I. Etiology
The etiology of capillary bronchitis is mainly respiratory syncytial virus, which can account for 80% or more; others are adenovirus, parainfluenza virus, rhinovirus, and influenza virus in that order; a few cases can be caused by Mycoplasma pneumoniae; after infection with the virus, the tiny capillary bronchioles become congested, edematous, and have increased mucus secretion, which, together with the shedding of necrotic mucosal epithelial cells and blockage of the lumen, leads to significant emphysema and pulmonary atelectasis. The inflammation often involves the alveoli, alveolar wall and interstitial lung, so it can be considered as a special type of pneumonia.
II. Clinical manifestations
1. The age is mostly seen in children under 1 year old, especially in infants under 6 months old.
2. The disease can develop throughout the year, but it is more common in winter and spring.
3. The onset of the disease is rapid, with pre-cold symptoms such as coughing and sneezing, and the coughing becomes worse after 1 to 2 days, with episodes of dyspnea, wheezing, pallor, cyanosis of the lips, and trigeminal signs (i.e., supraclavicular fossa, suprasternal fossa and epigastric depression during inspiration). 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℃, and the duration of the disease is 1 to 2 weeks.
4. Blood leukocytes are mostly normal or mildly increased. Blood gas analysis shows hypoxemia and decreased or increased partial pressure of arterial blood carbon dioxide. Chest x-ray shows thickened lung texture, increased translucency of both lungs or small shadows and pulmonary atelectasis. A rapid diagnosis of respiratory secretion virus can be done if available to clarify the virus type.
Third, complications
1, bronchopneumonia: children may develop high fever, hypoxia, dyspnea, acute respiratory failure, and even pulmonary atelectasis, emphysema, pus, pneumothorax, lung abscess, pericarditis, sepsis and other complications, which can be life-threatening.
2, bronchial dilatation: When capillary bronchitis is not treated properly, it can turn into chronic bronchial purulent inflammation, which destroys the bronchial wall so that the bronchial wall is deformed and dilated, and the wall tissue is destroyed, causing the bronchial tubes to lose their original natural defense ability, which also reduces the coughing efficiency and sputum removal function, providing conditions for further infection. Over time, the vicious circle expands further, aggravating the condition and making it difficult to cure. The child may develop a prolonged intermittent fever, copious pus sputum or hemoptysis. Further development can lead to pulmonary heart disease.
3. Chronic bronchitis, emphysema, pulmonary heart disease: If capillary bronchitis cannot be completely cured and repeatedly attacked, it will turn into chronic bronchitis, and further develop into emphysema and pulmonary heart disease. The child may have recurrent attacks with long-term intermittent coughing, sputum production, wheezing, exertional shortness of breath, panic, cyanosis, edema, and prolonged treatment.
IV. Treatment
1.General treatment
(1) Clean environment, fresh air, room temperature at about 20 ℃, relative humidity at about 55%, which is conducive to the removal of respiratory secretions.
(2) Elevate the head and chest of children with severe wheezing to reduce breathing difficulties.
(3) Irritability can aggravate hypoxia, at this time, we should try to avoid excessive treatment operations, if necessary, sedation can be given: Thorazine, promethazine: 0.5 ~ 1mg/kg/time, 4-6 hours once, intramuscular or intravenous injection. Chloral hydrate: 30～40 mg/kg・times, once every 6～8h, maximum 0.5g, 3 times a day.
(4) Pay attention to maintaining sufficient calories and various nutrients for the child.
(5) Replenish fluid orally several times to replenish the water lost due to rapid breathing, and use intravenous fluid drip, 1/5 of the fluid is appropriate when insufficient, but too much fluid will aggravate airway obstruction.
2.Oxygen therapy
Oxygen therapy is essential in the treatment of this disease. All children have hypoxemia, and oxygen therapy is required to maintain PaO2 at 9.30-12.0 kPa (70-90 mmHg) to improve the abnormal ventilation/perfusion ratio. Hypoxemia is usually corrected with 30% to 40% oxygen concentration. Wetting is generally required. Oxygen flow rate: infants and children: 2~4L/min FiO2: = (21 ten oxygen flow rate L×4)%.
3.Keep the airway open
Nebulized inhalation or ultrasonic nebulization can make the respiratory tract inhale water and dilute sputum; ultrasonic nebulization can be inhaled for 10min each time, too long can cause water poisoning. Regularly turn over and discharge the back, and aspirate sputum immediately after nebulized inhalation, 3 to 4 times a day, to clear the sputum and keep the respiratory tract unobstructed.
4.Antispasmodic and asthma
(1) Thorazine, isopromazine: when wheezing attack can be used thorazine and isopromazine each time 1mg/kg intramuscular injection, can relieve bronchospasm, but also has a sedative effect.
(2) Adrenocorticosteroids: hydrocortisone: 5-10mg/kg/day, methylprednisolone: 1-2mg/kg.
(3) Isoproterenol: add 0.5mg to 10% GS 100ml (5u per ml of isoproterenol) intravenously, initially 0.1ug/ml per minute is appropriate, if the efficacy is not satisfactory, the dose can be doubled every 15-30 minutes, the maximum rate should not exceed 6 ug/ml. after the symptoms improve can be maintained for 12-24h, usually not more than 2d. heart rate, blood pressure, etc. should be monitored. Heart rate, blood pressure, etc. should be monitored.
5.Pathogenetic treatment
(1) Virazole or ribavirin: It has inhibitory effect on RSV and can be used as 10mg/kg・d intravenous drip or 10-15mg/kg・d nebulized inhalation twice daily for 5-7 days as a course of treatment.
(2) Interferon: 200,000~1 million U each time, qd, 6 times continuously, has obvious effect on shortening the course of the disease.
(3) Diflucan: has an inhibitory effect on RSV RSV, 60 mg/kg, prepared into a 1.2% concentration solution, once daily for 1 week.
(4) If combined with bacterial infection, antibiotic treatment can be used appropriately.
V. Care
(1) Keep warm: temperature changes, especially cold stimulation can reduce the local resistance of the bronchial mucosa and aggravate bronchitis, therefore, parents should increase or decrease clothing for the child in time with temperature changes, especially when sleeping to cover the child well, so that the body temperature is kept above 36.5 ℃.
(2) Feeding water: When capillary bronchitis has varying degrees of fever, water evaporation is greater, so attention should be given to feeding the child more water. Available sugar water or sugar saline supplement, also available rice soup, egg soup supplement. The diet is mainly semi-liquid to increase body water and meet the needs of the organism.
(3) adequate nutrition: children suffering from capillary bronchitis nutrient consumption, coupled with fever and bacterial toxins affect the gastrointestinal function, digestion and malabsorption, so the lack of nutrients in the body of the child is not negligible. In this regard, parents should adopt a small number of meals for the child, give light, nutritious, balanced and easy to digest and absorb semi-liquid or liquid diet, such as thin rice, boiled noodles, egg custard, fresh vegetables, fruit juice, etc.
(4) Turn over and pat the back: when the child coughs and coughs up sputum, it indicates an increase in bronchial secretions. To promote the smooth discharge of secretions, nebulized inhalants can be used to help expectoration, 2-3 times a day for 5-20 minutes each time. In the case of infants, in addition to patting the back, you should also help turn the child over once every 1-2 hours to keep the child in a semi-recumbent position, which is conducive to the discharge of sputum.
(5) Antipyretic: In the case of capillary bronchitis, the fever is mostly low to moderate. If the body temperature is below 38.5℃, antipyretic drugs are generally not needed, and the main treatment is to address the root cause of the problem. If the temperature is high, older children can be given physical cooling, that is, wet compresses on the head with cold towels or baths with warm water, but young children should not use this method, if necessary, the application of drugs to lower the temperature.
(6) Maintain a good family environment: the room where the child lives should be warm, well ventilated and lit, and the air should have a certain amount of humidity to prevent excessive dryness. If there are smokers in the home, it is best to quit smoking or go outside to prevent the adverse effects of smoke on the affected child.