Muscle Ultrasound for the ICU Patient

Muscle ultrasound (US) imaging is a useful diagnostic technique. It is noninvasive, sensitive, inexpensive, safe, and available at bedside and allows repeated measurements. In the last years, it became routinely used in the intensive care unit (ICU) to study and evaluate muscle quality, function, and mass. In critical care patients, muscle wasting occurs early and rapidly, with subsequent impaired function and disruption of muscle architecture. This condition is defined ICU-acquired weakness (ICU-AW). Although there is no gold standard assessment method for diagnosing ICU-AW, many studies utilized US to interpret the association of muscle composition with functional or clinical outcome. US measurement of lower limb muscles is highly reproducible and can demonstrate changes in muscle thickness, loss of muscle mass, and changes of quality (echogenicity). In this regard, identifying as soon as possible the onset of ICU-AW could be critical for the optimization of nutritional therapy and physiokinesitherapy (FKT) programs.