Echogenicity Is Related to Skeletal Muscle Strength in Patients With Acute Respiratory Failure

Area of Science:

• Physiology
• Medical Imaging
• Rehabilitation Medicine

Background:

• Acute respiratory failure (ARF) is associated with alterations in skeletal muscle structure and function.
• Assessing muscle strength in ARF patients can be challenging due to their condition.

Purpose of the Study:

• To investigate the relationship between muscle thickness, echogenicity, and strength in patients diagnosed with ARF.
• To determine if ultrasound measures of skeletal muscle can predict strength deficits in ARF patients.

Main Methods:

• Thirteen patients with ARF underwent knee extensor strength testing using a handheld dynamometer.
• Quadriceps ultrasonography was performed to measure muscle thickness and echogenicity (mean ± SD) of the rectus femoris, vastus lateralis, and vastus medialis.
• Partial correlations, controlling for age, BMI, and fluid intake, were used to analyze relationships between strength and ultrasound parameters.

Main Results:

• A significant positive correlation was found between knee extensor strength and vastus lateralis standard deviation (SD) echogenicity (r = 0.69, P = .029), after controlling for covariates.
• No other significant correlations were observed between muscle strength and other ultrasound measures (thickness, mean echogenicity).

Conclusions:

• Skeletal muscle echogenicity, particularly of the vastus lateralis, is significantly correlated with muscle strength in patients with ARF.
• Ultrasound-derived muscle echogenicity may serve as a valuable tool for identifying muscle weakness in ARF patients who are unable to perform standard strength assessments.