China
Africa
Explore chapters and articles related to this topic
Answers
Published in Ken Addley, MCQs, MEQs and OSPEs in Occupational Medicine, 2023
The following may be useful: Medical history.Occupational history, smoking history, family history.Clinical examination.Lung function testing.Serial peak flow testing.Skin prick testing and blood testing for allergens.Bronchial challenge test.
Extrapulmonary – Treatable traits
Published in Vibeke Backer, Peter G. Gibson, Ian D. Pavord, The Asthmas, 2023
Vibeke Backer, Peter G. Gibson, Ian D. Pavord
Of patients with asthma who engage in regular physical activity, 80% experience exercise-induced reduction in lung function. Even patients who do not train daily or weekly do run for the bus or to catch up with their children or grandchildren; they climb stairs, perform intercourse, or engage in other daily activities. These patients often claim to be deconditioned when visiting an asthma specialist or GP, but they could also have severe respiratory illness with frequent EIB and not only deconditioning. This can be tested with a bronchial challenge test and a 6MWT or a modified shuttle test (MST) (Figure 3.2), which is easy to perform in a hallway; this combination of tests can document asthma control and level of conditioning. However, 6MWT might be somewhat reduced in deconditioned patients with asthma. In such cases, VO2max will show a low fitness score (low mL kg−1 min−1) as a measure of conditioning (fitness) but a normal one as a measure of asthma severity.
A strategy for interpretation of pulmonary function tests
Published in Jonathan Dakin, Mark Mottershaw, Elena Kourteli, Making Sense of Lung Function Tests, 2017
Jonathan Dakin, Mark Mottershaw, Elena Kourteli
An uncertain diagnosis of asthma may be supported by a variety of tests:Consider a period of peak flow monitoring, to detect variability. The sensitivity of this test is quite low, but it may be a reasonable measure in primary care or in the absence of more sophisticated investigations. Is there significant diurnal variability (10%) on twice daily monitoring? (see ‘Peak flow variability in the diagnosis of asthma’ in Chapter 2).Measurement of fractional concentration of expired nitric oxide (FeNO) may be helpful if positive at a level of >50 ppb. Some individuals without asthma may register positive results, but the higher the reading the more specific the result becomes. Note that FeNO may not be elevated in patients with non-eosinophilic asthma phenotypes nor smokers (see Chapter 5).Administration of bronchodilator would probably not evoke a positive response in those with normal baseline spirometry, so this test would add little at this point.Finally, a negative bronchial challenge test virtually excludes a diagnosis of asthma (see ‘Challenge testing’ in Chapter 4).A trial of treatment with inhaled corticosteroid which brings an improvement in FEV1 >400 mL would confirm a diagnosis of asthma.
Atypical asthma in children who present with isolated chest tightness: risk factors and clinical features
Published in Journal of Asthma, 2022
Wenjing Zhu, Chuanhe Liu, Li Sha, Kai Guan, Shuo Li, Mingjun Shao, Jing Zhao, Yuzhi Chen
All subjects who met the following requirements were included: (1) Chest tightness as a sole symptom and the chest was clear to auscultation, (2) No past history of episodic dyspnea, wheezing, or coughing, (3) Normal chest X-rays, electrocardiograms, and myocardial enzymes, (4) Completed the spirometry, bronchodilator response (BDR) test, bronchial challenge test, peak expiratory flow (PEF) variability test, and fractional exhaled nitric oxide (FeNO) test, (5) Serum allergen-specific IgE and peripheral bronchial eosinophil cells (PBEC) detection, (6) Excluded other diseases relevant to chest tightness, such as respiratory infection, cardiac diseases, neuromuscular disorders, endocrine diseases, etc. The diagnostic criteria of the atypical asthma group were as follows: (1) A positive bronchial challenge test, and (2) Symptoms improved or resolved in response to bronchodilator use. The control group was defined as having negative results to the bronchial challenge, diurnal PEF, and BDR tests (post-bronchodilator FEV1 < 12%), as well as no response to asthma treatment.
Practical approaches to the diagnosis of asthma in school-age children
Published in Expert Review of Respiratory Medicine, 2022
Pooja Devani, David K H Lo, Erol A Gaillard
During a direct bronchial challenge test, the chemical compound inhaled at increasing concentrations during the challenge directly interacts with receptors in the airways. Methacholine, for example, mimics the neurotransmitter acetylcholine and interacts with the muscarinic M3 receptor present on airway smooth muscle. Direct bronchial challenge tests are useful tests to rule out asthma. Indirect bronchial challenge tests are more specific and good tests to confirm the diagnosis of asthma but have low sensitivity. Indirect bronchial challenge tests such as exercise testing and inhaled dry powder mannitol challenge testing exert their effects on the bronchi by creating osmolar changes in the airway epithelium. Exercise causes the airways to dry and cool resulting in water loss and osmolar change at the level of the airway epithelium. Dry powder, mannitol increases the osmolarity of the bronchial mucosa triggering the release of mediators from mast cells and eosinophils including histamine, prostaglandins and leukotrienes. Indirect bronchial challenge tests are more specific but have low sensitivity to diagnose asthma [35].
The efficacy and safety of mannitol challenge in a workplace setting for assessing asthma prevalence
Published in Journal of Asthma, 2018
Marcelo B. de Menezes, Erica Ferraz, John D. Brannan, Edson Z. Martinez, Elcio O. Vianna
Epidemiological studies have relied either on response to a questionnaire alone or in combination with bronchial challenge tests to establish the diagnosis of asthma (1,2). The European Community Respiratory Health Survey II (ECRHS II) used a questionnaire and defined current asthma as the condition in which subjects had reported doctor-diagnosed asthma and if, in the previous 12 months they had had respiratory symptoms or had used asthma medications (3). The European Respiratory Society recommends the combination of using a positive bronchial challenge test and the documentation of recent wheezing (in the previous year) as a definition of asthma for epidemiology (4). In occupational settings, many patients with suspected work related asthma may be completely asymptomatic and have normal pulmonary function when non-exposed to the causative work agent, therefore the assessment of nonspecific bronchial hyperresponsiveness (BHR) through bronchial challenge tests with agents such as methacholine is suggested (5).