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Airway responsiveness
Published in Jonathan Dakin, Mark Mottershaw, Elena Kourteli, Making Sense of Lung Function Tests, 2017
Jonathan Dakin, Mark Mottershaw, Elena Kourteli
Safety precautions are required, should severe airway constriction occur. If a challenge test reveals evidence of bronchoconstriction then a bronchodilator should be administered to restore pre-test airway function. Nebulised bronchodilators, supplemental oxygen, and adrenaline should be readily available in case of a severe reaction, and these tests should only be performed within proximity of an emergency medical response team.
The Internal Milieu Brain and Body
Published in Rolland S. Parker, Concussive Brain Trauma, 2016
Cholinergic nerves are the major neural bronchoconstrictor mechanism in determining airway caliber, that is, controlling smooth muscle tone, airway blood flow, and mucus secretion. They arise in the nucleus ambiguus, travel down the vagus nerve, and synapse in parasympathetic ganglia (Barnes, 2003). Airway constriction is enhanced by vagus nerve (parasympathetic) stimulation of the smooth muscle of the cartilaginous airways, membranous bronchioles (primarily smooth muscle), and alveolar ducts. Sympathetic stimulation inhibits airway constriction (Guyton & Hall, 2000, pp. 440–441; Staub, 1998b). Although sympathetic innervation of the central portions of the lung is weak, the bronchial tree is exposed to circulating norepinephrine and EP (beta receptors) released into the blood by SNS stimulation of the adrenal medulla. PSNS fibers (vagus nerves) release acetylcholine (ACH), causing mild-to-moderate constriction of the bronchiole.
Management of Adolescent Asthma
Published in Jonathan A. Bernstein, Mark L. Levy, Clinical Asthma, 2014
Gina T. Cosia, Beverley J. Sheares, Jean-Marie Bruzzese
Over time, adolescents develop formal operational thinking, which encompasses the skills of abstract thinking, logical reasoning, and problem solving.31 Unlike children, who cannot think beyond the observable, adolescents can think abstractly, reflect upon their thoughts, and develop solutions accordingly. The hallmarks of asthma are chronic airway inflammation and bronchoconstriction. With more sophisticated thinking, adolescents are able to understand inflammation, something that they cannot necessarily see or feel. They can also begin to link the sensation of chest tightness to the concept of airway constriction. Moreover, they can differentiate between rescue medications and daily anti-inflammatory medications, and understand the role of each. Although early adolescents may not be ready to assume responsibility for taking daily medication,30 clinicians should begin to teach them about the pathophysiology of asthma and how bronchodilators and anti-inflammatory medications work.
Allergen-induced asthma, chronic rhinosinusitis and transforming growth factor-β superfamily signaling: mechanisms and functional consequences
Published in Expert Review of Clinical Immunology, 2019
Harsha H. Kariyawasam, Simon B. Gane
It is estimated that more than 339 million people worldwide have asthma [1]. From all aspects: immunopathogenesis, disease severity, and therapeutic response, asthma is clearly a heterogeneous syndrome. Whilst most patients have mild to moderate disease, up to 5-10% of the asthma population are defined as having severe asthma where treatment response is often refractory to standard guideline-based treatment approaches [2]. Clinical symptoms of asthma are nonspecific and broad, with shortness of breath, chest tightness, and excess mucus production, sometimes with cough and audible wheeze, as common presentations. Such symptoms, whatever the exact immunopathogenesis, are interpreted as the result of airway inflammation and variable airflow obstruction arising from airway narrowing termed bronchoconstriction. This abnormal tendency of airway constriction is termed airway hyper-responsiveness (AHR). A significant proportion of asthmatics will also demonstrate early decline in lung function and can sometimes proceed to fixed airway obstruction. Overall it is the excessive airway narrowing that leads to severe asthma exacerbation and asthma-related death. Airway inflammation and structural change (termed remodeling) are both implicated in disease pathogenesis and severity.
Perimenstrual asthma: Report of a case with therapeutic intervention of oral prednisone
Published in Journal of Asthma, 2018
Zhang Lei, Deng Yanhan, Wang Yi, Xiong Shengdao, Xiong Weining
Asthma is one of the most common chronic airway inflammatory diseases, affecting approximately 300 million people throughout the world. It is characterized by airway constriction that contributes to episodes of wheezing, coughing, chest tightness, and shortness of breath (1). Nowadays, it is estimated that up to 40% of asthmatic women of childbearing age may experience cyclical aggravation of asthmatic symptoms during the perimenstrual period. This phenomenon is referred to as perimenstrual asthma (PMA) (2,3) and is considered to be a difficult-to-treat asthma phenotype. Even though the associations between sex hormone (progesterone and estradiol) levels and airway hyperresponsiveness and between the menstrual cycle and airway hyperresponsiveness have been assessed (4), no specific relationship between these factors has been confirmed. Adrenocorticosteroid agents or hormone therapy have been used to treat PMA (5), but no internationally accepted therapeutic guidelines have been established to handle this troublesome type 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
Bronchial reactivity is often increased in patients with typical bronchial classic asthma, but the diagnosis of asthma should be objectively confirmed by physiological testing. In our study, there were differences in parameters of spirometry between the two groups, yet most of the patients in the atypical asthma group had a normal baseline pulmonary function, and only a few presented with mild obstruction dysfunction. To make an accurate diagnosis, additional tests, including BDR, bronchial challenge, and PEF variability tests were obviously necessary. As airway hyper responsiveness is a near universal finding in asthma with clinically current symptoms, and is considered the diagnostic gold standard, all of the patients in the atypical asthma group were confirmed with airway hyper responsiveness from the positive results of the bronchial challenge test. Bronchial challenge has produced a positive response more often in patients with allergic rhinitis (24), so to reduce the selection bias in our study, the bronchial challenge test was performed in the remission period of the subjects with rhinitis. Next, we found that less than 30% of the patients with atypical asthma had a positive BDR test, and only eight out of 58 patients had positive PEF variability. The low positive rate of BDR test was probably traceable, in part, to little opportunity for patients with normal baseline spirometry to reverse their obstruction (25). In addition, atypical asthma with chest tightness may be induced either by an airway constriction or by a non-constriction pathway, and in a study by Taniguchi et al., some of the patients without airway constriction were also found to have inflammation of the airways (5).