Screening for exercise-induced asthma

Effect of Submaximal Warm-up Exercise on Exercise-induced Asthma in African School Children

BACKGROUND

Regular physical activity has long been regarded as an important component of a healthy lifestyle. Exercise-induced asthma (EIA) is one of the major problems interfering with the performance of exercise. A warm-up exercise programme has been cited as a non-pharmacologic means of reducing EIA, but its effect has not been fully elucidated.

OBJECTIVE

The aims of this study were to determine the prevalence of unrecognized EIA in Pretoria primary school children, determine the effect of a warm-up exercise programme on EIA and to establish the relationship between history of allergy, family history of asthma and EIA.

METHODS

A random sample of 640 school children was selected. The study was divided into three phases. In phase one, a descriptive cross-sectional study was done using the standardized European Community Respiratory Health Survey (ECRHS) questionnaire. In phase two, non-asthmatic participants that returned a completed questionnaire were included in the field study. Pre-test and post-test experimental designs were used, where peak expiratory flow rate (PEFR) was measured at baseline and within ten minutes after exercise. A total of 340 subjects completed the Free Running Asthma Screening Test (FRAST); EIA was defined as a decrease in baseline PEFR ≥ 10% after exercise and 75 children (22%) had EIA. In phase three, 29 of the 75 subjects participated in the warm-up programme which was performed in the laboratory and subjects acted as their own controls. Predefined protocols for the study were followed.

RESULTS

Seventy-five (22%) of the 340 participants had EIA. The mean age, height and weight were 10.51 years, 139.26 cm and 33.45 kg, respectively. Exercise-induced asthma symptoms were cough (25%), chest pain (16%), wheeze (12%) and chest tightness (12%). The history of allergy was 75%, family history of allergy 40% and positive history of allergy when near animals, feathers or in dusty areas 38%. Wheezing during or after exercise, wheezing when near animals, feathers or in dusty areas and chest pain was significant (p < 0.05). The mean PEFR after exercise without warm-up was 4.43 L/min. The mean PEFR after exercise (warm-up) was 4.98. The mean percentage change in PEFR between exercise without warm-up and exercise with warm-up was 14.83%. The paired t-test showed a significant difference between PEFR with warm-up and PEFR without warm-up (p < 0.05).

CONCLUSION

There was a high prevalence of EIA among study participants. Exercise-induced asthma symptoms were significant for wheezing and chest pain. Exercise after warm-up was significant in reducing EIA. This study reports the effect of warm-up exercise on EIA and highlights the need to screen school children for EIA.

Exercise-induced asthma in children

Exercise-induced bronchoconstriction affects 40-90% of people with asthma, compared with 3-15% of the general population. Exercise-induced asthma (EIA) is diagnosed on the basis of subjective symptoms of airflow obstruction during and after exercise, objective measures of airflow obstruction and the exclusion of alternative diagnoses. Although the pathogenesis of EIA has not been fully elucidated, two major theories have been proposed: the airway rewarming theory and the hyperosmolarity theory. Increasing evidence suggests that airway inflammation plays a major role in the pathogenesis of EIA. In this article, we review the prevalence, pathogenesis, methods for diagnosis and treatment of EIA, as well as the responsiveness of children and adolescents to EIA therapies.

Exercise-induced bronchoconstriction in athletes-should we screen?

The fact that exercise-induced bronchoconstriction (EIB) may be both over- and underdiagnosed in athletes has led to calls for widespread screening for the condition. This article assesses such a strategy by employing the standard framework used when evaluating any screening policy. This approach highlights a number of concerns and allows recommendations to help optimize the success of such a strategy if it were to be implemented.

Screening for asthma: results from a rural cohort

BACKGROUND

Asthma, the leading cause of chronic illness in children, must be managed in both the home and school environments. Identification of children who have risk factors associated with asthma is the first step toward achieving one of the Healthy People 2010 (2000) objectives, which identifies that 25 states will establish a system of surveillance to track asthma mortality, morbidity, access to care, and asthma management.

PURPOSE

The purposes of this research were to: a) identify rural children who are at risk for asthma through written screening; b) assess parameters of respiratory health status of rural school-aged children as indicated by forced expiratory volume at l second (FEV1), forced vital capacity (FVC), peak expiratory flow (PEF), mean mid-expiratory flow (FEF(25-75)); and c) identify the number of rural school-aged children who sought and obtained follow-up from their primary health care provider and were given a definitive diagnosis of asthma.

FRAMEWORK

The Vulnerable Populations Framework (Flaskerud and Winslow, 1998) was used to organize this study.

METHODOLOGY

A prospective descriptive design was utilized for this research.

RESULTS

Approximately 12% of the children screened were referred to their primary care provider (PCP) for follow-up care. Of these approximately half of the children were seen by their PCP. Barriers to seeking follow-up care were: a) the child was not symptomatic all the time, b) reluctance to be diagnosed with asthma, and c) others, such as cost and time. Children who were not well controlled identified that they ran out of medicine and their parents did not refill their prescription.

CONCLUSION

Results from this descriptive study indicate that screening for asthma in school may be a way to identify those children who are at risk for asthma, and who are not diagnosed as well as those who are diagnosed with asthma but are not optimally managed. While many parents wanted their children to be screened, follow-up care was not critical to them.

IMPLICATIONS

Nurses working in a school setting are in a prime position to help identify those children with signs and symptoms of asthma. In addition, use of written screenings with or without spirometry may be helpful in identifying children at risk for asthma. Further studies need to be undertaken to determine if written screening is as efficacious as spirometry for school and other ambulatory care settings.

Screening elite winter athletes for exercise induced asthma: a comparison of three challenge methods

BACKGROUND

The reported prevalence of exercise induced asthma (EIA) in elite winter athletes ranges from 9% to 50%. Many elite winter athletes do not report symptoms of EIA. At present there is no gold standard test for EIA.

OBJECTIVE

To establish the efficacy of screening for EIA and examine the role of the eucapnic voluntary hyperventilation (EVH) challenge and laboratory based and sport specific exercise challenges in the evaluation of elite winter athletes.

METHODS

14 athletes (mean (SD) age 22.6 (5.7) years, height 177.2 (7.0) cm, body mass 68.9 (16.9) kg) from the Great Britain short-track speed skating (n = 10) and biathlon teams (n = 4) were studied. Each athlete completed a laboratory based and sport specific exercise challenge as well as an EVH challenge, in randomised order.

RESULTS

All 14 athletes completed each challenge. Two had a previous history of asthma. Ten (including the two with a previous history) had a positive test to at least one of the challenges. Ten athletes had a positive response to EVH; of these, only three also had a positive response to the sport specific challenge. No athletes had a positive response to the laboratory based challenge.

CONCLUSIONS

Elite athletes should be screened for EIA. EVH is a more sensitive challenge in asymptomatic athletes than sport specific and laboratory based challenges. If sporting governing bodies were to implement screening programmes to test athletes for EIA, EVH is the challenge of choice.

Exercise-induced bronchoconstriction in children with atopic eczema

Non-specific bronchial hyper-responsiveness has been reported in most of the eczematous children even in the absence of asthmatic symptoms. We therefore investigated the occurrence of exercise-induced bronchoconstriction (EIB) in children with atopic eczema (AE) and the predictors of EIB. Fifty-five children referred to the paediatric clinic for AE and a control group of 17 healthy children were recruited. They all carried out a physical examination and skin prick test (SPT) both to inhalant and food allergens, prior to the exercise challenge test. Their parents filled a questionnaire on atopic diseases. They underwent exercise challenge test that consisted in free running for 6 min. Spirometric measurements were carried out before running and till 11 min after. Exercise challenge test was positive in 13 (23%) children with AE. None of the children in the control group had a positive exercise challenge test [OR (95% CI) = 1.31 (1.13-1.51); p = 0.030]. Sixteen (29%) eczematous children had a history of EIB. Such history was not reliable for identifying children who had a positive exercise test. Twenty-nine (52%) children with AE had asthma. Allergic rhinitis affected 33 (60%) of eczematous children and allergic conjunctivitis 28 (50%). EIB was not related to any history of asthma, allergic rhinitis, allergic conjunctivitis, severity of eczema or SPT results. Our study shows that EIB is common in children with AE. Our data also indicate that screening by medical history and physical examination is not a sensitive marker of EIB. This may explain why EIB is often ignored in eczematous children.

Exercise-induced dyspnea in children and adolescents: if not asthma then what?

BACKGROUND

Exercise-induced dyspnea (EID) in children and adolescents is a common manifestation of asthma and is therefore commonly attributed to exercise-induced asthma (EIA) when present in otherwise healthy children.

OBJECTIVE

To report the outcome of evaluations for EID when other symptoms and signs of asthma were absent or if there was no response to previous use of an inhaled beta2-agonist.

METHODS

We reviewed the results of all exercise tests performed in otherwise healthy patients with EID during 1996 to 2003. Physiologic measures included preexercise and postexercise spirometry with the addition of oxygen uptake, carbon dioxide production, continuous oximetry, and electrocardiogram monitoring during most tests. EIA was diagnosed if symptoms were reproduced in association with a 15% or greater decrease in forced expiratory volume in 1 second from baseline. Endoscopy was performed if stridor and/or decreased maximal inspiratory flow were present. Criteria were established for restrictive abnormalities, physical conditioning, exercise-induced hyperventilation, and normal physiologic limitation.

RESULTS

A total of 142 patients met our criteria for inclusion. EID had been present in these patients for a mean duration of 30.2 months (range, <1 to 192 months) before evaluation and had been previously attributed to asthma by the referring physician in 98 of them. Symptoms of EID were reproduced during exercise testing in 117 patients. EIA was identified as the cause of EID in only 11 of those 117. Seventy-four demonstrated only normal physiologic exercise limitation; 48 of these 74 had normal to high cardiovascular conditioning, and 26 had poor conditioning. Other diagnoses associated with reproduced EID included restrictive abnormalities in 15, vocal cord dysfunction in 13, laryngomalacia in 2 (1 of whom had unilateral vocal cord paralysis), primary hyperventilation in 1, and supraventricular tachycardia in 1.

CONCLUSION

The diagnosis of EIA should be questioned as the etiology of EID in children and adolescents who have no other clinical manifestations of asthma and who do not respond to pretreatment with a beta2-agonist. Exercise testing that reproduces symptoms while monitoring cardiac and respiratory physiology is then indicated to identify causes of EID other than EIA.

Clinical and therapeutic aspects of allergic asthma in adolescents

Little is known about the management of asthma in adolescents. We aimed at evaluating these aspects, through a specific questionnaire, in the real life of adolescents with allergic asthma. The questionnaire was administered to a group of adolescents after a diagnosis of allergic asthma. The diagnosis was based on history, clinical examination, pulmonary function tests and allergy tests. One hundred and fifteen adolescents (65 males, mean age 16.5 years) fulfilled the criteria for allergic asthma. The questionnaire explored demography, family history, clinical history, previous diagnosis, therapy, attitude towards therapy and social aspects. The mean actual FEV1 was 87 +/- 10%. Methacholine challenge was carried out in 79 patients and was always positive (PD20 < 1,200 microg), whereas 36 patients underwent reversibility test. According to GINA guidelines, severity of asthma resulted intermittent in 62, mild persistent in 31, moderate in 19 and severe in three patients. In 61% of cases teachers were not aware of the disease. Asthma was managed by general practitioners, allergists and pulmonologists, but PFT/allergy tests had never been performed in 14% of patients. Forty-two per cent of the adolescents received no therapy at all, and only 15% of those with persistent asthma were receiving a stable treatment. Seventy-four per cent of adolescents preferred the inhaled, as against the oral, route. From a clinical and functional point of view, asthma in adolescents did not differ from other age ranges. Nevertheless, the management (diagnosis and therapy) emerged to be unsatisfactory from many points of view.