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Published on: July 26, 2024
Muscle Ultrasound Changes and Physical Function of Critically Ill Children: A Comparison of Rectus Femoris
Chengsi Ong1,2, Jan Hau Lee3,4, Melvin K S Leow4,5,6,7
1Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
Insights
Rectus femoris cross-sectional area (RFCSA) better reflects muscle changes and is associated with physical function in critically ill children compared to quadriceps thickness (QT). RFCSA may be more useful for in-hospital muscle monitoring.
Area of Science:
- Pediatric Critical Care Medicine
- Musculoskeletal Ultrasound
- Rehabilitation Science
Background:
- Quadriceps thickness (QT) and rectus femoris cross-sectional area (RFCSA) are utilized to assess muscle alterations in critically ill children.
- The comparative correlation and association of these measures with physical function remain under-explored.
Purpose of the Study:
- To compare changes in QT and RFCSA.
- To evaluate the association of these muscle measurements with physical function in critically ill children.
Main Methods:
- Secondary analysis of a prospective cohort study involving children (0-18 years) admitted to a tertiary mixed PICU.
- Ultrasound measurements of QT and RFCSA were taken at multiple time points: PICU admission, PICU discharge, hospital discharge, and 6 months post-discharge.
- Changes in muscle measures were correlated with changes in motor function, physical ability, and health-related quality of life (HRQOL).
Main Results:
- RFCSA changes were not significantly different from QT changes at PICU or hospital discharge.
- At 6 months post-discharge, RFCSA change was significantly greater than QT change (p < 0.001).
- Motor function and physical HRQOL changes at PICU and hospital discharge, respectively, were significantly associated with RFCSA change, but not QT change.
Conclusions:
- Ultrasound-derived RFCSA is associated with motor function and physical HRQOL changes in critically ill children.
- QT changes were not significantly associated with physical function outcomes.
- RFCSA may serve as a more valuable tool for monitoring muscle status in critically ill children during their hospital stay.
Abstract:
Quadriceps thickness (QT) and rectus femoris cross-sectional area (RFCSA) are both used to evaluate muscle changes in critically ill children. However, their correlation and association with physical function has not been compared.
Objectives:
To compare QT with RFCSA changes, and their association with physical function in critically ill children.
Design 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 RFCSA were measured at PICU admission, PICU discharge, hospital discharge, and 6 months post-discharge. QT and RFCSA changes from baseline were compared with each other and with change in motor function, physical ability, and physical health-related quality of life (HRQOL).
Results:
Two hundred thirty-seven images from 66 subjects were analyzed. RFCSA change was not significantly different from QT change at PICU (-8.07% [interquartile range (IQR), -17.11% to 4.80%] vs -4.55% [IQR, -14.32% to 4.35%]; p = 0.927) or hospital discharge (-5.62% [IQR, -15.00% to 9.42%] vs -8.81% [IQR, -18.67% to 2.39%]; p = 0.238) but was significantly greater than QT change at 6 months (32.7% [IQR, 5.74-109.76%] vs 9.66% [IQR, -8.17% to 25.70%]; p < 0.001). Motor function change at PICU discharge was significantly associated with RFCSA change (adjusted β coefficient, 0.02 [95% CI, 0.01-0.03]; p = 0.013) but not QT change (adjusted β coefficient, -0.01 [95% CI, -0.02 to 0.01]; p = 0.415). Similar results were observed for physical HRQOL changes at hospital discharge (adjusted β coefficient for RFCSA change, 0.51 [95% CI, 0.10-0.92]; p = 0.017 and adjusted β coefficient for QT change, -0.21 [-0.76 to 0.35]; p = 0.458). Physical ability was not significantly associated with RFCSA or QT changes at 6 months post-discharge.
Conclusions And Relevance:
Ultrasound derived RFCSA is associated with PICU motor function and hospital discharge physical HRQOL changes, unlike QT, and may be more useful for in-hospital muscle monitoring in critically ill children.
