Bronchiolitis usually is caused by a viral lower respiratory tract infection and most commonly causes morbidity and mortality in infants. The condition is characterized by acute inflammation, edema and necrosis of epithelial cells in the small airway, increased mucus production, and bronchospasm. Although mortality from respiratory syncytial virus (RSV; the most common etiology of bronchiolitis) has decreased, the infection leads to more than 90,000 hospitalizations annually, and many patients experience recurrent infection throughout life.

Studies on the diagnosis and management of bronchiolitis have had varying results; therefore, the best clinical practices are unclear. The American Academy of Pediatrics (AAP), with the support of other organizations, convened the Subcommittee on Diagnosis and Management of Bronchiolitis to create a practice guideline for treating patients with the infection. The guideline is based on an evidence report from the American Academy of Family Physicians (AAFP), the Agency for Healthcare Research and Quality, and the RTI International-University of North Carolina Evidence-Based Practice Center. The report, which was created using evidence-based literature, addressed four points: the effectiveness of diagnostic tools, the effectiveness of pharmaceutical therapies, the role of prophylaxis, and the cost-effectiveness of prophylaxis.

The guideline is meant to assist physicians in decision making. It does not apply to children with immunodeficiencies. Children with underlying respiratory illnesses or significant congenital heart disease are excluded from the management recommendations but not from the prevention recommendations.

Evidence levels are given to each recommendation based on the quality of the evidence used: A = well-designed, randomized controlled trials (RCTs) or diagnostic studies on relevant populations; B = RCTs or diagnostic studies with minor limitations or overwhelmingly consistent evidence from observational studies; C = observational studies (case control and cohort design); D = expert opinion, case reports, or reasoning from first principles; and X = exceptional situations where validating studies cannot be performed and there is a clear preponderance of benefit or harm.

Diagnosis

The diagnosis should be based on patient history and physical examination, and the assessment of disease severity should be based on risk factors (B recommendation). Routine laboratory and radiologic diagnostic studies should not be used in the diagnosis (B recommendation).

Goals of the evaluation include differentiating probable bronchiolitis from other disorders in infants presenting with coughing or wheezing, as well as assessing disease severity.

Bronchiolitis presents as a viral upper respiratory prodrome followed by increased respiratory effort and wheezing in children younger than two years. Other signs include rhinorrhea; coughing; wheezing; tachypnea; and grunting, nasal flaring, and intercostal or subcostal retractions from increased respiratory effort. Physical examination findings may include increased respiratory rate, accessory muscle use or retraction, and auscultatory findings (e.g., wheezing, crackles). Radiography may be considered in hospitalized patients who do not improve at a usual rate or if another diagnosis is suspected.

Because the disease course is variable, any history of underlying conditions (e.g., prematurity, cardiac or pulmonary disease, immunodeficiency, prior wheezing) should be identified, and serial observation over time may be needed.

Management

BRONCHODILATORS

Routine use of bronchodilators is not recommended; however, bronchodilator therapy may be considered if there is a positive clinical response to an alpha- or beta-adrenergic medication during a carefully managed trial (B recommendation).

The use of bronchodilator therapy is controversial, and RCTs have not shown a consistent benefit from alpha- or beta-adrenergic agents in patients with bronchiolitis. Studies also have not shown that bronchodilators have a long-term impact on the disease course.

Although RCTs do not support the routine use of bronchodilators, the therapy may improve the clinical condition of some infants. Therefore, it may be reasonable to administer a trial of nebulized bronchodilator use in selected infants to evaluate clinical response using an objective measure. Studies suggest that epinephrine may be preferred for inpatients, whereas albuterol (Ventolin) may be preferred for outpatients. If the bronchodilator trial does not lead to documented clinical improvement, the treatment should be discontinued.

CORTICOSTEROIDS

Routine use of corticosteroids is not recommended (B recommendation).

Although up to 60 percent of infants hospitalized for bronchiolitis receive corticosteroid therapy, studies have not provided sufficient evidence to support the use of steroids for the disease. Inhaled corticosteroids have not been shown to be beneficial, and the safety of high doses in infants is unclear. Until further studies are completed, recommendations cannot be made regarding the use of leukotriene modifiers in the management of bronchiolitis.

ANTIVIRAL THERAPY

Routine use of ribavirin (Virazole) is not recommended (B recommendation).

Studies of ribavirin in patients with bronchiolitis have been inconsistent, and other antiviral therapies have been studied. Antiviral therapy for RSV bronchiolitis is controversial because of its marginal benefit, cumbersome delivery, potential risk to caregivers, and high cost. However, ribavirin may be considered in patients with severe RSV bronchiolitis or those at high risk of severe disease.

ANTIBACTERIAL THERAPY

Antibacterial medications should be used only if the child has specific indications of a coexistent bacterial infection; treatment of the bacterial infection should be the same as that in children without bronchiolitis (B recommendation).

Although many children with bronchiolitis receive antibacterial therapy because of concerns about secondary bacterial infection, RCTs have not shown the therapy to be beneficial in the treatment of bronchiolitis. Furthermore, studies have shown that serious bacterial infection rates in patients with bronchiolitis are low, and if present, urinary tract infections are more common than bacteremia or meningitis.

Bacterial acute otitis media cannot be differentiated from the viral form. Acute otitis media in infants with bronchiolitis should be treated according to AAP/AAFP guidelines.

CHEST PHYSIOTHERAPY

Hydration and ability to take fluids orally should be assessed (X recommendation); routine chest physiotherapy is not recommended (B recommendation).

An assessment of respiratory distress should guide decisions about respiratory treatments. Infants with mild respiratory distress may only need observation; however, infants whose respiratory distress causes difficulty with feeding should receive intravenous fluids. Fluids should be adjusted if fluid retention occurs.

Airway edema may occur in infants with bronchiolitis. Studies on chest physiotherapy to clear the airway in these patients showed no clinical benefit from vibration and percussion techniques. Suctioning may temporarily relieve symptoms, but no evidence supports routine “deep” suctioning.

OXYGEN SUPPLEMENTATION

Supplemental oxygen should be administered if functional oxygen saturation (SpO₂) persistently falls below 90 percent and can be discontinued when an adequate level returns (D recommendation). Routine measurement of SpO₂ levels are not recommended (D recommendation), although high-risk infants (i.e., premature infants and those with heart or lung disease) should be monitored closely as they are weaned from the oxygen (B recommendation).

Healthy infants have an oxyhemoglobin saturation above 95 percent when breathing room-temperature air. Bronchiolitis can cause these levels to decrease. Studies support a 90 percent oxyhemoglobin saturation cutoff for initiation of oxygen supplementation in otherwise healthy infants who are feeding well and have minimal respiratory distress. A lower cutoff may be considered in children with risk factors such as fever, acidosis, and some hemoglobinopathies. The patient's respiratory effort also may be considered when determining the need for oxygen supplementation.

High-risk infants who are more likely to develop severe disease have abnormal baseline oxygenation and an inability to cope with the pulmonary inflammation of bronchiolitis. These infants may have more severe and prolonged hypoxia compared with normal infants; therefore, special consideration is needed when using oxygen supplementation in high-risk infants.

COMPLEMENTARY AND ALTERNATIVE MEDICINE

Physicians should inquire about complementary and alternative therapies (D recommendation).

There are limited data on the effectiveness of complementary and alternative therapies for bronchiolitis; therefore, a recommendation cannot be made. However, an increasing number of patients are using these therapies (e.g., herbal remedies, osteopathic manipulation, applied kinesiology), and more research is underway. Because of the number of patients using these therapies, physicians should be prepared to discuss them.

Prevention

PALIVIZUMAB PROPHYLAXIS

Palivizumab (Synagis) may be considered in select infants and children with chronic lung disease of prematurity, prematurity, or congenital heart disease (A recommendation). If used, palivizumab should be administered intramuscularly in five monthly doses of 15 mg per kg, usually beginning in November or December (C recommendation).

Studies have shown that palivizumab prophylaxis decreased RSV-related hospitalization in infants and children with prematurity, chronic lung disease, or congenital heart disease. RSV outbreaks usually begin in November or December, peak in January or February, and end in March or April; therefore, prophylaxis is most effective if initiated in November.

Cost-effectiveness analyses have not shown an overall savings in health care costs with prophylaxis because the cost of treating all high-risk children would be high. Other factors to consider include the cost-effectiveness of prophylaxis in outpatients and whether preventing RSV infection in infancy decreases the risk of wheezing and respiratory problems later in life.

HAND DECONTAMINATION

Hand decontamination is the most important measure in preventing RSV infection; hands should be washed before and after direct contact with a patient, after contact with an inanimate object in the direct vicinity of the patient, and after removing gloves (B recommendation). Alcohol-based rubs are preferred for hand decontamination, although antimicrobial soap is an alternative (B recommendation). Physicians should educate their staff and the patient's family members about the importance of hand sanitation (C recommendation).

Because RSV and other viruses can be spread easily through hand contact, the Centers for Disease Control and Prevention released an extensive review on hand sanitation. Although the use of masks has not been shown to control the spread of RSV, proper hand decontamination, medical staff and family education, and the use of gloves and gowns are effective. Isolation techniques also are effective but may not be practical in some settings.

SMOKE EXPOSURE

Passive smoke exposure in infants should be avoided (B recommendation).

Studies have shown that parental smoking affects the respiratory health of infants and children. Children whose mothers smoked during and after pregnancy have a significant decrease in pulmonary function compared with children whose mothers did not smoke. Forced expiratory flow and other pulmonary functions also are affected by passive smoke exposure.

BREASTFEEDING

Infants should be breastfed to decrease the risk of lower respiratory tract disease (C recommendation).

Studies have shown that breast milk provides immunity and neutralizing factors against RSV, decreasing hospitalization related to RSV infection and other lower respiratory tract infections.

Future Research

Many common diagnosis and treatment modalities have not been proven effective for bronchiolitis. Future research should be clinically relevant to parents, physicians, and the health care system and include outcomes of hospitalization rates, need for intensive care services, health care costs, and parental satisfaction with treatment. Bronchiolitis is self-limited; therefore, studies should enroll a large number of patients so that meaningful conclusions can be made.