What Is Acute Asthma Exacerbation?

Asthma is a common chronic inflammatory airway disease that affects approximately 300 million people worldwide. It is expected that by 2025, one third of the population will be affected by asthma. Reversible airway obstruction and airway hyperresponsiveness (AHR) in asthma patients can cause symptoms such as cough, wheezing, chest tightness, and dyspnea. These symptoms are the main clinical manifestations of asthma patients. Hyperresponsiveness (AHR) was significantly positively correlated. The WHO defined the definition of severe asthma in 2010: it refers to a state in which asthma symptoms are severe, accompanied by some chronic disease symptoms, the condition fluctuates, often exacerbates, and cannot be controlled with drugs.

Asthma is a common chronic inflammatory airway disease that affects approximately 300 million people worldwide. It is expected that by 2025, one third of the population will be affected by asthma. Reversible airway obstruction and airway hyperresponsiveness (AHR) in asthma patients can cause symptoms such as cough, wheezing, chest tightness, and dyspnea. These symptoms are the main clinical manifestations of asthma patients, and they are the same as those of asthma patients. Hyperresponsiveness (AHR) was significantly positively correlated. The WHO defined the definition of severe asthma in 2010: it refers to a state in which asthma symptoms are severe, accompanied by some chronic disease symptoms, the condition fluctuates, often exacerbates, and cannot be controlled with drugs.

Chinese name

Severe asthma

Foreign name

Severe asthma

Severe asthma I. Causes and related diseases

1 Severe asthma 1, severe asthma is related to the following factors

(1) Nasal polyps

According to research, nasal polyps are the most prominent risk factor for severe exacerbations of severe asthma.

(2) Smoking

Smoking can worsen the symptoms of asthma, accelerate the decline of lung function, and induce desensitization of corticosteroids. Nicotine, the main component of cigarettes, induces airway hyperresponsiveness (AHR). Cigarette smoke can affect metabolic signals of cells by regulating mitochondrial morphology and function in airway smooth muscle cells, which can cause metabolic disorders. For children and adolescents with asthma, their grade is the most important predictor of smoking status. Grade 9 and 10 asthma students have the highest smoking rates, so they are emphasized as the object of smoking bans.

(3) Obesity

Obesity is an independent risk factor for severe asthma. Overweight and obesity can increase the incidence and severity of asthma, especially in female patients, and can significantly increase serum IgE levels in female patients [3]. Hyperobese asthma patients have higher IgE levels, worse symptom scores, more severe airway obstruction, a higher percentage of allergen sensitization, and more patients requiring anti-IgE than asthma patients with normal body mass index (BMI) Monoclonal antibody (Omalizumab) treatment. In addition, compared with non-obese asthma patients, obese asthma patients tend to have more acute attacks, and glucocorticoid emergency treatment is more frequent.

(4) Air pollution

Air pollution can induce an acute attack of asthma. People exposed to traffic arterials have an increased risk of asthma and other respiratory diseases. Air pollution can increase regulatory T cells in children with asthma and is related to impaired function. Fine particulate matter (PM2.5) exposure can reduce glucocorticoid receptor activity in respiratory epithelial cells and increase lung inflammation.

(5) Psychological factors

Psychological factors can affect the control of asthma, especially depression and anxiety. Asthma accompanied by depression often has poor asthma control. In addition, asthmatic patients with anxiety and depression had more symptoms of gastroesophageal reflux and rhinitis than the control group, and they needed emotional support when coping with stress.

(6) Gender

There are gender differences in the incidence of severe asthma. The study found that female patients had higher levels of superoxide dismutase (SOD) than male patients, and that SOD increased with age. Higher levels of SOD and FEV1 / FVC in non-asthmatic women indicate that SOD may have some impact on the severity of asthma. Another study found that sex hormone levels affect the incidence of asthma in men and women. FEV1 is positively correlated with testosterone and progesterone and negatively correlated with estradiol. Therefore, testosterone and progesterone are lower in men with severe asthma, while estradiol is higher in women with severe asthma.

(7) Vitamin D deficiency

Vitamin D deficiency is associated with acute exacerbations of severe asthma in children and is more pronounced in nonspecific asthma. By regulating steroid production, 1,25-D3 can block the differentiation of CD8 + T cells into interleukin (IL) -13 + CD8 + T cells to regulate asthma susceptibility. Therefore, vitamin D supplementation may be the most effective treatment for hormone-resistant asthma with vitamin D deficiency and IL-13 + CD8 + T cell increase.

2 Severe asthma 2, related diseases

Severe asthma can be combined with other diseases. The study found that one-third of patients with moderate-severe asthma had bronchiectasis. These bronchiectasis is still mild, and asthma with bronchiectasis has an increase in pus and sputum.

Severe asthma 2. Differential diagnosis

The diagnostic criteria for severe asthma: recurrent episodes of wheezing, shortness of breath, chest tightness, or cough are mostly related to exposure to allergens, cold air, physical, chemical stimulation, viral upper respiratory infections, and exercise. In the lungs, snoring or diffuse, wheezing mainly in exhalation phase, prolonged exhalation phase can be heard in both lungs. Symptoms can be relieved by treatment or spontaneously. Atypical symptoms (if there is no obvious wheezing or signs) should have at least one of the following tests positive. a. Bronchial challenge test or exercise test is positive; b. Bronchodilator test is positive [1s forced expiratory volume (FEV1) increased by more than 15%, and FEV1 increased by an absolute value greater than 200mL]; c. Maximum expiratory flow (PEF) intra-day variation Rate or day-night volatility is greater than or equal to 20%. Exclude wheezing, shortness of breath, chest tightness and cough caused by other diseases.

Severe asthma III. Principles of treatment

1. Anticholinergic drugs

Tiotropium bromide once a day can improve children's lung function, improve children's asthma symptoms, reduce asthma-related hospitalization rates in children with difficult-to-control asthma, has high safety, and has a low incidence of adverse events.

2. Monoclonal antibodies

Monoclonal antibodies can be used in the treatment of severe asthma, but it is not clear to what extent there is overlap in the proportion of suitable asthma treatments and their therapeutic adaptability.

3. Janus kinase (JAK) inhibitor

The JAK inhibitor IJC-1 can improve airway obstruction, and a 10 mg dose of IJC-1 can maximally relax the bronchi and maintain it for 24 hours. Inhaled JAK inhibitors may have a broader anti-inflammatory effect than today's Th2 cytokine antibodies and can be used to treat severe asthma. Targeted JAK1 treatment by inhalation can block inflammation in many aspects, or it can be an effective supplementary treatment for severe asthma.

4.Imatinib

Mast cells are associated with the pathogenesis of asthma AHR and airway inflammation. Mast cell inhibitor imatinib can inhibit mast cell activation and improve AHR and FEV. Mast cells play an important role in the pathological mechanism of severe asthma, and inhibiting the activation of this cell may become an effective program for the treatment of severe asthma in the future.

5. Lung-targeted dual PI3K kinase inhibitors

Studies have shown that the use of lung-targeted dual PI3K kinase inhibitors can reduce the release of inflammatory mediators (such as IL-5 / 13) and the recruitment of eosinophils and neutrophils by> 80%. Equivalent or better than glucocorticoids. Inhaled lung targeting dual PI3K kinase inhibitors may be a new and effective treatment for a large number of patients with poorly controlled asthma.

6. Bronchoplasty (BT)

BT treats asthma by using bronchoscope-mediated heat energy to reduce the number of airway smooth muscles and prevent their chronic structure. Multiple studies have shown that BT can significantly improve lung function, improve asthma symptoms and asthma control levels, reduce asthma attacks and asthma-related hospitalization rates, and there are no related serious adverse events in asthma patients with severe airway obstruction after BT treatment.