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Biomedical subjects

J Crane

Publications and source records attributed to J Crane.

At least 109 records · Page 6Linked to original sources

A community trial of a written self management plan for children with asthma. Asthma Foundation of NZ Children's Action.

AIMS: To determine the effect of introducing an action plan to children with mild to moderate asthma, who have never used a plan before. METHODS: Children were recruited from general practitioner records with a diagnosis of asthma, and who agreed to participate, having identified that they had not used an action plan before and that they had mild or moderate asthma based upon symptoms, acute episodes and the need for preventative medication. The families were given a plan, and its use was explained to them by their general practitioner. A symptom diary was kept, and, where appropriate, peak flow measurements were recorded. A number of outcomes were measured to determine changes that could be attributed to the introduction of the plan. RESULTS: Following the introduction of the plan, the percentage of nights woken for asthma fell from 18.2% to 12.2% (P<0.001) and the number of days out of action fell from 6.4 to 4.1 (P<0.001). The requirement for acute medical treatment also fell during the intervention period with general practitioner visits falling from 129 to 42 (p<0.001). Most participants commented favourably about the usefulness of the plan in giving them a better idea of the state of their asthma at any time, and in knowing what to do about it. CONCLUSIONS: The children's action plan, when introduced into a group of asthmatic children was effective and acceptable in the self management of asthma.

Asthma↗

A pilot study to investigate the pulmonary effects of digoxin in patients with asthma.

AIM: A number of studies have shown that increased salt intake is associated with worsening asthma. The aim of this study was to investigate the respiratory effects of digoxin (a potent inhibitor of Na+K+ATPase) in patients with asthma. METHODS: Eight asthmatic patients were given digoxin (0.5 mg/daily) or matching placebo for 8 days. Treatments were assigned using a randomised double blind, crossover design. Bronchial hyperresponsiveness to methacholine, forced expiratory volume is one second (FEV1, serum potassium (K), urinary sodium and K, heart rate, blood pressure and the QTc interval of the ECG were measured on each treatment. RESULTS: When compared to placebo, digoxin significantly decreased FEV1 (p<0.03); the QTc interval (p<0.05), and increased serum K (p<0.02). There was a tendency for digoxin to increase bronchial hyperresponsiveness. CONCLUSION: In this small study digoxin resulted in a decline in spirometry. Further studies in a larger group of patients should be performed to assess this potentially adverse effect of digoxin.

Adult↗

Trial of a "credit card" asthma self-management plan in a high-risk group of patients with asthma.

BACKGROUND: The "credit card" asthma self-management plan provides the adult asthmatic patient with simple guidelines for the self-management of asthma, which are based on the self-assessment of peak expiratory flow rate recordings and symptoms. OBJECTIVE: The study was a trial of the clinical efficacy of the credit card plan in a high-risk group of asthmatic patients. METHODS: In this "before-and-after" trial, patients discharged from the emergency department of Wellington Hospital, after treatment for severe asthma were invited to attend a series of hospital outpatient clinics at which the credit card plan was introduced. Questionnaires were used to compare markers of asthma morbidity, requirement for emergency medical care, and medication use during the 6-month period before and after intervention with the credit card plan. RESULTS: Of the 30 patients with asthma who attended the first outpatient clinic, 26 (17 women and 9 men) completed the program. In these 26 participants, there was a reduction in both morbidity and requirement for acute medical services: specifically, the proportion waking with asthma more than once a week decreased from 65% to 23% (p = 0.005) and the proportion visiting the emergency department for treatment of severe asthma decreased from 58% to 15% (p = 0.004). The patients attending the clinics commented favorably on the plan, in particular on its usefulness as an educational tool for monitoring and treating their asthma. CONCLUSIONS: Although the interpretation of this study is limited by the lack of a randomized control group, the findings are consistent with other evidence that the credit card asthma self-management plan can be an effective and acceptable system for improving asthma care in a high-risk group of adult patients with asthma.

Adolescent↗

Problems of measuring asthma prevalence.

This review considers the issues involved in measuring the community prevalence of asthma, particularly in the context of international comparisons. We argue that there is no gold standard definition for measuring asthma prevalence, and discuss the currently available methods of case ascertainment. Prevalence studies, if they are to be generalizable, need to involve large sample sizes with high response rates. This necessitates methods that are simple, inexpensive and practicable, but also as sensitive and specific for asthma as possible. We discuss some of the issues that are specific to comparisons of asthma prevalence between diverse populations, and suggest that large surveys using written or video questionnaires of self reported symptoms validated in all of the target populations are the method of choice.

Asthma↗

Partial vs full beta-receptor agonism. A clinical study of inhaled albuterol and fenoterol.

STUDY OBJECTIVE: To compare the maximal extrapulmonary effects of the beta-agonists albuterol and fenoterol in eight healthy volunteers. SUBJECTS AND METHODS: In this double-blind study, we have examined the maximum cardiac effects (electromechanical systole [QS2I]--a measure of inotropy, heart rate, BP) and metabolic effects (plasma K+ and cyclic adenosine monophosphate [cAMP]) of repeated inhalation of albuternol and fenoterol. In eight healthy volunteers, 400 microg of each drug was administered every 10 min until QS2I and plasma K+ had reached a plateau (+/- 0.1 mmo l/L for K+, and +/- 10 ms for QS2I). The maximum response (Emax) and the dose of albuterol required to produce 50% of the maximum response to fenoterol (ED50F) were calculated. RESULTS: The Emax for fenoterol was significantly greater than albuterol for plasma K+ (-1.4 vs -1.03 mmol/L; p<0.002), QS2I (-71.8 vs 57.5 ms; p=0.047), and cAMP (33.8 vs 18.1 nmol/L; p<0.002). The dose required to produce the ED50f was significantly greater for albuterol than for fenoterol with potency ratios of 1.75, 1.61, and 2.26 for plasma K+, QS2I, and cAMP, respectively. There were no significant differences between fenoterol and albuterol with respect to heart rate (Emax, 44.9 vs 32.5 beats/min; p=0.19; potency ratio, 1.98; p=0.052). CONCLUSIONS: These findings suggest that albuterol behaves as a partial agonist at beta-receptors when compared with fenoterol, and that when inhaled in doses currently recommended for severe asthma, albuterol will result in lesser maximum cardiac and metabolic effects than fenoterol. These findings are consistent with the hypothesis that the property of full receptor agonism may contribute to the increased risk of death associated with fenoterol.

Administration, Inhalation↗

Visual-spatial localization by patients with frontal-lobe lesions invading or sparing area 46.

Monkeys with unilateral principal sulcus (PS) lesions show a contralateral deficit in localizing remembered targets, especially as the recall interval is lengthened. We tested 20 patients with unilateral frontal-lobe excisions that invaded (FI) or spared (FS) area 46 (putative homologue of PS) and 32 normal controls (NC) on a task where subjects had to indicate the location of a light dot either immediately, or after 30 s, with or without interference. The FI group was worse than the NC group following both delay conditions. NC and FS groups differed only after interference. We concluded that area 46 is involved in recalling the location of visual targets, but unlike the monkey, the deficit is not restricted to a particular part of the visual field.

Adult↗

Respiratory symptoms and environmental factors in schoolchildren in the Bay of Plenty.

AIMS: To determine the prevalence of respiratory symptoms in children and to examine associations with environmental factors in the Bay of Plenty. METHODS: International Study of Asthma and Allergies in Childhood (ISAAC) questionnaires were distributed to 13-14 year old children and to care-givers of 6-7 year old children as part of the ISAAC study. RESULTS: Completed questionnaires were received for 2614 primary and 2752 secondary students. Analysis by district showed no consistent association with exposure to industrial emissions from paper mills, natural sulphur fumes, or climatic variation. All districts are subject to high levels of pollen. Symptom prevalence was close to the mean for New Zealand centres participating in the ISAAC survey. Night cough and nasal symptoms were more common in secondary pupils exposed to smoking in the home, but there was no consistent association between passive smoking and wheeze or diagnosed asthma. Children from larger households reported less wheezy symptoms and less diagnosed asthma. CONCLUSIONS: There was no consistent evidence of an effect on respiratory morbidity from natural fumes, industrial air pollution, or climate. The indoor environment is probably of greater importance in this population.

Adolescent↗

End of the New Zealand asthma mortality epidemic.

In 1989, a case-control study reported that inhaled fenoterol was associated with the epidemic of asthma deaths that had affected New Zealand since 1976. The New Zealand Department of Health issued warnings about the safety of fenoterol and restricted its availability. The associated time trends are consistent with the hypothesis that fenoterol was the main factor in the New Zealand asthma mortality epidemic. The epidemic commenced when fenoterol was introduced in 1976, and the New Zealand death rate remained the highest in the world for more than a decade. After publication of the case-control study, the death rate fell by half and has now remained low for a further 3 years (1990-92). Time-trend data do not suggest a class effect of inhaled beta-agonists in the epidemic: there was no association between beta-agonist sales and the start of the epidemic, and total sales of inhaled beta-agonists actually increased slightly during 1989-90 when the epidemic came to an end. Time-trend data are also inconsistent with the hypothesis that the epidemic may have occurred because of underprescribing of inhaled corticosteroids. Similarly, time-trend data is incosistent with hypotheses postulating a major role of social factors such as unemployment. Data on time trends should be assessed with caution, because time trends in asthma deaths can be affected by many factors. Nevertheless, the New Zealand time trends are consistent with fenoterol being the main cause of the New Zealand asthma mortality epidemic and are inconsistent with a significant role for other suggested causes.

Administration, Inhalation↗

The effects of frontal- or temporal-lobe lesions on susceptibility to interference in spatial memory.

Patients with unilateral frontal- or temporal-lobe lesions and normal control subjects studied multiple arrays of pictures and were tested for recall of the locations of the pictures. One condition consisted of three trials of the same pictures in different spatial arrangements, recall being tested immediately after each presentation. In a second condition (using different stimuli), the subject was given two trials with one set of pictures, but a new set of pictures was viewed on the third trial. All groups showed a build-up of proactive interference across trials using the same pictures, and a release of proactive interference when they studied new pictures. Patients with frontal-lobe lesions were more susceptible to proactive interference than were the other groups.

Adolescent↗

Measuring the prevalence of bronchial hyper-responsiveness in children.

BACKGROUND: The aim of this study was to assess the effectiveness of an asthma prevalence video questionnaire (involving the audiovisual presentation of clinical asthma), a standard written questionnaire (based on the IUATLD Bronchial Symptoms Questionnaire) and a new written questionnaire (designed for an international study of asthma and allergies in childhood [ISAAC]) in predicting bronchial hyper-responsiveness (BHR) (PD20 < or = 7.8 mumol methacholine). METHODS: The IUATLD and video questionnaires were administered to 193 schoolchildren (13-16 years). The ISAAC questionnaire was administered to 87 of these children. All children subsequently underwent bronchial challenge to methacholine. RESULTS: The sensitivity and specificity for predicting BHR were similar for individual questions from the IUATLD and video questionnaires. The video questions with the highest Youden's index related to moderate wheezing at rest (0.46), severe wheezing at rest (0.38), and nocturnal wheezing (0.37). The ISAAC questionnaire was similar in effectiveness to the IUATLD questionnaire in predicting BHR. CONCLUSIONS: The video questionnaire is a valid method of assessing the prevalence of BHR, and may be particularly useful when comparing populations with differing languages and cultures. Some video questions appeared more effective than others in relation to predicting BHR. A new written questionnaire (ISAAC) designed for a large international asthma prevalence study in children also is an effective method for measuring the prevalence of BHR.

Adolescent↗