Novel High-Quality Sonographic Methods to Diagnose Muscle Wasting in Long-Stay Critically Ill Patients: Shear Wave Elastography, Superb Microvascular Imaging and Contrast-Enhanced Ultrasound

Abstract

Novel ultrasound (US) methods are required to assess qualitative changes in the quadriceps rectus femoris (QRF) muscle when evaluating mechanically ventilated, long-stay ICU patients with suspected neuromuscular acquired weakness (ICUAW). Our aim was to analyze novel US muscle assessment methods in these patients versus healthy controls by carrying out a prospective observational study. Shear wave elastography (SWE) showed, with a receiver operating characteristic (ROC) curve of 0.972 (95% confidence interval (CI) = 0.916–1.000), that patients increased muscle stiffness associated with muscle fibrosis when diagnosed with ICUAW. We also performed, for the first time, superb microvascular imaging (SMI), which is an innovative US technique designed for imaging microvascularization unseen with color Doppler US, and observed that 53.8% of cases had significantly lower QRF muscle microvascular angiogenic activity than controls (p < 0.001). Finally, we used contrast-enhanced ultrasound (CEUS) to analyze maximum and minimum QRF muscle perfusion and obtained a ROC curve of 0.8, but when used as markers for SMI, their diagnostic capacity increased to 0.988 (CI = 0.965–1) and 0.932 (CI = 0.858–1), respectively. These findings show, for the first time, that these novel sonographic muscle methods should be used for their diagnostic capacity when assessing sarcopenic processes associated with this group of critically ill patients.

Comparison of Different Ultrasound Methods to Assess Changes in Muscle Mass in Critically ill Patients

“…Puthucheary was one of the first to demonstrate the relevance of the first week of critical illness to muscle loss and the development of ICUAW. 25 Here, 63 ICU- Survivors experienced significant skeletal muscle weakness and physical disability. 23 Though this can be suggested by these data, severe muscle loss, as indicated by ultrasound, during critical illness does not occur in all of our patients.…”

“…Hernández-Socorro et al detected significantly greater levels of subcutaneous edema and fluid in critically ill patients as well as reduced microvascular angiogenic activity compared to a group of healthy controls. 25 Above that, their researched novel high-quality ultrasound tool showed a significant increase in muscle stiffness indicating a significant increase in muscle fibrosis. Although measurement of intrafascial or intramuscular fluid was not part of our study protocols, a different ultrasound technique would nevertheless have been necessary to quantify muscle perfusion or edema formation.…”

The application of quality control in pulmonary ultrasound practice for residents

“…Depending on the development of a standardized examination protocol, they successfully completed the examination, and the overall mean reached a general satisfaction level. The development of new technologies such as contrast-enhanced ultrasound, elastography, and ultra-micro ow imaging has expanded the application eld while improving diagnostic e ciency [8,9] . Standardized examination recommendations and guidelines can assist examiners to improve diagnostic quality and lay the foundation for advanced training programs.…”

A non-volitional skeletal muscle endurance test measures functional changes associated with impaired blood flow

“…We refer to this as a reduction in contraction magnitude. Inducing an ischemic environment should induce a clinically relevant decrease in skeletal muscle function because impaired blood flow is associated with clinical weakness 39 and increased fatiguability. 40 Healthy subjects were used in this study because there were concerns whether tourniquet use in clinical populations might elevate the risk for thrombosis.…”