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Biomedical subjects

R Beasley

Publications and source records attributed to R Beasley.

At least 109 records · Page 6Linked to original sources
PubMed1994

The relationship between pulmonary interstitial emphysema and clinical features in fatal asthma.

Using retrospective histological material and clinical data from the New Zealand National Asthma Mortality Study, we investigated whether there was a relationship between the presence of pulmonary interstitial emphysema (PIE) and different clinical features in fatal asthma, in particular precipitous asthma death. Histological evidence of PIE was determined in sections from 12 of the 60 patients who had died from asthma who fulfilled the pathological criteria for inclusion in the study. No significant correlation was found between the presence of PIE and the different clinical features examined. For example, of the 13 cases with precipitous fatal asthma (i.e., death occurred within 10 min of the onset of the attack), only two had PIE. This suggests that PIE is not an uncommon histological feature of fatal asthma and may, in fact, significantly contribute to an asthma death, but its presence does not appear to be associated with the specific clinical subgroups studied here.

Asthma↗
PubMed1994

Nebulized beta 2-adrenoceptor agonists do not affect plasma selenium or glutathione peroxidase activity in patients with asthma.

We investigated whether the beta 2-agonists fenoterol and salbutamol decreased plasma selenium and glutathione peroxidase activity in patients with asthma as this may partially explain the findings of reduced selenium status in asthmatic patients. Nine patients with asthma were studied on 3 occasions and inhaled either fenoterol (5 mg), salbutamol (5 mg) or ipratropium bromide (0.5 mg) administered by nebulization using a randomized, double blind, crossover design. Plasma selenium, glutathione peroxidase activity and potassium were measured prior to drug administration and at 15, 30 and 60 minutes after drug. None of the drugs had any effect on plasma selenium or glutathione peroxidase activity. Ipratropium bromide did not affect plasma potassium. Both beta 2-agonists significantly decreased plasma potassium. The mean (SD) maximum decrease was -0.79 (0-18) mmol/l for fenoterol and -0.26 (0-03) mmol/l for salbutamol (both p < or = 0.01) confirming systemic absorption of the drugs. beta 2-agonists are unlikely to be responsible for the reduced selenium status found in some patients with asthma.

Adrenergic beta-2 Receptor Agonists↗
PubMed1993

Trial of an asthma action plan in the Maori community of the Wairarapa.

AIMS: An asthma action plan has been tested in a study conducted by Wairarapa Maori community health workers and the Wellington asthma research group. There were several distinctive features of the project, including the programme of marae-based asthma clinics, and the partnership between the researchers and the Maori community groups. This paper describes the process by which the study was conducted since this experience may be relevant to future Maori health research projects. METHODS: The programme was launched with a series of hui at marae in the Wairarapa, and marae-based clinics were set up. These were followed up by further support from the Maori community health workers who helped people to keep diaries to monitor their asthma, and generally maintained contact. The severity of asthma in the participants was compared for a two-month period before the action plan was introduced, and for a four-month period after the plan was introduced. RESULTS: There was a high participation rate, with 91% (63/69) of participants finishing the programme, 75% of whom adequately completed their daily asthma diaries. Asthma control improved significantly in the participants. They commented positively on the programme, and particularly on the marae-based clinics. CONCLUSIONS: The study was successful in terms of participation in the marae-based clinics, acceptance and use of the plan, and improvement in asthma control of the participants. The findings indicate what can be achieved when researchers and Maori community groups work in partnership.

Asthma↗
PubMed1993

Prevalence of asthma symptoms among adolescents in the Wellington region, by area and ethnicity.

AIMS: To compare the self-reported prevalence of asthma symptoms, among 12 to 15 year olds in three districts in the greater Wellington region, and to compare prevalence among three ethnic groups--Maori, Pacific Island and others. METHODS: Third form students from 13 secondary schools in the Wellington region, were surveyed using a video questionnaire and a standardised written questionnaire, during July 1991. RESULTS: Using the video questionnaire, the prevalence of wheeze during the previous 12 months was similar in Wellington city (32%), Lower Hutt (38%), and Porirua (37%); the corresponding findings using the written questionnaire were 28%, 27% and 30% respectively. The reported prevalence was also similar among Maori (38% using the video and 29% using the written questionnaire) and other children (36% and 30% respectively), but lower among Pacific Island children (31% and 20% respectively). The prevalence and frequency of severe attack of wheezing was similar in all three districts and all three ethnic groups. CONCLUSIONS: These findings contradict previous speculations of possible differences in asthma prevalence or severity within the greater Wellington region. They are consistent with other evidence that there are at most minor differences in asthma prevalence between Maori and nonMaori children in New Zealand; however, asthma prevalence may be lower among Pacific Island children. Thus ethnic differences in asthma morbidity and mortality are not likely to be due to differences in prevalence, but more likely relate to differences in access to and delivery of asthma care.

Adolescent↗
PubMed1993

Prescribing for childhood asthma in the Wellington area: comparison with international guidelines.

AIMS: An international paediatric asthma consensus group has outlined the rational approach to the treatment of childhood asthma. We have examined the prescription of asthma treatment to children in Wellington to assess to what extent these guidelines have been adopted by general practitioners. METHODS: During the period 1 May-11 June 1991, the prescriptions for 228 asthmatic children, dispensed at 30 randomly selected pharmacies in the greater Wellington area, were reviewed. RESULTS: Eighty-four per cent of the children were prescribed beta 2 adrenoceptor agonists. Of these, 80% of those under five years, and 27% over five years of age, received these agents by the oral route. In almost half, these drugs were prescribed on a regular basis. Fifty-two per cent of patients were prescribed some form of antiinflammatory therapy (inhaled or oral steroids, ketotifen or sodium cromoglycate). Only 2% received sodium cromoglycate. CONCLUSION: Although approximately half of these children received some form of antiinflammatory therapy, the minimal use of sodium cromoglycate, and high frequency of regular scheduled beta 2 adrenoceptor agonist use, suggests that the guidelines for asthma management in children may not have been widely adopted by primary care physicians in Wellington.

Adolescent↗
PubMed1993

The extrapulmonary effects of inhaled hexoprenaline and salbutamol in healthy individuals.

We have investigated the cardiovascular and metabolic effects of multiple inhaled doses of salbutamol and hexoprenaline in 12 healthy volunteers. They inhaled 200 micrograms of salbutamol or hexoprenaline at 15 min intervals for 60 min from a metered dose inhaler (total dose 1000 micrograms). We measured heart rate, blood pressure, total electromechanical systole (as a measure of inotropic response), QTc interval on the ECG, and plasma potassium at baseline, 10 min after each inhalation, and 30 and 60 min after the last inhalation. There was no difference in the effects of the two drugs on blood pressure, total electromechanical systole, or QTc interval. Salbutamol significantly increased heart rate compared with hexoprenaline. Hexoprenaline caused a significantly greater fall in plasma potassium compared with salbutamol.

Administration, Inhalation↗
PubMed1993

Pathology of asthma and its clinical implications.

Although detailed histopathologic studies have described the inflammatory processes present in fatal asthma, until recently the pathology of less severe forms of the disease has been less well understood. Now a series of important studies has extended our understanding of the pathophysiology of mild asthma. Studies that examine sputum or fluid obtained by bronchoalveolar lavage from mildly asthmatic subjects revealed findings consistent with an active inflammatory process within the airways. The histopathologic examination of endobronchial biopsy specimens from stable asthmatic patients has shown that inflammatory cell infiltration of the mucosa is a distinctive feature of mildly asthmatic subjects requiring only intermittent inhaled beta-agonist therapy. These studies have also shown that marked tissue disruption may occur early in the natural history of mild asthma. These investigations have demonstrated that asthma is a disease characterized by acute and chronic inflammatory changes within the airways and that in many respects the histopathologic features of mild allergic asthma are similar to those observed in fatal asthma. The therapeutic implications of these findings are that management of mild asthma should be directed toward resolving this inflammatory process. There is now sufficient evidence to suggest that anti-inflammatory drugs such as cromolyn sodium, inhaled corticosteroids, and nedocromil sodium be used earlier in the course of the disease and that the use of these therapeutic agents should not be limited to patients with severe forms of asthma. This may be particularly important in view of the increasing awareness of the potential problems associated with the overreliance on beta-agonist therapy in patients with asthma.

Asthma↗
PubMed1993

A comparative study of the efficacy of beclomethasone dipropionate delivered from a breath activated and conventional metered dose inhaler in asthmatic patients.

In order to overcome the problem of poor co-ordination with the use of the conventional press and breathe metered dose inhaler, a breath-activated inhaler ('Autohaler' inhalation device) has been developed. The clinical response to equal doses of beclomethasone dipropionate administered from the 'Autohaler' device and the conventional metered dose inhaler was compared in 36 stable asthmatic patients receiving regular inhaled beclomethasone dipropionate. The study was performed using a double-blind, double-dummy crossover design. Each treatment was given for 4 weeks. Objective and subjective measures of asthma severity were compared in the second 14 days of each treatment period, with clinical equivalence defined as a difference of 20% or less in the adjusted mean values for the 30 patients with data from both treatment periods. Equivalence at the +/- 5% level was found in the objective measures of pre-bronchodilator FEV1 (p < or = 0.001); post-bronchodilator FEV1 (p < 0.001); morning and evening peak expiratory flow rate (both p < or = 0.001). Patient diary cards established there was equivalent usage of inhaled bronchodilator, and equivalent symptom scores for daytime disability and daytime and night-time breathlessness. The results show that, in stable asthmatics, treatment with beclomethasone dipropionate is clinically equivalent when delivered by the 'Autohaler' device or the conventional metered dose inhaler used efficiently.

Adult↗
PubMed1993

A comparison of the cardiovascular and metabolic effects of formoterol, salbutamol and fenoterol.

The cardiovascular and metabolic effects of the long-acting beta 2-agonist formoterol were compared with those of salbutamol, fenoterol and placebo in 12 healthy volunteers, using a randomised, double-blind, cross-over design. On the study days, the subjects inhaled either formoterol (24 micrograms), salbutamol (400 micrograms), fenoterol (400 micrograms) or placebo, at 30 min intervals for five doses. Heart rate (HR) total electromechanical systole (Q-S2I) (a measure of inotropy), the corrected QT interval (QTc), systolic and diastolic blood pressure, plasma glucose and plasma potassium (K+) were measured prior to drug administration, 10 min after each inhalation and at 30 min intervals for 3 h after the last inhalation. All of the active agents significantly increased HR, QTc and plasma glucose, and decreased Q-S2I, diastolic blood pressure and plasma K+ compared to placebo. Fenoterol had a significantly greater maximum effect on HR, QTc and Q-S2I than either salbutamol or formoterol. Formoterol and fenoterol caused a similar maximum reduction in plasma K+, greater than that due to salbutamol. We conclude that formoterol is a more selective beta 2-agonist than fenoterol, and has similar cardiovascular effects to salbutamol when inhaled repeatedly by normal volunteers.

Administration, Inhalation↗
PubMed1992

The use of a videotaped questionnaire for studying asthma prevalence. A pilot study among New Zealand adolescents.

OBJECTIVE: To examine the feasibility of measuring asthma prevalence by means of an audio-visual presentation of asthma symptoms and signs (video questionnaire) and to compare this technique with a standard written questionnaire for predicting bronchial hyperresponsiveness. DESIGN: A cross-sectional study comparing the ability of a video questionnaire and a written, interviewer administered questionnaire to predict bronchial hyperresponsiveness. Bronchial responsiveness was measured with hand held nebulisers. SETTING: Community survey of a New Zealand rural secondary school. SUBJECTS: A total of 456 adolescent school children aged 12-19 years (mean 15.5 years). OUTCOME MEASURES: Comparison of the sensitivity and specificity of a standard questionnaire versus a video questionnaire for bronchial hyperresponsiveness. RESULTS: The technique was easy to administer in the community setting. Overall sensitivity and specificity for the prediction of bronchial hyperresponsiveness were similar for the video and interviewer administered questionnaires. CONCLUSIONS: This new technique is easily used in the community setting, and gives predictions of bronchial hyperresponsiveness similar to those of a standard interviewer administered questionnaire. Further examination of the technique in comparisons of asthma prevalence among different populations is planned.

Adolescent↗
PubMed1992

A study of New Zealand wood workers: exposure to wood dust, respiratory symptoms, and suspected cases of occupational asthma.

A randomly selected group of 50 New Zealand wood workers was studied. The level of airborne wood dust to which they were exposed ranged from 1.0-24.5 mg/m3. The wood workers reported experiencing higher rates of both lower and upper respiratory tract symptoms than a control group of office workers. Inhaled wood dust, in particular from rimu (Dacrydium cupressinum), was frequently cited by workers as being associated with respiratory tract symptoms. The wood workers' responses to the respiratory symptom questionnaire, and serial recordings of peak expiratory flow rate were used to screen the group for suspected cases of occupational asthma. Five cases fulfilled the study's criteria for suspected occupational asthma. In four of these, further evidence was found to support this diagnosis. We conclude that exposure to wood dust may cause occupational asthma in the woodworking industry in New Zealand.

Adult↗