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Updated: Mar 9, 2026
Author Spotlight: Assessing Surgical Frailty with Point-of-Care Ultrasound of Quadriceps Muscles
Published on: July 26, 2024
Lower quadriceps muscle mass assessed by ultrasound predicts intensive care unit mortality: A cohort study with
Camila Ferri Burgel1, Juliana Umbelino Carneiro2, Alícia Sommer Hartmann3
1Health Science Postgraduate Program from Federal University of Health Sciences from Porto Alegre, Porto Alegre, Brazil.
Objectives:
The prognostic value of ultrasound-derived quadriceps muscle thickness (QMT), the Sonographic Thigh Adjustment Ratio (STAR), and quadriceps muscle volume (QMV) remains unclear. QMT may serve as a practical bedside tool, while STAR and QMV offer body composition-adjusted alternatives. Thus, we aimed to evaluate the association between QMT, STAR, and QMV with prolonged intensive care unit (ICU) length of stay (LOS) and mortality.
Methods:
Cohort study with prospective data collection, including adult patients admitted to the ICU within 24 h. QMT (rectus femoris + vastus intermedius) was measured using B-mode ultrasound. The STAR was calculated as the ratio of QMT to body mass index, and QMV was estimated using two predictive equations that include QMT and thigh length. All these indicators were categorized as lower based on the sex-specific 25th percentile of our sample. Patients were followed until ICU discharge to collect the outcomes. Multivariate Poisson and Cox regression models were performed.
Results:
A total of 400 patients were included (61.5 ± 14.95 years, 56.3% male). ICU mortality was 25.0%, and median ICU LOS was 6 (3.0-12.0) days. In multivariate analysis, QMT (HR = 1.72; 95% CI 1.11-2.65), STAR (HR = 1.60; 95% CI 1.04-2.46), and QMV values calculated by equation 1 (HR = 2.34; 95% CI 1.51-3.62) and equation 2 (HR = 2.32; 95% CI 1.50-3.59) below the 25th percentile were associated with an increased risk of mortality. None of the US-derived muscle indicators were predictive of prolonged ICU stay.
Conclusions:
Lower ultrasound-derived QMT, STAR, and QMV at ICU admission were independently associated with ICU mortality but not prolonged LOS.
Implications For Clinical Practice:
This study demonstrates that quadriceps muscle thickness (QMT), the Sonographic Thigh Adjustment Ratio (STAR), and quadriceps muscle volume (QMV) are independently associated with intensive care unit (ICU) mortality but not with prolonged ICU stay. Notably, adjusted measurements (STAR and QMV) did not outperform QMT alone. These results highlight the clinical relevance of using bedside US as a practical and non-invasive tool for early mortality risk detection in critically ill patients, supporting the implementation of simple QMT assessments in routine ICU care.
