Diagnosis and Management of Bronchiolitis

This guideline examines the published evidence on diagnosis and acute management of the child with bronchiolitis in both outpatient and hospital settings, including the roles of supportive therapy, oxygen, bronchodilators, antiinflammatory agents, antibacterial agents, and antiviral agents and make recommendations to influence clinician behavior on the basis of the evidence. Methods of prevention are reviewed, as is the potential role of complementary and alternative medicine (CAM).

The goal of this guideline is to provide an evidence-based approach to the diagnosis, management, and prevention of bronchiolitis in children from 1 month to 2 years of age. The guideline is intended for pediatricians, family physicians, emergency medicine specialists, hospitalists, nurse practitioners, and physician assistants who care for these children. The guideline does not apply to children with immunodeficiencies including HIV, organ or bone marrow transplants, or congenital immunodeficiencies. Children with underlying respiratory illnesses such as chronic neonatal lung disease (CLD; also known as bronchopulmonary dysplasia) and those with significant congenital heart disease are excluded from the sections on management unless otherwise noted but are included in the discussion of prevention. This guideline will not address long-term sequelae of bronchiolitis, such as recurrent wheezing, which is a field with distinct literature of its own.

Bronchiolitis is a disorder most commonly caused in infants by viral lower respiratory tract infection (LRTI). It is the most common lower respiratory infection in this age group. It is characterized by acute inflammation, edema and necrosis of epithelial cells lining small airways, increased mucus production, and bronchospasm. Signs and symptoms are typically rhinitis, tachypnea, wheezing, cough, crackles, use of accessory muscles, and/or nasal flaring.¹  Many viruses cause the same constellation of symptoms and signs. The most common etiology is the respiratory syncytial virus (RSV), with the highest incidence of RSV infection occurring between December and March.²  Ninety percent of children are infected with RSV in the first 2 years of life,³  and up to 40% of them will have lower respiratory infection.^4,5  Infection with RSV does not grant permanent or long-term immunity. Reinfections are common and may be experienced throughout life.⁶  Other viruses identified as causing bronchiolitis are human metapneumovirus, influenza, adenovirus, and parainfluenza. RSV infection leads to more than 90000 hospitalizations annually. Mortality resulting from RSV has decreased from 4500 deaths annually in 1985 in the United States^2,6  to an estimated 510 RSV-associated deaths in 1997⁶  and 390 in 1999.⁷  The cost of hospitalization for bronchiolitis in children less than 1 year old is estimated to be more than $700 million per year.⁸ 

Several studies have shown a wide variation in how bronchiolitis is diagnosed and treated. Studies in the United States,⁹  Canada,¹⁰  and the Netherlands¹¹  showed variations that correlated more with hospital or individual preferences than with patient severity. In addition, length of hospitalization in some countries averages twice that of others.¹²  This variable pattern suggests a lack of consensus among clinicians as to best practices.

In addition to morbidity and mortality during the acute illness, infants hospitalized with bronchiolitis are more likely to have respiratory problems as older children, especially recurrent wheezing, compared with those who did not have severe disease.^13–15  Severe disease is characterized by persistently increased respiratory effort, apnea, or the need for intravenous hydration, supplemental oxygen, or mechanical ventilation. It is unclear whether severe viral illness early in life predisposes children to develop recurrent wheezing or if infants who experience severe bronchiolitis have an underlying predisposition to recurrent wheezing.

To develop the clinical practice guideline on the diagnosis and management of bronchiolitis, the American Academy of Pediatrics (AAP) convened the Subcommittee on Diagnosis and Management of Bronchiolitis with the support of the American Academy of Family Physicians (AAFP), the American Thoracic Society, the American College of Chest Physicians, and the European Respiratory Society. The subcommittee was chaired by a primary care pediatrician with expertise in clinical pulmonology and included experts in the fields of general pediatrics, pulmonology, infectious disease, emergency medicine, epidemiology, and medical informatics. All panel members reviewed the AAP Policy on Conflict of Interest and Voluntary Disclosure and were given an opportunity to declare any potential conflicts.

The AAP and AAFP partnered with the AHRQ and the RTI International-University of North Carolina Evidence-Based Practice Center (EPC) to develop an evidence report, which served as a major source of information for these practice guideline recommendations.¹  Specific clinical questions addressed in the AHRQ evidence report were the (1) effectiveness of diagnostic tools for diagnosing bronchiolitis in infants and children, (2) efficacy of pharmaceutical therapies for treatment of bronchiolitis, (3) role of prophylaxis in prevention of bronchiolitis, and (4) cost-effectiveness of prophylaxis for management of bronchiolitis. EPC project staff searched Medline, the Cochrane Collaboration, and the Health Economics Database. Additional articles were identified by review of reference lists of relevant articles and ongoing studies recommended by a technical expert advisory group. To answer the question on diagnosis, both prospective studies and randomized, controlled trials (RCTs) were used. For questions related to treatment and prophylaxis in the AHRQ report, only RCTs were considered. For the cost-effectiveness of prophylaxis, studies that used economic analysis were reviewed. For all studies, key inclusion criteria included outcomes that were both clinically relevant and able to be abstracted. Initially, 744 abstracts were identified for possible inclusion, of which 83 were retained for systematic review. Results of the literature review were presented in evidence tables and published in the final evidence report.¹ 

An additional literature search of Medline and the Cochrane Database of Systematic Reviews was performed in July 2004 by using search terms submitted by the members of the Subcommittee on the Diagnosis and Management of Bronchiolitis. The methodologic quality of the research was appraised by an epidemiologist before consideration by the subcommittee.

The evidence-based approach to guideline development requires that the evidence in support of a policy be identified, appraised, and summarized and that an explicit link between evidence and recommendations be defined. Evidence-based recommendations reflect the quality of evidence and the balance of benefit and harm that is anticipated when the recommendation is followed. The AAP policy statement “Classifying Recommendations for Clinical Practice Guidelines”¹⁶  was followed in designating levels of recommendation (Fig 1; Table 1).

A draft version of this clinical practice guideline underwent extensive peer review by committees and sections within the AAP, American Thoracic Society, European Respiratory Society, American College of Chest Physicians, and AAFP, outside organizations, and other individuals identified by the subcommittee as experts in the field. Members of the subcommittee were invited to distribute the draft to other representatives and committees within their specialty organizations. The resulting comments were reviewed by the subcommittee and, when appropriate, incorporated into the guideline.

This clinical practice guideline is not intended as a sole source of guidance in the management of children with bronchiolitis. Rather, it is intended to assist clinicians in decision-making. It is not intended to replace clinical judgment or establish a protocol for the care of all children with this condition. These recommendations may not provide the only appropriate approach to the management of children with bronchiolitis.

All AAP guidelines are reviewed every 5 years.

Definitions used in the guideline are:

• Bronchiolitis: a disorder most commonly caused in infants by viral LRTI; it is the most common lower respiratory infection in this age group and is characterized by acute inflammation, edema and necrosis of epithelial cells lining small airways, increased mucus production, and bronchospasm.

• CLD, also known as bronchopulmonary dysplasia: an infant less than 32 weeks' gestation evaluated at 36 weeks' postmenstrual age or one of more than 32 weeks' gestation evaluated at more than 28 days but less than 56 days of age who has been receiving supplemental oxygen for more than 28 days.¹⁷ 

• Routine: a set of customary and often-performed procedures such as might be found in a routine admission order set for children with bronchiolitis.

• Severe disease: signs and symptoms associated with poor feeding and respiratory distress characterized by tachypnea, nasal flaring, and hypoxemia.

• Hemodynamically significant congenital heart disease: children with congenital heart disease who are receiving medication to control congestive heart failure, have moderate to severe pulmonary hypertension, or have cyanotic heart disease.

Clinicians should diagnose bronchiolitis and assess disease severity on the basis of history and physical examination. Clinicians should not routinely order laboratory and radiologic studies for diagnosis (recommendation: evidence level B; diagnostic studies with minor limitations and observational studies with consistent findings; preponderance of benefits over harms and cost).

Clinicians should assess risk factors for severe disease such as age less than 12 weeks, a history of prematurity, underlying cardiopulmonary disease, or immunodeficiency when making decisions about evaluation and management of children with bronchiolitis (recommendation: evidence level B; observational studies with consistent findings; preponderance of benefits over harms).

The 2 goals in the history and physical examination of infants presenting with cough and/or wheeze, particularly in the winter season, are the differentiation of infants with probable bronchiolitis from those with other disorders and the estimation of the severity of illness. Most clinicians recognize bronchiolitis as a constellation of clinical symptoms and signs including a viral upper respiratory prodrome followed by increased respiratory effort and wheezing in children less than 2 years of age. Clinical signs and symptoms of bronchiolitis consist of rhinorrhea, cough, wheezing, tachypnea, and increased respiratory effort manifested as grunting, nasal flaring, and intercostal and/or subcostal retractions.

Respiratory rate in otherwise healthy children changes considerably over the first year of life, decreasing from a mean of approximately 50 breaths per minute in term newborns to approximately 40 breaths per minute at 6 months of age and 30 breaths per minute at 12 months.^18–20  Counting respiratory rate over the course of 1 minute may be more accurate than measurements extrapolated to 1 minute but observed for shorter periods.²¹  The absence of tachypnea correlates with the lack of LRTIs or pneumonia (viral or bacterial) in infants.^22,23 

The course of bronchiolitis is variable and dynamic, ranging from transient events such as apnea or mucus plugging to progressive respiratory distress from lower airway obstruction. Important issues to assess include the impact of respiratory symptoms on feeding and hydration and the response, if any, to therapy. The ability of the family to care for the child and return for further care should be assessed. History of underlying conditions such as prematurity, cardiac or pulmonary disease, immunodeficiency, or previous episodes of wheezing should be identified.

The physical examination reflects the variability in the disease state and may require serial observations over time to fully assess the child's status. Upper airway obstruction may contribute to work of breathing. Nasal suctioning and positioning of the child may affect the assessment. Physical examination findings of importance include respiratory rate, increased work of breathing as evidenced by accessory muscle use or retractions, and auscultatory findings such as wheezes or crackles.

The evidence relating the presence of specific findings in the assessment of bronchiolitis to clinical outcomes is limited. Most studies are retrospective and lack valid and unbiased measurement of baseline and outcome variables. Most studies designed to identify the risk of severe adverse outcomes such as requirement for intensive care or mechanical ventilation have focused on inpatients.^24–26  These events are relatively rare among all children with bronchiolitis and limit the power of these studies to detect clinically important risk factors associated with disease progression.

Several studies have associated premature birth (less than 37 weeks) and young age of the child (less than 6–12 weeks) with an increased risk of severe disease.^26–28  Young infants with bronchiolitis may develop apnea, which has been associated with an increased risk for prolonged hospitalization, admission to intensive care, and mechanical ventilation.²⁶  Other underlying conditions that have been associated with an increased risk of progression to severe disease or mortality include hemodynamically significant congenital heart disease,^26,29  chronic lung disease (bronchopulmonary dysplasia, cystic fibrosis, congenital anomaly),²⁶  and the presence of an immunocompromised state.^26,30 

Findings on physical examination have been less consistently associated with outcomes of bronchiolitis. Tachypnea, defined as a respiratory rate of 70 or more breaths per minute, has been associated with increased risk for severe disease in some studies^24,27,31  but not others.³²  An AHRQ report¹  found 43 of 52 treatment trials that used clinical scores, all of which included measures of respiratory rate, respiratory effort, severity of wheezing, and oxygenation. The lack of uniformity of scoring systems made comparison between studies difficult.¹  The most widely used clinical score, the Respiratory Distress Assessment Instrument,³³  is reliable with respect to scoring but has not been validated for clinical predictive value in bronchiolitis. None of the other clinical scores used in the various studies have been assessed for reliability and validity. Studies that have assessed other physical examination findings have not found clinically useful associations with outcomes.^27,32  The substantial temporal variability in physical findings as well as potential differences in response to therapy may account for this lack of association. Repeated observation over a period of time rather than a single examination may provide a more valid overall assessment.

Pulse oximetry has been rapidly adopted into clinical assessment of children with bronchiolitis on the basis of data suggesting that it can reliably detect hypoxemia that is not suspected on physical examination.^27,34  Few studies have assessed the effectiveness of pulse oximetry to predict clinical outcomes. Among inpatients, perceived need for supplemental oxygen that is based on pulse oximetry has been associated with higher risk of prolonged hospitalization, ICU admission, and mechanical ventilation.^24,26,35  Among outpatients, available evidence differs on whether mild reductions in pulse oximetry (less than 95% on room air) predict progression of disease or need for a return visit for care.^27,32 

Radiography may be useful when the hospitalized child does not improve at the expected rate, if the severity of disease requires further evaluation, or if another diagnosis is suspected. Although many infants with bronchiolitis have abnormalities that show on chest radiographs, data are insufficient to demonstrate that chest radiograph abnormalities correlate well with disease severity.¹⁶  Two studies suggest that the presence of consolidation and atelectasis on a chest radiograph is associated with increased risk for severe disease.^26,27  One study showed no correlation between chest radiograph findings and baseline severity of disease.³⁶  In prospective studies including 1 randomized trial, children with suspected LRTI who received radiographs were more likely to receive antibiotics without any difference in time to recovery.^37,38  Current evidence does not support routine radiography in children with bronchiolitis.

The clinical utility of diagnostic testing in infants with suspected bronchiolitis is not well supported by evidence.^39–41  The occurrence of serious bacterial infections (SBIs; eg, urinary tract infections [UTIs], sepsis, meningitis) is very low.^42,43  The use of complete blood counts has not been shown to be useful in either diagnosing bronchiolitis or guiding its therapy.¹ 

Virologic tests for RSV, if obtained during peak RSV season, demonstrate a high predictive value. However, the knowledge gained from such testing rarely alters management decisions or outcomes for the vast majority of children with clinically diagnosed bronchiolitis.¹  Virologic testing may be useful when cohorting of patients is feasible.

• Aggregate evidence quality: B; diagnostic studies with minor limitations and observational studies with consistent findings

• Benefit: cost saving, limitation of radiation and blood tests

• Harm: risk of misdiagnosis

• Benefits-harms assessment: preponderance of benefit over harm

• Policy level: recommendation

• Aggregate evidence quality: B; observational studies with consistent findings

• Benefit: improved care of patients with risk factors for severe disease

• Harm: increased costs, increased radiation and blood testing

• Benefits-harms assessment: preponderance of benefit over harm

• Policy level: recommendation

Bronchodilators should not be used routinely in the management of bronchiolitis (recommendation: evidence level B; RCTs with limitations; preponderance of harm of use over benefit).

A carefully monitored trial of α-adrenergic or β-adrenergic medication is an option. Inhaled bronchodilators should be continued only if there is a documented positive clinical response to the trial using an objective means of evaluation (option: evidence level B; RCTs with limitations and expert opinion; balance of benefit and harm).

The use of bronchodilator agents continues to be controversial. RCTs have failed to demonstrate a consistent benefit from α-adrenergic or β-adrenergic agents. Several studies and reviews have evaluated the use of bronchodilator medications for viral bronchiolitis. A Cochrane systematic review⁴⁴  found 8 RCTs involving 394 children.^33,45–50  Some of the studies included infants who had a history of previous wheezing. Several used agents other than albuterol/salbutamol or epinephrine/adrenaline (eg, ipratropium and metaproterenol). Overall, results of the meta-analysis indicated that, at most, 1 in 4 children treated with bronchodilators might have a transient improvement in clinical score of unclear clinical significance. This needs to be weighed against the potential adverse effects and cost of these agents and the fact that most children treated with bronchodilators will not benefit from their use. Studies assessing the impact of bronchodilators on long-term outcomes have found no impact on the overall course of the illness.^1,44,51 

Some outpatient studies have demonstrated modest improvement in oxygen saturation and/or clinical scores. Schweich et al⁵²  and Schuh et al⁵³  evaluated clinical scores and oxygen saturation after 2 treatments of nebulized albuterol. Each study showed improvement in the clinical score and oxygen saturation shortly after completion of the treatment. Neither measured outcomes over time. Klassen et al⁴⁷  evaluated clinical score and oxygen saturation 30 and 60 minutes after a single salbutamol treatment. Clinical score, but not oxygen saturation, was significantly improved at 30 minutes, but no difference was demonstrated 60 minutes after a treatment. Gadomski et al⁵⁴  showed no difference between those in groups on albuterol or placebo after 2 nebulized treatments given 30 minutes apart.

Studies of inpatients have not shown a clinical change that would justify recommending albuterol for routine care. Dobson et al⁵⁵  conducted a randomized clinical trial in infants who were hospitalized with moderately severe viral bronchiolitis and failed to demonstrate clinical improvement resulting in enhanced recovery or an attenuation of the severity of illness. Two meta-analyses^1,56  could not directly compare inpatient studies of albuterol because of widely differing methodology. Overall, the studies reviewed did not show the use of albuterol in infants with bronchiolitis to be beneficial in shortening duration of illness or length of hospital stay.

The AHRQ evidence report¹  notes that the reviewed studies show that nebulized epinephrine has “some potential for being efficacious.” In contrast, a later multicenter controlled trial by Wainwright et al⁵¹  concluded that epinephrine did not impact the overall course of the illness as measured by hospital length of stay. Analysis of outpatient studies favors nebulized epinephrine over placebo in terms of clinical score, oxygen saturation, and respiratory rate at 60 minutes⁵⁷  and heart rate at 90 minutes.⁵⁸  However, the differences were small, and it could not be established that they are clinically significant in altering the course of the illness. One study⁵⁹  found significant improvement in airway resistance (but no change in oxygen need), suggesting that a trial of this agent may be reasonable for such infants.

Several studies have compared epinephrine to albuterol (salbutamol) or epinephrine to placebo. Racemic epinephrine has demonstrated slightly better clinical effect than albuterol. It is possible that the improvement is related to the α effect of the medication.⁶⁰  Hartling et al⁶¹  performed a meta-analysis of studies comparing epinephrine to albuterol and also participated in the Cochrane review of epinephrine.⁶²  The Cochrane report concluded: “There is insufficient evidence to support the use of epinephrine for the treatment of bronchiolitis among inpatients. There is some evidence to suggest that epinephrine may be favorable to salbutamol (albuterol) and placebo among outpatients.”

Although there is no evidence from RCTs to justify routine use of bronchodilators, clinical experience suggests that, in selected infants, there is an improvement in the clinical condition after bronchodilator administration.^{47,52,53,57,58}  It may be reasonable to administer a nebulized bronchodilator and evaluate clinical response. Individuals and institutions should assess the patient and document pretherapy and posttherapy changes using an objective means of evaluation. Some of the documentation tools that have been used can be found in articles by Alario et al,⁴⁵  Bierman and Pierson,⁶³  Gadomski et al,⁵⁴  Lowell et al,³³  Wainwright et al,⁵¹  Schuh et al,⁶⁴  and Gorelick et al.⁶⁵  In addition, a documentation tool has been developed by Cincinnati Children's Hospital (Cincinnati, OH).⁶⁶ 

Extrapolation from the studies discussed above suggests that epinephrine may be the preferred bronchodilator for this trial in the emergency department and in hospitalized patients. In the event that there is documented clinical improvement, there is justification for continuing the nebulized bronchodilator treatments. In the absence of a clinical response, the treatment should not be continued.

Because of a lack of studies, short duration of action, and potential adverse effects, epinephrine is usually not used in the home setting. Therefore, it would be more appropriate that a bronchodilator trial in the office or clinic setting use albuterol/salbutamol rather than racemic epinephrine. Parameters to measure its effectiveness include improvements in wheezing, respiratory rate, respiratory effort, and oxygen saturation.

Anticholinergic agents such as ipratropium have not been shown to alter the course of viral bronchiolitis. Although a minority of individual patients may show a positive clinical response to anticholinergic agents, studies have shown that the groups as a whole showed no significant improvement. At this point there is no justification for using anticholinergic agents, either alone or in combination with β-adrenergic agents, for viral bronchiolitis.^67–69 

• Aggregate evidence quality: B; RCTs with limitations

• Benefit: short-term improvement in clinical symptoms

• Harm: adverse effects, cost of medications, cost to administer

• Benefits-harms assessment: preponderance of harm over benefit

• Policy level: recommendation

• Aggregate evidence quality: B; RCTs with limitations

• Benefit: some patients with significant symptomatic improvement

• Harm: adverse effects, cost of medications, cost to administer

• Benefits-harms assessment: preponderance of benefit over harm in select patients

• Policy level: option

Corticosteroid medications should not be used routinely in the management of bronchiolitis (recommendation: evidence level B; based on RCTs with limitations and a preponderance of risk over benefit).

Reports indicate that up to 60% of infants admitted to the hospital for bronchiolitis receive corticosteroid therapy.^9,12,70  Systematic review and meta-analyses of RCTs involving close to 1200 children with viral bronchiolitis have not shown sufficient evidence to support the use of steroids in this illness.^1,71,72 

A Cochrane database review on the use of glucocorticoids for acute bronchiolitis⁷¹  included 13 studies.^{37,50,64,73–82}  The 1198 patients showed a pooled decrease in length of stay of 0.38 days. However, this decrease was not statistically significant. The review concluded: “No benefits were found in either LOS [length of stay] or clinical score in infants and young children treated with systemic glucocorticoids as compared with placebo. There were no differences in these outcomes between treatment groups; either in the pooled analysis or in any of the sub analyses. Among the three studies evaluating hospital admission rates following the initial hospital visit there was no difference between treatment groups. There were no differences found in respiratory rate, hemoglobin oxygen saturation, or hospital revisit or readmission rates. Subgroup analyses were significantly limited by the low number of studies in each comparison. Specific data on the harm of corticosteroid therapy in this patient population are lacking. Available evidence suggests that corticosteroid therapy is not of benefit in this patient group.”⁷¹ 

The 2 available studies that evaluated inhaled corticosteroids in bronchiolitis^83,84  showed no benefit in the course of the acute disease. Because the safety of high-dose inhaled corticosteroids in infants is still not clear, their use should be avoided unless there is a clear likelihood of benefit.

There are insufficient data to make a recommendation regarding the use of leukotriene modifiers in bronchiolitis. Until additional randomized clinical trials are completed, no conclusions can be drawn.

• Aggregate evidence quality: B; randomized clinical trials with limitations

• Benefit: possibility that corticosteroid may be of some benefit

• Harm: exposure to unnecessary medication

• Benefits-harms assessment: preponderance of harm over benefit

• Policy level: recommendation

Ribavirin should not be used routinely in children with bronchiolitis (recommendation: evidence level B; RCTs with limitations and observational studies; preponderance of harm over benefit).

The indications for specific antiviral therapy for bronchiolitis are controversial. A recent review of 11 randomized clinical trials of ribavirin therapy for RSV LRTIs, including bronchiolitis, summarized the reported outcomes.⁸⁵  Nine of the studies measured the effect of ribavirin in the acute phase of illness.^86–94  Two evaluated the effect on long-term wheezing and/or pulmonary function.^95,96  Three additional studies were identified with similar results. Two of these evaluated effectiveness in the acute phase^97,98  and one on subsequent respiratory status.⁹⁹ 

Each of the 11 studies that addressed the acute treatment effects of ribavirin included a small sample size ranging from 26 to 53 patients and cumulatively totaling 375 subjects. Study designs and outcomes measured were varied and inconsistent. Seven of the trials demonstrated some improvement in outcome attributed to ribavirin therapy, and 4 did not. Of those showing benefit, 4 documented improved objective outcomes (eg, better oxygenation, shorter length of stay), and 3 reported improvement in subjective findings such as respiratory scores or subjective clinical assessment. The quality of the studies was highly variable.

Of the studies that focused on long-term pulmonary function, one was an RCT assessing the number of subsequent wheezing episodes and LRTIs over a 1-year period.⁹⁶  Two others were follow-up studies of previous randomized trials and measured subsequent pulmonary function as well as wheezing episodes.^95,99  The first study⁹⁶  found fewer episodes of wheezing and infections in the ribavirin-treated patients, and the latter 2 studies^95,99  found no significant differences between groups. No randomized studies of other antiviral therapies of bronchiolitis were identified.

Specific antiviral therapy for RSV bronchiolitis remains controversial because of the marginal benefit, if any, for most patients. In addition, cumbersome delivery requirements,¹⁰⁰  potential health risks for caregivers,¹⁰¹  and high cost¹⁰²  serve as disincentives for use in the majority of patients. Nevertheless, ribavirin may be considered for use in highly selected situations involving documented RSV bronchiolitis with severe disease or in those who are at risk for severe disease (eg, immunocompromised and/or hemodynamically significant cardiopulmonary disease).

• Aggregate evidence quality: B; RCTs with limitations and observational studies

• Benefit: some improvement in outcome

• Harm: cost, delivery method, potential health risks to caregivers

• Benefits-harms assessment: preponderance of harm over benefit

• Policy level: recommendation

Antibacterial medications should be used only in children with bronchiolitis who have specific indications of the coexistence of a bacterial infection. When present, bacterial infection should be treated in the same manner as in the absence of bronchiolitis (recommendation: evidence level B; RCTs and observational studies; preponderance of benefit over harm).

Children with bronchiolitis frequently receive antibacterial therapy because of fever,¹⁰³  young age,¹⁰⁴  or the concern over secondary bacterial infection.¹⁰⁵  Early RCTs^106,107  showed no benefit from antibacterial treatment of bronchiolitis. However, concern remains regarding the possibility of bacterial infections in young infants with bronchiolitis; thus, antibacterial agents continue to be used.

Several retrospective studies^41,108–113  identified low rates of SBI (0%–3.7%) in patients with bronchiolitis and/or infections with RSV. When SBI was present, it was more likely to be a UTI than bacteremia or meningitis. In a study of 2396 infants with RSV bronchiolitis, 69% of the 39 patients with SBI had a UTI.¹¹⁰ 

Three prospective studies of SBI in patients with bronchiolitis and/or RSV infections also demonstrated low rates of SBI (1%–12%).^42,43,114  One large study of febrile infants less than 60 days of age⁴³  with bronchiolitis and/or RSV infections demonstrated that the overall risk of SBI in infants less than 28 days of age, although significant, was not different between RSV-positive and RSV-negative groups (10.1% and 14.2%, respectively). All SBIs in children between 29 and 60 days of age with RSV-positive bronchiolitis were UTIs. The rate of UTIs in RSV-positive patients between 28 and 60 days old was significantly lower than those who were RSV-negative (5.5% vs 11.7%).

Approximately 25% of hospitalized infants with bronchiolitis will have radiographic evidence of atelectasis or infiltrates, often misinterpreted as possible bacterial infection.¹¹⁵  Bacterial pneumonia in infants with bronchiolitis without consolidation is unusual.¹¹⁶ 

Although acute otitis media (AOM) in bronchiolitic infants may be caused by RSV alone, there are no clinical features that permit viral AOM to be differentiated from bacterial. Two studies address the frequency of AOM in patients with bronchiolitis. Andrade et al¹¹⁷  prospectively identified AOM in 62% of 42 patients who presented with bronchiolitis. AOM was present in 50% on entry to the study and developed in an additional 12% within 10 days. Bacterial pathogens were isolated from 94% of middle-ear aspirates, with Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis being the most frequent isolates. A subsequent report¹¹⁸  followed 150 children hospitalized for bronchiolitis for the development of AOM. Seventy-nine (53%) developed AOM, two thirds within the first 2 days of hospitalization. Tympanocentesis was performed on 64 children with AOM, and 33 middle-ear aspirates yielded pathogens. H influenzae, S pneumoniae, and M catarrhalis were the ones most commonly found. AOM did not influence the clinical course or laboratory findings of bronchiolitis. When found, AOM should be managed according to the AAP/AAFP guidelines for diagnosis and management of AOM.¹¹⁹ 

• Aggregate evidence quality: B; RCTs and observational studies with consistent results

• Benefit: appropriate treatment of bacterial infections, decreased exposure to unnecessary medications and their adverse effects when a bacterial infection is not present, decreased risk of development of resistant bacteria

• Harm: potential to not treat patient with bacterial infection

• Benefits-harms assessment: preponderance of benefit over harm

• Policy level: recommendation

Clinicians should assess hydration and ability to take fluids orally (strong recommendation: evidence level X; validating studies cannot be performed; clear preponderance of benefit over harm).

Chest physiotherapy should not be used routinely in the management of bronchiolitis (recommendation: evidence level B; RCTs with limitations; preponderance of harm over benefit).

The level of respiratory distress caused by bronchiolitis guides the indications for use of other treatments.

Infants with mild respiratory distress may require only observation, particularly if feeding remains unaffected. When the respiratory rate exceeds 60 to 70 breaths per minute, feeding may be compromised, particularly if nasal secretions are copious. Infants with respiratory difficulty may develop nasal flaring, increased intercostal or sternal retractions, and prolonged expiratory wheezing and be at increased risk of aspiration of food into the lungs.¹²⁰  Children who have difficulty feeding safely because of respiratory distress should be given intravenous fluids. The possibility of fluid retention related to production of antidiuretic hormone has been reported in patients with bronchiolitis.^121,122  Clinicians should adjust fluid management accordingly.

Bronchiolitis is associated with airway edema and sloughing of the respiratory epithelium into airways, which results in generalized hyperinflation of the lungs. Lobar atelectasis is not characteristic of this disease, although it can be seen on occasion. A Cochrane review¹²³  found 3 RCTs that evaluated chest physiotherapy in hospitalized patients with bronchiolitis.^124–126  No clinical benefit was found using vibration and percussion techniques. Suctioning of the nares may provide temporary relief of nasal congestion. There is no evidence to support routine “deep” suctioning of the lower pharynx or larynx.

• Aggregate evidence quality: evidence level X; validating studies cannot be performed

• Benefit: prevention of dehydration

• Harm: overhydration, especially if syndrome of inappropriate secretion of antidiuretic hormone (SIADH) is present

• Benefits-harms assessment: clear preponderance of benefit over harm

• Policy level: strong recommendation

• Aggregate evidence quality: B; RCTs with limitations

• Benefit: clearance of secretions, prevention of atelectasis

• Harm: stress to infant during procedure, cost of administering chest physiotherapy

• Benefits-harms assessment: preponderance of harm over benefit

• Policy level: recommendation

Supplemental oxygen is indicated if oxyhemoglobin saturation (Spo₂) falls persistently below 90% in previously healthy infants. If the Spo₂ does persistently fall below 90%, adequate supplemental oxygen should be used to maintain Spo₂ at or above 90%. Oxygen may be discontinued if Spo₂ is at or above 90% and the infant is feeding well and has minimal respiratory distress (option: evidence level D; expert opinion and reasoning from first principles; some benefit over harm).

As the child's clinical course improves, continuous measurement of Spo₂ is not routinely needed (option: evidence level D; expert opinion; balance of benefit and harm).

Infants with a known history of hemodynamically significant heart or lung disease and premature infants require close monitoring as the oxygen is being weaned (strong recommendation: evidence level B; observational studies with consistent findings; preponderance of benefit over harm).

Healthy infants have an Spo₂ greater than 95% on room air, although transient decreases to an Spo₂ of less than 89% occur.^127,128  In bronchiolitis, airway edema and sloughing of respiratory epithelial cells cause mismatching of ventilation and perfusion and subsequent reductions in oxygenation (Pao₂ and Spo₂).

In the clinical setting, pulse oximeters are convenient, safe tools to measure oxygenation status. Clinicians ordering pulse oximetry should understand that the shape of the oxyhemoglobin dissociation curve dictates that when Spo₂ is above 90%, large increases in Pao₂ are associated with small increases in Spo₂. In contrast, when Spo₂ is below 90%, a small decrease in Pao₂ is associated with large decreases in Spo₂ (Fig 2). This raises the question of whether there is a single value for Spo₂ that can serve as a decision point to hospitalize or initiate supplemental oxygen in infants with bronchiolitis.

In studies that examined treatment for bronchiolitis in hospitalized infants, some investigators started supplemental oxygen when Spo₂ fell below 90%, and others started oxygen before the Spo₂ reached 90%.^98,129 

Although data are lacking to codify a single value of Spo₂ to be used as a cutoff point for initiating or discontinuing supplemental oxygen, these studies and the relationship between Pao₂ and Spo₂ support the position that otherwise healthy infants with bronchiolitis who have Spo₂ at or above 90% at sea level while breathing room air likely gain little benefit from increasing Pao₂ with supplemental oxygen, particularly in the absence of respiratory distress and feeding difficulties. Because several factors including fever, acidosis, and some hemoglobinopathies shift the oxyhemoglobin dissociation curve so that large decreases in Pao₂ begin to occur at an Spo₂ of more than 90%, clinicians should consider maintaining a higher Spo₂ in children with these risk factors.^130,131 

Although widely used pulse oximeters have some shortcomings, under normal circumstances the accuracy of Spo₂ may vary slightly (most oximeters are accurate to ±2%). More importantly, poorly placed probes and motion artifact will lead to inaccurate measurements and false readings and alarms.¹³²  Before instituting O₂ therapy, the accuracy of the initial reading should be verified by repositioning the probe and repeating the measurement. The infant's nose and, if necessary, oral airway should be suctioned. If Spo₂ remains below 90%, O₂ should be administered. The infant's clinical work of breathing should also be assessed and may be considered as a factor in a decision to use oxygen supplementation.

Premature or low birth weight infants and infants with bronchopulmonary dysplasia or hemodynamically significant congenital heart disease merit special attention because they are at risk to develop severe illness that requires hospitalization, often in the ICU.^{7,29,133–135}  These infants often have abnormal baseline oxygenation coupled with an inability to cope with the pulmonary inflammation seen in bronchiolitis. This can result in more severe and prolonged hypoxia compared with normal infants, and clinicians should take this into account when developing strategies for using and weaning supplemental oxygen.

• Aggregate evidence quality: D; expert opinion and reasoning from first principles

• Benefit: use of supplemental oxygen only when beneficial, shorter hospitalization

• Harm: inadequate oxygenation

• Benefits-harms assessment: some benefit over harm

• Policy level: option

• Aggregate evidence quality: D; expert opinion

• Benefit: shorter hospitalization

• Harm: inadequate oxygenation between measurements

• Benefits-harms assessment: some benefit over harm

• Policy level: option

• Aggregate evidence quality: B; observational studies with consistent findings

• Benefit: improved care of high-risk infants

• Harm: longer hospitalization, use of oxygen when not beneficial

• Benefits-harms assessment: preponderance of benefit over harm

• Policy level: Strong recommendation

Clinicians may administer palivizumab prophylaxis to selected infants and children with CLD or a history of prematurity (less than 35 weeks' gestation) or with congenital heart disease (recommendation: evidence level A; RCT; preponderance of benefit over harm).

When given, prophylaxis with palivizumab should be given in 5 monthly doses, usually beginning in November or December, at a dose of 15 mg/kg per dose administered intramuscularly (recommendation: evidence level C; observational studies and expert opinion; preponderance of benefit over cost).

The 2006 Report of the Committee on Infectious Disease (Red Book) included the following recommendations for the use of palivizumab¹³⁶ :

• Palivizumab prophylaxis should be considered for infants and children younger than 24 months of age with chronic lung disease of prematurity who have required medical therapy (supplemental oxygen, bronchodilator or diuretic or corticosteroid therapy) for CLD within 6 months before the start of the RSV season. Patients with more severe CLD who continue to require medical therapy may benefit from prophylaxis during a second RSV season. Data are limited regarding the effectiveness of palivizumab during the second year of life. Individual patients may benefit from decisions made in consultation with neonatologists, pediatric intensivists, pulmonologists, or infectious disease specialists.

• Infants born at 32 weeks of gestation or earlier may benefit from RSV prophylaxis, even if they do not have CLD. For these infants, major risk factors to consider include their gestational age and chronologic age at the start of the RSV season. Infants born at 28 weeks of gestation or earlier may benefit from prophylaxis during their first RSV season, whenever that occurs during the first 12 months of life. Infants born at 29 to 32 weeks of gestation may benefit most from prophylaxis up to 6 months of age. For the purpose of this recommendation, 32 weeks’ gestation refers to an infant born on or before the 32nd week of gestation (ie, 32 weeks, 0 days). Once a child qualifies for initiation of prophylaxis at the start of the RSV season, administration should continue throughout the season and not stop at the point an infant reaches either 6 months or 12 months of age.

• Although palivizumab has been shown to decrease the likelihood of hospitalization in infants born between 32 and 35 weeks of gestation (ie, between 32 weeks, 1 day and 35 weeks, 0 days), the cost of administering prophylaxis to this large group of infants must be considered carefully. Therefore, most experts recommend that prophylaxis should be reserved for infants in this group who are at greatest risk of severe infection and who are younger than 6 months of age at the start of the RSV season. Epidemiologic data suggest that RSV infection is more likely to lead to hospitalization for these infants when the following risk factor are present: child care attendance, school-aged siblings, exposure to environmental air pollutants, congenital abnormalities of the airways, or severe neuromuscular disease. However, no single risk factor causes a very large increase in the rate of hospitalization, and the risk is additive as the number of risk factors for an individual infant increases. Therefore, prophylaxis should be considered for infants between 32 and 35 weeks of gestation only if 2 or more of these risk factors are present. Passive household exposure to tobacco smoke has not been associated with an increased risk of RSV hospitalization on a consistent basis. Furthermore, exposure to tobacco smoke is a risk factor that can be controlled by the family of an infant at increased risk of severe RSV disease, and preventive measures will be far less costly than palivizumab prophylaxis. High-risk infants never should be exposed to tobacco smoke. In contrast to the well-documented beneficial effect of breastfeeding against many viral illnesses, existing data are conflicting regarding the specific protective effect of breastfeeding against RSV infection. High-risk infants should be kept away from crowds and from situations in which exposure to infected individuals cannot be controlled. Participation in group child care should be restricted during the RSV season for high-risk infants whenever feasible. Parents should be instructed on the importance of careful hand hygiene. In addition, all high-risk infants and their contacts should be immunized against influenza beginning at 6 months of age.

• In the Northern hemisphere and particularly within the United States, RSV circulates predominantly between November and March. The inevitability of the RSV season is predictable, but the severity of the season, the time of onset, the peak of activity, and the end of the season cannot be predicted precisely. There can be substantial variation in timing of community outbreaks of RSV disease from year to year in the same community and between communities in the same year, even in the same region. These variations, however, occur within the overall pattern of RSV outbreaks, usually beginning in November or December, peaking in January or February, and ending by the end of March or sometime in April. Communities in the southern United States tend to experience the earliest onset of RSV activity, and Midwestern states tend to experience the latest. The duration of the season for western and northeast regions typically occurs between that noted in the South and the Midwest. In recent years, the national median duration of the RSV season has been 15 weeks and even in the South, with a seasonal duration of 16 weeks, the range is 13 to 20 weeks. Results from clinical trials indicate that palivizumab trough serum concentrations >30 days after the fifth dose will be well above the protective concentration for most infants. If the first dose is administered in November, 5 monthly doses of palivizumab will provide substantially more than 20 weeks of protective serum antibody concentrations for most of the RSV season, even with variation in season onset and end. Changes from this recommendation of 5 monthly doses require careful consideration of the benefits and costs.

• Children who are 24 months of age or younger with hemodynamically significant cyanotic and acyanotic congenital heart disease will benefit from palivizumab prophylaxis. Decisions regarding prophylaxis with palivizumab in children with congenital heart disease should be made on the basis of the degree of physiologic cardiovascular compromise. Children younger than 24 months of age with congenital heart disease who are most likely to benefit from immunoprophylaxis include: • Infants who are receiving medication to control congestive heart failure• Infants with moderate to severe pulmonary hypertension• Infants with cyanotic heart disease

Results from 2 blinded, randomized, placebo-controlled trials with palivizumab involving 2789 infants and children with prematurity, CLD, or congenital heart disease demonstrated a reduction in RSV hospitalization rates of 39% to 78% in different groups.^137,138  Results from postlicensure observational studies suggest that monthly immunoprophylaxis may reduce hospitalization rates to an even greater extent than that described in the prelicensure clinical trials.¹³⁹  Palivizumab is not effective in the treatment of RSV disease and is not approved for this indication.

Several economic analyses of RSV immunoprophylaxis have been published.^140–147  The primary benefit of immunoprophylaxis with palivizumab is a decrease in the rate of RSV-associated hospitalization. None of the 5 clinical RCTs have demonstrated a significant decrease in rate of mortality attributable to RSV infection in infants who receive prophylaxis. Most of the economic analyses fail to demonstrate overall savings in health care dollars because of the high cost if all at-risk children were to receive prophylaxis. Estimates of cost per hospitalization prevented have been inconsistent because of considerable variation in the baseline rate of hospitalization attributable to RSV in different high-risk groups. Other considerations that will influence results include the effect of prophylaxis on outpatient costs and a resolution of the question of whether prevention of RSV infection in infancy decreases wheezing and lower respiratory tract problems later in childhood.

• Aggregate evidence quality: A; RCTs

• Benefit: prevention of morbidity and mortality in high-risk infants

• Harm: cost

• Benefits-harms assessment: preponderance of benefit over harm

• Policy level: recommendation

• Aggregate evidence quality: C; observational studies and expert opinion

• Benefit: decreased cost resulting from using minimal number of needed doses

• Harm: risk of illness from RSV outside the usual season

• Benefits-harms assessment: preponderance of benefit over harm

• Policy level: recommendation

Hand decontamination is the most important step in preventing nosocomial spread of RSV. Hands should be decontaminated before and after direct contact with patients, after contact with inanimate objects in the direct vicinity of the patient, and after removing gloves (strong recommendation: evidence level B; observational studies with consistent results; strong preponderance of benefit over harm).

Alcohol-based rubs are preferred for hand decontamination. An alternative is hand-washing with antimicrobial soap (recommendation: evidence level B; observational studies with consistent results; preponderance of benefit over harm).

Clinicians should educate personnel and family members on hand sanitation (recommendation: evidence level C; observational studies; preponderance of benefit over harm).

Efforts should be made to decrease the spread of RSV and other causative agents of bronchiolitis in medical settings, especially in the hospital. RSV RNA has been identified in air samples as much as 22 feet from the patient's bedside.¹⁴⁸  Secretions from infected patients can be found on beds, crib railings, tabletops, and toys. Organisms on fomites may remain viable and contagious for several hours.¹⁴⁹ 

It has been shown that RSV as well as many other viruses can be carried and spread to others on the hands of caregivers.¹⁵⁰  Frequent hand-washing by health care workers has been shown to reduce RSV's nosocomial spread.¹⁵⁰  The Centers for Disease Control and Prevention published an extensive review of the hand-hygiene literature and made recommendations as to indications for hand-washing and hand antisepsis.¹⁵¹  Among the recommendations are that hands should be decontaminated before and after direct contact with patients, after contact with inanimate objects in the direct vicinity of the patient, and after removing gloves. If hands are not visibly soiled, an alcohol-based rub is preferred. An alternative is to wash hands with an antimicrobial soap. The guideline also describes the appropriate technique for using these products.

Other methods that have been shown to be effective in controlling the spread of RSV are education of personnel and family members; surveillance for the onset of RSV season; use of gloves, with frequent changes to avoid the spread of organisms on the gloves; and wearing gowns for direct contact with the patient. It has not been clearly shown that wearing masks offers additional benefit to the above-listed measures.¹⁴⁹  Isolation and/or cohorting of RSV-positive patients, including assignment of personnel to care only for these patients, is effective^152,153  but may not be feasible. Strict hand decontamination and education of staff and families about prevention of spread of organisms is essential regardless of whether isolation is used.

Programs that implement the above-mentioned principles have been shown to decrease the nosocomial spread of RSV. Johns Hopkins Hospital (Baltimore, MD) instituted a program of pediatric droplet precaution for all children less than 2 years old with respiratory symptoms during RSV season until the child is shown to not have RSV. Nosocomial transmission of RSV decreased by approximately 50%. Before intervention, a patient was 2.6 times more likely to have nosocomially transmitted RSV than after the intervention.¹⁵⁴  A similar program at Children's Hospital of Philadelphia (Philadelphia, PA) resulted in a decrease of nosocomial RSV infections of 39%.¹⁵⁵ 

• Aggregate evidence quality: B; observational studies with consistent findings

• Benefit: decreased spread of infection

• Harm: time

• Benefits-harms assessment: strong preponderance of benefit over harm

• Policy level: strong recommendation

• Aggregate evidence quality: B; observational studies with consistent findings

• Benefit: decreased spread of infection

• Harm: irritative effect of alcohol-based rubs

• Benefits-harms assessment: preponderance of benefit over harm

• Policy level: recommendation

• Aggregate evidence quality: C; observational studies

• Benefit: decreased spread of infection

• Harm: time, cost of gloves and gowns if used, barriers to parental contact with patient

• Benefits-harms assessment: preponderance of benefit over harm

• Policy level: recommendation

Infants should not be exposed to passive smoking (strong recommendation: evidence level B; observational studies with consistent results; strong preponderance of benefit over harm).

Breastfeeding is recommended to decrease a child's risk of having lower respiratory tract disease (LRTD) (recommendation: evidence level C; observational studies; preponderance of benefit over harm).

Passive smoking increases the risk of having an RSV infection with a reported odds ratio of 3.87.¹⁵⁶  There have been numerous studies on the effect of passive smoking on respiratory illness in infants and children. In a systematic review of passive smoking and lower respiratory illness in infants and children, Strachan and Cook¹⁵⁷  showed a pooled odds ratio of 1.57 if either parent smoked and an odds ratio of 1.72 if the mother smoked. Stocks and Dezateux¹⁵⁸  reviewed 20 studies of pulmonary function in infants. These studies showed a significant decrease in pulmonary function in infants of mothers who smoked during and after pregnancy. Forced expiratory flow was decreased by approximately 20%. Other measures of pulmonary function were likewise abnormal.

Paternal smoking also has an effect. The prevalence of upper respiratory tract illness increased from 81.6% to 95.2% in infants under 1 year of age in households where only the father smoked.¹⁵⁹ 

Breast milk has been shown to have immune factors to RSV including immunoglobulin G and A antibodies¹⁶⁰  and interferon-α.¹⁶¹  Breast milk has also been shown to have neutralizing activity against RSV.¹⁶²  In one study the relative risk of hospital admission with RSV was 2.2 in children who were not being breastfed.¹⁶³  In another study, 8 (7%) of 115 children hospitalized with RSV were breastfed, and 46 (27%) of 167 controls were breastfed.¹⁶⁴ 

A meta-analysis of the relationship of breastfeeding and hospitalization for LRTD in early infancy¹⁶⁵  examined 33 studies, all of which showed a protective association between breastfeeding and the risk of hospitalization for LRTD. Nine studies met all inclusion criteria for analysis. The conclusion was that infants who were not breastfed had almost a threefold greater risk of being hospitalized for LRTD than those exclusively breastfed for 4 months (risk ratio: 0.28).

• Aggregate evidence quality: B; observational studies with consistent findings

• Benefit: decreased risk of LRTI

• Harm: none

• Benefits-harms assessment: strong preponderance of benefit over harm

• Policy level: strong recommendation

• Aggregate evidence quality: C; observational studies

• Benefit: improved immunity, decreased risk of LRTI, improved nutrition

• Harm: implied inadequacy of mothers who cannot or prefer to not breastfeed

• Benefits-harms assessment: preponderance of benefit over harm

• Policy level: recommendation

Clinicians should inquire about use of CAM (option: evidence level D; expert opinion; some benefit over harm).

No recommendations for CAM for treatment of bronchiolitis are made because of limited data. Clinicians now recognize that an increasing number of parents/caregivers are using various forms of nonconventional treatment for their children. Treatments that have been used specifically for bronchiolitis include homeopathy, herbal remedies, osteopathic manipulation, and applied kinesiology. Substantially more data are available regarding the use of homeopathic and herbal remedies for the treatment of bronchitis and the common cold. Whether these therapies would prevent the development of bronchiolitis is unknown. A single recent trial indicated that an herbal preparation containing Echinacea, propolis, and vitamin C prevented the development of upper respiratory infections in children between the ages of 1 and 5 years.¹⁶⁶  Bronchiolitis was not specifically studied.

To date, there are no studies that conclusively show a beneficial effect of alternative therapies used for the treatment of bronchiolitis. Recent interest in the use of CAM has led to research efforts to investigate its efficacy. It is difficult to design and conduct studies on certain forms of CAM because of the unique nature of the treatment. Any study conducted will need to show proof of effectiveness of a specific therapy when compared with the natural history of the disease. Conclusions regarding CAM cannot be made until research evidence is available. However, because of the widespread use of CAM, clinicians should ask parents what alternative forms of treatment they are using and be ready to discuss potential benefits or risks.

• Aggregate evidence quality: D; expert opinion

• Benefit: improved parent-physician communication, awareness of other, possibly harmful treatments being used

• Harm: time required for discussion, lack of knowledge about CAM by many pediatricians

• Benefits-harms assessment: some benefit over harm

• Policy level: option

The AHRQ evidence report¹  points out that outcomes measured in future studies of bronchiolitis should be clinically relevant and of interest to parents, clinicians, and health systems. Among the recommended outcomes are rates of hospitalization, need for more intensive services in the hospital, costs of care, and parental satisfaction with treatment.¹  One of the difficulties with the bronchiolitis literature is the absence of validated clinical scoring scales that are objective, replicable, and can be easily be performed in the hospital, emergency department, and outpatient settings. Studies should also be of sufficient size to be able to draw meaningful conclusions for the above-mentioned outcomes. Because bronchiolitis is a self-limited disease, large numbers of patients would need to be enrolled to observe small changes in outcome. This would necessitate large multicenter study protocols. Currently, such multicentered studies are being conducted in the United States and Canada on the use of corticosteroids in the emergency department.

Future research should include:

• development of rapid, cost-effective tests for viruses other than RSV that may also play a role in bronchiolitis;

• studies to determine if there are selected patients who may benefit from bronchodilators or corticosteroids;

• clinical studies of the target Spo₂ for the most efficient use of oxygen and oxygen monitoring;

• development of new therapies including new antiviral medications;

• continued research into the development of an RSV vaccine; and

• continued development of immunoprophylaxis that would require fewer doses and decreased cost.

This clinical practice guideline provides evidence-based recommendations on the diagnosis and management of bronchiolitis in infants less than 2 years of age. It emphasizes using only diagnostic and management modalities that have been shown to affect clinical outcomes.

Bronchiolitis is a clinical diagnosis that does not require diagnostic testing. Many of the commonly used management modalities have not been shown to be effective in improving the clinical course of the illness. This includes the routine use of bronchodilators, corticosteroids, ribavirin, antibiotics, chest radiography, chest physiotherapy, and complementary and alternative therapies. Options for the appropriate use of oxygen and oxygen monitoring have been presented. Specific prevention with palivizumab and general prevention, particularly the use of hand decontamination to prevent nosocomial spread, were also discussed.

1. • Clinicians should diagnose bronchiolitis and assess disease severity on the basis of history and physical examination. Clinicians should not routinely order laboratory and radiologic studies for diagnosis (recommendation).

   • Clinicians should assess risk factors for severe disease such as age less than 12 weeks, a history of prematurity, underlying cardiopulmonary disease, or immunodeficiency when making decisions about evaluation and management of children with bronchiolitis (recommendation).

2. • Bronchodilators should not be used routinely in the management of bronchiolitis (recommendation).

   • A carefully monitored trial of α-adrenergic or β-adrenergic medication is an option. Inhaled bronchodilators should be continued only if there is a documented positive clinical response to the trial using an objective means of evaluation (option).

3. Corticosteroid medications should not be used routinely in the management of bronchiolitis (recommendation).

4. Ribavirin should not be used routinely in children with bronchiolitis (recommendation).

5. Antibacterial medications should only be used in children with bronchiolitis who have specific indications of the coexistence of a bacterial infection. When present, bacterial infection should be treated in the same manner as in the absence of bronchiolitis (recommendation).

6. • Clinicians should assess hydration and ability to take fluids orally (strong recommendation).

   • Chest physiotherapy should not be used routinely in the management of bronchiolitis (recommendation).

7. • Supplemental oxygen is indicated if Spo₂ falls persistently below 90% in previously healthy infants. If the Spo₂ does persistently fall below 90%, adequate supplemental oxygen should be used to maintain an Spo₂ at or above 90%. Oxygen may be discontinued if Spo₂ is at or above 90% and the infant is feeding well and has minimal respiratory distress (option).

   • As the child's clinical course improves, continuous measurement of Spo₂ is not routinely needed (option).

   • Infants with a known history of hemodynamically significant heart or lung disease and premature infants require close monitoring as oxygen is being weaned (strong recommendation).

8. • Clinicians may administer palivizumab prophylaxis for selected infants and children with CLD or a history of prematurity (less than 35 weeks' gestation) or with congenital heart disease (recommendation).

   • When given, prophylaxis with palivizumab should be given in 5 monthly doses, usually beginning in November or December, at a dose of 15 mg/kg per dose administered intramuscularly (recommendation).

9. • Hand decontamination is the most important step in preventing nosocomial spread of RSV. Hands should be decontaminated before and after direct contact with patients, after contact with inanimate objects in the direct vicinity of the patient, and after removing gloves (strong recommendation).

   • Alcohol-based rubs are preferred for hand decontamination. An alternative is hand-washing with antimicrobial soap (recommendation).

   • Clinicians should educate personnel and family members on hand sanitation (recommendation).

10. • Infants should not be exposed to passive smoking (strong recommendation).

    • Breastfeeding is recommended to decrease a child's risk of having LRTD (recommendation).

11. Clinicians should inquire about use of CAM (option).

Allan S. Lieberthal, MD, Chairperson

Howard Bauchner, MD

Caroline B. Hall, MD

David W. Johnson, MD

Uma Kotagal, MD

Michael J. Light, MD (on the AstraZeneca and MedImmune speakers' bureaus; research grant from MedImmune)

Wilbert Mason, MD (on the MedImmune speakers' bureau)

H. Cody Meissner, MD

Kieran J. Phelan, MD

Joseph J. Zorc, MD

Mark A. Brown, MD (on the GlaxoSmithKline, AstraZeneca, and MedImmune speakers' bureaus)

American Thoracic Society

Richard D. Clover, MD (continuing medical education presenter for institutions that received unrestricted educational grants from Sanofi Pasteur and Merck)

American Academy of Family Physicians

Ian T. Nathanson, MD

American College of Chest Physicians

Matti Korppi, MD

European Respiratory Society

Richard N. Shiffman, MD

Danette Stanko-Lopp, MA, MPH

Caryn Davidson, MA