Bronchiolitis is inflammation of the small airways in the lungs. Acute bronchiolitis is due to a viral infection usually affecting children younger than two years of age. Symptoms may include fever, cough, runny nose, wheezing, and breathing problems. More severe cases may be associated with nasal flaring, grunting, or the skin between the ribs pulling in with breathing. If the child has not been able to feed properly, signs of dehydration may be present.Chronic bronchiolitis is the general term used for small airways disease in adults, notably in chronic obstructive pulmonary disease.Acute bronchiolitis is usually the result of infection by respiratory syncytial virus (72% of cases) or human rhinovirus (26% of cases). Diagnosis is generally based on symptoms. Tests such as a chest X-ray or viral testing are not routinely needed.There is no specific treatment. Symptomatic treatment at home is generally sufficient. Occasionally, hospital admission for oxygen, support with feeding, or intravenous fluids is required. Tentative evidence supports nebulized hypertonic saline. Evidence for antibiotics, antivirals, bronchodilators, or nebulized epinephrine is either unclear or not supportive.About 10% to 30% of children under the age of two years are affected by bronchiolitis at some point in time. It commonly occurs in the winter in the Northern Hemisphere. It is the leading cause of hospitalizations in those less than one year of age in the United States. The risk of death among those who are admitted to hospital is about 1%. Outbreaks of the condition were first described in the 1940s.
Additionally, pulse oximetry is associated with frequent false alarms and parental stress and fatigue. Clinicians may choose not to given additional oxygen to children with bronchiolitis if their oxygen saturation is above 90%. Additionally, clinicians may choose not to use continuous pulse oximetry in these people.When choosing to use oxygen therapy for a child with bronchiolitis, there is evidence that home oxygen may reduce hospitalization rate and length of stay although readmission rates and follow-up visits are increased. Also, the use of humidified, heated, high-flow nasal cannula may be a safe initial therapy to decrease work of breathing and need for intubation. However, evidence is lacking regarding the use of high-flow nasal cannula compared to standard oxygen therapy or continuous positive airway pressure. These practices may still be used in severe cases prior to intubation.Blood gas testing is not recommended for people hospitalized with the disease and is not useful in the routine management of bronchiolitis. People with severe worsening respiratory distress or impending respiratory failure may be considered for capillary blood gas testing. Hypertonic saline
Guidelines recommend against the use of nebulized hypertonic saline in the emergency department for children with bronchiolitis but it may be given to children who are hospitalized.Nebulized hypertonic saline (3%) has limited evidence of benefit and previous studies lack consistency and standardization. A 2017 review found tentative evidence that it reduces the risk of hospitalization, duration of hospital stay, and improved the severity of symptoms.