Study Design and Data Source
This was a retrospective analysis of a single-center prospective cohort
study as previously described13 who were admitted with
PARDS between July 1, 2012, and April 30, 2018, requiring conventional
invasive mechanical ventilation, and who had a clinically indicated
echocardiogram performed within 24 hours of PARDS onset. Other inclusion
criteria were availability of paired end tidal PetCO2and PaCO2 measurements as well as echocardiogram images
of sufficient quality to perform RV strain analyses. Patients were
excluded for PARDS onset outside of the study center PICU, chronic
invasive mechanical ventilation, invasive mechanical ventilation
>7 days, and for respiratory failure primarily secondary to
congestive heart failure, fluid overload, or exacerbation of chronic
lung disease. Patients with paired PetCO2 and PaCO2 values that yielded
a negative AVDSf were also excluded. The study was approved by the
Children’s Hospital of Philadelphia’s (CHOP) Institutional Review Board
with a waiver of the need for informed consent.