Fetterplace Kate, Corlette Lucy, Abdelhamid Yasmine Ali, Presneill Jeffrey J, Paris Michael T, Stella Damien, Mourtzakis Marina, MacIsaac Christopher, Deane Adam M
Department of Allied Health (Clinical Nutrition), Royal Melbourne Hospital, Melbourne, Australia; Department of Medicine and Radiology, Melbourne Medical School, The University of Melbourne, Royal Melbourne Hospital, Parkville, Australia.
Department of Radiology, Royal Melbourne Hospital, Melbourne, Australia.
Aust Crit Care. 2021 Jul;34(4):303-310. doi: 10.1016/j.aucc.2020.10.008. Epub 2020 Nov 24.
Preserved skeletal muscle mass identified using computed tomography (CT) predicts improved outcomes from critical illness; however, CT imaging have few limitations such that it involves a radiation dose and transferring patients out of the intensive care unit. This study aimed to assess in critically ill patients the relationship between muscle mass estimates obtained using minimally invasive ultrasound techniques with both minimal and maximal pressure compared with CT images at the third lumber vertebra level.
All patients were treated in a single Australian intensive care unit. Eligible patients had paired assessments, within a 72-h window, of muscle mass by ultrasound (quadriceps muscle layer thickness in centimetres, with maximal and minimal pressure) and CT axial cross-sectional area (cm). Data are presented as mean (standard deviation), median (interquartile range), and frequencies [n (%)].
Thirty-five patients [mean (standard deviation) age = 55 (16) years, median (interquartile range) body mass index = 27 (25-32) kg/m, and 26 (74%) men] contributed 41 paired measurements. Quadriceps muscle thickness measured using the maximal pressure technique was a strong independent predictor of lumbar muscle cross-sectional area. Within a multivariate mixed linear regression model and adjusting for sex, age, and body mass index, for every 1 cm increase in quadriceps muscle layer thickness, the lumbar muscle cross-sectional area increased by 35 cm (95% confidence interval = 11-59 cm). Similar univariate associations were observed using minimal pressure; however, as per multivariate analysis, there was no strength in this relationship [8 cm (95% confidence interval = -5 to 22 cm)].
Ultrasound assessment of the quadriceps muscle using maximal pressure reasonably predicts the skeletal muscle at the third lumbar vertebra level of critically ill patients. However, there is substantial uncertainty within these regression estimates, and this may reduce the current utility of this technique as a minimally invasive surrogate for CT assessment of skeletal muscle mass.
使用计算机断层扫描（CT）识别出的保留骨骼肌质量可预测危重症患者的预后改善；然而，CT成像存在一些局限性，包括辐射剂量以及需要将患者转出重症监护病房。本研究旨在评估在危重症患者中，使用微创超声技术在最小和最大压力下获得的肌肉质量估计值与第三腰椎水平CT图像之间的关系。
所有患者均在澳大利亚的一个重症监护病房接受治疗。符合条件的患者在72小时内通过超声（股四头肌层厚度，以厘米为单位，测量最大和最小压力）和CT轴向截面积（平方厘米）进行肌肉质量的配对评估。数据以均值（标准差）、中位数（四分位间距）和频率[n（%）]表示。
35例患者[平均（标准差）年龄=55（16）岁，中位数（四分位间距）体重指数=27（25-32）kg/m²，26例（74%）为男性]提供了41对测量数据。使用最大压力技术测量的股四头肌厚度是腰椎肌肉截面积的强有力独立预测指标。在多变量混合线性回归模型中，并对性别、年龄和体重指数进行调整后，股四头肌层厚度每增加1厘米，腰椎肌肉截面积增加35平方厘米（95%置信区间=11-59平方厘米）。使用最小压力时观察到类似的单变量关联；然而，根据多变量分析，这种关系没有统计学意义[8平方厘米（95%置信区间=-5至22平方厘米）]。
使用最大压力对股四头肌进行超声评估可合理预测危重症患者第三腰椎水平的骨骼肌情况。然而，这些回归估计存在很大不确定性，这可能会降低该技术作为CT评估骨骼肌质量的微创替代方法的当前实用性。
