High-Flow Oxygen Therapy in Children with Asthma in the Emergency Department
Asthma is the most common chronic childhood disease, with a prevalence of 5%-20%. Acute asthma exacerbation episodes account for nearly 5% of pediatric emergency department (ED) visits, peaking to up to 10%-15% during certain times of the year, and approximately 15% of children require admission.
Despite a lack of randomized controlled trial evidence for the effectiveness of HFNC therapy in infants and older children, the increasing availability of HFNC devices, first in pediatric intensive care units (PICUs) and more recently in pediatric wards, as well as their ease of use and children’s tolerance of them, has led to the incorporation of this therapy into management protocols for children with respiratory diseases, especially bronchiolitis. Various observational studies in infants with bronchiolitis have found HFNC therapy to be feasible, safe, and effective, but further studies are needed to ensure that guidelines for its use are evidence-based. Recent publications suggest that it also may be effective and safe applied to a broader spectrum of ages and diagnoses.
This time reference to an open label prospective randomized pilot trial of children (aged 1-14 years) presenting to a tertiary academic pediatric emergency department near Bilbao with moderate-to-severe asthma exacerbations, between September 2012 and December 2015.
Its objective, assess the efficacy of HFNC therapy and safety in children with asthma and moderate respiratory failure in the ED.
Patients with a pulmonary score (PS) ≥6 or oxygen saturation <94% with a face mask despite initial treatment (salbutamol/ipratropium bromide and corticosteroids) were randomized to HFNC or to conventional oxygen therapy. Pharmacologic treatment was at the discretion of attending physicians. The primary outcome was a decrease in PS ≥2 in the first 2 hours. Secondary outcomes included disposition, length of stay, and need for additional therapies.
62 children were randomly allocated to receive either HFNC (n = 30) or standard oxygen therapy (n = 32). Baseline patient characteristics were similar in the 2 groups. At 2 hours after the start of therapy, PS had decreased by ≥2 points in 16 patients in the HFNC group (53%) compared with 9 controls (28%) (P = .01). Between group differences in disposition, length of stay, and need for additional therapies were not significant. No side effects were reported. The present study demonstrates that HFNC oxygen therapy is effective and safe for the treatment of children who experience episodes of severe asthma while in the ED.
HFNC appears to be superior to conventional oxygen therapy for reducing respiratory distress within the first 2 hours of treatment in children with moderate-to-severe asthma exacerbation refractory to first-line treatment.
In this study, most children in the experimental group were admitted to the PICU to continue HFNC therapy beyond 36 hours, because this treatment was not offered in their pediatric ward. Thus, had this type of therapy been available in the pediatric ward, the PICU admission rate could have been 50% lower. The benefits for patients and their families and potential cost savings highlight the possible advantages of using this therapy in the initial treatment of severe asthma exacerbation in the ED.
Continuing my previous line of thought, HFNC has proven efficacy in pediatric patients with Bronchiolitis. From a physiological perspective, HFNC therapy appears attractive for patients with asthma. As in bronchiolitis, the continuous positive airway pressure generated may reduce the burden on the inspiratory muscles related to auto-positive end expiratory pressure; however, there is limited evidence supporting this indication. Moving forward, I believe it will be best to consider in a near future, respiratory distress as its main indication in Pediatrics, rather than reducing it only to Bronchiolitis cases. Nonetheless, further studies are needed to demonstrate its overall efficacy in the management of asthma and respiratory failure in the ED.
(J Pediatr 2018;194:204-10).