Bronchiolitis is an acute viral infection of the lower respiratory tract that affects infants <24 months and is characterized by shortness of breath, wheezing and crackles. The diagnosis is based on history (including during the occurrence of a known epidemic.) Suspected; the primary cause, the RS virus may be identified with a rapid assay. The treatment is supportive with oxygen and hydration. The prognosis is generally excellent, but some patients develop apnea and respiratory failure.
Bronchiolitis often occurs as epidemic, mostly in children <24 months with a peak age 2 and 6 months. The annual incidence of the disease in the first year of life is 11 out of 100 children. In the temperate northern hemisphere, most cases occur from November to April, with a disease peak in January and February.
Bronchiolitis is an acute viral infection of the lower respiratory tract that affects infants <24 months and is characterized by shortness of breath, wheezing and crackles. The diagnosis is based on history (including during the occurrence of a known epidemic.) Suspected; the primary cause, the RS virus may be identified with a rapid assay. The treatment is supportive with oxygen and hydration. The prognosis is generally excellent, but some patients develop apnea and respiratory failure. Bronchiolitis often occurs as epidemic, mostly in children <24 months with a peak age 2 and 6 months. The annual incidence of the disease in the first year of life is 11 out of 100 children. In the temperate northern hemisphere, most cases occur from November to April, with a disease peak in January and February. Etiology Most cases of bronchiolitis caused by respiratory syncytial virus rhinovirus parainfluenza virus type 3 Less frequent causes are influenza A and B viruses, parainfluenza viruses types 1 and 2, metapneumovirus, adenovirus and Mycoplasma pneumoniae. Pathophysiology The virus spreads from the upper respiratory tract to the medium and small bronchi and bronchioles, and causes epithelial necrosis and inflammatory response. The developing edema and exudates result in partial obstruction, the most falls during expiration significant and has a "air trapping" result. With complete obstruction and adsorption of the enclosed air several atelectatic areas can arise in the lung, which can be worsened by the inhalation of high inspired oxygen concentrations. Symptoms Typically, an affected infant to an infection of the upper respiratory tract, leading to a rapid onset of shortness of breath with tachypnea, tachycardia, recoveries, wheezing and a dry cough. Young infants (<2 months) and premature babies can have recurrent apnea attacks, followed by more typical symptoms and symptoms of bronchitis in the next 24-48 hours. The increasing emergency situation is shown by the circumoral cyanosis, recessed recoveries and audible wheezing. Fever may or may not be present. The infants do not appear at the beginning, despite tachypnea and retractions toxic and without stress, but may be increasingly apathetic to the infection progresses. Hypoxemia is the rule in most affected infants. By vomiting and decreased oral intake is dehydration may develop. With increasing exhaustion breaths are always flat and ineffective and lead to respiratory acidosis. On auscultation can hear wheezing, prolonged exhalation and often a fine crackle. Many children have an accompanying otitis media. Diagnosis Clinical Findings pulse oximetry chest x-ray in more severe cases, RSV antigen test after cleaning the nose or nasal aspiration with seriously ill children the diagnosis of bronchiolitis is provided as part of an epidemic based on history, clinical examination and by the appearance of the disease. Symptoms that resemble a bronchiolitis occur in a worsening asthma, which is often caused by a respiratory viral infection and occurs> 18 months more likely in children, especially if previous episodes of wheezing and whistling or a family history are documented. Also, a reflux gastritis with aspiration of gastric contents can produce the clinical picture of bronchiolitis; many such episodes in a child the key to this diagnosis can then be. Foreign body aspiration can cause wheezing occasionally and should be considered when the symptoms of sudden onset and is not accompanied by the symptoms of an infection of the upper respiratory tract. Heart failure, which manifests itself with a left-right shunt at the age of 2-3 months, can be confused with bronchiolitis. Patients who are suspected of bronchiolitis should be studied pulse oximetry to determine oxygenation. Under normal oxygen saturation, it needs no further investigation. However occur hypoxia and severe shortness of breath on, the diagnosis is supported by an x-ray in which the typical hyperinflated lungs, the flattened diaphragm and the prominent Hili can be seen. Infiltrates may result from atelectasis as well as RSV pneumonia. This is relatively common in infants with RSV bronchiolitis. An RSV Rapid Test with a nasal lavage or by nasal aspiration is diagnostic helpful but not always necessary. He should be performed only in patients whose disease is severe enough to warrant hospitalization. Other laboratory tests are not specific and are not routinely display; about two-thirds of the children have a white blood cell count of 10,000 to 15,000 / ul. Most have 50-75% lymphocytes. Prognosis The prognosis is excellent. Most children recover after 3-5 days without sequelae, although wheezing and cough may persist for 2-4 weeks. Mortality is <0.1%, if medical care is sufficient. The assumption that children tend to bronchiolitis in early childhood are more likely to asthma is controversial. Treatment Supportive therapy oxygen supply needed hydration i.v. If desired, the therapy is supportive of bronchiolitis; most children can be treated at home with hydration and good care. The indications for hospitalization are increasing shortness of breath, sick appearance (z. B. cyanosis, lethargy, fatigue), apnea in the patient history, hypoxemia and false oral ingestion. Children with underlying cardiac diseases such. As heart disease, immunodeficiency or bronchopulmonary dysplasia, which are high-risk patients should also be admitted to the hospital. In hospitalized children ranging 30-40% sodium oxygen administered through a nasal cannula, oxygen tent or face mask, in order to ensure an adequate oxygen saturation> 90%. The indication for endotracheal intubation is in severe, repeated apnea, hypoxia, which is unresponsive to oxygen administration, CO2 retention or if the child can not cough up his bronchial secretions. High-flow nasal cannula therapy, CPAP (continuous positive airway pressure) or both are often used to avoid intubation in patients who have the risk of respiratory failure. The hydrogenation can be maintained by oral administration often small amounts of clear liquid. In sicker children, the liquid is administered intravenously at the beginning. The hydration can be monitored by the urinary excretion, the specific gravity of the urine and the determination of serum electrolytes. There is evidence that systemic corticosteroids, when given early in the disease, in children with a responsive corticosteroids underlying disease (eg. As bronchopulmonary dysplasia, asthma) may be helpful in treatment. There is no benefit in previously healthy children. If no secondary bacterial infection (a rare sequela) occurs, antibiotics should be avoided. Bronchodilators are not always effective, although some children may benefit from a brief improvement. This is especially true for children with previous wheezing. The hospital stay is thus unlikely to be shortened. It is also toxic to the hospital staff. Ribavirin, an antiviral drug that acts in vitro against RSV, influenza and measles is not clinically effective and is therefore no longer recommended except in immunocompromised children with severe RSV infection. RSV immunoglobulin was also tried, but it is not effective. The prevention of a RSV infection by passive immunoprophylaxis with monoclonal antibodies against RSV (palivizumab) reduces the number of hospitalizations, but is expensive and should be used primarily only in high-risk children (and dosage indication prevention). Key points Bronchiolitis is an acute viral infection of the lower respiratory tract that affects infants <24 months, and is typically caused by RSV or rhinovirus. Edema and exudation into the medium and small bronchi and bronchioles cause partial obstruction and air pockets; Atelectasis and / or pneumonia cause hypoxemia in severe cases. Typical manifestations include fever, tachypnea, retractions, wheezing and coughing. The clinical evaluation is appropriate for the diagnosis usually, but more severely ill children should receive pulse oximetry, chest x-ray and rapid antigen tests on RSV. The indications for hospitalization are increasing shortness of breath, sick appearance (z. B. cyanosis, lethargy, fatigue), apnea in the patient history, hypoxemia and false oral ingestion. Treatment is supportive; Bronchodilators sometimes relieve the symptoms, but probably will not shorten the hospital stay, and systemic corticosteroids are not indicated in previously healthy children with bronchiolitis. There is no vaccine; monoclonal antibodies to RSV (palivizumab) may be added to reduce the frequency of hospital stays certain high-risk infants.