Evaluation of two different educational interventions for adult patients consulting with an acute asthma exacerbation.

Asthma education decreases the number of emergency visits in specific subgroups of patients with asthma. However, it remains unknown whether this improvement is related only to the use of an action plan alone or to other components of the educational intervention. A total of 126 patients consulting urgently for an acute asthma exacerbation were recruited; 98 completed the study. The first 45 patients were assigned to Group C (control; usual treatment). Thereafter, patients were randomized to either Group LE (limited education; teaching of the inhaler technique plus self- action plan given by the on call physician) or Group SE (same as group LE plus a structured educational program emphasizing self-capacity to manage asthma exacerbations). At baseline, there was no difference between groups in asthma morbidity, medication needs, or pulmonary function. After 12 mo, only Group SE showed a significant improvement in knowledge, willingness to adjust medications, quality of life scores, and peak expiratory flows. In the last 6 mo, the number of unscheduled medical visits for asthma was significantly lower in Group SE in comparison with groups C and LE (p = 0.03). The number (%) of patients with unscheduled medical visits also decreased significantly in Group SE compared with Groups C and LE (p = 0.02). We conclude that a structured educational intervention emphasizing self-management improves patient outcomes significantly more than a limited intervention or conventional treatment.

What is new since the last (1999) Canadian Asthma Consensus Guidelines?

The objective of the present document is to review the impact of new information on the recommendations made in the last (1999) Canadian Asthma Consensus Guidelines. It includes relevant published studies and observations or comments regarding what are considered to be the main issues in asthma management in children and adults in office, emergency department, hospital and clinical settings. Asthma is still insufficiently controlled in a large number of patients, and practice guidelines need to be integrated better with current care. This report re-emphasises the need for the following: objective measures of airflow obstruction to confirm the diagnosis of asthma suggested by the clinical evaluation; identification of contributing factors; and the establishment of a treatment plan to rapidly obtain and maintain optimal asthma control according to specific criteria. Recent publications support the essential role of asthma education and environmental control in asthma management. They further support the role of inhaled corticosteroids as the mainstay of anti-inflammatory therapy of asthma, and of both long acting beta2-agonists and leukotriene antagonists as effective means to improve asthma control when inhaled corticosteroids are insufficient. New developments, such as combination therapy, and recent major trials, such as the Children's Asthma Management Project (CAMP) study, are discussed.

Prevalence of asthma symptoms among adults aged 20-44 years in Canada.

BACKGROUND: Reported prevalence rates of asthma vary within and between countries around the world. These differences suggest environmental factors in addition to genetic factors in the cause of the disease and may provide clues for preventive strategies. We examined the variability of asthma-related symptoms and medication use among adults in 6 sites across Canada (Vancouver, Winnipeg, Hamilton, Montreal, Halifax and Prince Edward Island) and compared our findings with those from sites that had participated in a recent European survey. METHODS: We used the same sampling strategy and standardized questionnaire as those used in the European Community Respiratory Health Survey (ECRHS). The 6 Canadian sites were selected to represent different environments with respect to climate, air pollution and occupational exposure. Community-based samples of 3000 to 4000 people aged 20-44 years were randomly selected in each site. Subjects were asked to complete the questionnaire by mail between March 1993 and November 1994. Prevalence rates (and 95% confidence intervals [CIs]) of asthma symptoms, self-reported asthma attacks and use of asthma medication were compared across the Canadian sites and with sites that had participated in the ECRHS. RESULTS: The overall response rate of those selected to receive the questionnaire was 86.5% (range 74.5%-92.8%). The prevalence rates of most asthma symptoms varied significantly among the Canadian sites. For instance, 21.9% (Montreal) to 30.4% (Halifax) of the men and 24.0% (Vancouver) to 35.2% (Halifax) of the women reported wheezing in the year before the survey. Depending on the site, 4.4% to 6.3% of the men and 5.2% to 9.5% of the women reported an asthma attack in the last year, and 4.0% to 6.1% of the men and 4.9% to 9.7% of the women were currently using asthma medication. Prevalence rates of symptoms, asthma attacks and medication use did not change with age, but they were higher among women than among men. Compared with the results from the ECRHS sites, those from the Canadian sites were among the highest. INTERPRETATION: Significant variation in the prevalence of asthma symptoms, asthma attacks and use of asthma medication between Canadian sites and international sites suggests environmental influences. Different combinations of factors in different sites may be responsible for the high prevalence rates and should be the subject of further research to guide clinical management and public health intervention.

Occupational asthma in adults in six Canadian communities.

We examined the prevalence, population attributable risk (PAR), and clinical characteristics of occupational asthma (OA) in a randomly selected population in six communities in Canada. Our study followed the European Community Respiratory Health Survey protocol. A randomly selected population of 18,701 (87% response rate) persons from the study communities, ranging in age from 20 to 44 yr, completed an initial questionnaire, of whom 2,974 (39% response rate) attended the laboratory and completed supplementary questionnaires. Of these latter individuals, 383 had asthma. Asthma was defined as physician-diagnosed asthma, and adult-onset asthma was defined as a first attack at age 15 yr or older. We used several methods for estimating OA as follows: (1) reporting of a high-risk job (occupation and industry) for OA at the time of asthma onset (Probable OA); (2) reporting of exposure to a substance that may cause OA (Possible OA) while not in a high-risk job at the time of asthma onset; and (3) combination of the PAR for high-risk jobs and exposures. The prevalence (95% confidence interval [CI]) of Probable OA and Possible OA combined was 36.1% (31.3 to 41.0%) among subjects with adult-onset asthma. The occupations most commonly reported in association with OA were nursing in the Probable OA group and clerical and food preparation in the Possible OA group. The clinical characteristics and exposures reported by both groups were similar. The PAR for adult-onset asthma in high-risk jobs and exposures was 18.2%. The assessment of occupation and industry alone, rather than of exposures, may underestimate the contribution of occupational exposures to asthma prevalence.

Airway hyperresponsiveness in elite athletes.

It has been suggested that high-level training could contribute to the development of airway hyperresponsiveness (AHR), but the comparative effects of different sports on airway function remains to be determined. We evaluated 150 nonsmoking volunteers 18 to 55 yr of age; 100 athletes divided into four subgroups of 25 subjects each according to the predominant estimated hydrocaloric characteristic of ambient air inhaled during training: dry air (DA), cold air (CA), humid air (HA) and a mixture of dry and humid air (MA), and 50 sedentary subjects. Each subject had a respiratory questionnaire, a methacholine challenge, allergy skin-prick tests, and heart rate variability recording for evaluation of parasympathetic tone. The athletes had a 49% prevalence of AHR (PC(20) < 16 mg/ml), with a mean PC(20) of 16.9 mg/ml, compared with 28% (PC(20): 35.4) in sedentary subjects (p = 0.009). The prevalence (%) of AHR and mean PC(20) (mg/ml) varied as followed in the four subgroups of athletes: DA: 32% and 30.9; CA: 52% and 15.8; HA: 76% and 7.3; and MA: 32% and 21.5 (p = 0.002). The estimated parasympathetic tone was higher in athletes (p < 0.001), but this parameter showed only a weak correlation with PC(20) (r = -0.17, p = 0.04). This study has shown a significantly higher prevalence of AHR in athletes than in the control group because of the higher prevalence in the CA and HA groups. Parasympathetic activity may act as modulator of airway responsiveness, but the increased prevalence of AHR in our athlete population may be related to the type and possibly the content of inhaled air during training.

Cardiovascular safety of high doses of inhaled fenoterol and albuterol in acute severe asthma.

BACKGROUND: It has been suggested that overuse of fenoterol metered-dose inhalers (MDIs) may increase the risk of death from asthma due to cardiac arrhythmias. Our primary objective was to compare the cardiovascular safety of fenoterol and albuterol MDIs when administered in maximal bronchodilating or maximal tolerated doses to an absolute maximum of 16 puffs, for the emergency department (ED) treatment of acute severe asthma. METHODS: Asthmatic patients presenting to the ED with acute severe asthma (FEV1 less than 50% of predicted) were enrolled in a multicenter, randomized, double-blind, parallel-group study. Following baseline measurements, (medical history, physical examination, determination of serum potassium and serum theophylline levels, oximetry, 12-lead ECG, and spirometry), each patient received 4 puffs of either fenoterol, 200 micrograms per puff, or albuterol, 100 micrograms per puff, 1 puff every 30 s via an MDI attached to a holding chamber. Additional doses of inhaled beta 2-agonist were administered by dose titration, 2 puffs every 10 min to a maximal cumulative dose of 16 puffs of albuterol or fenoterol, side effects were intolerable to the patient, or an FEV1 plateau (i.e., < 10% improvement for 2 consecutive doses) occurred. ECG was recorded continuously via Holter monitor, and respiratory rate, BP, dyspnea (Borg scale), and FEV1 were assessed after each dose. RESULTS: 128 patients were randomized to receive fenoterol and 129 to receive albuterol. Overall, fenoterol increased FEV1 160 mL more than albuterol. The mean (SEM) FEV1 increase from baseline was 0.75 +/- 0.06 L in the fenoterol group and 0.59 +/- 0.06 L in the albuterol group (p < 0.03). Both beta 2-agonists caused a decrease in serum potassium level that was significantly greater in the fenoterol (0.23 +/- 0.04 mmol/L) than in the salbutamol (0.06 +/- 0.03 mmol/L) group (p = 0.0002). There was also a greater increase in the Q-Tc interval in the fenoterol group, 0.011 +/- 0.003 s compared with 0.003 +/- 0.003 s in the albuterol group (p < 0.05). Differences in hypokalemia and Q-Tc prolongation associated with fenoterol and albuterol were significantly different only after 8 puffs of fenoterol had been given. 32 patients exhibited ventricular premature beats, 14 in the fenoterol group and 18 in the albuterol group. There were 34 patients with episodes of supraventricular premature beats, 17 in each group. No episodes of sustained ventricular tachycardia were detected in either group. CONCLUSIONS: In adequately oxygenated patients, using dose titration of fenoterol, in a formulation of 200 micrograms per puff by MDI valved holding chamber and mask, to a total dose of 3,200 micrograms and salbutamol (100 micrograms per puff) to a total dose of 1,600 micrograms over 90 min, showed cardiovascular safety in acute severe asthma. This was evidenced by absence of cardiovascular mortality or clinically significant arrhythmias in either group. The 100% greater dose of fenoterol improved FEV1 significantly more than salbutamol and was associated with a relatively small but significantly greater prolongation of the Q-Tc interval and decrease in serum potassium level. This study does not exclude the possibility that adverse cardiac events could occur with severe hypoxemia.

Constrictive bronchiolitis obliterans following gold therapy for psoriatic arthritis.

A 41 year old male with psoriatic arthritis developed progressive dyspnoea and airflow obstruction following 4 months of intramuscular gold therapy. Open lung biopsy revealed bronchiolitis obliterans of the constrictive type. This case suggests a possible aetiological role for gold in the pathogenesis of constrictive bronchiolitis obliterans, or alternatively an association between psoriatic arthritis and this inflammatory airway condition.

Treatment of Difficult Asthma: What do you do when asthma doesn't respond to therapy?

The difficult asthmatic patient should first be managed by confirming the diagnosis and eliminating any aggravating environmental or occupational factors, including medication use. Proper treatment requires rational addition of drugs in a logical sequence. It is most important to ensure proper inhaler technique, patient compliance, effective doctor-patient communication, and proper patient monitoring.

Breathlessness and exercise in patients with cardiorespiratory disease.

Previous studies have led to the revival of the hypothesis that breathlessness is the perception of respiratory muscle effort and is present when the tension developed by muscles increases, when the muscles are weak, or when both conditions are present simultaneously. Using a category scale, the intensity of breathlessness was measured in 20 subjects (2 normal subjects and 18 patients) undergoing an incremental exercise test (50 to 100 kpm/min) to maximal capacity. The patients were selected to provide a heterogeneous group of pulmonary diseases, obesity, muscular weakness, and cardiac disease, with a wide variability in exercise capacity (250 to 1,900 kpm/min) and severity of dyspnea. Maximal inspiratory pressure (MIP), pleural pressure (Ppl), the extent of shortening of the inspiratory muscles as indicated by the tidal volume expressed as a percent of vital capacity (VT/VC), the rate of shortening as indicated by flow rate, the frequency of contraction as indicated by breathing frequency (fb), and the duty cycle (TI/Ttot) were measured throughout exercise to assess their relative contribution to the intensity of breathlessness. Using multifactorial analysis, the perception of breathlessness was significantly (p less than 0.01) related to the Ppl, inspiratory flow rate (VI), VT/VC, TI/Ttot, and fb. A multiple linear regression equation that included all these variables explained 69% of the variance, with no single factor being identified as uniquely predominant: Breathlessness = 3.0 (Ppl/MIP) + 1.2 (VI) + 4.5 (VT/VC) + 0.13 (fb) + 5.6 TI/Ttot) - 6.2 (R = 0.83). The intensity of effort required to produce a given pressure increases when the muscle is weak, when the velocity of contraction increases, or when the muscle shortens.(ABSTRACT TRUNCATED AT 250 WORDS)

Pneumonia in renal transplant patients.

Between January 1976 and March 1982, 28 episodes of pneumonia occurred in 26 renal transplant patients. The overall mortality rate was 46%. Of the 16 patients with nosocomial pneumonia 9 (56%) died, whereas of the 12 patients with community-acquired pneumonia 4 (33%) died. In all 9 cases of unknown cause the response to empiric treatment was prompt, whereas in 4 of the 10 cases of monomicrobial pneumonia and 8 of the 9 cases of polymicrobial pneumonia the patient died. Cytomegalovirus was the sole cause of the pneumonia in two patients and a contributing cause, along with aerobic gram-negative bacteria, in another five, four of whom also had a fungal infection. Two patients, both of whom survived, had nosocomial Legionnaires' disease.