Background:High-flow nasal cannula (HFNC) has been increasingly utilized in PICUs for asthma, yet studies comparing it to 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 to 17 years) with a modified pulmonary index score (MPIS) ≥ 8 admitted to our PICU between June 2014 and March 2020 as part of an IRB-approved quality improvement project. Patients were managed with our MPIS-based respiratory therapist-driven protocol. We divided subjects into 2 cohorts by initial respiratory support (HFNC or aerosol mask). Data included demographics, baseline asthma severity, initial respiratory support, and MPIS over time. Primary outcome was hospital length of stay (LOS). Secondary outcomes were: MPIS at 6 hours, PICU LOS, time on continuous albuterol, change in MPIS over time, and need for non-invasive ventilation (NIV) or helium-oxygen mixture. We used nonparametric and chi-squared testing to compare continuous, presented as median (IQR), and categorical data, respectively. P <0.05 was considered statistically significant. Results:We included 171 subjects; 104 in the HFNC group and 67 in the aerosol mask group. HFNC subjects were younger 5 (4-9) vs. 7 (5-10) years; respectively. P = 0.006) while other demographic data were similar. Initial MPIS was similar between HFNC and aerosol mask groups 11 (9-12) vs 10 (9-12); P = 0.15. There were no significant differences between groups for hospital LOS 2.9 (2.1-3.9) vs 3.0 (2.3-4.4) days; P = 0.47, PICU LOS 1.9 (1.4-2.8) vs 1.8 (1.5-3.0) days; P = 0.92, or time to MPIS < 6 1.0 (0.6-1.6) vs 1.3 (0.8-1.9) days; P = 0.093. Median time on continuous albuterol was shorter in the HFNC group compared to the aerosol mask group 1.0 (0.7-1.8) vs 1.5 (0.9-2.3) days; P = 0.048. Of note, 16 (24%) patients in the aerosol mask group were eventually treated with HFNC. Heliox and NIV use was similar between groups. The progression of MPIS over time for both groups is shown in Figure 1. Conclusions:Hospital LOS and change in MPIS were similar between HFNC and aerosol mask. HFNC use was associated with a shorter time on continuous albuterol.
Gates et al. (Thu,) studied this question.