Study Measures and Data Collection
HFNC duration in hours was used as the primary outcome measure, while
PICU LOS, hospital LOS, and continuous albuterol duration in hours were
used as secondary outcome measures. Pre-intubation noninvasive
ventilation (NIV) use (bi-level positive airway pressure), invasive
mechanical ventilation (IMV) use, and 7-day PICU and hospital
readmission rate were used as balancing measures. Analysis was conducted
on data obtained from Virtual PICU Systems (VPS, Los Angeles,
California). We used VPS to collect admission and discharge dates, age,
sex, PRISM score, types of respiratory support, procedures (including
intubation and ECMO cannulation). Data on race and ethnicity were
collected from VPS but taken directly from the medical record (Cerner,
North Kansas City, MO); race was defined by the National Institutes of
Health (NIH) guidelines (21). We used Cerner to collect data on
medications and other adjunctive therapies, including albuterol,
magnesium sulfate, aminophylline, terbutaline and heliox. Patients
requiring NIV and IMV were also excluded from analysis of the outcome
measures but were used as balancing measures for the whole pediatric
critical asthma cohort. The pre-implementation period was between
January 2016 and September 2017. PDSA 1 period occurred from October
2017 through February 2019. PDSA 2 period occurred between March 2019
and June 2020, PDSA 3 period between July 2020 and September 2021, and
PDSA 4 period occurred between October 2021 and May 2022.