Muscle Ultrasound Changes and Physical Function of Critically Ill Children: A Comparison of Rectus Femoris Cross-Sectional Area and Quadriceps Thickness Measurements.

Quadriceps thickness (QT) and rectus femoris cross-sectional area (RF CSAOBJECTIVES:To compare QT with RF CSADESIGN SETTING AND PARTICIPANTS:Secondary analysis of a prospective cohort study of children 0-18 years old admitted to a tertiary mixed PICU between January 2015 and October 2018 with PICU stay greater than 48 hours and greater than or equal to one organ dysfunction. MAIN OUTCOMES AND MEASURES:Ultrasound QT and RF CSACSARESULTS:Two hundred thirty-seven images from 66 subjects were analyzed. RF CSApppCSAppCSAppCONCLUSIONS AND RELEVANCE:Ultrasound derived RF CSA