed tomography findings were retrospectively analyzed. Results ROC curve analysis showed that EI = 16.2% was the cutoff value for distinguishing COPD from CB. Groups 1 and 2 exhibited significantly higher maximal voluntary ventilation (MVV) percent predicted (pred), forced expiratory volume in 1 second (FEV1)/forced vital capacity (FVC), maximal midexpiratory flow of 25–75% pred, carbon monoxide-diffusing capacity (DLCO)/alveolar ventilation (VA), FEV1 % pred (p ≤ 0.013), and maximal expiratory flow 50% pred (all p < 0.05) than Group 4. FEV1/FVC and DLCO/VA were significantly lower in Group 3 than in Group 2 (p=0.002 and p < 0.001, respectively). The residual volume/total lung capacity was higher in Group 3 than in Groups 1 and 2 (p < 0.05). Conclusions The combination of EI and CAT was effective in the evaluation of COPD.

Is small airway dysfunction an abnormal phenomenon for patients with normal forced expiratory volume in 1 second and the ratio of forced expiratory volume in 1 second to forced vital capacity?

BackgroundThe clinical significance of small airway dysfunction (SAD) determined with spirometry in patients with normal forced expiratory volume in 1 second (FEV1) and the ratio of FEV1 to forced vital capacity (FVC) is controversial. ObjectiveTo determine whether SAD presents histologic abnormalities in the setting of normal computed tomography (CT) imaging and FEV1 and FEV1/FVC. MethodsA cross-sectional study was performed in 64 patients undergoing thoracotomy for pulmonary nodules. Thoracic high-resolution CT (HRCT), bronchodilation test, and fractional exhaled nitric oxide (FENO) and its alveolar component (nitric oxide alveolar concentration [CANO]) were obtained before surgery. Lung pathology and levels of cytokines in lung tissue were measured. The patients were divided into SAD and small airway normal function groups according to forced expiratory flow at 75% and 50% of the FVC (maximal expiratory flow [MEF] 25, MEF50) and maximum midexpiratory flow. ResultsThe MEF50, MEF25, and maximum midexpiratory flow were strongly negatively correlated with CANO (r, –0.42, –0.42, –0.40, respectively; P ≤ .001 for all). The MEFs were mildly negatively correlated with interleukin (IL)-6 and macrophages in lung tissue (r < –0.25, P < .001 for all). The CANO (P < .001), airspace size (mean linear intercept) (P = .02), macrophages (P = .003), IL-6 (P = .003), and IL-8 (P = .008) in lung tissue were higher in patients with SAD (n = 35) than those with small airway normal function (n = 29). A total of 8 patients (22.86%) with SAD and 2 (6.90%) without SAD had pneumatoceles (P = .10). ConclusionPatients with pulmonary nodules and SAD were more likely to have abnormal inflammation and emphysematous destruction than patients without SAD. Thus, SAD indicates histologic abnormalities in patients with normal CT imaging and FEV1 and FEV1/FVC.