Patterns of changes and diagnostic values of FEF50%, FEF25%-75% and FEF50%/FEF25%-75% ratio in patients with varying control of bronchial asthma

Role of FEF25-75 in characterizing outpatients with asthma in clinical practice

BACKGROUND

Asthma is characterized by variable airflow limitation. FEF25-75 has been proposed as a reliable marker for bronchial obstruction, especially when FEV1 and FEV1/FVC are normal.

OBJECTIVES

To investigate the role of FEF25-75 in patients with asthma seen in clinical settings.

MATERIALS AND METHODS

The cross-sectional study included 439 (181 females and 255 males; mean age 39 years) outpatients with asthma who consecutively visited an allergy clinic for a routine assessment. History, physical examination, asthma control, and spirometry were evaluated.

RESULTS

FEF25-75 was impaired (< 65% of predicted) in 136 (31%) outpatients. Considering only subjects with normal FEV1 and FEV1/FVC, FEF25-75 was impaired in 71 (19.6%) subjects. In this subset, impaired FEF25-75 was associated with low FEV1 and FEV1/FVC values (OR 0.91 and 0.85, respectively), and presence of asthma symptoms (OR 2.19).

CONCLUSION

FEF25-75 deserves adequate and careful consideration in patients with asthma and normal FEV1 and FEV1/FVC, as the presence of impaired FEF25-75 in this subset suggests a more specific approach.

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.

The pragmatic role of FEF25-75 in asymptomatic subjects, allergic rhinitis, asthma, and in military setting

Introduction: The forced expiratory flow between 25% and 75% of forced vital capacity (FEF_25-75) is a spirometry parameter that may be useful in many clinical settings. Values <65% of predicted have been defined as abnormal.Areas covered: The current report discusses the clinical value of FEF_25-75 in different settingv, namely military medicine, primary care, and specialized clinic. Moreover, the predictive role of FEF_25-75 was discussed considering different patients' populations, including patients suffering from allergic rhinitis and/or asthma, as well as normal subjects. The most recent literature concerning the assessment of FEF_25-75 in these covered areas was searched.Expert opinion: In clinical practice, impaired values have been defined as a reliable surrogate marker for bronchial airflow limitation associated with early onset of asthma, bronchial hyperresponsiveness, lower airway inflammation, reversibility to bronchodilation testing, allergic sensitization, and uncontrolled asthma. In the military medicine setting, simple spirometry, including FEF_25-75, may suggest a series of fruitful information.

Spirometric indices of early airflow impairment in individuals at risk of developing COPD: Spirometry beyond FEV1/FVC

Spirometry is the current gold standard for diagnosing and monitoring the progression of Chronic Obstructive Pulmonary Disease (COPD). However, many current and former smokers who do not meet established spirometric criteria for the diagnosis of this disease have symptoms and clinical courses similar to those with diagnosed COPD. Large longitudinal observational studies following individuals at risk of developing COPD offer us additional insight into spirometric patterns of disease development and progression. Analysis of forced expiratory maneuver changes over time may allow us to better understand early changes predictive of progressive disease. This review discusses the theoretical ability of spirometry to capture fine pathophysiologic changes in early airway disease, highlights the shortcomings of current diagnostic criteria, and reviews existing evidence for spirometric measures which may be used to better detect early airflow impairment.

Airway reversibility in asthma and phenotypes of Th2-biomarkers, lung function and disease control

Background

High bronchodilator reversibility in adult asthma is associated with distinct clinical characteristics. In this study, we aim to make a comparison with T-helper 2 (Th2)-related biomarkers, lung function and asthma control between asthmatic patients with high airway reversibility (HR) and low airway reversibility (LR).

Methods

Patients with asthma diagnosed by pulmonologist according to Global Initiative for Asthma guidelines were recruited from the outpatient department of our hospital from August 2014 to July 2017. Patients were divided into HR and LR subgroups based on their response to bronchodilators of lung function (HR = Δforced expiratory volume in one second (FEV1) postbronchodilator ≥ 20%). Blood eosinophil count and serum IgE level, which are biomarkers of T-helper (Th)-2 phenotypes, were detected for patients. Asthma Control Test (ACT) was used to assess asthma control after the first-month initial treatment.

Results

A total of 265 patients with asthma were followed 1 month after initial treatment. HR group shows a higher level of Th2-high biomarkers (blood eosinophil count (10^9/L): 0.49 ± 0.28 vs 0.36 ± 0.19, P < 0.01; IgE (ng/ml): 1306 ± 842 vs 413 ± 261, P < 0.01), lower baseline lung function (FEV1%pred: 51.91 ± 19.34% vs 60.42 ± 19.22%, P < 0.01; forced expiratory flow (FEF)25–75: 0.76 ± 0.37 vs 1.00 ± 0.67, P < 0.01; FEF25–75%pred: 21.15 ± 10.09% vs 29.06 ± 16.50%, P < 0.01), and better asthma control (ACT score: 22 ± 4 vs 20 ± 4, P = 0.01) than LR group. HR was associated with a decreased risk of uncontrolled asthma after the first-month initial treatment (adjusted OR: 0.12 [95% confidence intervals: 0.03–0.50]).

Conclusions

HR is a physiologic indicator of lower lung function and severer small airway obstruction, and is more related with an increased level of Th2-biomarkers than LR. Moreover, HR may indicate controlled asthma after the first-month initial treatment. This finding may contribute to identification of asthma endotype.