Related Experiment Video
Updated: Nov 4, 2025
Author Spotlight: Assessing Surgical Frailty with Point-of-Care Ultrasound of Quadriceps Muscles
Published on: July 26, 2024
Ultrasound Assessment of Quadriceps Femoris Muscle Thickness in Critically Ill Children
Robert M Hoffmann1,2, Katelyn A Ariagno1,3,4, Ivy V Pham3
1Department of Medicine, Boston Children's Hospital, Boston, MA.
Insights
Ultrasound reliably measures quadriceps femoris muscle thickness in critically ill children. Muscle thickness changes correlate with nutritional intake, not fluid balance, offering a tool to assess nutritional status.
Area of Science:
- Pediatric critical care medicine
- Diagnostic imaging
- Nutritional science
Background:
- Critically ill children often experience muscle wasting.
- Accurate monitoring of muscle mass is crucial for patient outcomes.
- Non-invasive methods for assessing muscle thickness are needed.
Purpose of the Study:
- To evaluate the reliability of ultrasound for measuring quadriceps femoris muscle thickness in critically ill children.
- To assess serial changes in muscle thickness relative to fluid balance and nutritional intake.
Main Methods:
- Prospective observational study in a tertiary care children's hospital.
- Ultrasound measurements of quadriceps femoris muscle thickness were taken in sedated, mechanically ventilated pediatric inpatients.
- Reliability was assessed between pediatric critical care providers and radiologists.
Main Results:
- Ultrasound measurements of quadriceps femoris muscle thickness showed good to excellent reliability among providers.
- No significant association was found between fluid balance and changes in muscle thickness.
- A significant association was observed between nutritional intake (calories and protein) and muscle thickness changes over 6 days.
Conclusions:
- Ultrasound is a reliable tool for measuring quadriceps femoris muscle thickness in critically ill children.
- Muscle thickness changes, reliably tracked by ultrasound, are associated with nutritional status.
- Ultrasound assessment of quadriceps femoris muscle may serve as a proxy for nutritional status in pediatric intensive care.
Objectives:
Evaluate the reliability of ultrasound to measure quadriceps femoris muscle thickness in critically ill children and to describe serial changes in quadriceps femoris muscle thickness in relation to fluid balance and nutritional intake.
Design:
Prospective observational study.
Setting:
Tertiary care children's hospital.
Patients:
Inpatients age 3 months to 18 years recently admitted to the ICU who were sedated and mechanically ventilated at the time of the first ultrasound scan.
Methods:
Prospective observational study to examine the reliability of averaged ultrasound measurements of quadriceps femoris muscle thickness. Change in average quadriceps femoris muscle thickness over time was correlated with fluid balance and nutritional intake.
Interventions:
None.
Measurements And Main Results:
Averaged quadriceps femoris muscle thickness demonstrated good to excellent reliability when comparing pediatric critical care providers to pediatric radiologists and when comparing between different pediatric critical care providers. We found no significant association between fluid balance over 1 or 3 days and change in quadriceps femoris muscle thickness over the same time frame. However, there was a significant association between percent of goal calories (p < 0.001) or percent of goal protein (p < 0.001) over 6 days and change in quadriceps femoris muscle thickness over the same time frame.
Conclusions:
Averaged ultrasound measurements of quadriceps femoris muscle thickness demonstrate good to excellent reliability, are not confounded by fluid balance, and are useful for tracking changes in muscle thickness that are associated with nutritional intake. Ultrasound-based assessment of quadriceps femoris is a clinically useful tool for evaluating muscle mass and may be a proxy for nutritional status.
