Ultrasonography to assess body composition: Relevance of training

Ultrasound for measurement of skeletal muscle mass quantity and muscle composition/architecture in critically ill patients: A scoping review on studies' aims, methods, and findings

AIMS

This scoping review aimed to identify, explore, and map the objectives, methodological aspects, and results of studies that used ultrasound (US) to assess skeletal muscle (SM) in critically ill patients.

METHODS

A scoping review was conducted according to the Joanna Briggs Institute's methodology. All studies that evaluated SM parameters from the US in patients admitted to the intensive care unit (ICU) were considered eligible. We categorized muscle thickness and cross-sectional area as parameters for assessing SM quantity, while echogenicity, fascicle length, and pennation angle analysis were used to evaluate muscle "quality" (composition/architecture). A literature search was conducted using four databases for articles published until December 2022. Independent reviewers selected the studies and extracted data. Descriptive statistics were calculated to present the results.

RESULTS

A total of 107 studies were included, the majority of which were prospective cohort studies (59.8 %) conducted in general ICUs (49.5 %). The most frequent objective of the studies was to evaluate SM quantity depletion during the ICU stay (25.2 %), followed by determining whether a specific intervention would modify SM (21.5 %). Most studies performed serial SM evaluations (76.1 %). The rectus femoris muscle thickness was evaluated in most studies (67.9 %), followed by the rectus femoris cross-sectional area (54.3 %) and the vastus intermedius muscle thickness (40.2 %). The studies demonstrated the feasibility and reproducibility of US for SM evaluation, especially related to quantitative parameters. Most studies (70.3 %) reported significant SM quantity depletion during hospitalization. However, the accuracy of the US in measuring SM varied across the studies.

CONCLUSIONS

The lack of detailed description and standardization in the protocols adopted by the studies included in this scoping review precludes the translation of the evidence related to US for SM assessment into clinical practice.

Ultrasonography and Other Nutrition Assessment Methods to Monitor the Nutrition Status of Critically Ill Patients

BACKGROUND

This study aims to evaluate the use of ultrasonography (US) as an instrument to assess the quadriceps muscles in patients admitted to intensive care units (ICUs), comparing the evolution of US-assessed mass muscle to other nutrition methods.

METHODS

We conducted a prospective observational study of adult patients aged ≥18 years admitted to an ICU of the Hospital das Clínicas in Brazil. Quadriceps muscle measurements were performed by US, and adductor pollicis muscle thickness and arm, calf, and thigh circumferences were measured at admission and every 2 days within the first week. Nutrition status was assessed at baseline by using the Subjective Global Assessment and the Global Leadership Initiative on Malnutrition criteria. Mechanical ventilation time, length of hospital and ICU stay, and mortality were recorded.

RESULTS

Sixty patients were included. Reductions in quadriceps thickness and rectus femoris cross-sectional area were observed at landmarks two-thirds reduction of both measurements from days 1 and 3 to days 5 and 7 (P = .017 and P = .000, respectively). The mid arm circumference (MAC) was reduced. Malnourished patients had lower initial muscle mass. However, muscle mass loss was similar between nourished and malnourished individuals (P > .005). Clinical outcomes were not impacted by muscle loss.

CONCLUSIONS

US muscle mass assessment was able to detect short-term changes in critically ill patients but must be used with caution. MAC was also identified as a useful follow-up tool.