Hypertonic Saline
Although hypertonic saline (HTS) has been increasingly studied for the treatment of bronchiolitis, the AAP does not recommend its use in the ED. Despite evidence that HTS may reduce hospital length of stay after 24 hours of use in settings where the typical duration of hospitalization exceeds 3 days, it has not been shown to reduce the rate of hospitalization when used in an emergency setting.2
Corticosteroids
While there is good evidence that corticosteroids are beneficial in treating some respiratory diseases, such as asthma and croup, numerous studies have repeatedly failed to show a benefit in treating bronchiolitis. One of the largest studies, a multicenter, randomized, controlled trial of dexamethasone for bronchiolitis by the Pediatric Emergency Care Applied Research Network, did not show any alteration in admission rates, respiratory status after 4 hours of observation, or length of hospital stay.12 Accordingly, the AAP strongly recommends against the administration of corticosteroids for bronchiolitis in any setting.2
Oxygen Therapy
Oxygen therapy is often necessary in patients with bronchiolitis who demonstrate hypoxia. The definition of hypoxia in this patient population has remained variable. The AAP has established a threshold of oxyhemoglobin saturation (SpO2) of less than 90% to define hypoxia and has empowered clinicians to not administer oxygen if the SpO2 exceeds 90%. Based on the oxyhemoglobin dissociation curve, the authors of the AAP guidelines note that when the SpO2 is less than 90%, small decreases in the arterial partial pressure of oxygen (PaO2) result in large decreases in the SpO2. When SpO2 is greater than 90%, however, large increases in PaO2 are associated with only small increased in SpO2. The AAP guidelines note, “In infants and children with bronchiolitis, no data exist to suggest that such increases [in PaO2 and SpO2] result in any clinically significant differences in physiologic function, patient symptoms, or clinical outcomes.”2
A relatively new method of administration of oxygen to infants with bronchiolitis is via a humidified, heated, high-flow nasal cannula (HHHFNC). This therapy has been shown to generate continuous positive airway pressure, which improves respiratory effort, reduces the work of breathing, and may decrease the need for intubation.2
Patient Disposition
One of the most challenging tasks for emergency physicians (EPs) is determining the appropriate disposition of infants with bronchiolitis. The variable presentation and dynamic nature of the disease make this particularly difficult. Patients at high risk for apnea should be admitted to the hospital for observation and further care as needed. Admission also should be strongly considered for those with significantly increased work of breathing and tachypnea that does not improve with suctioning—especially when these interfere with feeding. Infants with poor feeding or evidence of dehydration should be admitted to the hospital for intravenous (IV) fluid hydration or nasogastric feedings. Patients with hypoxia (SpO2 saturations <90%) should also be admitted for supplemental oxygen therapy. It should be noted, however, the AAP recommends “spot-checks” over continuous pulse oximetry in patients who do not require oxygen therapy.2
Another important factor affecting patient disposition is the ability of the caregiver to provide basic patient care and ensure close outpatient follow-up. Prior to discharge, caregivers should be educated on the highly dynamic nature of bronchiolitis and the signs and symptoms that would require prompt return to the ED—especially if the infant has risk factors for the development of severe disease.
Case Conclusion
Based on the patient’s symptoms, history (most notably, the recent incident of sleep apnea at home), and physical examination, the EP quickly identified this infant was at a high risk for both severe bronchiolitis and apnea and required aggressive management. Nasal suctioning was immediately performed to help clear the patient’s secretions; this, however, only slightly improved his RR and work of breathing. Although the infant’s SpO2 was greater than 90% on room air, the EP administered oxygen via HHHFNC at 6 L per minute, which produced a significant improvement in both RR and effort.
Given the patient’s age and the presence of a fever, a urinalysis was also obtained, the results of which showed no evidence of infection. Since the patient was only able to bottle-feed for a few minutes at a time, the EP initiated IV fluid hydration and contacted the hospitalist team for inpatient admission.
The infant was gradually weaned from HHHFNC on hospital day 2 but remained with suboptimal oral intake for another 24 hours. By hospital day 4, his work of breathing had improved significantly, and he was feeding well with through the assistance of pre-feeding nasal syringe suctioning. The patient was discharged home in the care of his parents later that same day with only mild tachypnea over baseline. At discharge, the EP emphasized the importance of providing close follow-up with their son’s pediatrician. The infant continued to gradually improve as an outpatient, with resolution of nasal congestion by day 12 of his illness; he returned to his baseline breathing and feeding pattern on day 14.