Showing papers by "Peter G. Gibson published in 2002"

Self-management education and regular practitioner review for adults with asthma

Abstract: Background A key component of many asthma management guidelines is the recommendation for patient education and regular medical review. A number of controlled trials have been conducted to measure the effectiveness of asthma education programmes. These programmes improve patient knowledge, but their impact on health outcomes is less well established. This review was conducted to examine the strength of evidence supporting Step 6 of the Australian Asthma Management Plan: "Educate and Review Regularly"; to test whether health outcomes are influenced by education and self-management programmes. Objectives The objective of this review was to assess the effects of asthma self-management programmes, when coupled with regular health practitioner review, on health outcomes in adults with asthma. Search methods We searched the Cochrane Airways Group trials register and reference lists of articles. Selection criteria Randomised trials of self-management education in adults over 16 years of age with asthma. Data collection and analysis Two reviewers assessed trial quality and extracted data independently. We contacted study authors for confirmation. Main results We included thirty six trials, which compared self-management education with usual care. Self-management education reduced hospitalisations (relative risk (RR) 0.64, 95% confidence interval (CI) 0.50 to 0.82); emergency room visits (RR 0.82, 95% CI 0.73 to 0.94); unscheduled visits to the doctor (RR 0.68, 95% CI 0.56 to 0.81); days off work or school (RR 0.79, 95% CI 0.67 to 0.93); nocturnal asthma (RR 0.67, 95% CI 0.0.56 to 0.79); and quality of life (standard mean difference 0.29,CI 0.11 to 0.47). Measures of lung function were little changed. Authors' conclusions Education in asthma self-management which involves self-monitoring by either peak expiratory flow or symptoms, coupled with regular medical review and a written action plan improves health outcomes for adults with asthma. Training programmes that enable people to adjust their medication using a written action plan appear to be more effective than other forms of asthma self-management.

Non-eosinophilic asthma: importance and possible mechanisms

Abstract: There is increasing evidence that inflammatory mechanisms other than eosinophilic inflammation may be involved in producing the final common pathway of enhanced bronchial reactivity and reversible airflow obstruction that characterises asthma. A review of the literature has shown that, at most, only 50% of asthma cases are attributable to eosinophilic airway inflammation. It is hypothesised that a major proportion of asthma is based on neutrophilic airway inflammation, possibly triggered by environmental exposure to bacterial endotoxin, particulate air pollution, and ozone, as well as viral infections. If there are indeed two (or more) subtypes of asthma, and if non-eosinophilic (neutrophil mediated) asthma is relatively common, this would have major consequences for the treatment and prevention of asthma since most treatment and prevention strategies are now almost entirely focused on allergic/eosinophilic asthma and allergen avoidance measures, respectively. It is therefore important to study the aetiology of asthma further, including the underlying inflammatory profiles.

Neutrophil degranulation and cell lysis is associated with clinical severity in virus-induced asthma

Abstract: Acute exacerbations of asthma are frequently caused by viral infections, but the inflammatory mechanisms in virus-induced asthma are poorly understood. The aim of the present study was to determine whether viral infection in acute asthma was associated with increased sputum neutrophil degranulation and increased cellular lysis and whether these changes are related to clinical severity. Adults (n=49) presenting to the emergency department with acute asthma were examined for infection by means of sputum direct-fluorescence antigen detection, sputum culture, and sputum polymerase chain reaction for Mycoplasma, Chlamydia and Legionella pneumophila, and all common respiratory viruses. Subjects infected with one of these agents were classed as having an infective exacerbation. Spirometry and sputum induction were performed on presentation and 4-5 weeks later. Thirty-seven subjects (76%) had virus infection and acute asthma. Those with virus infection had increased sputum neutrophils (p<0.05) and increased neutrophil elastase (p<0.05), this was related to increased elevated sputum lactate dehydrogenase (LDH). Subjects with noninfective asthma had an increase in the proportion of sputum eosinophils. Both groups had elevated sputum eosinophil cationic protein (ECP) concentrations. Higher levels of sputum LDH and ECP were associated with a longer hospital stay. Virus infection and acute asthma is associated with neutrophilic inflammation, cell lysis and more severe clinical disease.

Limited (information only) patient education programs for adults with asthma.

Abstract: Background A key component of many asthma management guidelines is the recommendation for patient education and regular medical review. A number of controlled trials have been conducted to measure the effectiveness of asthma education programmes. These programmes improve patient knowledge, but their impact on health outcomes is less well established. At its simplest level, education is limited to the transfer of information about asthma, its causes and its treatment. This review focused on the effects of limited asthma education. Objectives The objective of this review was to assess the effects of limited (i.e. information only) asthma education on health outcomes in adults with asthma. Search methods We searched the Cochrane Airways Group trials register and reference lists of articles. Selection criteria Randomised and controlled trials of individual asthma education involving information transfer only in adults over 16 years of age. Data collection and analysis Trial quality was assessed and two reviewers extracted data independently. Study authors were contacted for missing information. Main results Twelve trials were included. They were of variable quality. Limited asthma education did not reduce hospitalisation for asthma (weighted mean difference -0.03 average hospitalisations per person per year, 95% confidence interval -0.09 to 0.03). There was no significant effect on doctor visits, lung function and medication use. The effects on asthma symptoms were variable. There was no reduction in days lost from normal activity, but in two studies, perceived asthma symptoms did improve after limited asthma education (odds ratio 0.44, 95% confidence interval 0.26 to 0.74). In one study, limited asthma education was associated with reduced emergency department visits (reduction of -2.76 average visits per person per year, 95% confidence interval -4.34 to 1.18). Authors' conclusions Use of limited asthma education as it has been practiced does not appear to improve health outcomes in adults with asthma although perceived symptoms may improve. Provision of information in the emergency department may be effective, but this needs to be confirmed.

Options for self-management education for adults with asthma.

Abstract: Background Asthma education and self-management are key recommendations of asthma management guidelines because they improve health outcomes. There are several different modalities for the delivery of asthma self-management education. Objectives We evaluated programmes that: (1) Optimised asthma control through inhaled corticosteroid use by regular medical review or optimised asthma control by individualised written action plans; (2) Used written self-management plans based on peak expiratory flow self-monitoring compared with symptom self-monitoring; (3) Compared different options for the delivery of optimal self-management programmes. Search methods We searched the Cochrane Airways Group trials register and reference lists of articles. Selection criteria Randomised trials of asthma self-management education interventions in adults over 16 years of age with asthma. Data collection and analysis Fifteen trials met the inclusion criteria. Trial quality was assessed and data were extracted independently by two reviewers. Study authors were contacted for confirmation. Main results Six studies compared optimal self-management allowing self-adjustment of medications according to an individualised written action plan to adjustment of medications by a doctor. These two styles of asthma management gave equivalent effects for hospitalisation, emergency room (ER) visits, unscheduled doctor visits and nocturnal asthma. Self-management using a written action plan based on peak expiratory flow (PEF) was found to be equivalent to self-management using a symptoms based written action plan in the six studies which compared these interventions. Three studies compared self-management options. In one, that provided optimal therapy but tested the omission of regular review, the latter was associated with more health centre visits and sickness days. In another, comparing high and low intensity education, the latter was associated with more unscheduled doctor visits. In a third, no difference in health care utilisation or lung function was reported between verbal instruction and written action plans. Authors' conclusions Optimal self-management allowing for optimisation of asthma control by adjustment of medications may be conducted by either self-adjustment with the aid of a written action plan or by regular medical review. Individualised written action plans based on PEF are equivalent to action plans based on symptoms. Reducing the intensity of self-management education or level of clinical review may reduce its effectiveness.

Eosinophilic bronchitis: clinical manifestations and implications for treatment

Abstract: Airway inflammation with eosinophils is now reported to occur not only in asthma but in other airway diseases such as cough variant asthma, chronic cough, atopic cough, episodic symptoms without asthma, allergic rhinitis, and COPD. Although the prevalence of eosinophilic bronchitis (EB) is less than in asthma, the causes, mechanisms and treatment of EB in these conditions appears to be similar to asthma where allergen induced IL-5 secretion and symptoms are readily responsive to inhaled corticosteroids. The prognosis of EB without asthma is not known but it may be a precursor for asthma and, if so, recognition of this syndrome may permit effective treatment and reduction in the rising prevalence of asthma. Induced sputum analysis allows recognition of EB in clinical practice. The place of the asthma treatment paradigm with early and sustained corticosteroid treatment needs to be defined in EB without asthma. Airway wall remodelling can occur in rhinitis, COPD, and cough variant asthma with EB. The mechanisms and long term implications of this complication in EB without asthma need to be clarified.

Reduced 11β-Hydroxysteroid Dehydrogenase Type 2 Activity Is Associated with Decreased Birth Weight Centile in Pregnancies Complicated by Asthma

Abstract: Pregnancies complicated by asthma are associated with an increased risk of low birth weight. Currently, the mechanisms causing this outcome are unknown. To investigate whether impaired placental function may be a determinant, we measured placental 11-hydroxysteroid dehydrogenase type 2 (11-HSD2) activity, protein and mRNA, placental CRH mRNA, fetal cortisol, and fetal estriol concentrations at delivery. Asthmatic subjects were classified according to inhaled glucocorticoid intake during pregnancy and compared with a control nonasthmatic group. There was a 25% reduction in neonatal birth weight centile in asthmatic women who did not use inhaled glucocorticoid treatment. This was accompanied by significantly reduced placental 11-HSD2 activity, significantly increased fetal cortisol, and a trend toward increased placental CRH mRNA and reduced fetal estriol concentrations. The use of inhaled glucocorticoids for treatment was associated with birth weight centile, 11-HSD2 activity, CRH mRNA, fetal cortisol, and estriol concentrations similar to control levels. There was a significant inverse correlation between fetal cortisol and fetal estriol concentrations across all groups. These studies demonstrate that inhaled glucocorticoid intake for the treatment of asthma is associated with improved placental function and fetal outcome, suggesting that inflammatory factors associated with asthma may be detrimental to fetal growth and development in these pregnancies. (J Clin Endocrinol Metab 87: 1660 –1668, 2002)

Chlamydia pneumoniae immunoglobulin A reactivation and airway inflammation in acute asthma

Abstract: Infection with Chlamydia pneumoniae can trigger acute asthma and is associated with severe chronic asthma. The aim of the present study was to examine the relationship between airway inflammation and serological response to C. pneumoniae in acute severe asthma. Subjects (n=54) were recruited within 4 h of presentation to the emergency department with an acute exacerbation of asthma. Clinical history taking, sputum induction (0.9% saline), spirometry and acute and convalescent serology for C. pneumoniae immunoglobulins A and G were performed. At presentation, 47% of subjects had antibodies directed against C. pneumoniae, and 38% (20) demonstrated an increase in C. pneumoniae antibody levels, with 15 demonstrating a rise in immunoglobulin A concentration. C. pneumoniae responders exhibited significantly higher sputum neutrophil levels (4.6 x 10(6) cells x mL(-1)) compared to nonresponders (1.2 x 10(6) cells x mL(-1), p=0.02) and elevated sputum eosinophil cationic protein concentration (3,981 versus 1,122 ng x mL(-1), p=0.02). An acute antibody response to Chlamydia pneumoniae is common in exacerbations of asthma. The serological features suggest that Chlamydia pneumoniae reactivation may trigger neutrophilic airway inflammation in acute asthma.

Airway inflammation in thunderstorm asthma.

Abstract: Summary Background Epidemics of acute asthma associated with thunderstorms occur intermittently worldwide, though airway inflammation during these acute episodes has not been characterized. The aim of this study was to characterize airway inflammation in thunderstorm asthma. Methods Cases were recruited after presentation to the emergency room with acute asthma immediately following a thunderstorm (n = 6). They were compared to two control groups: a group of atopic asthmatics that had presented with acute asthma to the emergency room prior to the thunderstorm (n = 12), and a second group of corticosteroid naive asthmatics who presented to the emergency room in the prior 12 months (n = 6). Subjects had spirometry, sputum induction and allergy skin tests acutely and at review 4 weeks later. Results Thunderstorm (TS) cases were more likely to have a history of hay fever and grass pollen allergy, and less likely to be on inhaled corticosteroids (ICS) prior to presentation. Cases and control groups had a similar degree of moderate to severe acute airway obstruction (P = 1.0). TS cases had elevated sputum eosinophils (14.8% of total cell count) compared to controls (1%, 2.6%, P < 0.01). TS cases had higher sputum eosinophil cationic protein (ECP; 11 686 ng/mL) compared to controls (1883, 3300, P = 0.02) acutely. TS cases had more cells positive for IL-5 (30%) compared to controls (1, 1.5%, P = 0.02). When adjusted for ICS use, TS cases had a risk ratio for elevated sputum eosinophils of 2.4 (1.23–4.69). Conclusion Thunderstorm asthma is characterized by airway inflammation with IL-5-mediated sputum eosinophilia and eosinophil degranulation. These results are consistent with allergen exposure as the cause of the exacerbation, and are consistent with the thunderstorm-induced grass pollen deluge as the cause of epidemic asthma after thunderstorms.

Sputum induction in children

Abstract: Sputum induction has been used to study asthma in children since the first description of the technique in 1992 1. Since then, >20 reports (five reviews) have appeared in the literature describing sputum induction in children with airways disease. In general, sputum induction in children of >6 yrs is safe and has a satisfactory success rate. Approximately 500 children have been studied by sputum induction. The diagnoses of the studied children include stable asthma (n=308), acute asthma (n=18) and healthy control subjects (n=185). Studies have included children aged 5–18 yrs, with a mean age of 11.2 yrs. Most studies have included children of >6 yrs. Studies of children with asthma have included subjects across the spectrum of severity. The following issues regarding sputum induction in children are reviewed in the present article: 1) protocols used in children; 2) safety of induction; 3) management of airway obstruction during sputum induction; 4) sputum processing; 5) normal values in children; 6) findings in asthmatic children; 7) effect of treatment on induced sputum parameters; and 8) clinical applications. A wide variety of sputum induction protocols have been reported successful in children (table 1⇓). There is great variation as to the brands of nebuliser used. All of the studies have used ultrasonic nebulisers, but these were either high­ or low­output devices. Hypertonic saline has been used either at 4.5% (in four studies) or by increasing concentrations from 3 to 4 and then …

Cough, airway inflammation, and mild asthma exacerbation

Abstract: Background: Prospective data on the temporal relation between cough, asthma symptoms, and airway inflammation in childhood asthma is unavailable. Aims and methods: Using several clinical (diary, quality of life), lung function (FEV1, FEV1 variability, airway hyperresponsiveness), cough (diary, cough receptor sensitivity (CRS)), and inflammatory markers (sputum interleukin 8, eosinophilic cationic protein (ECP), myeloperoxidase; and serum ECP) of asthma severity, we prospectively described the course of these markers in children with asthma during a non-acute, acute, and resolution phase. A total of 21 children with asthma underwent these baseline tests; 11 were retested during days 1, 3, 7, and 28 of an exacerbation. Results: Asthma exacerbations were characterised by increased asthma and cough symptoms and eosinophilic inflammation. Sputum ECP showed the largest increase and peaked later than clinical scores. Asthma scores consistently related to cough score only early in the exacerbation. Neither CRS nor cough scores related to any inflammatory marker. Conclusion: In mild asthma exacerbations, eosinophilic inflammation is dominant. In asthmatic children who cough as a dominant symptom, cough heralds the onset of an exacerbation and increased eosinophilic inflammation, but cough scores and CRS do not reflect eosinophilic airway inflammation.

Regular treatment with long acting beta agonists versus daily regular treatment with short acting beta agonists in adults and children with stable asthma

Abstract: Background Selective beta-adrenergic agonists for use in asthma are: short acting (2-6 hours) and long acting (>12 hours). There has been little controversy about using short acting beta-agonists intermittently, but long acting beta-agonists are used regularly, and their regular use has been controversial. Objectives To determine the benefit or detriment of treatment with regular short- or long acting inhaled beta-agonists in chronic asthma. Search strategy A search was carried out using the Cochrane Airways Group register. Bibliographies of identified RCTs were searched for additional relevant RCTs. Authors of identified RCTs were contacted for other published and unpublished studies. Selection criteria All randomised studies of at least two weeks duration, comparing a long acting inhaled beta-agonist given twice daily with any short acting inhaled beta-agonist of equivalent bronchodilator effectiveness given regularly in chronic asthma. Data collection and analysis Two reviewers performed data extraction and study quality assessment independently. Authors of studies were contacted for missing data. Main results 31 studies met the inclusion criteria, 24 of parallel group and 7 cross over design. Salmeterol xinafoate was used as long acting agent in 22 studies and formoterol fumarate in 9. Salbutamol was the short acting agent used in 27 studies and terbutaline in 5. The treatment period was over 2 weeks in 29 studies, and at least 12 weeks in 20. 25 studies permitted a variety of co-intervention treatments, usually inhaled corticosteroid or cromones. One study did not permit inhaled corticosteroid. Long acting beta-agonists were significantly better than short acting for a variety of lung function measurements including morning PEF (Weighted Mean Difference (WMD) 33 l/min 95% CI 25, 42) or evening PEF (WMD 26 l/min 95% CI 18, 33); and had significantly lower scores for day and night time asthma symptom scores and percentage of days and nights without symptoms. They were also associated with a significantly lower use of rescue medication both during the day and night. Risk of exacerbations was not different between the two types of agent, but most studies were of short duration which limits the power to test for such differences. Reviewer's conclusions Long acting inhaled beta-agonists have advantages across a wide range of physiological and clinical outcomes for regular treatment.

Humidity control for chronic asthma.

Abstract: Background Humidity control measures in the home environment of patients with asthma have been recommended, however there is no consensus about the usefulness of these measures. Objectives To study the effect of dehumidification of the home environment on asthma control. Search strategy A search of the clinical trials registers of the Cochrane Collaboration and Cochrane Airways Group using search terms for asthma and [humid* OR water vapour OR water vapor* OR water-vapour* OR water-vapor*]. Selection criteria Randomized controlled trials on the use of humidity control measures in the home environment of patients with asthma were evaluated for inclusion. Only one trial could be included. Data collection and analysis Data was extracted using a predesigned data extraction form. No data was available for entering into RevMan for analysis. Main results The included trial using mechanical ventilation with or without high efficiency vacuum cleaners did not show any clinical benefit to asthma patients. There was a decline in the house dust mite count and the antigen level. This open trial had a low sample size. Reviewer's conclusions There is a need for studying the health benefits of dehumidification by a double blind randomized controlled trial with adequate sample size measuring clinical outcomes in patients of asthma.

Outpatient monitoring of asthma.

Abstract: Monitoring asthma outcomes is an essential step to the successful implementation of national asthma guidelines. Symptoms, airflow obstruction and exacerbations can be monitored by patients with asthma and by physicians. Patients who practise self-monitoring in conjunction with use of a written action plan and regular medical review have significantly fewer hospitalizations, emergency room visits and lost time from work. Additional monitoring tools are under evaluation, and these include measures of airway responsiveness, airway inflammation, and Internet-based monitoring systems.

Optimization of sputum-processing methods for the measurement of interleukin-5: Effects of protease inhibition

Abstract: Background: Interleukin (IL)-5 measurement in sputum samples has produced variable results that appear to be due to methodological problems. The aim of the present study was to investigate the effects of dithiothreitol (DTT), sputum protease inhibition and sample storage on IL-5 recovery in order to develop a method to accurately measure IL-5 in dispersed sputum supernatant. Methodology: Measurement of IL-5 in sputum was performed in 22 subjects with airway disease. Interleukin-5 recovery was measured in samples spiked with recombinant human IL-5 using a commercial ELISA. A mix of four protease inhibitors (PI) was added to sputum processed using the selection method with dispersion using DTT and stored with and without inhibitors. Results: The addition of PI to sputum resulted in a 24% increase in IL-5 recovery. Recovery was not further increased with the addition of a blocking protein. Storage of IL-5-spiked sputum gave significantly less recovery. The addition of PI to sputum processed with DTT had no effect on total cell count, viability or cell differential. Conclusion: Interleukin-5 recovery is increased by the addition of PI to samples processed using the selected portion method with DTT dispersion. A protease inhibitor cocktail should be added to sputum for IL-5 assay.

House dust mite allergen levels in carpeted sleeping accommodation are higher in private houses than public places

Abstract: OBJECTIVE To compare mite allergen levels in carpeted sleeping accommodation in private dwellings and public places. METHODS The concentration of Dermatophagoides pteronyssinus Group 1 allergen in house dust was measured in mat-tresses and bedroom floors in 12 homes, 5 hotels, 11 child care centres and a university hall of residence. Indoor temperature and relative humidity were also measured. A questionnaire clarified details regarding the age of the building, age of the carpet, method and frequency of cleaning, frequency of room use and use of air-conditioning. RESULTS Median allergen levels in mattresses and carpets in private homes (21.1 and 20.6 micro g/g dust, respectively) were significantly higher than in public places (2.5 and 3.1 micro g/g, respectively; P < 0.0001). Mean relative humidity was significantly higher in private houses (68.5%; 95% CI 67.2-69.3%) than in public places (56.4%; 95% CI 52.7-60.1%; P < 0.0001). CONCLUSIONS Carpeted sleeping accommodation in public places has lower house dust mite allergen levels than private houses. Lower levels of relative humidity may be an important component of the explanation.