Medical Intensive Care Unit, Montpellier University and Montpellier Lapeyronie Teaching Hospital, Avenue du Doyen Gaston Giraud, 34000, Montpellier, France.
INSERM U1046, CNRS UMR9214, Université de Montpellier, Montpellier, France.
Crit Care. 2020 Feb 3;24(1):34. doi: 10.1186/s13054-020-2745-6.
Muscle weakness following critical illness is the consequence of loss of muscle mass and alteration of muscle quality. It is associated with long-term disability. Ultrasonography is a reliable tool to quantify muscle mass, but studies that evaluate muscle quality at the critically ill bedside are lacking. Shear wave ultrasound elastography (SWE) provides spatial representation of soft tissue stiffness and measures of muscle quality. The reliability and reproducibility of SWE in critically ill patients has never been evaluated.
Two operators tested in healthy controls and in critically ill patients the intra- and inter-operator reliability of the SWE using transversal and longitudinal views of the diaphragm and limb muscles. Reliability was calculated using the intra-class correlation coefficient and a bootstrap sampling method assessed their consistency.
We collected 560 images. Longitudinal views of the diaphragm (ICC 0.83 [0.50-0.94]), the biceps brachii (ICC 0.88 [0.67-0.96]) and the rectus femoris (ICC 0.76 [0.34-0.91]) were the most reliable views in a training set of healthy controls. Intra-class correlation coefficient for inter-operator reproducibility and intra-operator reliability was above 0.9 for all muscles in a validation set of healthy controls. In critically ill patients, inter-operator reproducibility and intra-operator 1 and 2 reliability ICCs were respectively 0.92 [0.71-0.98], 0.93 [0.82-0.98] and 0.92 [0.81-0.98] for the diaphragm; 0.96 [0.86-0.99], 0.98 [0.94-0.99] and 0.99 [0.96-1] for the biceps brachii and 0.91 [0.51-0.98], 0.97 [0.93-0.99] and 0.99 [0.97-1] for the rectus femoris. The probability to reach intra-class correlation coefficient greater than 0.8 in a 10,000 bootstrap sampling for inter-operator reproducibility was respectively 81%, 84% and 78% for the diaphragm, the biceps brachii and the rectus femoris respectively.
SWE is a reliable technique to evaluate limb muscles and the diaphragm in both healthy controls and in critically ill patients.
The study was registered (ClinicalTrial NCT03550222).
危重病后肌肉无力是肌肉质量减少和肌肉质量改变的结果。它与长期残疾有关。超声检查是一种可靠的工具，可以定量测量肌肉质量，但缺乏在危重病床边评估肌肉质量的研究。剪切波超声弹性成像（SWE）提供了软组织硬度的空间表示，并测量了肌肉质量。SWE 在危重病患者中的可靠性和可重复性尚未得到评估。
两名操作人员在健康对照组和危重病患者中使用膈肌和肢体肌肉的横切面和纵切面测试了 SWE 的操作者内和操作者间可靠性。使用组内相关系数计算可靠性，并使用 bootstrap 采样方法评估其一致性。
我们共采集了 560 张图像。膈肌的纵切面（ICC 0.83 [0.50-0.94]）、肱二头肌（ICC 0.88 [0.67-0.96]）和股直肌（ICC 0.76 [0.34-0.91]）是健康对照组训练集中最可靠的切面。健康对照组验证集中，所有肌肉的操作者间可重复性和操作者内可靠性的组内相关系数均大于 0.9。在危重病患者中，膈肌的操作者间可重复性和操作者内 1 次和 2 次可靠性 ICC 分别为 0.92 [0.71-0.98]、0.93 [0.82-0.98]和 0.92 [0.81-0.98]；肱二头肌分别为 0.96 [0.86-0.99]、0.98 [0.94-0.99]和 0.99 [0.96-1]；股直肌分别为 0.91 [0.51-0.98]、0.97 [0.93-0.99]和 0.99 [0.97-1]。在 10,000 次 bootstrap 采样中，操作者间可重复性达到组内相关系数大于 0.8 的概率分别为 81%、84%和 78%，用于膈肌、肱二头肌和股直肌。
SWE 是一种可靠的技术，可用于评估健康对照组和危重病患者的肢体肌肉和膈肌。
该研究已注册（ClinicalTrial NCT03550222）。
