Bronchiolitis is the leading cause of hospitalization for infants. Respiratory syncytial virus (RSV) is the most common cause of bronchiolitis. Most children are infected with RSV by age 2, but many infections don’t lead to bronchiolitis. Other viruses that have been linked to bronchiolitis include adenovirus, parainfluenza, influenza A/B, human metapneumovirus, rhinovirus, coronavirus, human bocavirus and polyomavirus.
In order to more completely evaluate children presenting with bronchiolitis, many clinicians choose to order blood and urine tests as well as chest radiographs. In children younger than 2 months with RSV bronchiolitis and fever, the complete blood count has not been demonstrated to be helpful in assessing for serious bacterial infection (SBI). But, urinary tract infections occur in approximately 5 to 7 percent of these children. Recent data has shown that chest radiographs have limited utility in children who have a typical presentation of bronchiolitis with mild or moderate distress and a room air oxygen saturation greater than 92 percent.
It’s also common for clinicians to investigate the viral etiology of a child’s respiratory symptoms using nasal aspirates or swabs. Except for treating influenza with oseltamivir and for inpatient cohorting, the current consensus is that knowledge of the viral etiology—among those viruses with easily accessible testing—does not affect treatment of the individual patient. However, the utility of virus identification, especially rhinovirus, is an area of active research.
The most common medications given to children with bronchiolitis are nebulized albuterol and epinephrine. Most studies investigating these medicines have found either no or only short term improvements in hospitalized children. More promising is nebulized hypertonic saline (usually mixed with albuterol or epinephrine). The data regarding corticosteroid use in children with bronchiolitis is complex and evolving. Currently, the data do not support the routine use of corticosteroids in children with bronchiolitis.
Since the purpose of hospitalization is mostly to provide supportive care and monitor respiratory functioning, referrals should be based on the child’s respiratory status and the ability of the child to maintain hydration orally. Although assessing the degree of tachypnea, wheezing, retractions, air entry and oxygenation is helpful when assessing a child’s respiratory status in the office, there are no evidence-based, simple rules for when to refer a child with bronchiolitis to the Emergency Department or how to predict reliably which child with bronchiolitis will have an unanticipated respiratory deterioration. Developing these rules is an area of active research.
—Jonathan Mansbach, MD, MPH
Hospitalist and Physician in Adolescent Medicine
More information: childrenshospital.org/infectousdiseases