Disease diagnosis: Acute capillary bronchitis is a relatively common lower respiratory tract infection in infants and young children caused mainly by respiratory syncytial virus, and is seen only in infants and young children under 2 years of age, especially in small infants aged 1-6 months. Most cases occur in winter and spring in the north, and also in summer and autumn in the south. There can be small epidemics, and outbreaks are called epidemic wheezing pneumonia or epidemic capillary bronchitis, which will be described in a separate chapter. Capillary bronchitis often presents with a persistent dry cough and episodes of wheezing 2-3 days after the onset of upper respiratory tract infection, often with moderate to low fever. The disease is most severe 2-3 days after the onset of coughing and wheezing. Breathing is shallow and fast, often accompanied by expiratory wheezing sound, i.e., a sound like a bellows can be heard when exhaling, with 60-80 breaths per minute or even faster, and a fast heart rate of 160-200 breaths per minute, with obvious nasal flapping. In severe cases, the child may develop cyanosis around the mouth, lips and nails, and may be combined with heart failure, dehydration, metabolic acidosis and respiratory acidosis and other disorders of acid-base balance. Diagnosis of capillary bronchitis: 1. Age: Most commonly seen in children under 1 year of age, especially in infants under 6 months of age. 2. Season: The disease can develop all year round, but is more common in winter and spring. 3. Clinical manifestations: the onset of the disease is rapid, with pre-cold symptoms, such as coughing and sneezing, coughing worsens after 1-2 days, episodes of dyspnea, wheezing, pallor, lip cyanosis, trismus sign (+), early pulmonary signs mainly wheezing sounds, followed by wet sounds. In severe cases, the symptoms may be accompanied by congestive heart failure, respiratory failure, hypoxic encephalopathy, and water and electrolyte disturbances. The general temperature does not exceed 38.5°C and the duration of the disease is 1-2 weeks. Ancillary tests: total leukocyte count classification is mostly within the normal range, and collection of nasopharyngeal swabs or secretions using immunofluorescence techniques, immunoenzymatic techniques and molecular biology techniques can clarify the pathogen. The diagnosis is generally not difficult based on the fact that the disease occurs in small infants with typical wheezing and stridor. The treatment of capillary bronchitis is mainly oxygen therapy, wheezing control, pathogenic treatment and immunotherapy. Oxygen therapy All children with this disease have hypoxemia, so critically ill children can be given oxygen by different means, such as nasal vestibular catheter, face mask or oxygen tent, etc. 2.Control of wheezing Isopropazine and chlorpromazine, each 1mg/(mg.times) intramuscularly or orally, can be used to stop wheezing, cough and sedation, also can be used aminophylline orally, intravenously or reserved enema, severe children can be used salbutamol (gastrin) nebulized inhalation. Glucocorticoids are used for severe wheezing episodes or those who cannot be controlled by other treatments, hydrocortisone succinate 5-10mg/(kg.d) or methylprednisolone 1-2mg/(kg.d) intravenously over several hours. 3, anti-pathogenic drug therapy such as viral infection, triazolyl nucleoside intravenous drip or nebulized inhalation, can also try alpha-interferon injection, but its efficacy are not sure. If mycoplasma infection is suspected, macrolide antibiotics can be applied, and if there is bacterial infection, appropriate antibiotics should be applied. 4.Biological products treatment Intravenous immunoglobulin (IVIG) 400mg/(kg.d) for 3-5 days can relieve clinical symptoms, reduce the amount of detoxification and shorten the period of detoxification in children. The efficacy of intravenous anti-syncytial virus immunoglobulin (RSV-IVIG) is comparable to that of IVIG, and the recently produced anti-RSV monoclonal antibody is effective in preventing recurrent wheezing episodes in high-risk infants (prematurity, bronchopulmonary dysplasia, congenital heart disease, immunodeficiency disease) and after capillary bronchitis, but it tends to cause RSV Genetic mutation, and resistance to the monoclonal antibody. 5.Other Ensure fluid intake, correct acidosis, and timely detection and management of respiratory failure and other vital signs.