High-Flow Nasal Cannula in Pediatric Critical Asthma

Abstract

BACKGROUND: High-flow nasal cannula (HFNC) has been used in the treatment of pediatric asthma, although high-quality data comparing HFNC to aerosol mask nebulizer are lacking. We hypothesized that HFNC would perform similarly to the aerosol mask for meaningful clinical outcomes in children with critical asthma. METHODS: We retrospectively reviewed the medical records of children with critical asthma (age 2-17 y) with a modified pulmonary index score (MPIS) 6 8 admitted to our pediatric ICU as part of a quality improvement project. Patients were managed with our MPIS-based, respiratory therapist-driven protocol. Subjects were divided into 2 cohorts by initial respiratory support: HFNC or aerosol mask. Data included demographics, initial respiratory support, and MPIS over time. Primary outcome was hospital length of stay (LOS). Secondary outcome was difference in MPIS over time. RESULTS: We included 171 subjects, with 104 in the HFNC group and 67 in the aerosol mask group. Median (interquartile range [IQR]) age was lower in the HFNC group (5 [IQR 4-9] vs 7 [IQR 5-10] y, P 5 .006)], while other demographic characteristics were similar. Initial MPIS was similar between HFNC and aerosol mask groups (11)(12) vs 10 [IQR 9-12], P 5 .15). There were no significant differences for hospital LOS (2.9 [IQR 2.1-3.9] vs 3.0 [IQR 2.3-4.4] d, P 5 .47), pediatric ICU LOS (1.9 [IQR 1.4-2.8] vs 1.8 [IQR 1.5-3.0] d, P 5 .92), or time to MPIS < 6 (1.0 [IQR 0.6-1.6] vs 1.3 [IQR 0.8-1.9) d, P 5 .09) between the HFNC and aerosol mask groups, respectively. Median time on continuous albuterol was shorter in the HFNC group compared to the aerosol mask group (1.0 [IQR 0.7-1.8] vs 1.5 [IQR 0.9-2.3] d, P 5 .048). Of note, 16 (24%) subjects in the aerosol mask group were eventually treated with HFNC. Use of a helium-oxygen mixture and noninvasive ventilation was similar between groups. CONCLUSIONS: HFNC performed similarly to aerosol mask in pediatric patients with critical asthma.

High-Flow Nasal Cannula Oxygen Therapy: Physiological Mechanisms and Clinical Applications in Children

“…To date, researches performed in vivo about drug nebulization using HFNC system are still few. In these studies, performed in children with respiratory distress due to asthma exacerbation or bronchiolitis, the inhalation of a bronchodilator through a nebulizer placed within the HFNC circuit was as effective as the inhalation through conventional devices, but the level of comfort was greater (18)(19)(20). The positive results observed with bronchodilators may not be generalized to other drugs (21).…”

Is Delivery of Aerosolized Medication via HFNC for Critical Asthma Effective Concurrent Therapy?

“…In this edition of RESPIRATORY CARE, Gates et al 8 performed a retrospective analysis that compared delivery of aerosol therapy via an aerosol mask or HFNC of 171 children ages 2-17 years who, between June 2014 and March 2020, were admitted to the pediatric ICU with critical asthma. Placement into each therapy group was determined by the initiating device on admission to the ICU and was broadly chosen by the preference of the clinician.…”

“…Placement into each therapy group was determined by the initiating device on admission to the ICU and was broadly chosen by the preference of the clinician. 8 The determination of bronchodilator dose was in accordance with an established respiratory therapist-driven protocol by using the modified pulmonary index score. A cutoff value of $8 indicated critical asthma.…”

“…Primary and secondary outcome metrics were pediatric ICU and hospital length of stay, time on continuous albuterol, and the modified pulmonary index score over time with the primary hypothesis as no change in hospital length of stay between the HFNC and aerosol mask groups. 8 Additional comparisons were made between $0.5 and <0.5 L/kg/min HFNC to determine any flow-related effects. 8 The results did not show any difference in hospital or pediatric ICU length of stay (P ¼ .47 and P ¼ .95, respectively); however, there was a difference in the time on continuous albuterol, with the HFNC group having a shorter duration (P ¼ .048).…”

“…8 Additional comparisons were made between $0.5 and <0.5 L/kg/min HFNC to determine any flow-related effects. 8 The results did not show any difference in hospital or pediatric ICU length of stay (P ¼ .47 and P ¼ .95, respectively); however, there was a difference in the time on continuous albuterol, with the HFNC group having a shorter duration (P ¼ .048). 8 There was also no difference in any outcome metric between the 2 flow-range groups.…”