Skoczynski Rachel, Hansen Jonathan, Adhikary Sanjib Das, Lehman Erik, Bonavia Anthony S
Department of Anesthesiology and Perioperative Medicine, Penn State Milton S Hershey Medical Center, Hershey, PA 17036, USA.
Department of Public Health Sciences, Penn State College of Medicine, Hershey, PA, USA.
medRxiv. 2025 Mar 20:2025.03.19.25324253. doi: 10.1101/2025.03.19.25324253.
Muscle wasting is a major concern in ICUs, contributing to morbidity, mortality, and prolonged rehabilitation. While CT-derived L3 Skeletal Muscle Index (L3SMI) assesses core muscle mass, it may not capture peripheral muscle atrophy or fluid-based changes. Point-of-care ultrasound (POCUS) offers a rapid, non-invasive alternative. This study evaluated the prognostic value of POCUS-based muscle measurements compared with L3SMI in predicting mortality, frailty, and functional outcomes.
In this prospective study, 50 critically ill adults meeting Sepsis-3 criteria or requiring respiratory/vasopressor support underwent POCUS assessments of biceps brachii, rectus femoris, and vastus intermedius thickness at days 1, 7, and 14 post-ICU admission. Twenty-eight patients also had CT scans within seven days for L3SMI calculation. The primary outcome was 90-day mortality; secondary outcomes included in-hospital and 30-day mortality, Clinical Frailty Score, and Zubrod/ECOG performance status. Muscle measurements were analyzed both raw and indexed to body surface area, with predictive performance assessed via correlation and ROC analysis.
Day 1 biceps brachii thickness strongly predicted in-hospital mortality (AUC 0.84; sensitivity 1.0, specificity 0.67) and retained predictive value for 30-day and 90-day mortality. Vastus intermedius thickness on day 1 was moderately predictive (AUC 0.79). At later time points, larger vastus intermedius measurements correlated negatively with ICU- and ventilator-free days, suggesting edema-related pseudohypertrophy. L3SMI did not significantly correlate with ultrasound-based muscle measurements or clinical outcomes. POCUS-derived peripheral muscle indexing was associated with frailty indices, highlighting its role in capturing meaningful functional deficits.
POCUS-based muscle assessments, particularly of the biceps brachii and vastus intermedius, provide valuable prognostic insights beyond conventional L3SMI. While L3SMI remains a core muscle measure, fluid shifts and localized muscle wasting in critical illness may be better captured by ultrasound.
肌肉萎缩是重症监护病房（ICU）中的一个主要问题，会导致发病率、死亡率升高以及康复时间延长。虽然基于CT的L3骨骼肌指数（L3SMI）可评估核心肌肉质量，但它可能无法检测到外周肌肉萎缩或基于液体的变化。床旁超声（POCUS）提供了一种快速、无创的替代方法。本研究评估了与L3SMI相比，基于POCUS的肌肉测量在预测死亡率、虚弱程度和功能结局方面的预后价值。
在这项前瞻性研究中，50名符合脓毒症-3标准或需要呼吸/血管活性药物支持的危重症成人在入住ICU后的第1、7和14天接受了肱二头肌、股直肌和股中间肌厚度的POCUS评估。28名患者还在7天内进行了CT扫描以计算L3SMI。主要结局是90天死亡率；次要结局包括住院期间和30天死亡率、临床虚弱评分以及Zubrod/ECOG体能状态。对肌肉测量值进行原始分析并根据体表面积进行指数化分析，通过相关性分析和ROC分析评估预测性能。
第1天的肱二头肌厚度对住院死亡率有很强的预测作用（AUC为0.84；敏感性为1.0，特异性为0.67），并且对30天和90天死亡率仍具有预测价值。第1天的股中间肌厚度具有中等预测性（AUC为0.79）。在随后的时间点，股中间肌测量值越大与无ICU和无呼吸机天数呈负相关，提示与水肿相关的假性肥大。L3SMI与基于超声的肌肉测量值或临床结局无显著相关性。基于POCUS的外周肌肉指数与虚弱指数相关，突出了其在检测有意义的功能缺陷方面的作用。
基于POCUS的肌肉评估，尤其是肱二头肌和股中间肌的评估，提供了超越传统L3SMI的有价值的预后见解。虽然L3SMI仍然是核心肌肉测量指标，但超声可能更能检测到危重症中的液体转移和局部肌肉萎缩。
