P4A097: Characterizing High-flow Nasal Cannula Use Beyond Bronchiolitis

Background: High-flow nasal cannula (HFNC) is increasingly used as non-invasive respiratory support despite concerns for HFNC overutilization and lack of evidence for widespread use. Initial characterizations of HFNC practices have focused primarily on bronchiolitis. Little is known about the broader scope of HFNC use. We aimed to characterize HFNC use at a large freestanding children’s hospital.

Methods: We conducted a retrospective analysis of all hospitalized children (1 month – 5 years old) treated with HFNC admitted between 06/01/2022 and 11/30/2022 at a 364 bed, academic, quaternary care, freestanding children’s hospital. Individual charts were reviewed by a physician for data extraction. Outcomes included HFNC indication, underlying comorbidities, treatment failure, temporal relation of HFNC to non-invasive ventilation (NIV) and invasive mechanical ventilation (IMV), length of treatment (LOT), and length of stay (LOS). Treatment failure was defined as required escalation to NIV or IMV while on HFNC. Patients were categorized into three weight groups for flow rate interpretation: ≤ 15 kg, 16-25 kg, 26-35 kg. Subtherapeutic flow rates were defined for each group as < 1 L/min/kg, < 15 L/min, and < 18 L/min respectively.

Results: Four hundred forty-eight encounters of 412 unique patients were reviewed. Patient and encounter characteristics are summarized in Table 1. Median age was 14 months with an interquartile range (IQR) of 6-43 months. Median weight was 10.4 kg (IQR 7.5-13.6). Approximately one-third of patients (n=123, 30%) had at least one comorbidity; most commonly cardiac disease (N=71, 17%) or lung disease (N=24, 6%). Leading indications for HFNC use included bronchiolitis (N=202, 45%), postextubation respiratory failure (N=73, 16%), asthma (N=58, 13%), lower respiratory tract infection (N=50, 11%), pneumonia (N=27, 6%), other respiratory conditions (N=14, 3%), and other non-respiratory conditions (N=15, 3%). HFNC was utilized as initial non-invasive respiratory support in 76% of encounters (n=340) and as sequential respiratory support after withdrawal of NIV/IMV in 45% of encounters (n=202). One hundred three encounters (23%) had treatment failure and required escalation to NIV/IMV. Most encounters (n=385, 86%) included the use of subtherapeutic flow rates. Median length of treatment was 55 hours (IQR 29-94) for patients receiving HFNC only and 34 hours (IQR 16-68) for patients receiving HFNC as sequential respiratory support following NIV/IMV. Median LOS for all patients was 125 hours (IQR 69-243).

Conclusion: HFNC was used for a variety of conditions with over 50% of use for indications other than bronchiolitis at our institution during the study period. Given the widespread adoption of HFNC and increasing evidence suggesting its potential negative impacts on patient outcomes and cost for bronchiolitis, characterizing trends and utilization of HFNC in additional populations is important to identify focus areas for future research and quality improvement efforts to minimize potential misuse and overutilization.