Clinic vs Home Spirometry for Monitoring Lung Function in Patients With Asthma

Relation of changes in peak expiratory flow (PEF) and forced expiratory volume in 1 s (FEV1) during bronchoconstriction

Diagnosis of asthma can be confirmed based on variability in peak expiratory flow (PEF) or changes in forced expiratory volume in 1 s (FEV1) measured with spirometry. Our aim was to use methacholine challenge as a model of induced airway obstruction to assess how well relative changes in PEF reflect airway obstruction in comparison to relative changes in FEV1. We retrospectively studied 878 patients who completed a methacholine challenge test. To assess congruency along with differences between relative changes in FEV1 and PEF during airway obstruction, a regression analysis was performed, and a Bland & Altman plot was constructed. ROC analysis, sensitivity, specificity, positive and negative predictive values and κ-coefficient were used to analyze how decrease in PEF predicts decrease of 10% or 15% in FEV1. The relative change in PEF was on average less than the relative change in FEV1. In the ROC analysis areas under the curve were 0.844 and 0.893 for PEF decrease to predict a 10% and 15% decrease in FEV1, respectively. The agreement between changes in PEF and FEV1 varied from fair to moderate. Airway obstruction detected by change in PEF was false in about 40% of cases when compared to change in FEV1. Change in PEF is not a very accurate measure of airway obstruction when compared to change in FEV1. Replacing peak flow metre with a handheld spirometer might improve diagnostic accuracy of home monitoring in asthma.

Enhancing Adult Asthma Management: A Review on the Utility of Remote Home Spirometry and Mobile Applications

Asthma is a prevalent chronic disease, contributing significantly to the global burden of disease and economic costs. Despite advances in treatment, inadequate disease management and reliance on reliever medications lead to preventable deaths. Telemedicine, defined as the use of information and communication technology to improve healthcare access, has gained global attention, especially during the COVID-19 pandemic. This systematic review examines the effectiveness of home monitoring systems in managing severe asthma. A systematic literature search was conducted in PubMed, Web of Science, Scopus, and Cochrane Library, focusing on studies from 2014 to 2024. Fourteen studies involving 9093 patients were analyzed. The results indicate that telemedicine, through tools such as mobile applications and portable spirometers, positively impacts asthma control, self-management, and quality of life. Home spirometry, in particular, shows strong agreement with clinic spirometry, offering a feasible alternative for continuous monitoring. Digital coaching and machine learning-based telemedicine applications also demonstrate significant potential in improving asthma outcomes. However, challenges such as technology accessibility, data privacy, and the need for standardized protocols remain. This review highlights the promise of telemedicine in asthma management and calls for further research to optimize its implementation and address existing barriers.

Day-to-Day Variability in Measurements of Respiration Using Bioimpedance from a Non-Standard Location

Non-invasive monitoring of pulmonary health may be useful for tracking several conditions such as COVID-19 recovery and the progression of pulmonary edema. Some proposed methods use impedance-based technologies to non-invasively measure the thorax impedance as a function of respiration but face challenges that limit the feasibility, accuracy, and practicality of tracking daily changes. In our prior work, we demonstrated a novel approach to monitor respiration by measuring changes in impedance from the back of the thigh. We reported the concept of using thigh-thigh bioimpedance measurements for measuring the respiration rate and demonstrated a linear relationship between the thigh-thigh bioimpedance and lung tidal volume. Here, we investigate the variability in thigh-thigh impedance measurements to further understand the feasibility of the technique for detecting a change in the respiratory status due to disease onset or recovery if used for long-term in-home monitoring. Multiple within-session and day-to-day impedance measurements were collected at 80 kHz using dry electrodes (thigh) and wet electrodes (thorax) across the five healthy subjects, along with simultaneous gold standard spirometer measurements for three consecutive days. The peak-peak bioimpedance measurements were found to be highly correlated (0.94 ± 0.03 for dry electrodes across thigh; 0.92 ± 0.07 for wet electrodes across thorax) with the peak-peak spirometer tidal volume. The data across five subjects indicate that the day-to-day variability in the relationship between impedance and volume for thigh-thigh measurements is smaller (average of 14%) than for the thorax (40%). However, it is affected by food and water and might limit the accuracy of the respiratory tidal volume.

Current technological advancement in asthma care

INTRODUCTION

Asthma is a common chronic respiratory disease affecting 262 million people globally, causing half a million deaths each year. Poor asthma outcomes are frequently due to non-adherence to medication, poor engagement with asthma services, and a lack of objective diagnostic tests. In recent years, technologies have been developed to improve diagnosis, monitoring, and care.

AREAS COVERED

Technology has impacted asthma care with the potential to improve patient outcomes, reduce healthcare costs, and provide personalized management. We focus on current evidence on home diagnostics and monitoring, remote asthma reviews, and digital smart inhalers. PubMed, Ovid/Embase, Cochrane Library, Scopus and Google Scholar were searched in November 2023 with no limit by year of publication.

EXPERT OPINION

Advanced diagnostic technologies have enabled early asthma detection and personalized treatment plans. Mobile applications and digital therapeutics empower patients to manage their condition and improve adherence to treatments. Telemedicine platforms and remote monitoring devices have the potential to streamline asthma care. AI algorithms can analyze patient data and predict exacerbations in proof-of-concept studies. Technology can potentially provide precision medicine to a wider patient group in the future, but further development is essential for implementation into routine care which in itself will be a major challenge.

Feasibility and value of a domiciliary spirometry programme in the assessment of severe asthma: a real-world evaluation

Background

Domiciliary spirometry (DS) is a novel tool that is widely employed in the assessment of respiratory disease. We assessed real-world feasibility, effectiveness and value of a physiologist-led home spirometry programme in patients with treatment-refractory severe asthma.

Methods

Patients were referred and provided with a hand-held DS device. Patients completed baseline measurements in a physiologist-led virtual clinic and were instructed to provide further values during any periods of respiratory symptoms. Outcome measures included prevalence of new obstructed events, DS adherence and uptake of this approach.

Results

112 patients were enrolled from November 2020 to January 2023. 102 individuals, mean±sd age 44±13 years (86% female) with median (IQR) forced expiratory volume in 1 s % predicted 88% (77-97%), successfully recorded baseline spirometry values. During follow-up (24 months), 11 (11%) were identified with new obstructive spirometry and were subsequently able to be commenced on biologic therapy. Patient engagement was poor with median (IQR) of 4 (2-6) attempts of contact made before baseline values were recorded, and 2 (1-3) attempts required to record technically acceptable values. Continued DS use was suboptimal; 34% failed to use their device after baseline and only 10% continued at the end of the study period. The cost of DS measurements was greater than a single hospital-based visit but enables multiple event capture.

Conclusion

Overall, DS measurement uptake was poor, with a minority of patients continuing to use the device at the end of the study period. However, for those that engage, DS provides an alternative approach to traditional hospital-based spirometry measurements that can alter clinical management.

COVID-19 and Its Impact on Common Diseases in the Allergy Clinics

Coronavirus disease 2019 (COVID-19) is a highly contagious viral disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). It has various effects on asthma, allergic rhinitis, atopic dermatitis, and urticaria and may change the course of the disease depending on the severity of the infection and control status of the disease. Conversely, these diseases may also impact the course of COVID-19. Patients with chronic urticaria and atopic dermatitis may have COVID-19-induced disease exacerbations and biological treatments reduce the risk of exacerbations. Poor asthma control is linked to severe COVID-19 while allergic asthma is associated with lower risk of death and a lower rate of hospitalization due to COVID-19 compared with nonallergic asthma. The use of intranasal corticosteroids is associated with lower rates of hospitalization due to COVID-19 in patients with allergic rhinitis, whereas the effect of inhaled corticosteroids is confounded by asthma severity. These observations reinforce the importance of keeping allergic diseases under control during pandemics. The use of biologicals during COVID-19 is generally regarded as safe, but more evidence is needed. The pandemic substantially changed the management of allergic disorders such as home implementation of various biologicals, allergen immunotherapy, food introduction, and increased use of telemedicine and even home management of anaphylaxis to reduce emergency department burden and reduce risk of infection. Physicians need to be aware of the potential impact of COVID-19 on allergic diseases and educate their patients on the importance of continuing prescribed medications and adhering to their treatment plans to maintain optimal control of their disease.