High-Flow Nasal Cannula in Pediatric Critical Asthma

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) ≥ 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 = .006)], while other demographic characteristics were similar. Initial MPIS was similar between HFNC and aerosol mask groups (11 [IQR 9-12] vs 10 [IQR 9-12], P = .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 = .47), pediatric ICU LOS (1.9 [IQR 1.4-2.8] vs 1.8 [IQR 1.5-3.0] d, P = .92), or time to MPIS < 6 (1.0 [IQR 0.6-1.6] vs 1.3 [IQR 0.8-1.9) d, P = .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 = .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.