Perception of dyspnea during exercise-induced bronchoconstriction

The course of specific self-reported exercise-induced airway symptoms in adolescents with and without asthma

Airway symptoms in conjunction with exercise can take on many forms and can have several contributory factors such as exercise-induced bronchoconstriction (EIB), exercise-induced laryngeal obstruction or hyperventilation [1]. Previous longitudinal studies on self-reported exercise-induced airway symptoms among adolescents have primarily studied single symptoms, focusing on dyspnoea or wheeze, often as a way to investigate the prevalence of asthma [2, 3]. To the best of our knowledge, there are, as yet, no population-based studies investigating the difference between adolescents with and without current asthma regarding the development of different specific exercise-induced airway symptoms. Therefore, we studied the natural course of self-reported exercise-induced dyspnoea, throat tightness, wheeze, chest tightness, cough, stridor and hoarseness over a 5-year period among adolescents with and without current asthma.

In a general population, the prevalence of exercise-induced cough, dyspnoea, throat and chest tightness, wheeze, and stridor increases from adolescence to young adulthood among individuals without asthma in contrast to individuals with asthmahttps://bit.ly/3hR57OX

Reported Exercise-Related Respiratory Symptoms and Exercise-Induced Bronchoconstriction in Asthmatic Children

Background

Unlimited physical activity is one of the key issues of asthma control and management. We investigated how reliable reported exercise-related respiratory symptoms (ERRS) are in predicting exercise-induced bronchoconstriction (EIB) in asthmatic children.

Methods

In this prospective study, 179 asthmatic children aged 7 - 15 years were asked for specific questions on respiratory symptoms related to exercise and allocated into two groups according to whether they complained about symptoms. Group I (n = 134) consisted of children answering “yes” to one or more of the questions and group II (n = 45) consisted of children answering “no” to all of the questions.

Results

Sixty-four of 179 children showed a positive exercise challenge test (ECT). There was no difference in the frequency of a positive test between children in group I (n = 48) and group II (n = 12) (P = 0.47). The sensitivity of a positive report for ERRS to predict a positive ECT was only 37%, with a specificity of 0.72.

Conclusion

According to current guidelines, the report or lack of ERRS has direct consequences on treatment decisions. However, the history of ERRS did not predict EIB and one-third of asthmatic children without complaints of ERRS developed EIB during the ECT. This raises the question of the need for objective measures of bronchial hyperresponsiveness (BHR) in pediatric asthma management.

Dalhousie Pictorial Scales Measuring Dyspnea and Perceived Exertion during Exercise for Children and Adolescents

RATIONALE

Alternative scales to measure dyspnea and perceived exertion have been sought due to concerns regarding understanding and validity of any Borg scale in pediatric populations.

OBJECTIVES

To demonstrate content validity of Dalhousie Dyspnea and Perceived Exertion Scales developed for children and adolescents.

METHODS

We obtained ratings for dyspnea and perceived exertion using both Borg CR-10 and Dalhousie Scales during incremental cycle exercise in 100 children and adolescents, healthy or with respiratory disease. Content validity was determined by correlating perceived leg exertion rating versus heart rate or %peak work capacity and dyspnea rating versus ventilation expressed as %peak ventilation. The stimulus-perceptual response was modeled as a quadratic function with a delay term. Reproducibility, cross-modality usage, and language effects were assessed in a small group of Italian children during treadmill exercise.

MEASUREMENTS AND MAIN RESULTS

Pictorial ratings of dyspnea and perceived exertion measured by both scale ratings rose as expected with increasing exercise intensity in children and adolescents, demonstrating excellent correlation between perceived leg exertion versus exercise intensity and dyspnea rating versus ventilation (median Spearman ρ ≥ 0.9) with either scale. There were no systematic differences in dyspnea or perceived exertion ratings between children with or without respiratory disease. Understandability and reproducibility of the Dalhousie scales was affirmed in Italian-speaking subjects performing treadmill exercise.

CONCLUSIONS

Dalhousie Dyspnea and Perceived Exertion Scales offer an alternative to the Borg scale for use during exercise in pediatric subjects. Children and adolescents exhibit large variation in patterns of ratings of dyspnea and perceived exertion in incremental exercise.

Perception of bronchoconstriction following methacholine and eucapnic voluntary hyperpnea challenges in elite athletes

OBJECTIVE

Self-reported respiratory symptoms are poor predictors of exercise-induced bronchoconstriction (EIB) in athletes. The objective of this study was to determine whether athletes have an inadequate perception of bronchoconstriction.

METHODS

One hundred thirty athletes and 32 nonathletes completed a standardized questionnaire and underwent eucapnic voluntary hyperpnea (EVH) and methacholine inhalation test. Perception scores were quoted on a modified Borg scale before each spirometry measurement for cough, breathlessness, chest tightness, and wheezing. Perception slope values were also obtained by plotting the variation of perception scores before and after the challenges against the fall in FEV1 expressed as a percentage of the initial value [(perception scores after - before)/FEV1].

RESULTS

Up to 76% of athletes and 68% of nonathletes had a perception score of ≤0.5 at 20% fall in FEV1 following methacholine. Athletes with EIB/airway hyperresponsiveness (AHR) had lower perception slopes to methacholine than nonathletes with asthma for breathlessness only (P=.02). Among athletes, those with EIB/AHR had a greater perception slope to EVH for breathlessness and wheezing (P=.02). Female athletes had a higher perception slope for breathlessness after EVH and cough after methacholine compared with men (P<.05). The age of athletes correlated significantly with the perception slope to EVH for each symptom (P<.05).

CONCLUSIONS

Minimal differences in perception of bronchoconstriction-related symptoms between athletes and nonathletes were observed. Among athletes, the presence of EIB/AHR, older age, and female sex were associated with slightly higher perception scores.

Exercise-induced bronchoconstriction in Tunisian elite athletes is underdiagnosed

Many studies have shown an increased risk of developing exercise-induced bronchoconstriction among the athletic population, particularly at the elite level. Subjective methods for assessing exercise-induced bronchoconstriction such as surveys and questionnaires have been used but have resulted in an underestimation of the prevalence of airway dysfunction when compared with objective measurements. The aim of the present study was to compare the prevalence of exercise-induced bronchoconstriction among Tunisian elite athletes obtained using an objective method with that using a subjective method, and to discuss the possible causes and implications of the observed discrepancy. As the objective method we used spirometry before and after exercise and for the subjective approach we used a medical history questionnaire. All of the recruited 107 elite athletes responded to the questionnaire about respiratory symptoms and medical history and underwent a resting spirometry testing before and after exercise. Post-exercise spirometry revealed the presence of exercise-induced bronchoconstriction in 14 (13%) of the elite athletes, while only 1.8% reported having previously been diagnosed with asthma. In conclusion, our findings indicate that medical history-based diagnoses of exercise-induced bronchoconstriction lead to underestimations of true sufferers.

Perceptions and pathophysiology of dyspnea and exercise intolerance

Dyspnea is a complex psychophysiologic sensation that requires intact afferent and efferent pathways for the full perception of the neuromechanical dissociation between the respiratory effort attempted and the work actually accomplished. The sensation is triggered or accentuated by a variety of receptors located in the chest wall, respiratory muscles, lung parenchyma, carotid body, and brain stem. The sensation of dyspnea is stronger in patients with higher scores for anxiety and has been reported in patients with anxiety disorders with no cardiopulmonary disease. These observations demonstrate the importance of cerebral cognition in this complex symptom. Ten cases are presented that illustrate different clinical manifestations of dyspnea.

Dyspnoea in children. Does development alter the perception of breathlessness?

Dyspnoea, the perception of an unpleasant and/or uncomfortable sensation of breathlessness, offers several physiological, anatomical and teleological analogies with pain. Pain perception has been shown to exist in the newborn, suggesting that dyspnoea may also occur from birth onwards. The perception of breathlessness will be subservient to developmental changes in the behaviour of sensors and lung and muscular receptors implicated in dyspnoea, some of which are known to be active at time of birth. For example, perinatal resetting of the arterial chemoreceptor could lead to transient depression of the dyspnoeic response to hypoxia. However, though early evoked ventilatory responses and peripheral receptor maturation do exist, dyspnoea will only occur if the corresponding central neural circuitry undergoes parallel maturation. Our knowledge of dyspnoea in later childhood is based on a small number of clinical or psychophysical studies, predominantly dealing with asthma and exercise. There is a thus a clear need for systematic assessment of the existence and severity of dyspnoea sensing in younger children that takes into account its role as an alarm mechanism for triggering adaptive and/or protective responses.

Exploring and explaining low participation in physical activity among children and young people with asthma: a review

BACKGROUND

Asthma is the most common chronic illness among children and accounts for 1 in 5 of all child GP consultations. This paper reviews and discusses recent literature outlining the growing problem of physical inactivity among young people with asthma and explores the psychosocial dimensions that may explain inactivity levels and potentially relevant interventions and strategies, and the principles that should underpin them.

METHODS

A narrative review based on an extensive and documented search of search of CinAHL, Embase, Medline, PsycINFO and the Cochrane Library.

RESULTS & DISCUSSION

Children and young people with asthma are generally less active than their non-asthmatic peers. Reduced participation may be influenced by organisational policies, family illness beliefs and behaviours, health care advice, and inaccurate symptom perception and attribution. Schools can be reluctant to encourage children to take part in physical education or normal play activity due to misunderstanding and a lack of clear corporate guidance. Families may accept a child's low level of activity if it is perceived that breathlessness or the need to take extra inhalers is harmful. Many young people themselves appear to accept sub-optimal control of symptoms and frequently misinterpret healthy shortness of breath on exercising with the symptoms of an impending asthma attack.

CONCLUSION

A multi-faceted approach is needed to translate the rhetoric of increasing activity levels in young people to the reality of improved fitness. Physical activity leading to improved fitness should become part of a goal orientated management strategy by schools, families, health care professionals and individuals. Exercise induced asthma should be regarded as a marker of poor control and a need to increase fitness rather as an excuse for inactivity. Individuals' perceptual accuracy deserves further research attention.

Continuous ratings of breathlessness during exercise by children and young adults with asthma and healthy controls

Although it is recommended and common practise for adults with respiratory disease to rate symptoms (e.g., dyspnea and/or leg discomfort) during exercise testing, there are no reports on whether children can rate their perception of breathlessness during exercise. Our aims were to evaluate the ability of children and young adults with asthma to continuously rate breathlessness on the 0-10 category-ratio (CR-10) scale with a computerized system during cycle ergometry, and to compare their results with those of healthy subjects. At an initial visit, subjects were familiarized with equipment and exercise protocol, and practised rating breathlessness while cycling. At a follow-up visit (2-4 days later), subjects performed incremental exercise and rated breathlessness using a computer system, mouse, and monitor. Changing the position of the mouse caused movement of a vertical bar located adjacent to the CR-10 scale to indicate the severity of breathlessness. Baseline characteristics of the 14 subjects with asthma (age, 15 +/- 3 years) and 33 healthy subjects (age, 16 +/- 2 years) were similar. The two groups had comparable levels of fitness as measured by peak oxygen consumption (VO(2)). Correlations between exercise physiologic variables (power production, VO(2), and minute ventilation) and breathlessness ratings were >0.90. Subjects reported progressively more ratings of breathlessness with increasing exercise intensities. There were no differences between groups for slopes, x-intercepts, and absolute thresholds relating physiologic variables and breathlessness. In conclusion, children and young adults with asthma as well as healthy individuals of comparable age successfully used the computerized system to rate breathlessness continuously during cycle ergometry. Both groups reported more ratings of breathlessness with this technique as exercise progressed.

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.