Pulmonary function testing differentiates exercise-induced bronchoconstriction from deconditioning.
the verdict
INSUFFICIENT LEANING
refutedsupported
the weight of evidence
3 sources for · 0 against
The retrieved evidence indicates that exercise challenge testing and pulmonary function testing are used alongside clinical evaluations to differentiate various causes of exertional dyspnea, such as exercise-induced bronchoconstriction and physical deconditioning, but does not fully establish that pulmonary function testing alone definitively differentiates the two conditions.
Exercise-induced bronchoconstriction (EIB) is a common clinical entity in people with asthma. EIB is characterized by postexercise airway obstruction that results in symptoms such as coughing, dyspnea, wheezing, chest tightness, and increased fatigue. The underlying mechanism of EIB is not completely understood. "Osmotic theory" and "thermal or vascular theory" have been proposed. Initial assessment must include a specific work-up to exclude alternative diagnoses like exercise-induced laryngeal obstruction (EILO), cardiac disease, or physical deconditioning. Detailed medical history and clinical examination must be followed by basal spirometry and exercise challenge test. The standardized treadmill running (TR) test, a controlled and standardized method to assess bronchial response to exercise, is the most adopted exercise challenge test for children aged at least 8 years. In the TR test, the goal is to reach the target heart rate in a short period and maintain it for at least 6 min. The test is then followed by spirometry at specific time points (5, 10, 15, and 30 min after exercise). In addition, bronchoprovocation tests like dry air hyperpnea (exercise and eucapnic voluntary hyperpnea) or osmotic aerosols (inhaled mannitol) can be considered when the diagnosis is uncertain. Treatment options include both pharmacological and behavioral approaches. Considering medications, the use of short-acting beta-agonists (SABA) just before exercise is the commonest option strategy, but daily inhaled corticosteroids (ICS) can also be considered, especially when EIB is not controlled with SABA only or when the patients practice physical activity very often. Among the behavioral approaches, warm-up before exercise, breathing through the nose or face mask, and avoiding polluted environments are all recommended strategies to reduce EIB risk. This review summarizes the latest evidence published over the last 10 years on the pathogenesis, diagnosis using spirometry and indirect bron
Keywords: EIB, asthma, exercise induced asthma, exercise induced bronchoconstriction, children, EILO, vocal cord dysfunction, athletes, deconditioning status released display-pdf yes is-olf no is-manuscript no is-preprint no is-journal-matter no is-scanned no is-retracted no Received 2024 Jun 13; Revised 2024 Jul 17; Accepted 2024 Jul 26; Collection date 2024 Aug. 1. Introduction Exercise-induced respiratory symptoms were first described in 1962 by Jones et al. [ 1 ] and then in 1968 by Fitch, who observed severe bronchial obstruction in an 18-year-old Olympic Gold Medalist swimmer after strenuous muscular activity [ 2 ].
The recent American Thoracic Society (ATS) Clinical Practice Guideline proposed to differentiate EIB between exercise-induced bronchoconstriction occurring in asthmatic patients (EIBa—EIB with asthma) and exercise-induced bronchoconstriction in patients without typical signs or symptoms of asthma (EIBwa—EIB without asthma) [ 9 , 10 ]. EIB is usually associated with bronchial hyperresponsiveness [ 4 , 10 , 11 , 12 , 13 ], a condition that refers to the tendency of the airways to constrict more easily and severely than normal airways in response to various stimuli [ 14 ].
The exercise challenge test is a noninvasive test conducted in a real-life setting, usually in a controlled environment such as a pulmonary function testing laboratory or a clinic. It contributes to understanding the underlying causes of exertional dyspnea, particularly by evaluating bronchial hyperreactivity to exercise [ 87 ]. The standardized treadmill running (TR) test is the most adopted exercise challenge test as it represents a controlled and standardized method to assess bronchial response to exercise [ 9 ].
Indirect bronchoprovocation testing may represent a diagnostic option to establish EIB diagnosis [ 99 ]. Indirect bronchial provocation tests use external stimuli like dry air hyperpnea (exercise and eucapnic voluntary hyperpnea) or osmotic aerosols (inhaled mannitol) to cause the endogenous release of bronchoconstrictor mediators from airway inflammatory cells. The eucapnic voluntary hyperventilation (EVH) test is a well-known tool for exercise-induced bronchoconstriction diagnosis but data on its feasibility in children remain limited.
Role of Cardio-Pulmonary Exercise Testing (CPET) CPET can be considered in the following cases: (1) assessment of dyspnea of unknown origin (i.e., with inconclusive respiratory function test); (2) differential diagnosis between pulmonary dyspnea and cardiac dyspnea; (3) functional assessment in chronic lung disease; and (4) follow-up in rehabilitation/retraining program. CPET identifies the anaerobic threshold (AT) and measures the maximum oxygen consumption (VO 2 max).
Causes Alternative Diagnosis Respiratory - Asthma without EIB - EILO, dysfunctional breathing disorders - Vascular malformations (vascular rings, pulmonary arteriovenous malformations) - Tracheobronchomalacia - Infectious diseases - Foreign body inhalation - Tumors - Interstitial diseases Cardiac - Arrhythmias (EIVT, SVT) - Pericarditis/Myocarditis - Shunting, vascular malformations - Cardiomyopathies - Pulmonary hypertension - Valvular abnormalities Metabolic/ Neuromuscular - Mitochondrial disorders, mitochondrial enzyme deficiencies - Storage diseases (glycogenosis, sphingolipidoses) - Motor neuron
Figure 3 Diagnostic flowchart for EIB. EIB: exercise-induced bronchoconstriction; ECT: exercise challenge test; EVH: Eucapnic Voluntary Hyperpnea; EILO: Exercise-Induced Laryngeal Obstruction; CLE: Continuous Laryngeal Exercise Test; CPET: Cardio-Pulmonary Exercise Test; COPD: Chronic Obstructive Pulmonary Disease; GERD: Gastro-Esophageal Reflux Disease; ECG: electrocardiogram. 8.1. Exercise-Induced Laryngeal Obstruction (EILO) EILO is a specific type of laryngeal disorder characterized by inappropriate closure or narrowing of the vocal folds and/or supraglottic structures during exercise [ 40 , 106 , 107 , 108 , 109 , 110 ].
Exertional dyspnea is a common symptom in childhood which can induce avoidance of physical activity, aggravating the original symptom. Common causes of exertional dyspnea are exercise induced bronchoconstriction (EIB), dysfunctional breathing, physical deconditioning and the sensation of dyspnea when reaching the physiological limit. These causes frequently coexist, trigger one another and have overlapping symptoms, which can impede diagnoses and treatment. In the majority of children with exertional dyspnea, EIB is not the cause of symptoms, and in asthmatic children it is often not the only cause. An exercise challenge test (ECT) is a highly specific tool to diagnose EIB and asthma in children. Sensitivity can be increased by simulating real-life environmental circumstances where symptoms occur, such as environmental factors and exercise modality. An ECT reflects daily life symptoms and impairment, and can in an enjoyable way disentangle common causes of exertional dyspnea.
Abstract Exertional dyspnea is a common symptom in childhood which can induce avoidance of physical activity, aggravating the original symptom. Common causes of exertional dyspnea are exercise induced bronchoconstriction (EIB), dysfunctional breathing, physical deconditioning and the sensation of dyspnea when reaching the physiological limit. These causes frequently coexist, trigger one another and have overlapping symptoms, which can impede diagnoses and treatment. In the majority of children with exertional dyspnea, EIB is not the cause of symptoms, and in asthmatic children it is often not the only cause.
Keywords: asthma, exercise induced bronchoconstriction, dyspnea, child, physiological limit, dysfunctional breathing, spirometry and other lung function tests, exercise test status released display-pdf yes is-olf no is-manuscript no is-preprint no is-journal-matter no is-scanned no is-retracted no Received 2021 Sep 10; Accepted 2021 Dec 13; Collection date 2021. Introduction Exertional dyspnea is a common presenting symptom within the pediatric population; up to 14% of the adolescent population experience exercise-induced dyspnea yearly ( 1 ). Exertional dyspnea can be detrimental for children, impairing participation in play and sports.
Exertional Dyspnea—Coexisting Diagnoses Dyspnea is a subjective phenomenon, influenced by interacting physiological and psychological factors, along with social and environmental input ( 12 ). Exertional dyspnea has an extensive differential diagnosis ( Table 1 ). Exertional dyspnea in children, especially when having a history of asthma, is often primarily assumed to be caused by exercise induced bronchoconstriction (EIB), as asthma is a common and known entity in childhood. Other prevalent, but less known causes of exertional dyspnea are dysfunctional breathing, Exercise Induced Larygneal Obstruction (EILO) and dyspnea when reaching the physiological limit ( 13 – 18 ). Abu-Hasan et al.
Diagnosis Red flags Respiratory Low airway obstruction -Asthma/Exercise induced bronchocontriction -Vascular ring -Stenosis or airway malacia -Tumor Upper airway obstruction -Exercise induced laryngeal obstruction -Corpus alienum Dysfunctional breathing Infectious lung diseases Fever Interstitial lung diseases Diaphragma paralysis Pneumothorax Cardial Cardiac shunting -Atrial and/or ventricular septum defect -Significant arteriovenous malformation Oxygen desaturation Arrhythmia Family history, (pre-)syncope Pulmonary hypertension Lung embolism Pericarditis Fever, chest pain Cardiomyopathy Family history Neuromuscular Myasthenia gravis Metabolic Glycogen storage disease (e.g., McArdle) Sudden muscle cramps Mitochondrial enzyme deficiency Thyroid disease Other Physical deconditioning Reaching physiological limit Ear nose throat pathology Anemia Gastro-oesophagal reflux All these common causes of exertional dyspnea regularly coexist, influence one another and have overlapping symptoms which can impede diagnosis and treatment ( 20 ).
The purpose of this article is to provide an overview of the causes of exertional dyspnea and the diagnostic approach toward the child with exertional dyspnea, which is visualized in the Supplementary Figure 1 . Exercise Induced Bronchoconstriction Exercise induced bronchoconstriction (EIB) is a common, highly specific symptom in childhood asthma and is a useful objective marker to indicate poor asthma control ( 21 – 24 ). It is a sign of bronchial hyperresponsiveness caused by airway inflammation and can present with the classic symptoms of asthma, such as dyspnea, wheezing, cough, mucus hyper-secretion, chest tightness and/or nocturnal wakening ( 25 ).
Treadmill speed in relation to heart rate and/or ventilation and age provides an indication of cardiovascular condition. The quick rise in ventilation makes the treadmill a very suitable way of testing, since too long of a warming-up period may decrease the likelihood of identifying mild EIB ( 48 ). Alternatives to running are cycle ergometry or a jumping castle. Environmental Factors Environmental factors such as smoke, dust, pollen, swimming pool trichloramines and (changes in) air temperature and humidity can trigger exercise-induced symptoms ( 53 ). To elicit the reported symptoms, the real-life environmental conditions where symptoms occur should be simulated.
This condition can be individually different but it is often outdoors. Testing in cold and/or dry air enhances the stimulus for bronchoconstriction in asthmatic patients ( 48 ). Cold and/or dry air therefore significantly increases sensitivity and repeatability of the ECT for EIB compared to testing at normal room temperature ( 54 ). In a climate chamber outdoor conditions can be approximated while the child can exercise without wearing a facial mask or mouthpiece and is therefore preferred. However, when suspicion of EIB is low and symptoms predominantly arise indoors, cold and/or dry air is not compulsory.
Cardiopulmonary exercise testing (CPET) is a comprehensive and invaluable assessment used to identify the mechanisms that limit exercise capacity. However, its interpretation remains poorly standardised. This scoping review aims to investigate which limitations to exercise are differentiated by the use of incremental CPET in literature and which criteria are used to identify them. We performed a systematic, electronic literature search of PubMed, Embase, Cochrane CENTRAL, Web of Science and Scopus. All types of publications that reported identification criteria for at least one limitation to exercise based on clinical parameters and CPET variables were eligible for inclusion. 86 publications were included, of which 57 were primary literature and 29 were secondary literature. In general, at the level of the cardiovascular system, a distinction was often made between a normal physiological limitation and a pathological one. Within the respiratory system, ventilatory limitation, commonly identified by a low breathing reserve, and gas exchange limitation, mostly identified by a high minute ventilation/carbon dioxide production slope and/or oxygen desaturation, were often described. Multiple terms were used to describe a limitation in the peripheral muscle, but all variables used to identify this limitation lacked specificity. Deconditioning was a frequently mentioned exercise limiting factor, but there was no consensus on how to identify it through CPET. There is large heterogeneity in the terminology, the classification and the identification criteria of limitations to exercise that are distinguished using incremental CPET. Standardising the interpretation of CPET is essential to establish an objective and consistent framework.
https://bit.ly/3Vs3cHE pmc-status-qastatus 0 pmc-status-live yes pmc-status-embargo no pmc-status-released yes pmc-prop-open-access yes pmc-prop-olf no pmc-prop-manuscript no pmc-prop-legally-suppressed no pmc-prop-has-pdf yes pmc-prop-has-supplement yes pmc-prop-pdf-only no pmc-prop-suppress-copyright no pmc-prop-is-real-version no pmc-prop-is-scanned-article no pmc-prop-preprint no pmc-prop-in-epmc yes pmc-license-ref CC BY-NC Introduction Cardiopulmonary exercise testing (CPET) is a type of stress test predominantly performed on a cycle ergometer or treadmill during which pulmonary gas exchange, heart rate, blood pressure, electrocardiogram and oxygen saturation are recorded at rest and while exercising, along with symptoms.
Although CPET rarely pinpoints a specific diagnosis, it helps to narrow the differential diagnosis and guide further investigations [ 7 ]. CPET results within normal limits can also limit further, unnecessary testing. In patients with known cardiac or pulmonary disease, identification of the cause(s) of exercise limitation can reveal potential therapeutic targets and guide therapy or rehabilitation strategies, especially when multiple comorbidities are present [ 8 – 10 ]. The interpretation of CPET is dominated by the principle that the body's oxygen consumption ( V ʹ O 2 ) is the primary measure of exercise capacity [ 10 ].
In general, cardiac output is regarded as the principal determinant of maximal V ʹ O 2 in healthy subjects, but recently there has been debate on whether oxygen diffusion into the muscle tissue is a (contributing) limiting step of the cascade [ 13 , 14 ]. Additionally, even though historically the pulmonary system was considered overbuilt for exercise in healthy individuals, it is now known that well-trained subjects can reach or even surpass their predicted pulmonary ventilation, as they have superior cardiovascular function [ 15 , 16 ].
TABLE 1 Characteristics of the included publications (total, n=86) Characteristic Number of publications, n (%) Primary literature 57 ( 66) Publication type Research article 47 (54) Conference abstract 9 (10) Research letter 1 (1) Study design Prospective 42 (48) Retrospective 15 (17) Method of conducting CPET Cycle ergometer 37 (43) Treadmill 15 (17) Not mentioned 5 (6) Study population # Pulmonary disorder 40 Healthy subjects 9 Cardiac disorder 4 Other 11 Population size (range) 8–304 Secondary literature 29 ( 33) Publication type Review article 21 (24) Statement 5 (6) Textbook 2 (2) Editorial 1 (1) CPET: cardiopulmonary exercise testing.
Limitations to exercise at the level of the respiratory and cardiovascular system that were reported twice or less were included in the category “other”, while for limitations at the level of the peripheral muscle and other limitations only limitations mentioned once were included in this category. # : Pulmonary vascular limitation was categorised as a limitation at the level of the respiratory system, but it also involves the cardiovascular system. EIB: exercise-induced bronchoconstriction.
Various studies found that the measurement of dynamic respiratory mechanics is complementary to the use of BR to identify ventilatory limitation, but no consensus exists on which markers of dynamic respiratory mechanics should be used [ 57 – 59 ]. Limitations of the measurement of dynamic respiratory mechanics are the inability to account for the thoracic gas compression artifact or exercise induced bronchodilation/bronchoconstriction when comparing exercise tidal and maximal FVLs and the risk of incorrect alignment of the tidal breathing curve with the maximal FVL.
In line with this, deconditioning represents a broad adaptation within the body impacting various organ systems, including a lower cardiac stroke volume and impaired peripheral muscle function, rather than constituting a distinct physiological limitation [ 16 ]. Despite its frequent mention as an exercise limiting factor, it is important to note that no specific CPET parameter exclusively characterises the presence of deconditioning. The heterogeneity we found in CPET interpretation can be attributed to the lack of its standardisation.
Everything we examined (3)
This check searched the claim as stated. It did not run a separate search for evidence against it.