Specialty: Anesthesiology, Critical Care Medicine

Keywords: Frailty, Sarcopenia, Point-of-care Ultrasound

Background:
Frailty is a state of declining physical, physiologic, and cognitive reserve that increases vulnerability to stressors including surgery or acute and chronic illness. Frailty has been shown to lead to poor health outcomes, especially in critically ill patients in the ICU. Sarcopenia, the progressive loss of muscle mass and strength, is an objective marker of frailty. Traditional imaging modalities like CT can assess sarcopenia but are not practical for serial monitoring in ICU settings. Point-of-care ultrasound (POCUS) offers a promising, non-invasive, and repeatable method to quantify muscle mass and track sarcopenia kinetics during hospitalization.

Objective:
To evaluate the feasibility and reliability of serial POCUS-based muscle measurements to assess sarcopenia progression in ICU patients and to identify modifiable risk factors such as nutritional status and mobility that influence frailty trajectories.

Methods:
This ongoing prospective cohort study includes adult ICU patients with expected length of stay >24 hours. POCUS measurements of the rectus femoris and pectoralis major are performed at baseline and serially throughout admission. Additional data include clinical frailty scores, demographics, comorbidities, and biomarkers obtained during routine blood draws. Inter-rater reliability was established through paired scans with an expert ultrasound technician. Muscle size metrics (cross-sectional area, circumference, and depth) are tracked using standardized protocols.

Preliminary Results:
To date, 75 patients have undergone ultrasound-based frailty assessment, with most completing 3 to 5 serial scans before hospital discharge. Inter-rater reliability between student and expert sonographer was high. Descriptive analysis suggests an association between muscle loss and length of stay. Ongoing data analysis will correlate muscle kinetics with biomarkers and clinical interventions such as physical therapy.

Conclusions:
POCUS is a feasible and reliable modality for tracking sarcopenia in critically ill patients. Preliminary data support its potential to inform dynamic frailty assessment and guide individualized interventions. Continued enrollment and analysis will clarify modifiable contributors to sarcopenia and frailty progression in the ICU.