Therapy is supportive. No medication appears to be beneficial in patients with bronchiolitis, although this is an area of extensive, ongoing research. Most children with bronchiolitis will have some degree of hypoxia; monitoring of oximetry and provision of oxygen, if needed, is important. The AAP practice guidelines state that supplemental oxygen is indicated if SpO2 falls persistently below 90% in previously healthy infants. Oxygen may be discontinued if SpO2 is at or above 90% and the infant is feeding well and has minimal respiratory distress.1 Patients who are dehydrated and unable to take adequate oral fluids may require intravenous hydration. As discussed above, a chest radiograph often reveals areas of opacity suggestive of pneumonia. However, no significant benefit was demonstrated from routine antibiotic usage in patients with a clinical diagnosis of bronchiolitis.1,16,17
The similarities and association between bronchiolitis and the development of asthma have led some physicians to advocate the use of steroids in bronchiolitis. Although small studies have suggested their benefit,18 more robust studies and large meta-analyses have failed to demonstrate any clinical benefit to support use of oral or inhaled steroids.19,20
The use of inhaled bronchodilators in bronchiolitis remains controversial. Many clinicians believe that bronchodilators produce clinical improvement in some patients with bronchiolitis; some small studies support this.21 However, systematic reviews looking at studies of the efficacy of oral or inhaled β-agonists and anticholinergic agents in bronchiolitis have not demonstrated a significant benefit in their routine use.22,23 A systematic review, assessing the use of any bronchodilator therapy in bronchiolitis, demonstrated a modest improvement in clinical scores that was of questionable clinical significance. No difference was found in oxygenation or rates of hospitalization.24 Despite the lack of proven benefit, the most recent AAP practice guidelines on bronchiolitis suggest that a carefully monitored trial of α-adrenergic or β-adrenergic medication is an option and should be continued only if there is a documented positive clinical response.1
Some authors have suggested that nebulized epinephrine therapy is superior to nebulized albuterol therapy in patients with bronchiolitis based on the α-adrenergic–mediated vasoconstriction ameliorating airway edema. Earlier studies comparing nebulized epinephrine with nebulized albuterol in patients with bronchiolitis did not reveal a significant difference in benefit.24,25 However, a recent meta-analysis suggests that use of nebulized epinephrine may reduce hospital admissions.26 Another high-quality study suggests that combination therapy with nebulized epinephrine and dexamethasone may produce synergistic effects and reduce hospital admissions and result in earlier hospital discharge27; however, additional research is needed.
There has been research on the use of nebulized hypertonic saline in the treatment of bronchiolitis. This therapy is thought to work by enhancing mucociliary clearance via osmotic hydration and disruption of mucous strand cross-linking, decreasing epithelial swelling, and decreasing airway obstruction.28 Although a meta-analysis has demonstrated that this therapy can reduce hospitalization length of stay without any adverse clinical effects, there is no definitive evidence that it reduces hospital admission.29
There has been extensive research into additional therapies for bronchiolitis, including montelukast,30,31 topical nasal phenylephrine,32 chest physiotherapy,33 and inhaled furosemide.34 The use of ribavirin35 or surfactant therapy36 is best left to the discretion of the intensivist once the child is admitted based on the particular clinical circumstances.
Two to five percent of infants hospitalized for bronchiolitis will go on to develop respiratory failure and require some level of mechanical support. A mixture of helium and oxygen (Heliox) and continuous positive airway pressure may be of benefit as noted by some authors; however, there is a paucity of good evidence documenting decreased rates of intubation.37–40 There are no absolute criteria for endotracheal intubation. Suggested indications include PCO2 greater than 60 to 65 mm Hg, recurrent apneic spells, decreasing mental status, and hypoxia despite oxygen therapy. Once intubated, these infants have many of the same problems that intubated asthmatics have and are at risk for air trapping and the development of air leaks, including pneumothorax. There are also reports of successful management of severe bronchiolitis with high-frequency oscillatory ventilation and extracorporeal membrane oxygenation (ECMO) in patients unresponsive to conventional therapy.