Feasibility of anterior temporalis muscle ultrasound for assessing muscle wasting in ICU: a prospective cohort study

Purpose: Skeletal muscle ultrasound is a valuable tool for assessing muscle wasting in ICU. Previous studies on skeletal muscle ultrasound in ICU have been performed on lower limb muscles. The current study is formulated to assess the feasibility and reliability of anterior temporalis (AT) muscle ultrasound for measuring muscle wasting in ICU.

Methods: In this prospective cohort study in 48 critically ill patients with sepsis, muscle layer thicknesses (MLTs) and mean grayscale (GS) values of anterior temporalis muscles and quadriceps femoris (Q) were measured at baseline and serially till 7 days. Correlation was made between baseline and change in MLT and GS values of AT and Q muscle and these parameters were compared between ICU survivors and non survivors.

Results: Baseline anterior temporalis MLTs or their longitudinal changes over 7 days did not correlate significantly with the corresponding parameters of quadriceps femoris muscles. The baseline GS values of two muscle groups correlated weakly at baseline, but the change in GS over 7 days showed no correlation. The baseline MLTs of both muscle groups and their longitudinal change over 7 days did not correlate with ICU length of stay. The change in MLT of AT over 7 days was significantly greater in ICU non-survivors compared to survivors.

Conclusion: Measurement of ultrasonographic muscle layer thickness and grayscale parameters of anterior temporalis muscle did not show good correlation with that of quadriceps muscle.