Bronchiolitis is the most common cause of hospitalization among infants during the first 12 months of life. Approximately 100,000 bronchiolitis admissions occur annually in children in the United States, at an estimated cost of $1.73 billion. The American Academy of Pediatrics recently published new guidelines for the diagnosis, management, and prevention of bronchiolitis in children younger than 2 years.
Dr. Neil Skolnik and Dr. Neha Rastogi
Diagnosis
Diagnosis is based on patient history and physical examination. The course and severity of bronchiolitis vary, ranging from mild disease with simple runny nose and cough, to transient apneic events, and on to progressive respiratory distress secondary to airway obstruction. Management of bronchiolitis must be determined in the context of increased risk factors for severe disease, including age less than 12 weeks, history of prematurity, underlying cardiopulmonary disease, and immunodeficiency. Current evidence does not support routine labs or diagnostic imaging as helping with risk assessment. Abnormalities on chest x-ray, which are common in children with bronchiolitis, do reliably predict severity of disease, so chest x-rays are only indicated when another etiology of respiratory distress such as pneumothorax or pneumonia is a concern. Routine virologic testing is not recommended, as it does not appear to aid in guiding the treatment of the child with bronchiolitis.
Management
Randomized trials have not shown any benefit from alpha- or beta-adrenergic agonist administration. Bronchodilators can lessen symptoms scores, but their use does not speed disease resolution or decrease the length of stay or need for hospitalization. A Cochrane analysis concluded that there was no benefit to giving bronchodilators to infants with bronchiolitis. Adverse effects included tachycardia, tremors, and cost, all of which outweigh potential benefits. While previous versions of the AAP guidelines recommended bronchodilators as an option, the 2014 guidelines state, “Clinicians should not administer albuterol (or salbutamol) to infants and children with a diagnosis of bronchiolitis (Evidence Quality: B; Recommendation Strength: Strong).” It is noted that there may be some children who have reversible airway obstruction, but it is impossible to tell ahead of time who they are; and due to the variability of the disease, it is even hard to tell in whom the medication is effective. It is acknowledged that children with severe disease were usually excluded from the studies of bronchodilators. Epinephrine should also not be used except potentially as a rescue agent in severe disease.
Nebulized hypertonic saline appears to increase mucociliary clearance. Nebulized 3% saline is safe and effective in improving symptoms of mild to moderate bronchiolitis when measured after 24 hours of use, and it possibly decreases the length of hospital stay in studies where the length of stay exceeded 3 days. The guidelines conclude that hypertonic saline may be helpful to infants who are hospitalized with bronchiolitis, but probably is of very little benefit when administered in an emergency department setting.
Although there is strong evidence of benefit of systemic corticosteroids in asthma and croup, there is no evidence that systemic corticosteroids provide benefit in bronchiolitis. In addition, there is some evidence that corticosteroids may prolong viral shedding. For these reasons, the 2014 guidelines state, “Clinicians should not administer systemic corticosteroids to infants with a diagnosis of bronchiolitis in any setting (Evidence Quality: A; Recommendation Strength: Strong Recommendation).”
Physicians may choose not to give supplemental oxygen if oxyhemoglobin saturation is more than 90%, and also not to use continuous pulse oximetry given that it is prone to errors of measurement. Chest physiotherapy is not recommended. Antibiotics use is not recommended unless there is a concomitant bacterial infection or strong suspicion of one.
Prevention
The guidelines advise that palivizumab (Synagis) should not be given to otherwise healthy infants with a gestational age of 29 weeks or greater. Palivizumab should be given in the first year of life to infants with hemodynamically significant heart disease or chronic lung disease of prematurity (defined as infants of less than 32 weeks’ gestation who required more than 21% oxygen for at least the first 28 days of life). Infants who qualify for palivizumab at the start of respiratory syncytial virus season should receive a maximum of five monthly doses (15 mg/kg per dose) of palivizumab or until the end of RSV season, whichever comes first. Because of the low risk of RSV hospitalization in the second year of life, palivizumab prophylaxis is not recommended for children in the second year of life, unless the child meets the criteria for chronic lung disease and continues to require supplemental oxygen or is on chronic corticosteroids or diuretic therapy within 6 months of the onset of the second RSV season.