Validation of Bedside Ultrasound of Muscle Layer Thickness of the Quadriceps in the Critically Ill Patient (VALIDUM Study)

Background: In critically ill patients, muscle atrophy is associated with long‐term disability and mortality. Bedside ultrasound may quantify muscle mass, but it has not been validated in the intensive care unit (ICU). Here, we compared ultrasound‐based quadriceps muscle layer thickness (QMLT) with precise quantifications of computed tomography (CT)–based muscle cross‐sectional area (CSA). Methods: Patients ≥18 years old with abdominal CT scans performed for clinical reasons were recruited from 9 ICUs for an ultrasound assessment of the quadriceps. CT scans of the third lumbar vertebra, performed <24 hours before or <72 hours after ICU admission, were analyzed for CSA. Low muscularity was defined as 170 cm² for men and 110 cm² for women. The ultrasound probe was maximally compressed against the skin and QMLT was measured on 2 sites of each quadriceps <72 hours of the CT scan. Results: Mean CT‐derived muscle CSA was 109 ± 25 cm² for women and 168 ± 37 cm² for men, where 58% of patients exhibited low muscularity; only 2.7% patients were underweight according to body mass index. QMLT was positively correlated with CT CSA (r = 0.45, P < .001). Based on logistic regression to predict low muscularity, QMLT independently generated a concordance index (c) of 0.67 (P < .002), which increased to 0.77 (P < .001) when age, sex, body mass index, Charlson Comorbidity Index, and admission type (surgical vs medical) were added. Conclusions: Our results suggest that QMLT alone with our current protocol may not accurately identify patients with low muscle mass.     

Association of Ultrasound-Derived Metrics of the Quadriceps Muscle with Protein Energy Wasting in Hemodialysis Patients: A Multicenter Cross-Sectional Study

This study aimed to assess muscle wasting and risk of protein energy wasting (PEW) in hemodialysis (HD) patients using an ultrasound (US) imaging method. PEW was identified using the ISRNM criteria in 351 HD patients. Quadriceps muscle thickness of rectus femoris (RF) and vastus intermedius (VI) muscles and cross-sectional area (CSA) of the RF muscle (RF_CSA) were measured using US and compared with other physical measures. Associations of US indices with PEW were determined by logistic regression. Irrespective of gender, PEW vs. non-PEW patients had smaller RF, VI muscles, and RF_CSA (all p < 0.001). US muscle sites (all p < 0.001) discriminated PEW from non-PEW patients, but the RF_CSA compared to bio-impedance spectroscopy had a greater area under the curve (AUC, 0.686 vs. 0.581), sensitivity (72.8% vs. 65.8%), and specificity (55.6% vs. 53.9%). AUC of the RF_CSA was greatest for PEW risk in men (0.74, 95% CI: 0.66–0.82) and women (0.80, 95% CI: 0.70–0.90) (both p < 0.001). Gender-specific RF_CSA values (men < 6.00 cm²; women < 4.47 cm²) indicated HD patients with smaller RF_CSA were 8 times more likely to have PEW (AOR = 8.63, 95% CI: 4.80–15.50, p < 0.001). The US approach enabled discrimination of muscle wasting in HD patients with PEW. The RF_CSA was identified as the best US site with gender-specific RF_CSA values to associate with PEW risk, suggesting potential diagnostic criteria for muscle wasting.     

An Analysis of Reliability and Accuracy of Muscle Thickness Ultrasonography in Critically Ill Children and Adults

Background: Muscle wasting starts already within the first week in critically patients and is strongly related to poor outcome. Nevertheless, the early detection of muscle wasting is difficult. Therefore, we investigated the reliability and accuracy of ultrasonography to evaluate skeletal muscle wasting in critically ill children and adults. Methods: This prospective observational study enrolled 30 sedated critically ill children and 14 critically ill adults. Two independent investigators made 210 ultrasonographical assessments of muscle thigh thickness. Inter‐ and intraobserver reliability and cutoff levels were calculated as a function of muscle thickness and the expected reduction in muscle size (predefined at 20% and 30%). Results: Mean ± SD muscle thickness was 1.67 ± 0.55 cm in the pediatric and 2.10 ± 0.85 cm in the adult population. The median absolute interobserver variability was 0.07 cm (interquartile range [IQR], 0.04–0.20 cm) in the pediatric population and 0.05 cm (IQR, 0.03–0.09 cm) in the adult population. However, the absolute intraobserver accuracy had a 95% confidence interval of 0.43 cm in children and 0.22 cm in adults. Only a 30% decrease (0.50 cm) in muscle thickness can be detected in critically ill children. Conclusion: Although the interobserver variability is acceptable in the pediatric population, the intraobserver variability is too large with respect to the expected reduction in muscle thickness. In adults, ultrasonography may be a reliable tool for early detection of muscle mass wasting.     

Muscle Ultrasound and Sarcopenia in Older Individuals: A Clinical Perspective

Introduction

A precise quantitative measurement of skeletal muscle mass is fundamental for diagnosing sarcopenia in older individuals. The current techniques of assessment, including dual-energy x-ray absorptiometry (DXA), bioimpedance analysis (BIA), and magnetic resonance imaging (MRI) are either difficult to perform in everyday clinical practice or biased by concurrent clinical confounders. B-mode muscle ultrasound can be helpful in assessing muscle mass and architecture, and thus possibly useful for diagnosing or screening sarcopenia.

定量超声在肌肉评估中的应用

肌肉是构成人体的重要组织,通过肌肉的收缩可以引导和控制身体的运动.目前可以通过肌电图学(Electromyography)、核磁共振成像(Magnetic Resonance Imaging)和超声成像的方法来评估肌肉功能.定量超声(Quantitative Ultrasound)可以提供有关肌肉结构的定量数据及其在收缩过程中的实时变化,正逐步成为一种可靠的研究和临床工具,在肌肉功能的评估中正扮演着越来越重要的角色.本文总结了定量超声在肌肉评估中的三个方面:肌肉功能性评估、人体运动分析和肌肉硬度(弹性)检测,并且讨论了当前定量超声在肌肉评估中的主要问题和困难.     

Acute Muscle Mass Loss Predicts Long-Term Fatigue,Myalgia, and Health Care Costs in COVID-19 Survivors

ObjectiveWe examined the impact of loss of skeletal muscle mass in post-acute sequelae of SARS-CoV-2 infection, hospital readmission rate, self-perception of health, and health care costs in a cohort of COVID-19 survivors.DesignProspective observational study.Setting and ParticipantsTertiary Clinical Hospital. Eighty COVID-19 survivors age 59 ± 14 years were prospectively assessed.MethodsHandgrip strength and vastus lateralis muscle cross-sectional area were evaluated at hospital admission, discharge, and 6 months after discharge. Post-acute sequelae of SARS-CoV-2 were evaluated 6 months after discharge (main outcome). Also, health care costs, hospital readmission rate, and self-perception of health were evaluated 2 and 6 months after hospital discharge. To examine whether the magnitude of muscle mass loss impacts the outcomes, we ranked patients according to relative vastus lateralis muscle cross-sectional area reduction during hospital stay into either “high muscle loss” (?18 ± 11%) or “low muscle loss” (?4 ± 2%) group, based on median values.ResultsHigh muscle loss group showed greater prevalence of fatigue (76% vs 46%, P = .0337) and myalgia (66% vs 36%, P = .0388), and lower muscle mass (?8% vs 3%, P < .0001) than low muscle loss group 6 months after discharge. No between-group difference was observed for hospital readmission and self-perceived health (P > .05). High muscle loss group demonstrated greater total COVID-19-related health care costs 2 ($77,283.87 vs. $3057.14, P = .0223, respectively) and 6 months ($90,001.35 vs $12, 913.27, P = .0210, respectively) after discharge vs low muscle loss group. Muscle mass loss was shown to be a predictor of total COVID-19-related health care costs at 2 (adjusted β = $10, 070.81, P < .0001) and 6 months after discharge (adjusted β = $9885.63, P < .0001).Conclusions and ImplicationsCOVID-19 survivors experiencing high muscle mass loss during hospital stay fail to fully recover muscle health. In addition, greater muscle loss was associated with a higher frequency of post-acute sequelae of SARS-CoV-2 and greater total COVID-19-related health care costs 2 and 6 months after discharge. Altogether, these data suggest that the loss of muscle mass resulting from COVID-19 hospitalization may incur in an economical burden to health care systems.     

Novel High-Quality Sonographic Methods to Diagnose Muscle Wasting in Long-Stay Critically Ill Patients: Shear Wave Elastography,Superb Microvascular Imaging and Contrast-Enhanced Ultrasound

Novel ultrasound (US) methods are required to assess qualitative changes in the quadriceps rectus femoris (QRF) muscle when evaluating mechanically ventilated, long-stay ICU patients with suspected neuromuscular acquired weakness (ICUAW). Our aim was to analyze novel US muscle assessment methods in these patients versus healthy controls by carrying out a prospective observational study. Shear wave elastography (SWE) showed, with a receiver operating characteristic (ROC) curve of 0.972 (95% confidence interval (CI) = 0.916–1.000), that patients increased muscle stiffness associated with muscle fibrosis when diagnosed with ICUAW. We also performed, for the first time, superb microvascular imaging (SMI), which is an innovative US technique designed for imaging microvascularization unseen with color Doppler US, and observed that 53.8% of cases had significantly lower QRF muscle microvascular angiogenic activity than controls (p < 0.001). Finally, we used contrast-enhanced ultrasound (CEUS) to analyze maximum and minimum QRF muscle perfusion and obtained a ROC curve of 0.8, but when used as markers for SMI, their diagnostic capacity increased to 0.988 (CI = 0.965–1) and 0.932 (CI = 0.858–1), respectively. These findings show, for the first time, that these novel sonographic muscle methods should be used for their diagnostic capacity when assessing sarcopenic processes associated with this group of critically ill patients.     

胎儿颈项透明层厚度检查联合孕中期四维彩超在产前胎儿畸形筛查中的应用价值

目的:分析在产前胎儿畸形筛查中采取胎儿颈项透明层厚度(NT)检查联合孕中期四维彩超检查的应用价值。方法:选取本中心2017年11月~2018年6月进行产前检查的200例产妇,在孕11~14周进行NT检查,孕22~28周进行四维彩超检查。分析两种检查方式在胎儿畸形筛查中的准确率。结果:NT检查胎儿异常检查准确率93.10%,孕中期四维彩超胎儿异常检查准确率为100.00%。结论:采取NT检查联合孕中期四维彩超检查在产前胎儿畸形筛查中应用效果良好。     

Temporal Muscle and Stroke—A Narrative Review on Current Meaning and Clinical Applications of Temporal Muscle Thickness,Area, and Volume

Background: Evaluating muscle mass and function among stroke patients is important. However, evaluating muscle volume and function is not easy due to the disturbances of consciousness and paresis. Temporal muscle thickness (TMT) has been introduced as a novel surrogate marker for muscle mass, function, and nutritional status. We herein performed a narrative literature review on temporal muscle and stroke to understand the current meaning of TMT in clinical stroke practice. Methods: The search was performed in PubMed, last updated in October 2021. Reports on temporal muscle morphomics and stroke-related diseases or clinical entities were collected. Results: Four studies reported on TMT and subarachnoid hemorrhage, two studies on intracerebral hemorrhage, two studies on ischemic stroke, two studies on standard TMT values, and two studies on nutritional status. TMT was reported as a prognostic factor for several diseases, a surrogate marker for skeletal muscle mass, and an indicator of nutritional status. Computed tomography, magnetic resonance imaging, and ultrasonography were used to measure TMT. Conclusions: TMT is gradually being used as a prognostic factor for stroke or a surrogate marker for skeletal muscle mass and nutritional status. The establishment of standard methods to measure TMT and large prospective studies to further investigate the relationship between TMT and diseases are needed.     

Predictors of Sarcopenia in Outpatients with Post-Critical SARS-CoV2 Disease. Nutritional Ultrasound of Rectus Femoris Muscle,a Potential Tool

Background and Objectives: The loss of muscle mass in post-critical COVID-19 outpatients is difficult to assess due to the limitations of techniques and the high prevalence of obesity. Ultrasound is an emerging technique for evaluating body composition. The aim is to evaluate sarcopenia and its risk factors, determining ultrasound usefulness as a potential tool for this purpose according to established techniques, such as the bioimpedance vector analysis (BIVA), handgrip strength, and timed up-and-go test. Methods: This is a transversal study of 30 post-critical COVID-19 outpatients. We evaluated nutritional status by ultrasound (Rectus Femoris-cross-sectional-area (RF-CSA), thickness, and subcutaneous-adipose-tissue), BIVA, handgrip strength, timed up-and-go test, and clinical variables during admission. Results: According to The European Society for Clinical Nutrition and Metabolism and the European Association for the Study of Obesity (ESPEN&EASO) Consensus for Sarcopenic and Obesity, in terms of excess fat mass and decreased lean mass, the prevalence of class-1 sarcopenic obesity was 23.4% (n = 7), and class-2 sarcopenic obesity was 33.3% (n = 10) in our study. A total of 46.7% (n = 14) of patients had a handgrip strength below the 10th percentile, and 30% (n = 9) achieved a time greater than 10s in the timed up-and-go test. There were strong correlations between the different techniques that evaluated the morphological (BIVA, Ultrasound) and functional measurements of muscle. Intensive care unit stay, mechanical ventilation, and age all conditioned the presence of sarcopenia in COVID-19 outpatients (R² = 0.488, p = 0.002). Predictive models for sarcopenic diagnosis based on a skeletal muscle index estimation were established by RF-CSA (R² 0.792, standard error of estimate (SEE) 1.10, p < 0.001), muscle-thickness (R² 0.774, SEE 1.14, p < 0.001), and handgrip strength (R² 0.856, SEE 0.92, p < 0.001). RF-CSA/weight of 5.3 cm²/kg × 100 was the cut-off value for predicting sarcopenia in post-critical COVID-19 outpatients, with 88.2 sensitivity and 69.2% specificity. Conclusion: More than half of the post-critical COVID-19 survivors had sarcopenic obesity and functional impairment of handgrip strength. Intensive care unit stay, age, and mechanical ventilation all predict sarcopenia. An ultrasound, when applied to the assessment of body composition in post-critical COVID-19 patients, provided the possibility of assessing sarcopenia in this population.     

基于振动-超声法测量肌肉硬度

现有的各种研究肌肉硬度的方法有其各自的优点和局限性。在过去的此类研究中,很少使用肌肉最大自主收缩（Maximum Voluntary Contraction,MVC）扭矩的百分比来表达相对收缩水平,而且缺少高收缩水平（40%MVC以上）下测量肌肉硬度的手段。本文采用了一种基于振动-超声法测量剪切波波速,继而计算肌肉剪切模量的新方法,解决了高收缩水平下肌肉硬度的测量问题。我们以右腿股中间肌为目标,测量了从0%～100%MVC共11个不同等长收缩水平下的肌肉剪切模量。两组年轻的健康男性和女性受试者（各10名）自愿参加了本次研究。研究结果表明,股中间肌沿肌纤维方向的剪切模量,与肌肉的相对收缩水平正相关,它们之间的拟合结果接近二次多项式关系。在相同的相对收缩水平下,男性的肌肉硬度大于女性。     

Augmented Renal Clearance,Muscle Catabolism and Urinary Nitrogen Loss: Implications for Nutritional Support in Critically Ill Trauma Patients

The main objective of this pilot study was to determine the association between augmented renal clearance (ARC), urinary nitrogen loss and muscle wasting in critically ill trauma patients. We conducted a retrospective analysis of a local database in 162 critically ill trauma patients without chronic renal dysfunction. Nutritional-related parameters and 24 h urinary biochemical analyses were prospectively collected and averaged over the first ten days after admission. Augmented renal clearance was defined by a mean creatinine clearance (CL_CR) > 130 mL/min/1.73 m². The main outcome was the cumulated nitrogen balance at day 10. The secondary outcome was the variation of muscle psoas cross-sectional area (ΔCSA) calculated in the subgroup of patients who underwent at least two abdominal CT scans during the ICU length of stay. Overall, there was a significant correlation between mean CL_CR and mean urinary nitrogen loss (normalized coefficient: 0.47 ± 0.07, p < 0.0001). ARC was associated with a significantly higher urinary nitrogen loss (17 ± 5 vs. 14 ± 4 g/day, p < 0.0001) and a lower nitrogen balance (−6 ± 5 vs. −4 ± 5 g/day, p = 0.0002), without difference regarding the mean protein intake (0.7 ± 0.2 vs. 0.7 ± 0.3 g/kg/day, p = 0.260). In the subgroup of patients who underwent a second abdominal CT scan (N = 47), both ΔCSA and %ΔCSA were higher in ARC patients (−33 [−41; −25] vs. −15 [−29; −5] mm²/day, p = 0.010 and −3 [−3; −2] vs. −1 [−3; −1] %/day, p = 0.008). Critically ill trauma patients with ARC are thus characterized by a lower nitrogen balance and increased muscle loss over the 10 first days after ICU admission. The interest of an increased protein intake (>1.5 g/kg/day) in such patients remains a matter of controversy and must be confirmed by further randomized trials.     

Muscle Thickness and Echogenicity Measured by Ultrasound Could Detect Local Sarcopenia and Malnutrition in Older Patients Hospitalized for Hip Fracture

Background: The aim of this work was to assess whether the muscle thickness and echogenicity were associated with dysphagia, malnutrition, sarcopenia, and functional capacity in acute hospital admission for a hip fracture. Methods: Observational study that assessed nutritional status by Global Leadership Initiative on Malnutrition, risk of dysphagia and sarcopenia by European Working Group on Sarcopenia in Older People and Barthel functional index. We measured muscle thickness and echogenicity of masseter, bicipital, and quadriceps rectus femoris (RF) and vastus intermedius (VI) by ultrasound. Results: One hundred and one patients were included in the study (29.7% sarcopenia and 43.8% malnutrition). Logistic regression models adjusted for age, sex, and body mass index showed an inverse association of the masseter thickness with both sarcopenia (OR: 0.56) and malnutrition (OR: 0.38) and quadriceps with sarcopenia (OR: 0.74). In addition, patients at high risk of dysphagia had lower masseter thickness (p: 0.0001) while patients able to self-feeding had thicker biceps (p: 0.002) and individuals with mobility on level surfaces higher thickness of biceps (p: 0.008) and quadriceps (p: 0.04). Conclusion: Thickness of the masseter was associated with risk of dysphagia, biceps with the ability to self-feed, and that of the quadriceps RF-VI with mobility.     

Association of Energy and Protein Delivery on Skeletal Muscle Mass Changes in Critically Ill Adults: A Systematic Review

Critically ill patients experience significant and rapid loss of skeletal muscle mass, which has been associated with negative clinical outcomes. The aetiology of muscle wasting is multifactorial and nutrition delivery may play a role. A systematic literature review was conducted to examine the association of energy and/or protein provision on changes in skeletal muscle mass in critically ill patients. Key databases were searched up until March 2016 to identify studies that measured skeletal muscle mass and/or total body protein (TBP) at 2 or more time points during acute critical illness (up to 2 weeks after an intensive care unit [ICU] stay). Studies were included if there was documentation of participant energy balance or mean energy delivered to participants during the time period between body composition measurements. Six studies met inclusion criteria. A variety of methods were used to assess skeletal muscle mass or TBP. Participants in included studies experienced differing levels of muscle loss (0%–22.5%) during the first 2 weeks of ICU admission. No association between energy and protein delivery and changes in skeletal muscle mass were observed. This review highlights that there is currently limited high‐quality evidence to clearly define the association between energy and/or protein delivery and skeletal muscle mass changes in acute critical illness. Future studies in this area should be adequately powered, account for all potential confounding factors to changes in skeletal muscle mass, and detail all sources and quantities of energy and protein delivered to participants.     

Assessing Additional Characteristics of Muscle Function With Digital Handgrip Dynamometry and Accelerometry: Framework for a Novel Handgrip Strength Protocol

Maximal handgrip strength (HGS) is a convenient and reliable, but incomplete, assessment of muscle function. Although low HGS is a powerful predictor of poor health, several limitations to maximal HGS exist. The predictive value of HGS is restricted because low HGS is associated with a wide range of unspecified health conditions, and other characteristics of muscle function aside from strength capacity are not evaluated. Current HGS protocol guidelines emphasize the ascertainment of maximal force, which is only a single muscle function characteristic. Muscle function is intrinsically multivariable, and assessing other attributes in addition to strength capacity will improve screenings for age-related disabilities and diseases. Digital handgrip dynamometers and accelerometers provide unique opportunities to examine several aspects of muscle function beyond strength capacity, while also maintaining procedural ease. Specifically, digital handgrip dynamometry and accelerometry can assess the rate of force development, submaximal force steadiness, fatigability, and task-specific tremoring. Moreover, HGS protocols can be easily refined to include an examination of strength asymmetry and bilateral strength. Therefore, evaluating muscle function with new HGS technologies and protocols may provide a more comprehensive assessment of muscle function beyond maximal strength, without sacrificing feasibility. This Special Article introduces a novel framework for assessing multiple attributes of muscle function with digital handgrip dynamometry, accelerometry, and refinements to current HGS protocols. Such framework may aid in the discovery of measures that better predict and explain age-related disability, biological aging, and the effects of comorbid diseases that are amenable to interventions. These additional HGS measures may also contribute to our understanding of concepts such as resilience. Using sophisticated HGS technologies that are currently available and modernizing protocols for developing a new muscle function assessment may help transform clinical practice by enhancing screenings that will better identify the onset and progression of the disabling process.     

EMG Biofeedback as a Tool for Simulating the Effects of Specific Leg Muscle Weakness on a Lifting Task

This study investigated the use of EMG biofeedback to simulate weakened rectus femorii and gastrocnemii muscles during the performance of a lifting task. Eight healthy women performed 15 kg free-style lifts from floor level. Three conditions were tested: unconstrained lifting, lifting with rectus femorii activity volitionally limited bilaterally through EMG biofeedback to less than 45% of maximal EMG activity, and lifting with the gastrocnemii limited to a similar level. Limiting leg muscle activity through biofeedback led to an alteration of lifting strategy, with resulting performance variables (joint angles and torques, angular velocities, center of pressure excursion, and segment coordination) comparing favorably with those from lifting trials performed by six women with moderate leg muscle weaknesses. The data indicate that EMG biofeedback can be used to simulate the effects of leg muscle weakness during these lifts, providing a new tool to study the biomechanics of muscle weakness.     

Developing and Testing a Measurement Tool for Assessing Predictors of Breakfast Consumption Based on a Health Promotion Model

ObjectiveTo develop an instrument for measuring Health Promotion Model constructs in terms of breakfast consumption, and to identify the constructs that were predictors of breakfast consumption among Iranian female students.DesignA questionnaire on Health Promotion Model variables was developed and potential predictors of breakfast consumption were assessed using this tool.ParticipantsOne hundred female students, mean age 13 years (SD ± 1.2 years).SettingsTwo middle schools from moderate-income areas in Qom, Iran.Variables MeasuredHealth Promotion Model variables were assessed using a 58-item questionnaire. Breakfast consumption was also measured.AnalysisInternal consistency (Cronbach alpha), content validity index, content validity ratio, multiple linear regression using stepwise method, and Pearson correlation.ResultsContent validity index and content validity ratio scores of the developed scale items were 0.89 and 0.93, respectively. Internal consistencies (range, .74–.91) of subscales were acceptable. Prior related behaviors, perceived barriers, self-efficacy, and competing demand and preferences were 4 constructs that could predict 63% variance of breakfast frequency per week among subjects.Conclusions and ImplicationsThe instrument developed in this study may be a useful tool for researchers to explore factors affecting breakfast consumption among students. Students with a high level of self-efficacy, more prior related behavior, fewer perceived barriers, and fewer competing demands were most likely to regularly consume breakfast.