Bronchial asthma is characterized by airflow limitation by:

The characteristics of dyspnea in patients with bronchial asthma include the following:

1. Expiratory dyspnea is a prominent clinical feature;

2. Hypoxemia is usually accompanied by hypocapnia in the early stage.

The main reason for expiratory dyspnea in patients with bronchial asthma is that patients with bronchial asthma do not have obvious large airway obstruction, and in the process of active inhalation, the airway and alveoli are actively expanded, the thoracic cage is actively expanded, and the increase in inspiratory airway resistance is not obvious. The airway resistance caused by bronchospasm during expiration consumes the alveolar elastic retraction pressure and the passive collapse of the thoracic cage as the driving pressure for expiration, so that a part of the air cannot be exhaled, resulting in excessive alveolar distension, and the percentage of residual air in the total lung volume increases, affecting the inhalation of fresh oxygen in the next respiratory cycle, which may lead to varying degrees of hypoxemia after a long time.

The diffusion degree of carbon dioxide and oxygen is different, and the expiratory dyspnea of patients with bronchial asthma will increase the excretion of carbon dioxide while causing hypoxemia, resulting in the early manifestations of hypoxemia with varying degrees of hypocapnia in patients with bronchial asthma.

The reason why bronchial asthma is not clinically treated in chronic obstructive pulmonary disease** is that most of the alveolar hyperinflation and increased residual volume caused by acute exacerbations of bronchial asthma may be temporary manifestations. With the relief of bronchospasm, the alveolar elastic fibers are not broken, the alveolar elasticity is not destroyed, the residual air can be discharged, and the hyperventilation and alveolar overexpansion can be relieved. When bronchial asthma is reversed, the alveolar elastic fibers are broken, and the alveolar overdistension develops irreversibly, it may lead to obstructive ventilatory dysfunction.

Answer]: The causes of airflow limitation in patients with bronchial asthma are: inflammatory cell infiltration of the airway wall; hypersecretion of glands and impaired clearance of mucus segments; airway smooth muscle spasm; Sullen reputation for airway mucosal edema.

C, the decrease of alveolar elastic retraction and the destruction of alveolar hollow wall were the main pathological changes of bronchopneumonia.

Answer]: bronchial asthma is a chronic inflammatory disease of the airways involving a variety of cells and cellular components. This chronic inflammation is associated with airway hypersusceptibility (AHR), usually with reversible airflow limitation with variable slip numbers. Shilu.

Answer]: This question is a clinical thinking judgment question, which is of medium difficulty, and tests the candidate's understanding of the clinical manifestations of bronchial asthma. Asthma is a chronic inflammatory disease of the airways involving eosinophils, mast cells and other cells and cellular components, which can cause reversible airflow limitation, so its clinical manifestations can show episodic changes, more than night and early morning attacks and aggravation, while exercise-induced asthma is mostly attacked during exercise, so a, b, and d are all correct answers and can be ruled out; Patients with severe asthma can have a pulsus paradoxus due to severe hypoxia, so option E can also be ruled out; Since asthma is a reversible airflow limitation disease, which can be relieved with bronchodilators, but there are still some patients who can be relieved on their own, such as getting rid of allergens, etc., so option C cannot fully express the characteristics of asthma symptoms, so option C is the correct answer.

The description of the basic concepts of bronchial asthma is not clear, and the correct one is () aAsthma is characterized by airflow limitation that is not completely reversible.

b.Airway hyperresponsiveness is a common pathophysiologic feature in patients with asthma.

c.The essence of asthma is chronic inflammation of the airways.

d.The prevalence of asthma is higher in children than in young adults.

e.Asthma can be clinically controlled through prevention and treatment.

Correct Answer: a

Describe the mechanism of airflow obstruction in bronchial asthma: Zaizi.

1) Lumen mucus embolism.

2) Bronchospasm. Sail is hungry.

3) Inflammation of the airway mucosa and re-swelling in water.

4) Airway smooth muscle remodeling.

Answer]: c Thoracic fullness, widening of the intercostal space, decreased chest tremor on palpation, and chest hyperresonance on percussion are all signs of emphysema.