（1) mucus plug obstruction and atelectasis
Mucus plug obstruction and atelectasis is more common complications of bronchial asthma, an incidence of about 11%, and most occur in children, patients, the impact of the disease depends on the location and extent of obstruction. Bronchial tree can be Kachu tube by mucus and eosinophil formed. Bronchial for containing viscous sputum, in the smaller bronchi or bronchiole is always possible to discover a particular strong and thick mucus plug. Bronchial mucus plug is a clinical syndrome in patients with asthma so it developed into an important factor. Sputum dry Tushman spirochete that is made of thin plastic within the bronchial mucus plug. Due to severe asthma attack, patients with mouth breathing, excessive sweating, so that excessive wear and tear fluid, or the use of aminophylline diuretic water loss, so that viscous sputum is not easy Kachu; application of excessive sedative, antitussive agents suppress cough reflex, so that mucus discharge problems; suddenly out adrenal cortex hormones, resulting in bronchospasm aggravated secretion. These factors may promote the formation of mucus plug. Due to mucus plug blocks the bronchioles, and bronchial wall thickening, and mucous membranes due to congestion, edema and the formation of folds which contribute to the formation of atelectasis.
Treatment of the main points include: active and effective control of bronchial asthma and pay attention to the balance of access to water to prevent dehydration from occurring, as soon as possible to take an active respiratory tract drainage and back postural drainage and percussion therapy measures, after the above-mentioned treatment, about 75% of patients can be in 4 weeks to restore, if the results are poor, as soon as possible with the bronchoscope suction out mucus plug.
(2), pneumothorax, and pneumomediastinum
This complication is in critical condition signs and pathological physiological changes as follows: bronchial spasm caused obstructive ventilatory defect, alveolar gas emissions rather difficult to over-inflated, alveolar pressure increased, the final alveolar rupture, the gas spread along the following channels: ① gases into the chest the formation of pneumothorax; ② gases into the lung interstitium, through the bronchi and pulmonary vascular sheath to the roots, through the hilum and to the mediastinum, the formation of mediastinal emphysema, pulmonary artery pressure and pulmonary veins, so that blocked circulation. Immediately after diagnosis to be urgently addressed, affecting breathing and circulation should be done suprasternal fossa cut exhaust; if complicated by tension pneumothorax should be water-sealed bottle closed drainage exhaust line.
(3) respiratory tract infections
Bronchial asthma, respiratory tract infections are one of the most common complication. The infection can also promote disease development, affecting the therapeutic effect, forming a vicious cycle. Respiratory tract infections are mainly: ① virus infection; ② mycoplasma infections; ③ bacterial infection. Infection often can promote the development of asthma, for two main reasons: ① the media to promote the release of asthma; ② β-receptor function can weaken, resulting in bronchial smooth muscle contraction; ③ can vagus nerve activity increased; ④ to bronchial epithelial cell damage , epithelial cells, increased permeability of subcutaneous nerve endings exposed, exposed nerve endings and receptors more vulnerable to stimulation, and thus to cause reflex bronchospasm.
(4) respiratory failure
Bronchial asthma complicated by respiratory failure incidence of 53% of the mortality rate of 8%, so we have to actively prevent bronchial asthma, respiratory failure from occurring. Common incentives are: ① Infection: Because infection increases airway reactivity and small airway inflammation, promote the formation of IgE, and accompanied by an increase in the release of histamine, reducing the β-receptor function, increasing the vagus nerve reflex bronchial smooth muscle contraction. Result of these changes is ongoing bronchospasm, respiratory muscle fatigue, eventually lead to the occurrence of respiratory failure. ② improper treatment of: isoprenaline can make patients with bronchial asthma ventilation / perfusion ratio changes, aggravated hypoxemia, such as excessive use may induce the occurrence of respiratory failure. The long-term use of corticosteroids persons, such as sudden discontinuation or reduction, and can be the incentive for respiratory failure. ③ sedatives: sedatives suppress the respiratory center to drive less, especially for the repeated attacks, longer duration, poorer lung function were more apparent. ④ Other factors: asthma and other complications such as pneumothorax, pulmonary edema, atelectasis Deng Jun enable the patients to ventilation / perfusion ratio change, diversion increase, leading to respiratory failure.
(5) pulmonary edema
The clinical manifestations of pulmonary edema is often masked by symptoms of bronchial asthma in itself is not easy to find. The event of pulmonary edema, potentially high risk and must be a high priority. Swelling depends on the occurrence of edema and interstitial pulmonary vascular hydrostatic pressure, colloid osmotic pressure balance, membrane permeability and lymphatic flow. Performance than the occult, a serious attack of bronchial asthma, often have severe respiratory difficulties, cyanosis can not lie horizontally. If the merging infection, auscultation wheezing sound when you are not only, but also a moist mouth rale. It is precisely because these symptoms often overlap with symptoms of pulmonary edema, so that sicker, but it is difficult for clinical found the presence of pulmonary edema. Pulmonary edema can increase airway resistance, aggravation of asthma attacks, a vicious cycle.