(also see Synagis)



Infants have small airways, high closing volumes, and insufficient collateral ventilation; thus, they are affected most often. Recovery begins with regeneration of bronchiolar epithelium after 3-4 days, but cilia do not appear for up to 2 weeks. Mucus plugs are removed by macrophages. Risk factors include the following:



Sex: Boys are affected 1.7 times more than girls; the male-to-female ratio of hospitalization among these children is 1.5:1.




Causes: RSV is the most commonly isolated agent in 75% of children younger than 2 years and who are hospitalized for bronchiolitis.



Foreign body aspiration
Congenital structural anomaly
Congenital lobar emphysema
Tracheal ring
Bronchial cleft cyst
Congenital heart disease

Medical Care:

Shown not to work in the management of the infant with RSV and wheezing. : corticosteroids , Ipratropium bromide (atrovent), an aerosolized anticholinergic agent

Hospital care

Consultations: When a healthy infant presents with a history, physical examination, and course that is consistent with uncomplicated bronchiolitis, no consultations are necessary; however, refer infants with comorbidities, atypical histories, or critical conditions to a pediatrician, preferably at a center that can provide a spectrum of pediatric subspecialists in critical care, pulmonology, and infectious disease.

Diet: Although young infants have the unique ability to breathe and swallow simultaneously, risk of aspiration when the respiratory rate is above 60 breaths per minute is significant. Fever and hyperpnea may contribute to excessive fluid losses. For these reasons, infants who are hospitalized with bronchiolitis require careful fluid monitoring and provision of intravenous fluids when hyperpnea precludes safe oral feeding.


Although a number of medications and interventions have been used to treat bronchiolitis, at present, only oxygen and racemic epinephrine have been shown to affect the condition of the young child with bronchiolitis appreciably. Neither of these appreciably shortens the duration of the disease; however, each may prevent complications and improve comfort.

Therapeutic use to treat bronchiolitis in infants and young children has been controversial. Efficacy in infants is complex because it can be a function of the pharmacologic agent, the route of administration, the clinical status of the patient, or the adequacy of the outcome measure used to demonstrate an effect.

A meta-analysis reviewed 15 randomized placebo-controlled trials of bronchodilator treatment in bronchiolitis. It concluded that bronchodilators produce modest short-term improvement in clinical features of mild or moderately severe bronchiolitis.

A more recent meta-analysis of 8 clinical trials noted that conclusive analysis for the efficacy of beta2-agonist therapy for bronchiolitis remains unavailable and that the routine use of beta2-agonist therapy for bronchiolitis is not supported.

A recent study compared nebulized albuterol to normal saline in an age-matched and severity-matched trial of 52 infants over 72 hours of treatment. Nebulized albuterol did not improve recovery or attenuate severity, as indicated by improvement in oxygen saturation, length of stay, or clinical score.

Although evidence about the efficacy of bronchodilators in bronchiolitis is conflicting, administering a beta-agonist, such as albuterol (0.15 mg/kg/dose), on a trial basis to patients with bronchiolitis (particularly if a history of asthma exists) and assessing the clinical response in 10-15 minutes is reasonable. If improvement in retractions, respiratory rate, and wheezing is noted, scheduled aerosol treatments may be continued, with additional treatments administered as needed.

Ribavirin, a nucleotide analog, may have a role in certain unique situations.

Ribavirin treatment for RSV infections has been controversial because of the aerosol route of administration, the variable course of RSV infection, drug cost, toxicity, and adverse effects.

The current recommendations of the Academy of Pediatrics are that ribavirin aerosol therapy may be considered in selected infants and young children at high risk for serious RSV disease.

This includes patients with complicated congenital heart disease, including pulmonary hypertension; patients with bronchopulmonary dysplasia, cystic fibrosis, and other chronic lung disease; patients with underlying immunosuppressive disease; patients who are severely ill with or without mechanical ventilation; and hospitalized patients who are younger than 6 weeks or who have underlying conditions, such as multiple congenital anomalies or certain neurological and metabolic diseases.

The academy added, "More definitive answers to the questions of ribavirin efficacy and effectiveness require multi-institutional prospective randomized clinical trials. Recommendations may be modified as new information becomes available."

Subsequent studies have shown that ribavirin does not reduce mortality rate significantly or lower the probability of respiratory deterioration. Ribavirin treatment did not reduce the diagnosis of reactive airway disease, and pulmonary function test results did not show any differences when assessed 5-6 years after initial RSV infection.

Oxygen -- Decreases the work of breathing, hence, delaying the onset of respiratory muscle fatigue, allowing other therapies to work.

Bronchodilators -- Act by decreasing muscle tone in both the small and large airways in the lungs, thereby increasing ventilation.

Immunoglobulins -- Specific immunoglobulin products with anti-RSV activity have been developed for the prophylaxis of high-risk patients against RSV infection. Palivizumab (Synagis) -- Humanized monoclonal antibody directed against the F (fusion) protein of RSV. Given monthly through the RSV season, it has been demonstrated to decrease the chances of RSV hospitalization in premature babies who are at increased risk for severe RSV-related illness.

Antibiotics -- Viruses are the primary etiologic agents in bronchiolitis; therefore, routine administration of antibiotics has not been shown to influence the course of this disease. Although rapid diagnostic techniques are available to identify RSV as a causative agent in bronchiolitis, they are not readily available for other viruses. In small, acutely ill infants, clinically excluding the existence of secondary bacterial invasion may be difficult. Administration of broad-spectrum antibiotics in critically ill infants often is justified until culture results prove to be negative.

Nucleoside analogs -- Ribavirin (1-beta-D-ribafuranosyl-1,2,4-triazole-3-carboxamide) is a synthetic nucleoside analog that resembles guanosine and inosine. It appears to interfere with the expression of messenger RNA and inhibit viral protein synthesis. Ribavirin has a broad spectrum of antiviral activity in vitro, inhibiting replication of RSV, influenza, parainfluenza, adenovirus, measles, Lassa fever, and Hantaan viruses. Ribavirin (Virazole) -- Appears to be safe but expensive. Efficiency and effectiveness have not been demonstrated clearly in large, randomized, placebo-controlled trials. Routine use at this time cannot be recommended. In adults, ribavirin can be used for the treatment of other infections, including hepatitis C.


Further Inpatient Care:

In/Out Patient Meds:





Patient Education:

Medical/Legal Pitfalls:

Bronchiolitis. Last Updated: July 17, 2003.
Other references
(1) Pediatr Inf Dis J. 2009;28:25-29