Rectus Femoris Cross-sectional Area Research Articles

Intra-Rater Reliability of Panoramic Ultrasound Imaging for Determining Quadriceps Muscle Cross-Sectional Area inMiddle-Aged and Elderly Adults.

Panoramic ultrasound (US) is an extended field-of-view (EFOV) imaging technique that enables visualization of large-scale skeletal muscles. This technique has previously been found to produce valid and reliable quantifications of muscle morphology in primarily young male subjects. The purpose was to investigate the intra-rater between-session test-retest reliability of panoramic US imaging for determining vastus lateralis (VL) and rectus femoris (RF) cross-sectional area (mCSA) in healthy middle-aged to elderly adults. In this cross-sectional study, axial panoramic US images of the RF and VL muscles were captured in 23 healthy females and males aged 47 to 78. Assessed across two sessions 3-7 days apart, intra-rater reliability was evaluated by intraclass correlation coefficients (ICC3,2), within-subject coefficient of variation , standard error of measurement (SEM), and minimal detectable change (MDC). Mean mCSA for RF was mean ± SD, 7.5 ± 2.7 cm2 on both test days, with a numeric difference of 0.8%. Mean VL mCSA was 20.6 ± 6.6 cm2 and 20.5 ± 6.5 cm2 on test days 1 and 2, respectively. Test-retest ICC were: 0.997 (95% CI: 0.994-0.999) for RF and 0.995 (95% CI: 0.989-0.998) for VL. was 2.6% for RF and 2.4% for VL. SEM was 0.2 cm2 for RF and 0.5 cm2 for VL. MDC was 0.4 cm2 for RF and 1.3 cm2 for VL. In conclusion, panoramic EFOV US is a highly reliable imaging technique for assessing RF and VL mCSA in middle-aged and elderly adults. These findings endorse the clinical and research utility of EFOV US and its sensitivity for detecting even minor changes in skeletal muscle size.

Evaluating Muscle Mass Changes in Critically Ill Patients: Rehabilitation Outcomes Measured by Ultrasound and Bioelectrical Impedance.

The loss of muscle mass is common in critically ill patients and is associated with poor prognosis, and efforts have been made to mitigate muscle loss through rehabilitation. This study aimed to evaluate changes in muscle mass in critically ill patients following rehabilitation. We enrolled 53 patients expected to stay in the ICU for more than 7 days, dividing them into rehabilitation (15 patients) and no rehabilitation groups (38 patients). Muscle mass was measured using ultrasound and bioelectrical impedance analysis (BIA). Baseline characteristics and comorbidities showed no statistical differences between the two groups. Initial measurements of muscles showed no significant differences between the groups in rectus femoris thickness, total anterior thigh muscle thickness, cross-sectional area, echogenicity, or in-body skeletal muscle mass at baseline and 7 days. However, at 14 days, significant differences emerged. The rehabilitation group had greater rectus femoris thickness (1.42 cm vs. 0.81 cm, p = 0.007) and total anterior thigh muscle thickness (3.79 cm vs. 2.32 cm, p = 0.007) compared to the no rehabilitation group. Additionally, the rehabilitation group experienced a significantly smaller reduction in rectus femoris cross-sectional area (-4.6% vs. -22.8%, p = 0.021). Although survival rates were higher in the rehabilitation group (73.3% vs. 52.6%), this difference was not statistically significant (p = 0.096). Our findings suggest that rehabilitation in critically ill patients is associated with a slower rate of muscle loss, particularly in the cross-sectional area of the rectus femoris muscle, which may be beneficial for patient recovery.

Multiparametric Approach to the Colorectal Cancer Phenotypes Integrating Morphofunctional Assessment and Computer Tomography.

(1) Background: Accurate body composition assessment in CCR patients is crucial due to the high prevalence of malnutrition, sarcopenia, and cachexia affecting survival. This study evaluates the correlation between body composition assessed by CT imaging as a reference technique, BIVA, nutritional ultrasound, and handgrip strength in CCR patients. (2) Methods: This retrospective study included CCR patients assessed by the Endocrinology and Nutrition Services of Virgen de la Victoria in Malaga and Vall d'Hebron in Barcelona from October 2018 to July 2023. Assessments included anthropometry, BIVA, NU, HGS, and AI-assisted CT analysis at the L3 level for body composition. Pearson's analysis determined the correlation of CT-derived variables with BIVA, NU, and HGS. (3) Results: A total of 267 CCR patients (mean age 68.2 ± 10.9 years, 61.8% men) were studied. Significant gender differences were found in body composition and strength. CT-SMI showed strong correlations with body cell mass (r = 0.65), rectus femoris cross-sectional area (r = 0.56), and handgrip strength (r = 0.55), with a Cronbach's alpha of 0.789. CT-based adipose tissue measurements showed significant correlations with fat mass (r = 0.56), BMI (r = 0.78), A-SAT (r = 0.49), and L-SAT (r = 0.66). Regression analysis indicated a high predictive power for CT-SMI, explaining approximately 80% of its variance (R2 = 0.796). (4) Conclusions: Comprehensive screening of colorectal cancer patients through BIVA, NU, HGS, and CT optimizes the results of the evaluation. These methods complement each other in assessing muscle mass, fat distribution, and nutritional status in CCR. When CT is unavailable or bedside assessment is needed, HGS, BIVA, and NU provide an accurate assessment of body composition.

Short-Term Multicomponent Exercise Impact on Muscle Function and Structure in Hospitalized Older at Risk of Acute Sarcopenia.

Hospitalization exacerbates sarcopenia and physical dysfunction in older adults. Whether tailored inpatient exercise prevents acute sarcopenia is unknown. This study aimed to examine the effect of a multicomponent exercise programme on muscle and physical function in hospitalized older adults. We hypothesized that participation in a brief tailored exercise regimen (i.e., 3-5 days) would attenuate muscle function and structure changes compared with usual hospital care alone. This randomized clinical trial with blinded outcome assessment was conducted from May 2018 to April 2021 at Hospital Universitario de Navarra, Spain. Participants were 130 patients aged 75 years and older admitted to an acute care geriatric unit. Patients were randomized to a tailored 3- to 5-day exercise programme (n = 64) or usual hospital care (control, n = 66) consisting of physical therapy if needed. The coprimary endpoints were between-group differences in changes in short physical performance battery (SPPB) score and usual gait velocity from hospital admission to discharge. Secondary endpoints included changes in rectus femoris echo intensity, cross-sectional area, thickness and subcutaneous and intramuscular fat by ultrasound. Among 130 randomized patients (mean [SD] age, 87.7 [4.6] years; 57 [44%] women), the exercise group increased their mean SPPB score by 0.98 points (95% CI, 0.28-1.69 points) and gait velocity by 0.09 m/s (95% CI, 0.03-0.15 m/s) more than controls (both p < 0.01). No between-group differences were observed in any ultrasound muscle outcomes. There were no study-related adverse events. Three to 5 days of tailored multicomponent exercise provided functional benefits but did not alter muscle or fat architecture compared with usual hospital care alone among vulnerable older patients. Brief exercise may help prevent acute sarcopenia during hospitalization. ClinicalTrials.gov identifier: NCT04600453.

The Role of Cystic Fibrosis Transmembrane Conductance Regulator in Skeletal Muscle Contractile Function

Purpose: Genetic mutations in cystic fibrosis (CF) result in CF transmembrane conductance regulator (CFTR) dysfunction. CFTR is expressed in human skeletal muscle; its effect on skeletal muscle abnormalities is unknown. The study objective is to investigate the role of CFTR in skeletal muscle contractile function. Methods: We conducted a prospective, cross-sectional study comparing 34 adults with minimal and 18 with residual function CFTR mutations, recruited from Toronto Adult CF Centre, St. Michael's Hospital, Unity Health Toronto. Quadriceps, biceps brachii, and handgrip strength was measured with dynamometers; leg muscle power with the stair climb power test. Quadriceps muscle contractility was determined by quadriceps muscle strength normalized to quadriceps muscle size, measured with ultrasound images. Multivariable regression was used for analysis. Results: People with residual function CFTR mutations had higher quadriceps muscle torque normalized to quadriceps layer thickness and to rectus femoris cross-sectional area by 27.5 Nm/cm [95% CI (2.2, 52.8) Nm/cm, P = .034] and 5.6 Nm/cm2 [95% CI (0.3, 10.9) Nm/cm2, P = .041], respectively, compared with those with minimal function CFTR mutations. There were no differences in quadriceps muscle torque (P = .58), leg muscle power (P = .47), biceps brachii muscle force (P = .14), or handgrip force (P = .12) between the 2 mutation groups. Conclusions: CFTR protein may play a role in muscle contractility, implying a limited capacity to exert muscle force per unit of muscle size in people with CF. This suggests that building a greater muscle mass through resistance exercises focusing on muscle hypertrophy in exercise prescription may improve muscle strength in people with CF.

Use of muscular ultrasound to detect intensive care unit-acquired weakness: a systematic review and Meta-analysis.

This systematic review and meta-analysis aims to detecting performance of muscular ultrasound for intensive care unit (ICU)-acquired weakness (ICUAW). We searched PubMed, Web of Science, Embase, Cochrane library, CNKI, VIP, and Wanfang databases for articles published before July 2024. A random-effects model was utilized to derive the summary estimates of sensitivity, specificity, and diagnostic odds ratio (DOR) with 95% confidence interval (CI). Additionally, the sources of heterogeneity were explored by subgroup analysis and meta-regression. This meta-analysis comprised ten prospective studies involving 561 participants, of whom 241 (42.96%) were diagnosed as ICUAW. Overall, muscular ultrasound exhibited good performance for detecting ICUAW, with the area of SROC curve of 0.85 (95%CI 0.82-0.88), sensitivity of 0.76 (95%CI 0.70-0.81), specificity of 0.80 (95%CI 0.74-0.84), and DOR of 12.43 (95%CI 7.98-19.38). Upon pre-defined subgroup analysis, the rectus femoris exhibited significantly superior discriminatory ability in identifying ICUAW than the non-rectus femoris, with higher SROC (0.88 [95%CI 0.85-0.91] vs. 0.76 [95%CI 0.72-0.79], p < 0.01). Moreover, cross-sectional area was more effective than thickness, with higher specificity (0.86 [95%CI 0.80-0.91] vs. 0.74 [95%CI 0.68-0.79], p = 0.02) and SROC (0.89 [95%CI 0.86-0.92] vs. 0.76 [95%CI 0.72-0.80], p < 0.01). Furthermore, integrated analysis of these two indicators revealed that the cross-sectional area of rectus femoris was statistically superior to the thickness of rectus femoris, with higher sensitivity (0.82 [95%CI 0.74-0.87] vs. 0.75 [95%CI 0.65-0.83], p < 0.05) and AUC (0.91 [95%CI 0.88-0.93] vs. 0.80 [95%CI 0.76-0.83], p < 0.01). Muscular ultrasound could be a reliable tool for ICUAW detection. Compared with alternative indices, the cross-sectional area of the rectus femoris exhibits superior detection efficacy and may be considered as a valuable parameter for clinical application.

IA-Body Composition CT at T12 in Idiopathic Pulmonary Fibrosis: Diagnosing Sarcopenia and Correlating with Other Morphofunctional Assessment Techniques.

Body composition (BC) techniques, including bioelectrical impedance analysis (BIVA), nutritional ultrasound® (NU), and computed tomography (CT), can detect nutritional diagnoses such as sarcopenia (Sc). Sc in idiopathic pulmonary fibrosis (IPF) is associated with greater severity and lower survival. Our aim was to explore the correlation of BIVA, NU and functional parameters with BC at T12 level CT scans in patients with IPF but also its relationship with degree of Sc, malnutrition and mortality. This bicentric cross-sectional study included 60 IPF patients (85.2% male, 70.9 ± 7.8 years). Morphofunctional assessment (MFA) techniques included BIVA, NU, CT at T12 level (T12-CT), handgrip strength, and timed up and go. CT data were obtained using FocusedON®. Statistical analysis was conducted using JAMOVI version 2.3.22 to determine the cutoff points for Sc in T12-CT and to analyze correlations with other MFA techniques. the cutoff for muscle area in T12-CT was ≤77.44 cm2 (area under the curve (AUC) = 0.734, sensitivity = 41.7%, specificity = 100%). The skeletal muscle index (SMI_T12CT) cutoff was ≤24.5 cm2/m2 (AUC = 0.689, sensitivity = 66.7%, specificity = 66.7%). Low SMI_T12CT exhibited significantly reduced median survival and higher risk of mortality compared to those with normal muscle mass (SMI cut off ≥ 28.8 cm/m2). SMI_T12CT was highly correlated with body cell mass from BIVA (r = 0.681) and rectus femoris cross-sectional area (RF-CSA) from NU (r = 0.599). Cronbach's α for muscle parameters across different MFA techniques and CT was 0.735, confirming their validity for evaluating muscle composition. T12-CT scan is a reliable technique for measuring low muscle mass in patients with IPF, specifically when the L3 vertebrae are not captured. An SMI value of <28.8 is a good predictor of low lean mass and 12-month mortality in IPF patients.

The Role of Combined Muscle Ultrasound and Bioimpedentiometry Parameters for Sarcopenia Diagnosis in a Population of Hospitalized Older Adults.

For the study of quantitative and qualitative muscle parameters, ultrasound and bioelectric impedance analysis are reliable, non-invasive, and reproducible. The aim of this study was to test the combined role of those techniques for the diagnosis of sarcopenia in a population of hospitalized older males and females. A total of 70 subjects were recruited, including 10 healthy adults and 60 hospitalized elderly patients with a good level of independence and cooperation, with and without sarcopenia. The rectus femoris cross-sectional area (CSA), thickness, echogenicity, and compressibility were measured with ultrasound echography. The phase angles (PhAs) and skeletal muscle mass were calculated by bioimpedence analysis. The muscle quality index (MQI) was calculated as the product of CSA and PhA. Muscle compressibility was greater and PhA was lower in sarcopenic when compared with non-sarcopenic subjects. The threshold values for sarcopenia diagnosis in both sexes of CSA, of PhA, and of the MQI were identified. The obtained CSA values showed an AUC of 0.852 for women and 0.867 for men, PhA of 0.792 in women and 0.898 in men, while MQI was 0.900 for women and 0.969 for men. The newly calculated cut-off values of CSA, PhA, and MQI predicted the presence of sarcopenia with good sensitivity and specificity values. The use of the MQI proved to be more promising than the separate use of CSA and PhA in both male and female subjects.

Handheld Ultrasound Parameters of Lower Limb Muscles versus Bioelectrical Impedance Analysis Parameters for Skeletal Muscle Assessments in Arabic Female Adults.

Ultrasound (US) is a promising tool for skeletal muscle assessment; however, US studies have scarcely focused on Arabic populations. This study examined the association of handheld US indicators and bioelectrical impedance analysis (BIA) parameters in healthy Arabic females. A cross-sectional study was conducted on 60 healthy Arabic females whose muscle thickness (MT) and cross-sectional area (CSA) of the rectus femoris (RF) were measured alongside their MT and pennation angle (PA) of the medial gastrocnemius (MG) muscle (both muscles on the dominant side). Anthropometric and body composition analyses quantified fat-free mass (FFM) and appendicular skeletal muscle mass (ASMM). Muscle strength was assessed using a handgrip dynamometer, and physical activity levels were recorded with the Global Physical Activity Questionnaire (GPAQ). The CSA of the RF and the MT of both the RF and MG correlated significantly with FFM and ASMM. The PA of MG showed no significant correlations with ASMM, FFM, or handgrip strength. The CSA of RF was significantly correlated with handgrip strength (r = 0.313, p = 0.015), while the PA of MG correlated positively with GPAQ score (r = 0.346, p = 0.007). The CSA of RF significantly predicted both ASMM (β = 0.883, p = 0.0002) and FFM (β = 1.935, p = 0.0001). In conclusion, handheld US parameters, especially the RF's CSA, correlate with and can predict BIA-based FFM and ASMM in healthy females.

Early predictive value of ultrasound measurements of rectus femoris cross-sectional area to diagnose ICU-acquired weakness in patients undergoing invasive mechanical ventilation: a prospective cohort study

BackgroundThe diagnosis of ICU-acquired weakness (ICUAW) may be delayed due to the complexity of critically ill patients. This study aimed to investigate the value of ultrasound measurements of rectus femoris cross-sectional area (RFCSA) in predicting ICUAW in patients undergoing invasive mechanical ventilation.MethodsThis was a prospective cohort study of patients undergoing mechanical ventilation for at least 48 h. RFCSA was measured using ultrasound in patients upon ICU admission and followed until discharge. Using the Medical Research Council score as the gold standard, we evaluated the diagnostic value of ultrasound measurements in predicting ICUAW. Kaplan–Meier curves were constructed to evaluate and compare the length of ICU stay and duration of invasive mechanical ventilation between patients with and without ICUAW.ResultsAmong the 76 patients, 34 (44.7%) were diagnosed with ICUAW using the Medical Research Council score as the gold standard. The RFCSA atrophy rate between day 1 and day 3 was significantly higher in the ICUAW group (7.9 ± 2.8% vs. 4.3 ± 2.1%, p < 0.001). By utilizing a cutoff point of 6.9%, we discovered that the RFCSA atrophy rate exhibited excellent diagnostic accuracy in predicting ICUAW, with a sensitivity of 76.5% and specificity of 92.9%. In ICUAW patients diagnosed based on an RFCSA atrophy rate, the proportion of patients with an ICU stay longer than 14 days was 42.9%, which was significantly higher compared to 22.9% in the non-ICUAW group (HR: 1.768; 95% CI 1.128–2.772; p = 0.006). Similarly, the proportion of patients continuing mechanical ventilation at 14 days was 28.6% versus 4.2% between the two groups (HR: 1.988; 95% CI 1.266–3.120; p < 0.001).ConclusionUltrasound measurements of RFCSA provide a reliable method for diagnosing ICUAW and indicating prognosis in patients undergoing invasive mechanical ventilation.

The effect of protein administration during critical illness depends on body composition: A secondary analysis of a prospective, observational study

Background & AimsThe most adequate amount of protein that should be administered to critically ill patients is still debated and diverging findings are recently accumulating. We hypothesized that the effect of protein administration might depend on the amount of muscle mass. MethodsA secondary analysis of a single-centre prospective observational study of body composition in critically ill patients. Mechanically-ventilated subjects with an expected intensive care unit (ICU) stay >72h were enrolled. Within 24h from ICU admission, bioimpedance-derived muscle mass (BIA MM) and rectus femoris cross-sectional area (RF CSA) were measured. The amount of proteins and calories administered on the 7th ICU day was recorded. ResultsWe enrolled 94 subjects (65 males, actual body weight 72.9±14.4 Kg, BMI 26.0±4.8 kg/m2). Actual body weight was only weakly related to BIA MM (R=0.478, p<0.001) and not related to RF CSA (R=0.114, p=0.276). A higher protein intake was associated with a reduced mortality in the highest quartile of BIA MM (OR 0.68 [0.46; 0.99] per each 10g of proteins administered) and in the third (OR 0.74 [0.57; 0.98]) and highest quartile of RF CSA (OR 0.68 [0.48; 0.96]). ConclusionA higher protein intake was associated with lower ICU mortality only in patients admitted with a higher muscle mass, as either assessed by BIA or muscle ultrasound.

Recovery from severe cardio-respiratory failure: the trajectory of muscle mass, strength, function and health related quality of life

Abstract Background The impact of intensive care unit acquired weakness (ICUAW) is associated with reduced muscle mass, strength, function and health related quality of life (HRQoL). Patients suffering from severe cardio-respiratory failure are known to lose considerable muscle mass and strength in the first 7 days of admission to the intensive care unit (ICU). Furthermore, patients surviving critical illness have a considerable less HRQoL and physical function with long term outcomes such as inability to return to work being reported. However, more information regarding muscle loss and recovery is required when patients leave hospital. Currently there are no treatments for ICUAW as once the process is established management is supportive, such as physical therapy. Purpose We Sought to investigate the effects of severe cardio-respiratory failure, in patients receiving extra corporeal membrane oxygenation (ECMO), on ICUAW (including muscle mass, strength, function and HRQoL). Researching a real life model of ICUAW allows the observation of the loss of muscle mass and strength in the first stages of critical illness and severe cardio-respiratory failure. Methods Adults receiving ECMO for severe cardiorespiratory failure were included. Muscle mass was measured using ultrasound of the rectus femoris cross sectional area (RFcsa). Muscle strength was measured using hand held dynamometry for both hand held grip strength and isometric leg extension. HRQoL was measured using the EQ-5D-5L. Function was measured using the short physical performance battery (SPPB). Measurements were taken on day 0, day 7, ICU discharge, hospital discharge and at out-patient follow up. Results 17 patients were recruited with 10 patients completing follow up. Patients lost 24% muscle mass in the first 7 days of ICU admission and ECMO initiation, with muscle loss continuing up until ICU discharge. Contrary to the hypothesis only 50% of the patients were seen to recover muscle mass at follow up. Strength and function all considerably improved between ICU discharge and out patient follow up. The EQ5D crosswalk index supported this suggesting considerable functional improvement. Conclusion Patients in severe cardio-respiratory failure lose considerable muscle mass in the first 7 days of admission, with only 50% of these patients recovering the initial muscle loss at follow up. However, strength, function and HRQoL all improve following ICU discharge suggesting an element of functional recovery. Strength and function have shown to improve regardless of the status of the muscle mass. Therefore, given the advantages of the real-life model and novel findings, this could serve as a platform to assess muscle loss and recovery over a longer time frame continuing to build the understanding of the patients recovery trajectory from critical illness.Rectus Femoris Muscle MassHand-Held Grip Strength

Longitudinal change in ultrasound-derived rectus femoris cross-sectional area in COPD.

Skeletal muscle dysfunction is common in COPD. Ultrasound-derived rectus femoris cross-sectional area (RFCSA) is a radiation free, non-invasive measure of muscle bulk that relates to quadriceps strength in people with COPD. However, there are limited longitudinal data for RFCSA, and it is not known whether longitudinal change in RFCSA reflects change in quadricep strength, exercise capacity, lower limb function or muscle mass. We aimed to quantify longitudinal change in ultrasound-derived RFCSA and assess its relationship with change in quadriceps maximal voluntary contraction (QMVC), incremental shuttle walk test (ISWT), five-repetition sit-to-stand (5STS) and fat-free mass (FFM) over 12 months in people with COPD. We measured ultrasound-derived RFCSA, QMVC, ISWT, 5STS and FFM (measured by bioelectric impedance analysis) at baseline and 12 months in 169 people with stable COPD. Change was correlated using Pearson's or Spearman's coefficients. Baseline characteristics: mean±sd age 70.4±9.4 years; FEV1 53.3±18.9% predicted. Over the course of 12 months mean RFCSA change was -33.7 mm2 (99% CI -62.6- -4.9 mm2; p=0.003) representing a mean±sd percentage change of -1.8±33.5%. There was a weak correlation between change in RFCSA and FFM (r=0.205, p=0.009), but not with change in QMVC, ISWT or 5STS. There is a statistically significant decrease in ultrasound-derived RFCSA over 12 months in people with stable COPD, but this decrease does not correlate with change in quadriceps strength, exercise capacity, FFM or lower limb function.

Impact of early high protein intake in critically ill patients: a randomized controlled trial

BackgroundConflicting findings regarding the impact of High protein intake during the early phase in critically ill patients have been reported. Therefore, we aimed to assess the influence of higher early protein intake on the prognosis of critically ill patients.MethodsThis randomized controlled trial involved 173 critically ill patients who stayed in the Intensive Care Unit/Emergency ICU (ICU/EICU) for at least 7 days. The Low group (n = 87) and High group (n = 86) received protein supplementation of 0.8 g/kg.d and 1.5 g/kg.d, respectively, within 1–3 days of enteral nutrition (EN) initiation, with both groups transitioning to 1.5 g/kg.d on the 4th day. The serum prealbumin (PA), blood urea nitrogen/creatinine, and rectus femoris muscle thickness and cross-sectional area of all patients was measured on the 1th, 3rd, 5th, 7th day, and the day of ICU/EICU discharge.ResultsPatients in both Low and High groups showed no significant differences in age, APACHE II scores, or other demographic and baseline characteristics. There were also no significant differences in the primary outcome (28-day mortality rate) and secondary outcomes (incidence rate of refeeding syndrome and EN tolerance score) between the two groups. However, the Low group exhibited a significantly higher 28-day mortality rate (HR = 2.462, 95% CI: 1.021–5.936, P = 0.045) compared to High group, as determined by Cox proportional hazards models incorporating the time factor. The High group exhibited significantly shorter durations of mechanical ventilation and ICU stay compared to the Low group. Serum PA levels were higher, and rectus femoris muscle atrophy rates were lower in the High group. Furthermore, for septic patients, high protein intake significantly reduced the 28-day mortality rate despite a small sample size (n = 34).ConclusionsOur study indicates that increasing early protein intake to 1.5 g/kg.d may be safe and help improve the nutritional status and prognosis of critically ill patients.Trial registrationThis study was registered with the Chinese Clinical Trial Registry (ChiCTR2000039997, https://www.chictr.org.cn/).

Clinical evaluation of AI-assisted muscle ultrasound for monitoring muscle wasting in ICU patients

Muscle ultrasound has been shown to be a valid and safe imaging modality to assess muscle wasting in critically ill patients in the intensive care unit (ICU). This typically involves manual delineation to measure the rectus femoris cross-sectional area (RFCSA), which is a subjective, time-consuming, and laborious task that requires significant expertise. We aimed to develop and evaluate an AI tool that performs automated recognition and measurement of RFCSA to support non-expert operators in measurement of the RFCSA using muscle ultrasound. Twenty patients were recruited between Feb 2023 and July 2023 and were randomized sequentially to operators using AI (n = 10) or non-AI (n = 10). Muscle loss during ICU stay was similar for both methods: 26 ± 15% for AI and 23 ± 11% for the non-AI, respectively (p = 0.13). In total 59 ultrasound examinations were carried out (30 without AI and 29 with AI). When assisted by our AI tool, the operators showed less variability between measurements with higher intraclass correlation coefficients (ICCs 0.999 95% CI 0.998–0.999 vs. 0.982 95% CI 0.962–0.993) and lower Bland Altman limits of agreement (± 1.9% vs. ± 6.6%) compared to not using the AI tool. The time spent on scans reduced significantly from a median of 19.6 min (IQR 16.9–21.7) to 9.4 min (IQR 7.2–11.7) compared to when using the AI tool (p < 0.001). AI-assisted muscle ultrasound removes the need for manual tracing, increases reproducibility and saves time. This system may aid monitoring muscle size in ICU patients assisting rehabilitation programmes.

Acute Skeletal Muscle Wasting is Associated with Prolonged Hospital Stay in Critical Illness with Brain Injury.

Acute muscle wasting is common in critically ill patients, and this can lead to unfavorable clinical outcomes. The aim of this study was to identify factors associated with muscle wasting and to investigate the association between skeletal muscle wasting and prolonged hospital stay in critically ill patients with acute brain injury. This single-center prospective observational study was conducted in critically ill patients with acute brain injury who stayed in the intensive care unit for at least 1week. The rectus femoris cross-sectional area was measured via ultrasound at baseline and a week after the first assessment. Univariate and multivariate logistic regression analyses were performed to identify factors that predicted prolonged hospital stay. A total of 86 patients were included in the study. Their mean age was 49.4 ± 16.9years, 57% were male, and 46.5% had an admission diagnosis of subarachnoid hemorrhage. The percentage change in the rectus femoris cross-sectional area was 15.8% (95% confidence interval [CI] - 19.8% to - 12.0%; p < 0.001), and 57% of all patients had acute muscle wasting. According to the univariate analysis, there was a significant association between prolonged hospital stay and acute muscle wasting (odds ratio [OR] 3.677; 95% CI 1.487-9.043; p = 0.005), mechanical ventilation status (OR 3.600; 95% CI 1.455-8.904; p = 0.006), and Glasgow Coma Scale score (OR 0.888; 95% CI 0.808-0.976; p = 0.014) at intensive care unit admission. The multivariate analysis demonstrated that acute muscle wasting (OR 3.449; 95% CI 1.344-8.853; p = 0.010) was an independent risk factor for prolonged hospital stay. There was considerable muscle wasting in critically ill patients with brain injuries over a 1-week period. Acute muscle wasting was associated with prolonged hospital stay in critically ill patients with acute brain injury.

Relationship between quadriceps muscle architecture and lower limb strength and physical function in older adults community-dwelling individuals: a cross-sectional study.

Factors related to muscle architecture may lead to functional limitations in activities of daily living in the older adults. This study aimed to investigate the relationship between quadriceps femoris (QF) architecture and physical function in older adults community-dwelling people. The study included 25 community-dwelling older adults participants aged over 60 years (14 women and 11 men) who were not engaged in regular physical activity. The rectus femoris (RF) and vastus intermedius (VI) muscle thicknesses as well as the RF cross-sectional area (CSA) were assessed using 2D ultrasonography. The 30 Seconds Chair Stand test (30sCST) and Timed Up and Go Test (TUG) were used to assess lower body muscle power and functional mobility, respectively. The QF muscle architecture showed moderate and large correlations with the 30sCST (r range = 0.45-0.67, p < 0.05) and TUG (r range = 0.480-0.60, p < 0.05). RF thickness was a significant (p < 0.01) independent predictor of 30sCST (R 2 = 0.45) and TUG (R 2 = 0.36). VI thickness was a significant (p < 0.05) independent predictor of 30sCST (R 2 = 0.20) and TUG (R 2 = 0.231). RF CSA was a significant independent predictor of the 30sCST (R 2 = 0.250, p < 0.05) and TUG (R 2 = 0.27, p < 0.01). Multiple linear regression models explained 38% of the 30sCST variance and 30% of the TUG variance in the older adults group. Quadriceps muscle group directly affects basic activities of daily living in the older adults. Ultrasound measurements, which are non-invasive tools, are extremely valuable for understanding the limitations of activities of daily living in the older adults.

Ultrasound-derived rates of muscle wasting in the intensive care unit and in the post-intensive care ward for patients with critical illness: Post hoc analysis of an international, multicentre randomised controlled trial of early rehabilitation

Background and aimsMuscle wasting results in weakness for patients with critical illness. We aim to explore ultrasound-derived rates of change in skeletal muscle in the intensive care unit (ICU) and following discharge to the post-ICU ward. DesignPost hoc analysis of a multicentre randomised controlled trial of functional–electrical stimulated cycling, recumbent cycling, and usual care delivered in intensive care. MethodParticipants underwent ultrasound assessment of rectus femoris at ICU admission, weekly in the ICU, upon awakening, ICU discharge, and hospital discharge. The primary outcome was rate of change in rectus femoris cross-sectional area (ΔRFCSA) in mm2/day in the ICU (enrolment to ICU discharge) and in the post-ICU ward (ICU discharge to hospital discharge). Secondary outcomes included rate of change in echo intensity (ΔEI), standard deviation of echo intensity (ΔEISD), and the intervention effect on ultrasound measures. Echo intensity is a quantitative assessment of muscle quality. Elevated echo intensity may indicate fluid infiltration, adipose tissue, and reduced muscle quality. Results154 participants were included (mean age: 58 ± 15 years, 34% female). Rectus femoris cross-sectional area declined in the ICU (−4 mm2/day [95% confidence interval {CI}: −9 to 1]) and declined further in the ward (−9 mm2/day [95% CI: −14 to −3]) with a mean difference between ICU and ward of −5 mm2/day ([95% CI: −2, to 11]; p = 0.1396). There was a nonsignificant difference in ΔEI between in-ICU and the post-ICU ward of 1.2 ([95% CI: −0.1 to 2.6]; p = 0.0755), a statistically significant difference in ΔEISD between in-ICU and in the post-ICU ward of 1.0 ([95% CI, 0.5 to 1.5]; p = 0.0003), and no difference in rate of change in rectus femoris cross-sectional area between groups in intensive care (p = 0.411) or at hospital discharge (p = 0.1309). ConclusionsMuscle wasting occurs in critical illness throughout the hospital admission. The average rate of loss in muscle cross-sectional area does not slow after ICU discharge, even with active rehabilitation.

Dynamic changes of diaphragm and limb skeletal muscle in patients with sepsis assessed by bedside ultrasound and their correlation with blood urea/creatinine ratio

To investigate the dynamic changes of diaphragm and limb skeletal muscle in patients with sepsis by bedside ultrasound and their correlation with the ratio of blood urea/creatinine ratio (UCR) in 7 days after intensive care unit (ICU) admission. A prospective observational study was conducted. A total of 55 patients with sepsis admitted to ICU of General Hospital of Ningxia Medical University from June 2022 to February 2023 were selected as the research objects. General information, laboratory indicators [urea, serum creatinine (SCr), and UCR] on days 1, 4, and 7 of ICU admission, and prognostic indicators were observed. Bedside ultrasound was used to assess the dynamic changes of diaphragm morphology [including diaphragmatic excursion (DE), end-inspiratory diaphragm thickness (DTei), and end-expiratory diaphragm thickness (DTee)] on days 1, 4, and 7 of ICU admission, as well as limb skeletal muscle (quadriceps femoris) morphology [including rectus femoris-muscle layer thickness (RF-MLT), vastus intermedius-muscle layer thickness (VI-MLT), and rectus femoris-cross sectional area (RF-CSA)]. Diaphragm thickening fraction (DTF) and RF-CSA atrophy rate were calculated, and the incidence of diaphragm and limb skeletal muscle dysfunction was recorded. The correlation between ultrasound morphological parameters of diaphragm and quadriceps and UCR at each time points in 7 days after ICU admission was analyzed by Pearson correlation. A total of 55 patients with sepsis were included, of which 29 were in septic shock. As the duration of ICU admission increased, the incidence of diaphragm dysfunction in patients with sepsis increased first and then decreased (63.6%, 69.6%, and 58.6% on days 1, 4, and 7 of ICU admission, respectively), while the incidence of limb skeletal muscle dysfunction showed an increasing trend (54.3% and 62.1% on days 4 and 7 of ICU admission, respectively), with a probability of simultaneous occurrence on days 4 and 7 of ICU admission were 32.6% and 34.5%, respectively. The UCR on day 7 of ICU admission was significantly higher than that on day 1 [121.77 (95.46, 164.55) vs. 97.00 (70.26, 130.50)], and RF-CSA atrophy rate on day 7 was significantly higher than that on day 4 [%: -39.7 (-52.4, -22.1) vs. -26.5 (-40.2, -16.4)]. RF-CSA was significantly lower on day 7 compared to day 1 [cm2: 1.3 (1.0, 2.5) vs. 2.1 (1.7, 2.9)], with all differences being statistically significant (all P < 0.05). Pearson correlation analysis showed that RF-CSA on day 7 of ICU admission was negatively associated with the UCR on the same day (r = -0.407, P = 0.029). Diaphragmatic dysfunction in patients with sepsis occurred early and can be improved. Limb skeletal muscle dysfunction occurred relatively later and progresses progressively. The RF-CSA on day 7 of ICU admission may be a reliable measure of limb skeletal muscle dysfunction in patients with sepsis, can be an indicator of early identification and diagnosis of ICU-acquired weakness (ICU-AW). Continuous loss of muscle mass occurring in septic patients is mainly associated with persistent organismal catabolism, and undergoes significant changes around a week in ICU.

Skeletal Muscle Texture Assessment Using Ultrasonography: Comparison with Magnetic Resonance Imaging in Chronic Kidney Disease.

Skeletal muscle dysfunction is common in chronic kidney disease (CKD). Of interest is the concept of "muscle quality," of which measures include ultrasound-derived echo intensity (EI). Alternative parameters of muscle texture, for example, gray level of co-occurrence matrix (GCLM), are available and may circumvent limitations in EI. The validity of EI is limited in humans, particularly in chronic diseases. This study aimed to investigate the associations between ultrasound-derived parameters of muscle texture with MRI. Images of the thigh were acquired using a 3 Tesla MRI scanner. Quantification of muscle (contractile), fat (non-contractile), and miscellaneous (connective tissue, fascia) components were estimated. Anatomical rectus femoris cross-sectional area was measured using B-mode 2D ultrasonography. To assess muscle texture, first (i.e., EI)- and second (i.e., GLCM)-order statistical analyses were performed. Fourteen participants with CKD were included (age: 58.0 ± 11.9 years, 50% male, eGFR: 27.0 ± 7.4 ml/min/1.73m2, 55% Stage 4). Higher EI was associated with lower muscle % (quadriceps: β = -.568, p = .034; hamstrings: β = -.644, p = .010). Higher EI was associated with a higher fat % in the hamstrings (β = -.626, p = .017). A higher angular second moment from GLCM analysis was associated with greater muscle % (β = .570, p = .033) and lower fat % (β = -.534, p = .049). A higher inverse difference moment was associated with greater muscle % (β = .610, p = .021 and lower fat % (β = -.599, p = .024). This is the first study to investigate the associations between ultrasound-derived parameters of muscle texture with MRI. Our preliminary findings suggest ultrasound-derived texture analysis provides a novel indicator of reduced skeletal muscle % and thus increased intramuscular fat.