Buried in mid-winter, January generally portends the ramping up of bronchiolitis season in the majority of the United States. Of particular note for this season, the American Academy of Pediatrics has published a new clinical practice guideline, updated from the 2006 edition.¹

The guideline document is divided into three sections: diagnosis, treatment, and prevention. Only the diagnosis and treatment sections have relevance to emergency physicians. Specifically covered by these guidelines are infants ages 1 month to 23 months, but reasonable generalizations may be made beyond the upper limit of this population. As with all guidelines, it should be emphasized that these reflect reasonable practice principles, and acknowledging appropriate variation may be considered both acceptable and necessary.

The pattern toward simplicity starts with making the initial diagnosis. Bronchiolitis is a clinically distinct syndrome generally recognizable by history and physical examination alone. After confounders of upper respiratory illness and other diagnoses are adequately considered, classic tachypnea, wheezing, and rales in the proper context support the diagnosis. Assessment of the severity of bronchiolitis is best made, again, solely on the basis of clinical evaluation. The best predictors of complicated disease course, including apnea and critical illness, are underlying comorbid conditions such as prematurity, neuromuscular disease, or reported witnessed episodes of apnea.

The use of pulse oximetry has proven to be controversial as otherwise well-appearing children with bronchiolitis frequently display impaired oxygen exchange. The best evidence suggests utilizing pulse oximetry as part of a decision-making process to predict disease severity is not appropriate and even harmful. A recent trial published in JAMA systematically altered pulse oximetry readings of patients with bronchiolitis, displaying higher numbers to treating clinicians than actually present.² Patients randomized to such artifice had reductions in hospitalization without corresponding increases in adverse outcomes. The implication is that clinicians were giving oximetry readings too much importance compared to their clinical evaluation. These guidelines go on to state that supplemental oxygen is unnecessary unless ≤89 percent, and mild hypoxemia is reasonable.

No testing in the evaluation of bronchiolitis has been demonstrated to confer individual benefit. Viral testing for the etiologic agent, such as readily available respiratory syncytial virus assays, provides no additional prognostic information. Chest radiography is also of routine disutility, with no specific radiologic findings providing additive value for prediction of disease severity. Furthermore, use of radiography frequently identifies abnormalities leading to initiation of antibiotic therapy, which is unwanted, unnecessary, and obviously of no benefit for a viral process. Only children with severe or complicated symptoms are appropriate for radiography.

The best predictors of complicated disease course, including apnea and critical illness, are underlying comorbid conditions such as prematurity, neuromuscular disease, or reported witnessed episodes of apnea.

One of the biggest changes from the 2006 guideline, and almost certainly part of most current routine practice, is a trial of bronchodilator therapy in children suspected of viral bronchiolitis. The authors use the phrase “overall ineffectiveness outweighs possible transient benefit,” which very precisely describes the reasonable elimination of albuterol (or salbutamol) from therapy for children with bronchiolitis. The limited subjective improvement observed in trials did not translate to any meaningful or durable clinical improvement and only subjected patients to, albeit mild, adverse effects of beta-agonist therapy.

Similarly, use of two other nebulized therapies, epinephrine and hypertonic saline, is discouraged in the emergency department. Using the same language regarding lack of effectiveness, the authors found no value from use, or trial, of nebulized epinephrine compared with placebo. Nebulized hypertonic saline has had a slightly more favorable evaluation in the recent literature. Unfortunately, the pooled data from multiple trials finds the best—yet still weak—evidence for benefit was by decreasing the length of stay of patients whose hospitalization might exceed three days. This is clearly the exception to the cohort evaluated in the emergency department, and given the lack of prognostic tools at our disposal, there is no reason to routinely consider nebulized hypertonic saline.

Finally, the last pharmacological intervention covered by this clinical policy recommends against use of systemic corticosteroids. Outside of one aberrant and controversial trial showing an unexpected reduction in hospitalization for patients receiving both nebulized epinephrine and oral dexamethasone, multiple other reviews and meta-analyses of corticosteroids alone observed no benefit.

Despite all of our advances in the evaluation and treatment in other areas of medicine, we’ve simply circled back to square one with bronchiolitis: no useful testing and no effective interventions. Just as our ancestors assessed and treated these patients, clinical evaluation should guide hospitalization, and supportive care, hydration, nutrition, and respiratory support remain the most important elements of management.

So, in summary:

• Do not perform chest radiography or viral testing routinely as part of individual patient clinical evaluation.
• There is no routine role for use of albuterol, nebulized epinephrine, or nebulized hypertonic saline in the emergency department. The use of steroids is likewise not indicated.
• Pulse oximetry alone should not determine the need for admission, and patients are unlikely to have tissue effects of hypoxemia at 90 percent or above.
• As challenging as it may be to present our limited and lacking treatment options to parents and families, the prudent course is the simplest one.

Dr. Radecki is assistant professor of emergency medicine at The University of Texas Medical School at Houston. He blogs at Emergency Medicine Literature of Note (emlitofnote.com)and can be found on Twitter @emlitofnote.

References

1. Ralston SL, Lieberthal AS, Meissner HC, et al. Clinical practice guideline: the diagnosis, management, and prevention of bronchiolitis. Pediatrics. 2014;134:e1474-502.
2. Schuh S, Freedman S, Coates A, et al. Effect of oximetry on hospitalization in bronchiolitis: a randomized clinical trial. JAMA. 2014;312:712-8.