Outcomes for Differing High-Flow Nasal Cannula Rates in Pediatric Critical Asthma

Tuesday, March 24, 2026

12:30 PM - 1:30 PM Central Time

Location: Connections Central - RST 13

Marybeth Burriss-West, M.D. (she/her/hers)

North Carolina

Disclosure(s): No relevant financial relationship(s) to disclose.
RW

Rachel Watts, RRT

Respiratory Therapist
Duke University Hospital

Disclosure information not submitted.
JB

Julia Brown, BSN

Nurse
Duke University Hospital

Disclosure information not submitted.
KH

Kaitlyn Haynes, RRT

Respiratory Therapist
Duke University Hospital

Disclosure information not submitted.
LB

Laura Bacigalupi, NP

Nurse Practitioner
Duke University Hospital

Disclosure information not submitted.
MA

Monica Alvarez, MD, PhD

Pediatric Critical Care Medicine Fellow
Duke University Medical Center

Disclosure information not submitted.
KR

Kyle Rehder, MD, FCCM, CPPS

Professor
Duke University Hospital

Disclosure information not submitted.
Alexandre Rotta, MD, FCCM

Duke University Medical Center, North Carolina

Disclosure information not submitted.
Andrew G. Miller, MSc, RRT, RRT-ACCS, FAARC, FCCM

Duke University Medical Center

Disclosure(s): Aerogen: Advisory Board (Terminated, October 18, 2025)

Introduction: High flow nasal cannula (HFNC) is commonly used in the pediatric intensive care unit (PICU) in the care of children admitted with critical asthma. There is controversy around the HFNC flow rate in this setting due to its potential impact on aerosol delivery. This study aimed to determine whether HFNC flow rate (≤ to 0.5 L/kg/min versus > 0.5 L/kg/min) would influence hospital length of stay (LOS) of patients admitted with critical asthma. We hypothesized that HFNC flow rate would not be associated with hospital LOS.

Methods: We included patients 2 to 18 years admitted to our PICU between January 2021 and December 2023 with a primary diagnosis of critical asthma. We collected data on demographics, respiratory support, respiratory scoring, medications, and outcomes via Duke’s Virtual Pediatric Systems (VPS) data and retrospective chart review. We compared patients initiated on ≤ 0.5 L/kg/min and > 0.5 L/kg/min of HFNC using chi-squared and Mann-Whitney tests for categorical and normally distributed data, respectively.

Results: Of the 134 patients included in the study, 64 (47.8 %) had HFNC started at ≤ 0.5 L/kg/min and 70 (52.2 %) had HFNC started at > 0.5 L/kg/min. Those started on ≤ 0.5 L/kg/min were older (8.6 [6.1-12.7] vs 4.3 [3.1-6.0] years, P < 0.001), less likely to be male (45% vs 64%, P=0.03), and heavier (41.5 [24.3-63.0] vs 17.5 [14.0-23.3] kg, P < 0.001). Asthma scores (modified pulmonary index score) were similar on admission and over the first 24 hours. The > 0.5 L/kg/minute group received HFNC for a longer duration (30.0 [21.8-47.3] vs (24.5 [13.3-40.0] hours, P = 0.045) and were more likely to be discharged home from the PICU rather than from the general inpatient unit (65.7% vs 48.4%, P = 0.04). There were no significant observable differences in hospital LOS (2.4 [1.9-3.4] vs 2.6[1.9-3.2] days, P = 0.88), PICU LOS, duration of continuous albuterol therapy, and need for support escalation between the groups.

Conclusions: HFNC initial flow above or below 0.5 L/kg/min was not associated with differences in asthma severity, hospital LOS, PICU LOS, duration of continuous albuterol, or escalation of respiratory support. Results from this study suggest that concerns about HFNC flow affecting clinical response to albuterol and patient trajectory may be clinically insignificant.