Peak Expiratory Flow Monitoring Research Articles

Occupational asthma, rhinitis and contact urticaria from greenhouse work.

The current knowledge about occupational allergic diseases among greenhouse workers is scant. To describe greenhouse workers' occupational allergic diseases. We identified 28 greenhouse workers with occupational allergic diseases in 2002-2020 by conducting a systematic search in the patient register of the Finnish Institute of Occupational Health. All the patients worked in tomato- or cucumber-growing greenhouses and showed immunoglobulin-E-mediated sensitization to occupational agents. Specific inhalation challenges or workplace peak expiratory flow monitoring confirmed occupational asthma (OA), nasal allergen challenges confirmed occupational rhinitis (OR) and open skin tests confirmed occupational contact urticaria (OCU). Most patients had more than one occupational disease and were sensitized to several workplace agents. Tomato plants were the most common cause of occupational diseases and induced 22 allergic diseases in 14 patients. Cucumber plants caused occupational diseases in 10 patients (3 OA, 7 OR and 6 OCU). The pest control mite Amblyseius swirskii and a mixture of parasitic wasps Encarsia formosa and Eretmocerus eremicus both induced two OA cases. Three patients had an occupational disease caused by storage mites and three others had a work-related systemic reaction to a bumblebee sting. The greenhouse workers typically suffered from several occupational allergic diseases and were sensitized to cultivated plants, various pest control organisms and storage mites. All these can cause OA and OR, but in this study, OCU was only induced by cultivation plants. Cucumber plant is a novel cause of OA and OR, and A. swirskii is a novel cause of OA.

Cold temperature and sudden temperature drop as novel risk factors of asthma exacerbation: a longitudinal study in 18 Chinese cities

BackgroundFew studies have explored the role of ambient temperature in asthma exacerbation. ObjectiveWe aimed to explore the association of temperature with diurnal peak expiratory flow (PEF) variation and asthma exacerbation. MethodWe developed a longitudinal study among asthmatic adults in 18 Chinese cities. Subjects recorded PEF in dynamic pulmonary function monitoring from 2017 to 2020. Linear mixed-effect model and generalized additive model with distributed non-linear models were used to assess the effect of temperature and temperature change between neighboring days (TCN) on diurnal PEF variation and the risk of asthma exacerbation. ResultWe evaluated a total of 79,217 daily PEF monitoring records from 4467 adult asthmatic patients. There were significant increase of diurnal PEF variation and higher risk of asthma exacerbation with cold and sudden temperature drop. Compared with the referent temperature (99th percentile, 32 °C), exposure to moderate cold (25th percentile, 3 °C) and extreme cold (2.5th percentile, −7 °C) was associated with elevations of 1.28% and 1.16% in diurnal PEF variation over lag 0–2 days, respectively. The odds ratios of asthma exacerbation (determined by diurnal PEF variation >20%) at the two temperature cutoffs were 1.68 and 1.73. A sudden temperature drop (2.5th percentile of TCN, −5 °C) was associated with 1.13% elevation in diurnal PEF variation, and with increased risk of asthma exacerbation (odd ratio = 1.50) over lag 0–4 days. ConclusionThis large multicenter study provided the first-hand empirical evidence that cold temperature and a temperature drop may increase the risk of asthma exacerbation.

Perspectives and Management of Atypical Asthma in Chinese Specialists and Primary Care Practitioners-A Nationwide Questionnaire Survey.

Background and objective: To evaluate the awareness/knowledge and clinical practice for the treatment of atypical asthma among respiratory specialists and primary care practitioners (PCPs) in China.Methods: A total number of 1,997 physicians participated in the survey via WeChat. The questionnaire included six main items: physician demographic characteristics, awareness, diagnosis, medical prescription, assessment/education, and proposal.Results: Cough variant asthma (CVA) was recognized by 97.51% of physicians (1,166 respiratory specialists and 799 PCPs), followed by chest tightness variant asthma (CTVA, 83.72%) and occult asthma (73.54%). Specialists were more likely to follow diagnostic recommendations than PCPs (P < 0.01); however, 34.15% of physicians reported the utility of bronchodilation tests, airway provocation tests, and peak expiratory flow monitoring. A total of 91.70% and 92.01% of physicians prescribed inhaled corticosteroids (ICS) or ICS plus long-acting beta-agonists (LABA) for CVA and CTVA, respectively. Physicians prescribed an ICS or ICS/LABA for 4 (2–8) or 8 (4–12) weeks for CVA and 4 (2–8) or 5 (4–12) weeks for CTVA, and the prescription durations were significantly shorter for PCPs than for specialists (P < 0.01). Further, 52.42% and 35.78% reported good control of CVA and CTVA, respectively, with significantly lower control rates for PCPs than for specialists (P < 0.01). Additionally, specialists exhibited better assessment and educational habits than PCPs.Conclusion: While atypical asthma was identified by most specialists and PCPs, there remains a gap between management in real clinical practice and guideline recommendations, especially for PCPs. Further training of PCPs and clinical studies of atypical asthma are required to improve practice.

Role of peak expiratory flow in the assessment and management of asthma in children

Peak expiratory flow (PEF) is a portable, reliable, and inexpensive method for lung function assessment. PEF can reflect expiratory airflow limitation and its variability can document reversibility, which provides an objective basis for the diagnosis of asthma in children. Short-term PEF monitoring can be an important aid in the management of acute asthma exacerbations, identification of possible triggers, and assessment of response to treatment. Long-term PEF monitoring can assist in the assessment of asthma control and warning of acute exacerbations, and this is useful for children with severe asthma. This article reviews the measurements, influencing factors, interpretation, and application of PEF, and its role in the diagnosis and management of asthma in children, to provide references for the clinical application of PEF in children.

Validation of a Portable Game Controller to Assess Peak Expiratory Flow Against Conventional Spirometry in Children: Cross-sectional Study.

BackgroundInternational asthma guidelines recommend the monitoring of peak expiratory flow (PEF) as part of asthma self-management in children and adolescents who poorly perceive airflow obstruction, those with a history of severe exacerbations, or those who have difficulty controlling asthma. Measured with a peak flow meter, PEF represents a person’s maximum speed of expiration and helps individuals to follow their disease evolution and, ultimately, to prevent asthma exacerbations. However, patient adherence to regular peak flow meter use is poor, particularly in pediatric populations. To address this, we developed an interactive tablet-based game with a portable game controller that can transduce a signal from the user’s breath to generate a PEF value.ObjectiveThe purpose of this study was to evaluate the concordance between PEF values obtained with the game controller and various measures derived from conventional pulmonary function tests (ie, spirometry) and to synthesize the participants’ feedback.MethodsIn this cross-sectional multicenter study, 158 children (aged 8-15 years old) with a diagnosis or suspicion of asthma performed spirometry and played the game in one of two hospital university centers. We evaluated the correlation between PEF measured by both the game controller and spirometry, forced expiratory volume at 1 second (FEV1), and forced expiratory flow at 25%-75% of pulmonary volume (FEF25-75), using Spearman correlation. A Bland-Altman plot was generated for comparison of PEF measured by the game controller against PEF measured by spirometry. A post-game user feedback questionnaire was administered and analyzed.ResultsThe participants had a mean age of 10.9 (SD 2.5) years, 44% (71/158) were female, and 88% (139/158) were White. On average, the pulmonary function of the participants was normal, including FEV1, PEF, and FEV1/forced vital capacity (FVC). The PEF measured by the game controller was reproducible in 96.2% (152/158) of participants according to standardized criteria. The PEF measured by the game controller presented a good correlation with PEF measured by spirometry (r=0.83, P<.001), with FEV1 (r=0.74, P<.001), and with FEF25-75 (r=0.65, P<.001). The PEF measured by the game controller presented an expected mean bias of –36.4 L/min as compared to PEF measured by spirometry. The participants’ feedback was strongly positive, with 78.3% (123/157) reporting they would use the game if they had it at home.ConclusionsThe game controller we developed is an interactive tool appreciated by children with asthma, and the PEF values measured by the game controller are reproducible, with a good correlation to values measured by conventional spirometry. Future studies are necessary to evaluate the clinical impact this novel tool might have on asthma management and its potential use in an out-of-hospital setting.

Promising peak flow diary compliance with an electronic peak flow meter and linked smartphone app

Peak expiratory flow (PEF) monitoring is recommended in the management of asthma. However, compliance is poor, and this is often attributed to the burden of measurement and recording. The Smart Peak Flow (SPF) device and app allow self-measuring and self-monitoring of PEF. Compliance with self-monitoring was promising in 399 UK users, calling for research to confirm these results and explore its potential as an intervention to improve self-monitoring.

Influence of five-in-one management mode on disease prevention and control of school children with asthma

Objective: To investigate the influence of five-in-one management mode(standardized asthma treatment, asthma diary, peak expiratory flow (PEF) monitoring, reasonable diet and physical exercise) on disease prevention and control of school children with asthma. Methods: From April to October 2018, 70 children with asthma in clinical remission were selected from Affiliated Hospital of Qingdao University using randomized controlled study design. These children were randomly divided into study group and control group, with 35 cases in each group. In the study group, 5 cases were lost to follow-up, and 30 cases were actually enrolled. In the control group, 6 cases were lost to follow-up, and 29 cases were actually enrolled. Children in the control group received routine medication and regular outpatient consultation, and children in the study group received the five-in-one asthma management model. In the first time of seeing a doctor, after 3 months and 6 months of follow-up, asthma control test score, medication compliance index score and lung function index (forced expiratory volume in 1 second (FEV1), PEF were evaluated respectively.Parental satisfaction, asthma acute episodes, weight, height and biochemical index were recorded during the 6 months of follow-up. Pulmonary function index, asthma control score and body mass index of overweight children with asthma were compared with t-test, medication compliance was compared with chi-square test, and the rank sum test was used for the comparison of the number of emergency visits of asthma attacks and parents' satisfaction. Results: A total of 59 children with asthma were included, among them 30 were in the study group (8.1±1.5) years old and 29 in the control group (9.2±1.1) years old. After 3 months of follow-up, FEV1, PEF, asthma control score in the study group were (86.3±1.5)%, (83.3±2.4)%, (24.7±2.6) points respectively; and in the control group, FEV1, PEF, asthma control score were (84.4±2.5)%, (82.2±1.9)%, (21.1±1.3) points respectively. The indicators in the study group were higher than those in the control group (t=3.62, 1.97, 6.64, P<0.05). After 6 months of follow-up, FEV1, PEF, asthma control score in the study group were (88.4±2.3)%, (85.4±2.2)%, (26.8±1.8) points respectively; and in the control group, FEV1, PEF, asthma control score were (85.5±1.9)%, (83.2±1.7)%, (22.5±1.4) points respectively. The indicators in the study group were significantly higher than those in the control group (t=5.34, 4.24, 10.41, P<0.05). During the 6-month follow up, the number of emergency visits of asthma attacks in the study group and in the control group were 0.42(0.36, 0.51) and 0.92(0.72, 1.27) respectively. The indicator in the study group was significantly lower than that in the control group (Z=3.21, P<0.05). After 3 months of follow-up, the proportions of children with good compliance in the study group and control group were 67% (20/30) and 62% (18/29), the proportions of poor compliance were 27% (8/30) and 34% (10/29), the proportions of non-compliance were 7% (2/30) and 7% (2/29). There were no statistically significant differences (χ(2)=0.14, 0.43, 0.00, P=0.71, 0.51, 0.97). After 6 months of follow-up, the proportions of children with good compliance in the study group and control group were 87% (26/30) and 69% (20/29), the proportion of poor compliance were 10% (3/30) and 28% (8/29), the proportion of non-compliance were 3% (1/30) and 7% (2/29), There were no statistically significant differences (χ(2)=2.70, 3.00, 0.39, P=0.10, 0.08, 0.53). After 6 months of follow-up, the number of great satisfaction, satisfaction and dissatisfaction in the study group were 20, 10 and 0 respectively, the satisfaction rate was 100%, meanwhile those indicators in the control group were 4, 15 and 10 respectively, the satisfaction rate was 66%, The indicator in the study group was significantly higher than that in the control group (Z=4.60, P<0.05). Conclusions: The application of "five-in-one" asthma management model (standardized asthma treatment, asthma diary, PEF monitoring, reasonable diet and physical exercise) for school-age children with asthma can significantly improve lung function, as well as reduce the number of acute asthma attacks. It has a high parent satisfaction, therefore it should be recommended for clinical implementation.

Vortex Whistle and Smart Phone Application for Peak Flow Recordings in Asthmatic Children: A Feasibility Study.

Introduction: Variable airflow obstruction that can be confirmed by diurnal variability of peak expiratory flow (PEF) >13% is an important characteristic of asthma. Home monitoring of PEF may be helpful to diagnose and monitor asthma. In this feasibility study, we aimed to study if asthmatic children can measure PEF at home twice daily during a 4-week period using a device designed as a “whistle” and a smart phone software application.Materials and Methods: Twice daily during 4 weeks, children aged 5–12 years with current asthma rated their asthma condition electronically on the smart phone application Blowfish before inhaling deeply then exhaling into the device to produce a high-pitched sound recorded by the application. Through mathematical algorithms, the sound was transferred to PEF, which was uploaded to a server. At inclusion, the Pediatric Asthma Quality of Life Questionnaire and the Childhood Asthma Control Test were answered. At the end, the parents graded the device and application.Results: One child did not manage to upload PEF. For the remaining 21 children, the median (quartiles) days with at least one measurement during the period were 27 (21–29.5), and on median 18 (9–24) days PEF was recorded twice daily. The median parental score (potential score 0–20) of the application was 18 (15–20).Discussion/Conclusion: The study shows promising results for home monitoring of PEF by an electronic device with automatic teletransmission. The high rate of successful recordings and parental satisfaction suggests that the clinical utility of the solution should be further studied.

The prognostic value of spirometric tests in Amyotrophic Lateral Sclerosis patients

ObjectiveAmyotrophic lateral sclerosis (ALS) patients tend to develop progressive respiratory muscle weakness, leading to ventilatory failure and ineffective cough, principal causes of morbidity and mortality. Since patients are usually unaware of these symptoms, these are generally not noticed until the advanced stages and are associated with poor prognosis. The monitoring of respiratory function on a regular basis is therefore of great importance. Despite the availability of several pulmonary function tests, none of them was found to be the best indicator of the disease progression throughout the course of this condition.The main aim of our work was to evaluate the prognostic value of these respiratory measures evaluated in a brief period of observation and their correlation with motor functional impairments in an ALS cohort. Patients and MethodsPatients with ALS who had respiratory assessments performed and functional motor scales administered at baseline and six months later were included. All patients were assessed with forced vital capacity, both in seated and supine position (FVC; sFVC), peak expiratory flow (PEF), peak expiratory cough flow (PCEF), the revised ALS functional rating scale (ALSFRS-R), at baseline and after six months, and their disease progression rate (ΔFS) was obtained. ResultsWe included 73 patients with probable or definite ALS according to El-Escorial revised Criteria. At baseline, PCEF and PEF significantly correlated with ALSFRS-R total, bulbar and spinal subscores and ΔFS, while FVC% significantly correlated with ΔFS. After 6 months all the respiratory parameters significantly correlated with ALSFRS-R and all its subscores. Longitudinally, FVC%, sFVC% and PCEF significantly correlated with ΔFS and some of ALSFRS-R subscores. As concerns the survival analysis, monthly declines of FVC% and sFVC%, significantly correlated with the survival. The worse prognosis in terms of survival was finally found in those whose FVC% and sFVC% dropped below their respective cut-offs. ConclusionThroughout the course of ALS disease, the monitoring of several respiratory markers, namely FVC, sFVC, PEF and PCEF, plays a critical role in predicting the prognosis of these subjects, both in terms of survival and functional ability. The implementation of monthly cut-offs in the evaluation of FVC and sFVC may allow a faster recognition of those patients with worse prognosis and therefore an optimized tailored clinical care, as well as a better stratification in clinical trials.

Revising the Criteria for Occupational Mould-Related Disease: Arguments, Misconceptions, and Facts

Occupational exposure to indoor air moulds and the consequent development of dampness and mould hypersensitivity syndrome (DMHS) may cause lung damage; in most cases, this is not allergic asthma mediated by specific immunoglobulin E-class antibodies. Instead, it is often a hypersensitivity pneumonitis or bronchopneumonitis. In Finland, the current diagnostic criteria for occupational DMHS have been adapted from knowledge of immunoglobulin E-mediated asthma; however, the safety of the methods used in occupational medicine have been insufficiently addressed in the literature. Accordingly, the aim of this paper is to raise awareness about the safety of current methods: specific inhalation challenge, workplace peak expiratory flow monitoring, and histamine provocation tests, by illustrating four cases. The medical records of these four cases with documented occupational DMHS were reviewed. The presented evidence suggests that the methods applied to study the occupational nature of lung damage are not suitable and the current ethics are questionable. The authors claim that, in particular, serial inhalation challenge with extracts from moulds, workplace serial peak expiratory flow leading to continuous exposure to mycotoxins, and histamine provocation tests may irreversibly damage the health of DMHS patients. Therefore, there is a prompt need to revise current practice guidelines to assess occupational DMHS. The guidelines should not be based on old dogmas, nor should they be influenced by insurance considerations. Instead, they should be based solely on medical evidence and, crucially, they should be safe for the patient and, therefore, should be implemented with caution.

Long-term prognosis of chronic cough: a prospective, observational cohort study

BackgroundThe long-term prognosis of chronic cough and its determinants need to be clarified.MethodsThis is a prospective, observational cohort study. Eighty-nine unselected subjects with chronic (> 8 weeks’ duration) cough were carefully investigated: Clinical examination, symptom questionnaire, Leicester Cough Questionnaire (LCQ), skin prick tests, ambulatory peak expiratory flow monitoring, spirometry before and after 0.4 mgs of salbutamol, exhaled nitric oxide concentration measurement, hypertonic saline cough provocation test, and histamine bronchial provocation test. After five years, a letter was sent to the subjects containing questions about continuation of cough, smoking, indoor exposures, presence of co-morbidities, and current medication. It also contained LCQ and Cough Clinic diagnostic questionnaire. Sixty-eight subjects (76%) responded.ResultsAt five years, continuing regular cough was present in 31 (46%) of the subjects and continuing impairment in cough-related quality of life (less than 1.3 points’ improvement in LCQ) in 32 (47%). Continuing regular cough was associated with presence of chronic rhinitis or esophageal reflux disease, baseline mild airway responsiveness to histamine, and baseline strong cough responsiveness to hypertonic saline. Continuing impairment in cough-related quality of life was associated with high body mass index, absence of atopy, absence of pets, and high number of background disorders (esophageal reflux disease, asthma, or chronic rhinitis).ConclusionsAlmost half of subjects with chronic cough suffered of the disorder at five years from initial assessment. Several possible determinants of poor prognosis could be identified.

Randomized Trial of Interventions to Improve Childhood Asthma in Homes with Wood-burning Stoves.

Background:Household air pollution due to biomass combustion for residential heating adversely affects vulnerable populations. Randomized controlled trials to improve indoor air quality in homes of children with asthma are limited, and no such studies have been conducted in homes using wood for heating.Objectives:Our aims were to test the hypothesis that household-level interventions, specifically improved-technology wood-burning appliances or air-filtration devices, would improve health measures, in particular Pediatric Asthma Quality of Life Questionnaire (PAQLQ) scores, relative to placebo, among children living with asthma in homes with wood-burning stoves.Methods:A three-arm placebo-controlled randomized trial was conducted in homes with wood-burning stoves among children with asthma. Multiple preintervention and postintervention data included PAQLQ (primary outcome), peak expiratory flow (PEF) monitoring, diurnal peak flow variability (dPFV, an indicator of airway hyperreactivity) and indoor particulate matter (PM) .Results:Relative to placebo, neither the air filter nor the woodstove intervention showed improvement in quality-of-life measures. Among the secondary outcomes, dPFV showed a 4.1 percentage point decrease in variability [ to ] for air-filtration use in comparison with placebo. The air-filter intervention showed a 67% (95% CI: 50% to 77%) reduction in indoor , but no change was observed with the improved-technology woodstove intervention.Conclusions:Among children with asthma and chronic exposure to woodsmoke, an air-filter intervention that improved indoor air quality did not affect quality-of-life measures. Intent-to-treat analysis did show an improvement in the secondary measure of dPFV.Trial registration:ClincialTrials.gov NCT00807183. https://doi.org/10.1289/EHP849

Does the medical diagnosis of occupational asthma coincide with the legal diagnosis?

ABSTRACTObjective: The incidence of occupational asthma (OA) is increasing worldwide. In this study, we first aimed to document the rate of diagnosis of OA among patients who were referred to our clinic from the Social Security Institution and the factors that affected diagnosis; secondly, we aimed to assess the consistency of the medical and legal diagnoses. Methods: The study involved 132 consecutive patients who were referred to our clinic for the evaluation of OA between 2010 and 2015. Detailed workplace history, the tools used in the diagnosis such as peak expiratory flow (PEF) monitoring and bronchial provocation tests, and the final medical diagnosis were recorded from case files. Results: Asthma was diagnosed in 75% (n = 99) of the patients. Among them, 22.2% were diagnosed as having OA. The diagnosis was confirmed by serial PEF measurements, non-specific bronchial hyperreactivity assessment or both of the tests both at work and off-work periods. OA diagnosis was mostly established in active workers (72.7%). The legal diagnosis period was completed in 54.5% of these 22 patients, and 50% (n = 11) were officially diagnosed as having OA with a 91.6% concordance with medical diagnosis. Conclusion: This study verifies the importance of diagnosing asthma correctly as a first step in the evaluation of OA. Diagnostic tests other than specific provocation tests could be preferential in patients who still work in the same field. We believe that cooperation with the patient's occupational physician and adequate recognition of the work environment will improve the consistency of legal and medical diagnoses.

New causes of immunologic occupational asthma, 2012-2014.

The objective of this study was to review all new causes of well documented immunologic occupational asthma (IOA) published in the English and French medical literature between January 2012 and mid-2014. Ten case reports of new causes of IOA were reported during that period. The diagnosis was either confirmed by specific inhalation challenges (n = 5) or a combination of peak expiratory flow monitoring at and off work, confirmation of specific sensitisation, and asthma (n = 3). These involved both high (mites contaminating cured ham, various enzymes used as detergents and food additives, aquarium fish food, and orange allergens) and low-molecular-weight agents (spruce wood dust, a biocide, and an halogenated platinum compound used in cytotoxic drugs). Furthermore, eight studies reported cases of IOA with agents already known as airway sensitizers but in working environments that were unusual and reported for the first time. There are more than 400 known causes of IOA and the list grows continuously with the development of new technologies and better recognition of the diagnosis by physicians. IgE-mediated sensitization was confirmed in all new cases involving high-molecular-weight agents and in two of the three new cases involving low-molecular-weight agents. Symptoms of rhinitis were often associated with both types of agents. Physicians should stay alert and suspect occupational asthma in any adult with new-onset asthma or with newly uncontrolled asthma.

Increased asthma risk and impaired quality of life after bronchiolitis or pneumonia in infancy

Recent studies have revealed that adulthood asthma has its origin in early childhood. The aim of the present study was to evaluate the prevalence of asthma and respiratory health-related quality of life in adults 30 years after hospitalization for bronchiolitis or pneumonia in infancy. Patients who were hospitalized for bronchiolitis or pneumonia at age under 24 months in 1981-1982 have been followed in repeated visits. In 2010, 48 of the 83 former patients with bronchiolitis (57.8%), 22 of the 44 former patients with pneumonia (50.0%), and 138 matched controls participated in the clinical study at the age of 28-31 years. The participants completed a structured questionnaire on respiratory symptoms, the Saint George's Respiratory Questionnaire (SGRQ), and underwent 2-week peak expiratory flow (PEF) monitoring. Asthma was defined as doctor-diagnosed and self-reported asthma based on doctor-prescribed medication for asthma, the presence of asthma-presumptive symptoms, and the results of home PEF monitoring. Both doctor-diagnosed asthma (31.3% vs. 10.9% adjusted P = 0.002) and self-reported asthma (35.4% vs. 14.5% 0.003), as well as repeated on-demand use of bronchodilators (35.4% vs. 14.5% 0.002), and regular use of inhaled corticosteroids (20.8% vs. 8.7% 0.023) were more common in former bronchiolitis patients than in controls. Former bronchiolitis and pneumonia patients had higher total SGRQ scores than controls. The median scores were 5.4 (IQ(25-75) 0.0-14.7, P < 0.001) in bronchiolitis group, 4.9 (1.3-14.8, 0.012) in pneumonia group compared to controls 1.5 (0.0-6.0). Hospitalization for bronchiolitis in infancy is associated with an increased risk of asthma, and an increased use of asthma medication in adulthood at the age of 28-31 years. Impaired respiratory health-related quality of life in adulthood as measured by the SGRQ is present after bronchiolitis and pneumonia in infancy.

Detection of exacerbations in asthma based on electronic diary data: results from the 1-year prospective BIOAIR study

BackgroundObjective measures are required that may be used as a proxy for exacerbations in asthma. The aim was to determine the sensitivity and specificity of electronic diary data to detect...

Determinants of asthma control and quality of life in stable asthma: evaluation of two new cough provocation tests

Asthma control and quality of life are poorly associated with traditional asthma biomarkers. In the present study, we evaluated two new cough provocation tests in this respect. Asthma Control Questionnaire and Leicester Cough Questionnaire were completed by 36 stable asthmatics. Cough provocation tests with hypertonic saline and isocapnic hyperpnoea of dry air were performed, as well as spirometry, ambulatory peak expiratory flow (PEF) monitoring and exhaled nitric oxide (eNO) measurement. Leicester Cough Questionnaire score correlated closely with cough responsiveness to hypertonic saline and isocapnic hyperpnoea (R = -0.66, P < 0.001 and R = -0.49, P = 0.002, respectively). Asthma Control Questionnaire score also correlated with the cough responsiveness to these tests (R = 0.52, P = 0.001 and R = 0.43, P = 0.008, respectively). Forced expiratory volume in 1 s (%predicted), diurnal PEF variation and eNO did not correlate with cough-related quality of life but showed some association with asthma control. There was a significant correlation between Leicester Cough Questionnaire and Asthma Control Questionnaire (R = -0.54, P = 0.001). Asthma control and cough-related quality of life are more closely associated with cough responsiveness to the investigated cough provocation tests than to eNO and traditional indices of bronchial obstruction. Cough is a major contributor to poor asthma control.

Interest of Exhaled Biomarkers in Occupational Asthma to Latex: A Case Report

ABSTRACT New methods for exploring pulmonary inflammation might be useful: measurements of exhaled nitric oxide (NO) and hydrogen peroxide (H2O2) in exhaled breath condensate (EBC). The authors describe the application and utility of these methods in a case report of pediatric nurse presenting an occupational asthma to latex. Despite compliance with avoidance measures, respiratory discomfort had worsened during work. Classical tests (spirometry, monitoring of peak expiratory flow) were not contributing to objectify the discomfort. Exhaled NO and H2O2 in EBC increased immediately after work periods, compared with rest periods. Application of these new methods, at the same time, in workplace appears useful in the objective demonstration of a temporal relation between work and respiratory problems. The results allowed the occupational physician to transfer the patient to a new work station more appropriate for her respiratory health status.

Utility of Exhaled Breath Condensate pH for Diagnosing Occupational Asthma

Introduction: The current reference standard method for diagnosing occupational asthma (OA) is specific inhalation challenge (SIC) with the suspected agent. The alternative method is serial peak expiratory flow (PEF) monitoring. Nevertheless, PEF does not have optimal sensitivity and specificity for this purpose. The aim of this study was to evaluate the utility of exhaled breath condensate (EBC) pH for the diagnosis of OA. Material and Methods: A prospective study was performed in 37 subjects with suspected OA. Serial PEF monitoring was carried out for 2 weeks at work and for 2 weeks off work. At the end of each period, the EBC pH and the methacholine concentration resulting in a 20% FEV₁ decrease (PC20) were measured. SIC was subsequently performed. PEF graphs were interpreted visually by 3 experienced independent readers. Results: Seventeen patients tested positive with SIC. Receiver-operating characteristic curves showed that a decrease in EBC pH greater than 0.4 units during the period at work compared to the off-work period achieved the most satisfactory sensitivity (40%, CI 19.4–66.5) and specificity (90%, CI 66.9–98.2) for diagnosing OA. When EBC pH findings were added to PEF results, the diagnostic yield of PEF generally increased. Other test combinations (e.g. EBC pH plus PC20 or EBC pH plus PC20 plus PEF) did not improve diagnostic performance. Conclusions: Acidification of EBC pH at work and adding the EBC pH measurement to PEF monitoring during periods at work and off work may be useful for improving the diagnosis of OA.

A Mobile Phone Short Message Service Improves Perceived Control of Asthma: A Randomized Controlled Trial

Mobile phone short message service (SMS) has been suggested as a potentially powerful tool to improve asthma outcomes, and it can overcome external barriers such as time and distance to participate education programs. We wanted to know whether SMS can help to overcome intrinsic barriers such as perceived control of asthma (PCA). One hundred fifty outpatients with asthma were randomly assigned to the control, traditional, and SMS groups. Patients in all groups received verbal education based on the Global Initiative for Asthma, and patients in the traditional group received additional individualized asthma action plan for self-management with peak expiratory flow monitoring and recording asthma diary, while patients in the SMS group received additional daily SMS reminders on their mobile phone. The six-item PCA Questionnaire (PCAQ-6), Standard Asthma-Specific Quality of Life [AQLQ(S)], spirometry, blood and induced sputum cell count, follow-up compliance rate, medicine compliance rate, and emergency department (ED) visits data were collected at the initial visit and at 12 weeks. In total, 71 participants completed the trial for analysis. Patients' PCAQ-6 score was significantly increased in the SMS and traditional groups (p<0.001) after 12 weeks, and the change of patients' PCAQ-6 score in the SMS group was higher than in the traditional group (p=0.018). Patients in the SMS group had the highest AQLQ(S) score and follow-up rate after 12 weeks. The change in PCAQ-6 score was associated with change in AQLQ(S) score (r=0.442). Patients in all groups had better forced expiratory volume in 1 s (FEV1%) and fewer ED visits after 12 weeks, but no significant differences were found among the three groups in the changes of FEV1% and blood and induced sputum eosinophil counts and neutrophil counts. SMS can improve PCA, and it has a greater advantage in improving follow-up rate and asthma-specific quality of life than traditional programs.