Correlation between Reduced FEF25-75% and a Positive Methacholine Challenge Test in Adults with Nonobstructive Baseline Spirometry

Rationale. FEF25-75% is routinely reported on spirometry and is thought to be a marker of small airway obstruction. It is reduced in children with asthma, but its significance in adults and especially those without asthma diagnosis remains unclear. Objective. To clarify whether in adults with a nonobstructive spirometry a reduced FEF25-75% is associated with a positive methacholine challenge test (MCT). Methods. Data was collected for all the patients who had a MCT done between April 2014 and January 2020 but had nonobstructive baseline spirometry. Logistic regression was utilized to estimate the log odds of a positive methacholine test as a function of FEF25-75% and also for age, gender, BMI, FEV1, and FEV1/FVC. Results. Out of 496 patients, 187 (38%) had a positive MCT. Baseline characteristics in two groups were similar except that patients with positive MCT were younger ( 32 ± 11.57 vs. 38 ± 13.25 years, respectively, p < 0.001 ). Mean FEF25-75% was lower in MCT positive ( 3.12 ± 0.99 L/s) vs. MCT negative ( 3.39 ± 0.97 L/s) patients, p = 0.003 . Logistic regression results suggest that MCT outcome is inversely related to FEF25-75%, age, and gender. Specifically, as FEF25-75% percentage of predicted value increases, the log odds of a positive MCT decrease ( odds ratio OR = 0.90 , 95% confidence intervals CI = 0.84 ‐ 0.96 , p = 0.002 ). Also, as age increases, the log odds of a positive MCT decrease ( OR = 0.95 , 95 % CI = 0.94 ‐ 0.97 , p < 0.001 ). Conclusions. Reduced FEF25-75% in adults with nonobstructive spirometry can predict a positive response to MCT in younger patients. However, this relationship becomes weaker with increasing age.

Evaluation of Glucocorticoid Therapy in Asthma Children with Small Airway Obstruction Based on CT Features of Deep Learning

This study was aimed at exploring the treatment of asthma children with small airway obstruction in CT imaging features of deep learning and glucocorticoid. A total of 145 patients meeting the requirements in hospital were included in this study, and they were randomly assigned to receive aerosolized glucocorticoid ( n = 45 ), aerosolized glucocorticoid combined with bronchodilator ( n = 50 ), or oral steroids ( n = 50 ) for 4 weeks after discharge. The lung function and fractional exhaled nitric oxide (FENO) indexes of the three groups were measured, respectively, and then the effective rates were compared to evaluate the clinical efficacy of glucocorticoids with different administration methods and combined medications in the short-term maintenance treatment after acute exacerbation of asthma. Deep learning algorithm was used for CT image segmentation. The CT image is sent to the workbench for processing on the workbench, and then the convolution operation is performed on each input pixel point during the image processing. After 4 weeks of maintenance treatment, FEF50 %, FEF75 %, and MMEF75/25 increased significantly, and FENO decreased significantly ( P < 0.01 ). The improvement results of FEF50 %, FEF75 %, MMEF75/25, and FENO after maintenance treatment were as follows: the oral hormone group was the most effective, followed by the combined atomization inhalation group, and the hormone atomization inhalation group was the least effective. The differences among them were statistically significant ( P < 0.05 ). The accuracy of artificial intelligence segmentation algorithm was 81%. All the hormones were more effective than local medication in the treatment of small airway function and airway inflammation. In the treatment of aerosol inhalation, the hormone combined with bronchiectasis drug was the most effective in improving small airway obstruction and reducing airway inflammation compared with single drug inhalation. Deep learning CT images are simple, noninvasive, and intuitively observe lung changes in asthma with small airway functional obstruction. Asthma with small airway functional obstruction has high clinical diagnosis and evaluation value.

Smoking Status Modifies the Relationship between Th2 Biomarkers and Small Airway Obstruction in Asthma

Background. Cigarette smoking and Th2-inflammation are both crucial in the pathogenesis of asthma. However, it is unknown whether smoking can affect the association between Th2-inflammation and small airway obstruction in adults with asthma. Methods. Adults diagnosed with asthma by a pulmonologist according to Global Initiative for Asthma guidelines were recruited from September 2016 to April 2018 to participate in this study. Participants were divided into two groups, the small airway obstruction group (those with FEF25–75% predicted value ≤ 65%) and the normal small airway function group (those with FEF25–75% predicted value > 65%). Final data analysis included 385 and 93 people in the Obstructive Group and the Normal Group, respectively. Total serum IgE level and blood eosinophil count were used as biomarkers of the Th2 phenotype. Results. The Obstructive Group had a larger fraction of smokers, higher blood eosinophil count, and lower lung function than the Normal Group. Current-smoking status was associated with an increased risk of small airway obstruction (adjusted odds ratio = 4.677, 95% confidence interval [1.593–13.730]); and log-IgE level was associated with a decreased risk of small airway obstruction (0.403 [0.216–0.754]). Smoking status stratified analysis showed an association between log-IgE level and a decreased risk of small airway obstruction only in never-smoker asthmatics (0.487 [0.249–0.954]). Conclusions. Current-smoking status and total serum IgE are, respectively, associated with small airway obstruction. Smoking status modifies the relationship between Th2 biomarkers and small airway function. These findings contribute to the understanding of risk factors associated with asthma endotyping.

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.

Mixed-dust Pneumoconiosis in a Dental Technician: A Multidisciplinary Diagnosis

BackgroundExposure to crystalline silica in dental laboratories can occur during procedures that generate suspended mineral dusts, e.g. dispersion of mixing powders, removal of castings from moulds grinding and polishing castings and porcelain, and use of silica sand for blasting. Case presentationWe report a 55-year-old male dental technician who, after about 15 years of work, began to suffer from a dry cough and dyspnoea on exertion. The operations included in his job resulted in the generation of crystalline silica, aluminium, chromium, titanium dust. The worker did not regularly wear personal protective equipment and some of the above operations were not carried out in closed circuit systems.The Chest X-ray showed diffuse micronodulation in the lung interstitium in the upper-middle lobes bilaterally and a modest left basal pleural effusion, simple spirometry showed initial small airway obstruction, High Resolution Computerized Tomography of the chest showed bilateral micronodulation of a miliariform type, with greater profusion in the upper lobes, also present in the visceral pleura, bilaterally. Histological examination showed aggregates of pigment-laden macrophages forming perivascular macules or arranged in a radial pattern around a core of sclerohyalinosis. Scanning Electron Microscopy and Energy Dispersive Spectrometry revealed several mineral particles, whose composition is characterised by the presence of aggregates of crystalline silica and metals. The ambient concentrations of total dust and its respirable fraction were all lower than the relative TLV-TWA - ACGIH, but did not negligible. ConclusionsThe above findings and a multidisciplinary assessment led to the diagnosis of mixed dust pneumoconiosis s/q with 2/2 profusion of occupational origin. This diagnosis in a dental technician was supported by environmental exposure analysis for the first time in the literature.

Assessment of the effect of non-asthmatic allergic rhinitis on pulmonary functions - A prospective case-control study

Introduction Allergic rhinitis, beginning from childhood, is a global health problem. According to the literature, allergic rhinitis has been found to be associated with asthma and other allergic manifestations. In this study we like to find out the significance and prognostic importance of pulmonary function test (PFT) in allergic rhinitis. Design and setting: The study was carried out over a period of 2 years, with 63 cases and controls each. Subjects in the age of 20-55 years with allergic rhinitis and SFAR score of >/=7 were included as a case. Participants were interviewed and sent for PFT. Controls were recruited from the retrospective data of healthy individuals with pulmonary function parameters done for health checkup. These controls had an SFAR score of <7. Main outcome measures: Clinical data and PFT of cases and controls was used for the study. SFAR score was used to recruit the cases and controls. All the data obtained were analyzed and compared between cases and controls. Results The mean age of the cases and controls were 33.17 +/- 10.817 and 44.41 +/- 7.4, respectively. Majority of cases and controls were males (60.3% and 57.1%). A statistically significant difference in FEF25-75% among cases and controls was noted (p=0.00), thus proving probability of developing small airway obstruction in subjects with allergic rhinitis. Conclusion Subjects with allergic rhinitis have a probability of developing small airway obstruction with subclinical changes, hence necessitating the need of regular follow-up.

FVC, FEV1, FEV1/FVC % and their Relationship with EF% in Patients with Chronic Heart Failure

Background: Chronic heart failure (CHF) causes multiple lung complications and lung functions are reduced in CHF patients. Objective: To observe FVC, FEV1, FEV1/FVC% and their relationship with EF% in patients with chronic heart failure. Methods: This cross sectional study was conducted in the Department of Physiology of Bangabandhu Sheikh Mujib Medical University (BSMMU), Shahbag, Dhaka, during 2016. For this, 60 diagnosed stable male, aged 35-65 years CHF patients were randomly selected from the Cardiology Department of BSMMU, Dhaka. On the basis of staging of the disease (Stage C) and New York Heart Association (NYHA) functional classification, the study subjects were divided into two groups, 30 patients of NYHA Class- I and 30 patients of NYHA class –II. Thirty (30) apparently healthy Age, Sex and BMI matched subjects were taken as control. To assess the ventilatory function, Forced vital capacity (FVC), Forced expiratory volume in 1st second (FEV1), Forced expiratory ratio (FEV1/FVC%) of all subjects were measured by a portable Digital Spirometer. Again, Ejection fraction (EF%) ranged (≥35% to ≤50%) were measured by Echocardiogram to observe left ventricular function of the heart. For statistical analysis, Independent sample‘t’ test and Pearson’s correlation co-efficient test was performed by using SPSS for windows version-16 & p≤0.05 was accepted as level of significance. Results: The mean percentage of predicted values of FVC and FEV1 were significantly lower but FEV1/FVC% was significantly higher in CHF patients comparison to the healthy control. All the study variables were significantly lower in patients of NYHA class–II as compared to patients of NYHA class–I. 73.33% CHF patients had restrictive, 10.00% small airway obstruction and 16.67% combined restrictive and small airway obstruction feature. In addition, FVC and FEV1 (p<0.05) was positively and FEV1/FVC% (p<0.05) negatively correlated with EF% in chronic heart failure patients. Conclusion: Left ventricular dysfunction may be silently associated with decrease ventilatory function mainly restrictive type of pulmonary disorder. University Heart Journal Vol. 16, No. 2, Jul 2020; 59-64

AB0597 PULMONARY FUNCTION IN PATIENTS DIAGNOSED OF EARLY SYSTEMIC SCLEROSIS: A NEW TOOL FOR SYSTEMIC SCLEROSIS CLASIFFICATION?

Background:Interstitial lung disease (ILD) is a frequent complication of systemic sclerosis (SSc) and is often progressive and has a poor prognosis. A restrictive ventilatory defect could suggest ILD either alone or in combination with pulmonary arterial hypertension.Nowadays, Early-SSc is well defined as preliminary stage of SSc. Patients who meet criteria for Early-SSc could benefit from an early diagnosis of pulmonary involvement.Objectives:Our aim was to assess the pulmonary function in patients diagnosed of Early SSc.Methods:Retrospective observational study of a wide and unselected series of patients diagnosed as Early-SSc from a single university hospital from 2012 to 2019. Patients were classified as Early-SSc following Le Roy criteria. Despite this, patients already did not meet 2013 ACR/EULAR classification criteria for SSc. We reviewed pulmonary function through conventional spirometry and diffusing capacity of lung for carbon monoxide (DLCO).Results:We included 56 patients with a mean age of 52.3±12.1 years (96.4% women; 3.6% men).At the diagnosis of Early-SSc, no one of our patients evidenced a restrictive ventilatory pattern. DLCO was below normal limits in 18 patients (32.1%). Small airway obstruction expressed according decreased maximal (mid-) expiratory flow (MMEF) 25-75 was present in 24 patients (42.8%).After a mean follow-up period of 38.3±2.4 months, 29 (51.8%) patients fulfilled 2013 ACR/EULAR criteria. The average time between diagnosis of Early-SSc and achieve SSc classification was 24.4±1.8 months. The remaining 27 patients continued classified as Early-SSc.An analysis of the subgroup of patients which progressed to SSc showed that DLCO was decreased in 15 of those 29 patients (51.7%) and 18 of 29 patients (62.1%) presented decreased MMEF 25-75. Comparing with the subgroup of patients which not progressed to SSc were significant differences (Decreased DLCO: 51.7% vs 11.1%; p=0.02 and decreased MMEF 25-75: 42.8% vs 22.2%; p=0.05).The analysis of pulmonary function of the subgroup of patients continued classified as Early-SSc after follow-up period did not show significative changes after follow-up.Conclusion:In our study, a third of the patients classified as Early-SSc presented at diagnosis abnormal values of DLCO and/or signs of small airway obstruction without the presence of a restrictive ventilatory pattern. Moreover, this pulmonary disfunction was significantly more frequent in patients who progressed to definitive SSc. Patients which remains classified as Early-SSc did not experience significative changes.Our results support the concept that pulmonary function was impaired in Early-SSc and that I should probably be considered for future Early-SSc classification criteria.Disclosure of Interests:None declared