Human limb skeletal muscle wasting and architectural remodeling during five to ten days intubation and ventilation in critical care - an observational study using ultrasound

Developing a reliable and convenient methodology for ultrasound muscle assessment in critically ill patients: A reliability study

This study proposed a reliable and convenient methodology to assess rectus femoris (RF) and gastrocnemius muscles using ultrasound in critically ill patients. The focus was on reliability and convenience, considering both intra- and inter-observer reliability in the ICU and outpatient clinical settings. The RF and gastrocnemius muscles of 23 patients in the ICU were assessed using ultrasound. Two assessors, an expert and a novice, performed measurements across 2 consecutive days. Muscle thickness (MT), cross-sectional area (CSA), and echogenicity were measured in the RF, while MT, echogenicity, and pennate angle were measured in the gastrocnemius. The intra-class correlation coefficient (ICC) was assessed for intra- and inter-rater reliability for all markers. Intra- and inter-observer reliability was almost perfect (ICC > 0.80) for all markers, irrespective of the assessor's expertise. The CSA of the RF muscle exhibited the highest reliability (ICC > 0.95). MT of the gastrocnemius also demonstrated high intra- and inter-observer reliability (ICC > 0.91). In echogenicity measurements, gastrocnemius showed the highest (ICC > 0.91) intra- and inter-observer reliability. Ultrasound measurement of RF and gastrocnemius muscles in critically ill patients using the proposed methods demonstrated almost perfect reliability in both muscle mass and quality measurements. These methodologies, prioritizing convenience and reliability, could be employed for evaluating muscle status and changes in ICU settings and outpatient follow-ups.

Skeletal Muscle: A Critical Organ for Survival and Recovery in Critical Illness

The intensive care unit (ICU) environment is one of the most challenging for skeletal muscle health. Atrophy associated with clinical care is distinct from that seen with inactivity or immobilization in the absence of disease and is exacerbated by aging. The substantial muscle loss in the ICU is likely due to the presence of inflammation, elevated proteolysis, bedrest, and undernutrition. Skeletal muscle parameters at admission are predictive of mortality and other clinically important outcomes. Treatment goals to mitigate muscle loss are early mobilization and adequate nutrient supply, especially protein, using an individualized approach to support skeletal muscle maintenance and recovery.

Assessing Intensive Care Unit Acquired Weakness: An Observational Study Using Quantitative Ultrasound Shear Wave Elastography of the Rectus Femoris and Vastus Intermedius

INTRODUCTION

Intensive care unit-acquired weakness (ICUAW) is associated with unfavorable outcomes. The current diagnostic tools for ICUAW are invasive, yield delayed results, and lack precision. This study explored the potential of shear wave elastography (SWE), an innovative ultrasound technique, to evaluate the quality changes in the lower extremity muscles of ICU patients, potentially aiding the early detection of ICUAW.

MATERIALS AND METHODS

We included adult patients diagnosed with ICUAW (average Medical Research Council score < 48) from December 2020 to October 2021. ICU patients were continuously monitored twice daily. Using ultrasonography, we measured the thickness (TH), cross-sectional area (CSA), pennation angle (PA), and SWE (SWE-values) modulus of the bilateral rectus femoris (RF) and vastus intermedius (VI). The diagnostic performance of each parameter was evaluated using sensitivity, specificity, and area under the receiver operating characteristic curve.

RESULTS

Ultrasound quantification assessments were performed in 47 patients, 24 with ICUAW and 23 without ICUAW. Notably, PA decreased (RF: 11.33%, VI: 10.51%), while muscle rigidity increased (RF: 22.39%, VI: 22.50%) in ICUAW patients compared with non-ICUAW patients. The sensitivity and specificity for PA in the RF were 79.17% and 91.30%, respectively, and those for PA in VI were 79.17% and 78.26%, respectively. The use of both combinations yielded 91.67% and 73.91% sensitivity and specificity, respectively. Employing the PA of RF and SWE-values of RF together, we observed a diagnostic prediction sensitivity of 91.67% and a specificity of 60.87%.

CONCLUSIONS

ICUAW patients exhibited increased rigidity of the lower extremity muscles during their hospital stay. Ultrasonic SWE emerged as a reliable and objective tool, offering significant diagnostic value for ICUAW.

Acute Sarcopenia: Systematic Review and Meta-Analysis on Its Incidence and Muscle Parameter Shifts During Hospitalisation

BACKGROUND

Acute sarcopenia is sarcopenia lasting less than 6 months, typically following acute illness or injury. It may impact patient recovery and quality of life, advancing to chronic sarcopenia. However, its development and assessment remain poorly understood, particularly during hospitalisation. This systematic review aimed to elucidate the incidence of acute sarcopenia and examine changes in muscle parameters during hospitalisation.

METHODS

Eighty-eight papers were included in the narrative synthesis; 33 provided data for meta-analyses on the effects of hospitalisation on handgrip strength (HGS), rectus femoris cross-sectional area (RFCSA) and various muscle function tests. Meta-regressions were performed for length of hospital stay (LoS) and age for all meta-analyses; sex was also considered for HGS.

RESULTS

Acute sarcopenia development was assessed in four studies with a pooled incidence of 18% during hospitalisation. Incidence was highest among trauma patients in intensive care (59%), whereas it was lower among medical and surgical patients (15%-20%). Time of development ranged from 4 to 44 days. HGS remained stable during hospitalisation (SMD = 0.05, 95% CI = -0.18:0.28, p = 0.67) as did knee extensor strength. LoS affected HGS performance (θ = 0.04, 95% CI = 0.001:0.09, p = 0.045) but age (p = 0.903) and sex (p = 0.434) did not. RFCSA, reduced by 16.5% over 3-21 days (SMD = -0.67, 95% CI = -0.92:-0.43, p < 0.001); LoS or time between scans did significantly predict the reduction (θ = -0.04, 95% CI = -0.077:-0.011, p = 0.012). Indices of muscle quality also reduced. Muscle function improved when assessed by the short physical performance battery (SMD = 0.86, 95% CI = 0.03:1.69, p = 0.046); there was no change in 6-min walk (p = 0.22), timed up-and-go (p = 0.46) or gait speed tests (p = 0.98). The only significant predictor of timed up-and-go performance was age (θ = -0.11, 95% CI = -0.018:-0.005, p = 0.009).

CONCLUSIONS

Assessment and understanding of acute sarcopenia in clinical settings are limited. Incidence varies between clinical conditions, and muscle parameters are affected differently. HGS and muscle function tests may not be sensitive enough to identify acute changes during hospitalisation. Currently, muscle health deterioration may be underdiagnosed impacting recovery, quality of life and overall health following hospitalisation. Further evaluation is necessary to determine the suitability of existing diagnostic criteria of acute sarcopenia. Muscle mass and quality indices might need to become the primary determinants for muscle health assessment in hospitalised populations.

USE OF MUSCULAR ULTRASOUND TO DETECT INTENSIVE CARE UNIT-ACQUIRED WEAKNESS: A SYSTEMATIC REVIEW AND META-ANALYSIS

ABSTRACT

Background : This systematic review and meta-analysis aims to detecting performance of muscular ultrasound for intensive care unit (ICU)-acquired weakness (ICUAW). Methods : 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. Results : This meta-analysis comprised 10 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 summary receiver operating characteristic (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 predefined 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). Conclusions : 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.

Different trend of muscle wasting extracted from computed tomography in patients with severe acute pancreatitis

PURPOSE

The trend of muscle wasting in patients with acute severe and moderately severe pancreatitis (AP) remains unclear. This retrospective study aimed to investigate the trend of skeletal muscle area (SMA) changes and its impact on patients with severe and moderately severe AP.

METHODS

Patients diagnosed with AP who had repeated CT scans after intensive care unit (ICU) admission were included. The patients were categorized into moderately severe AP or severe AP groups. The generalized additive mixed model (GAMM) was used to analyze the SMA trajectories.

RESULTS

A total of 126 patients were included. The patients in the severe AP group had more rapid muscle wasting during the first 3 weeks following ICU admission. The SMA decreased by 1.1 cm2 (95% CI: 1.3 to 0.8) per day in the severe AP group, while the SMA decreased by 0.5 cm2 (95% CI: 0.6 to 0.4) in the moderately severe AP group in the GAMM model. A larger change in the SMA during the first 10 days after admission was significantly associated with prolonged length of hospital stay (LOS) (β = - 0.205, P = 0.036).

CONCLUSIONS

Patients with severe AP experienced more muscle wasting during the first 3 weeks after ICU admission. A larger reduction in the SMA was associated with prolonged LOS.

CLINICAL IMPLICATIONS

Different patterns of muscle wasting were present during the first 3 weeks after ICU admission in moderately severe and severe AP patients. Accordingly, different nutrition and rehabilitation strategies might be employed depending upon the severity of AP.

Ultrasound-Defined Sarcopenia Independently Predicts Acute Decompensation in Advanced Chronic Liver Disease

BACKGROUND

It has been shown that in patients with liver cirrhosis, sarcopenia is a predictor of acute decompensation (AD), acute-on-chronic liver failure (ACLF) and death. However, computer tomography (CT), as a suggested standard method for diagnosing sarcopenia, is resource intensive and involves radiation exposure. Therefore, in this study, we evaluate the muscle thickness of quadriceps femoris measured by ultrasound (US) as a prognostic parameter for AD and all-cause mortality in chronic liver disease.

METHODS

Sixty-three patients with chronic liver disease and signs of portal hypertension were analysed in this prospective monocentric study for the occurrence of acute decompensation such as hepatic encephalopathy, ascites, haemorrhage and liver-related death within 1 year. We assessed muscle thickness at three different heights in terms of suitability as a predictor.

RESULTS

Among all 63 patients, 15 patients experienced acute decompensation, and 9 patients died due to liver-related death. We found the upper third of the muscle, measured without applying pressure with the transducer, to be the most significant for predicting AD/ACLF [AUC 0.739 (confidence interval (CI) 0.604-0.874, p = 0.006]. A cut-off value of US-defined muscle thickness standardized per height for identifying sarcopenia was determined (1.83 cm/m). Patients with US-defined sarcopenia showed significantly higher rates of AD (38.9% vs. 3.7%, p = 0.001) and all-over 1-year mortality (27.8% vs. 3.7%, p = 0.013). The mean AD free survival time is 8.3 months (95% CI 6.6-9.9) for sarcopenic patients and 11.8 months (95% CI 11.0-12.6) for the non-sarcopenic cohorts. Corresponding CT analysis displayed similar results for AD free survival for both groups (40% AD rate in the sarcopenic group vs. 7% AD rate in the non-sarcopenic group, p = 0.001). The risk for AD was significantly higher in the sarcopenic cohort compared with those without sarcopenia in both US and CT (US: HR 16.6; p = 0.009; 95% CI 2.0-136.0; CT: HR 8.7; p = 0.017; 95% CI 1.5-51.0). CT and US displayed a moderate agreement (p = 0.006; κ = 0.379).

CONCLUSIONS

Sarcopenia classification based on US measurements is shown to be an independent predictor of AD occurrence within 1 year. This pilot study is the first to suggest that screening for sarcopenia by ultrasonography may be useful for risk assessment in patients with chronic liver disease and signs of portal hypertension.

Methodologies and clinical applications of lower limb muscle ultrasound in critically ill patients: a systematic review and meta-analysis

BACKGROUND

Reduced muscle mass upon admission and development of muscle wasting are frequent in critically ill patients, and linked to unfavorable outcomes. Muscle ultrasound is a promising instrument for evaluating muscle mass. We summarized the findings of lower limb muscle ultrasound values and investigated how the muscle ultrasound parameters of the examination or the patient characteristics influence the results.

METHODS

Systematic review and meta-analysis of studies of lower limb ultrasound critically ill adults. PubMed, CINAHL, Embase, PEDro and Web of Science were searched. PRISMA guidelines were followed, and studies evaluated with the appropriate NIH quality assessment tool. A meta-analysis was conducted to compare the values at admission, short and long follow-up during ICU stay, and the association between baseline values and patient characteristics or ultrasound parameters was investigated with a meta-regression.

RESULTS

Sixty-six studies (3839 patients) were included. The main muscles investigated were rectus femoris cross-sectional area (RF-CSA, n = 33/66), quadriceps muscle layer thickness (n = 32/66), and rectus femoris thickness (n = 19/66). Significant differences were found in the anatomical landmark and ultrasound settings. At ICU admission, RF-CSA ranged from 1.1 [0.73-1.47] to 6.36 [5.45-7.27] cm2 (pooled average 2.83 [2.29-3.37] cm2) with high heterogeneity among studies (I2 = 98.43%). Higher age, higher BMI, more distal landmark and the use of probe compression were associated with lower baseline muscle mass.

CONCLUSIONS

Measurements of muscle mass using ultrasound varied with reference to patient characteristics, patient position, anatomical landmarks used for measurement, and the level of compression applied by the probe; this constrains the external validity of the results and highlights the need for standardization.

STUDY REGISTRATION

PROSPERO CRD42023420376.

The Diagnostic Value of Musculoskeletal Ultrasound in the Quantitative Evaluation of Skeletal Muscle in Chronic Thyrotoxic Myopathy: A Single-Center Study in China

Objective

This study aimed to evaluate the quadriceps femoris in patients with chronic thyrotoxic myopathy (CTM) using musculoskeletal ultrasound and to explore its practical clinical value for the diagnosis of CTM.

Methods

A total of 241 subjects recruited from the First Affiliated Hospital of Guangxi Medical University were surveyed for detailed medical history and underwent grip strength tests, fixed-distance walking, and quadriceps femoris ultrasound examinations. Differences in muscle parameters between the CTM, non-CTM, and healthy groups were analyzed. An Receiver operating characteristic (ROC) curve was established to analyze the predictive value of various ultrasound measurements for CTM, and Spearman correlation analysis and binary logistic regression were applied to explore the factors associated CTM.

Results

The quadriceps femoris contraction index, muscle thickness, muscle cross-sectional area, and pennation angle in the CTM group were significantly lower than those in the non-CTM and healthy groups (p<0.01). The ROC curve prediction showed that the pennation angle had the best sensitivity and specificity for diagnosing myogenesis, with an area under the curve of 89%. Moreover, the pennation angle of the CTM group was positively correlated with step speed (r=0.245, p=0.031) and body surface area (r=0.276, p=0.014), but negatively correlated with age (r=-0.306, p=0.007). Regression analysis showed that the quadriceps femoris contraction index, muscle thickness, pennation angle, and cross-sectional area were factors that related the CTM. After adjusting for potential confounding factors, the association between Muscle Bundle Length and CTM became significant (OR=1.99, 95% CI: 1.22, 3.35, p=0.007). Muscular echo in patients was observed to varying degrees of enhancement.

Conclusion

Musculoskeletal ultrasonography in the quantitative analysis of muscle parameters and muscle echo of the quadriceps femoris can provide essential imaging evidence for predicting CTM.

Ultrasound for measurement of skeletal muscle mass quantity and muscle composition/architecture in critically ill patients: A scoping review on studies' aims, methods, and findings

AIMS

This scoping review aimed to identify, explore, and map the objectives, methodological aspects, and results of studies that used ultrasound (US) to assess skeletal muscle (SM) in critically ill patients.

METHODS

A scoping review was conducted according to the Joanna Briggs Institute's methodology. All studies that evaluated SM parameters from the US in patients admitted to the intensive care unit (ICU) were considered eligible. We categorized muscle thickness and cross-sectional area as parameters for assessing SM quantity, while echogenicity, fascicle length, and pennation angle analysis were used to evaluate muscle "quality" (composition/architecture). A literature search was conducted using four databases for articles published until December 2022. Independent reviewers selected the studies and extracted data. Descriptive statistics were calculated to present the results.

RESULTS

A total of 107 studies were included, the majority of which were prospective cohort studies (59.8 %) conducted in general ICUs (49.5 %). The most frequent objective of the studies was to evaluate SM quantity depletion during the ICU stay (25.2 %), followed by determining whether a specific intervention would modify SM (21.5 %). Most studies performed serial SM evaluations (76.1 %). The rectus femoris muscle thickness was evaluated in most studies (67.9 %), followed by the rectus femoris cross-sectional area (54.3 %) and the vastus intermedius muscle thickness (40.2 %). The studies demonstrated the feasibility and reproducibility of US for SM evaluation, especially related to quantitative parameters. Most studies (70.3 %) reported significant SM quantity depletion during hospitalization. However, the accuracy of the US in measuring SM varied across the studies.

CONCLUSIONS

The lack of detailed description and standardization in the protocols adopted by the studies included in this scoping review precludes the translation of the evidence related to US for SM assessment into clinical practice.

Ultrasonographic Features of Muscular Weakness and Muscle Wasting in Critically Ill Patients

Muscle wasting begins as soon as in the first week of one's ICU stay and patients with multi-organ failure lose more muscle mass and suffer worse functional impairment as a consequence. Muscle wasting and weakness are mainly characterized by a generalized, bilateral lower limb weakness. However, the impairment of the respiratory and/or oropharyngeal muscles can also be observed with important consequences for one's ability to swallow and cough. Muscle wasting represents the result of the disequilibrium between breakdown and synthesis, with increased protein degradation relative to protein synthesis. It is worth noting that the resulting functional disability can last up to 5 years after discharge, and it has been estimated that up to 50% of patients are not able to return to work during the first year after ICU discharge. In recent years, ultrasound has played an increasing role in the evaluation of muscle. Indeed, ultrasound allows an objective evaluation of the cross-sectional area, the thickness of the muscle, and the echogenicity of the muscle. Furthermore, ultrasound can also estimate the thickening fraction of muscle. The objective of this review is to analyze the current understanding of the pathophysiology of acute skeletal muscle wasting and to describe the ultrasonographic features of normal muscle and muscle weakness.

Association of SOFA Score with Severity of Muscle Wasting in Critically Ill Patients: A Prospective Observational Study

Background

Muscle wasting is a frequent complication in critically ill patients. This study aimed to evaluate whether muscle wasting occurs in these patients and its association with the severity of the disease.

Materials and methods

This was a prospective, observational study including 50 patients admitted to the multidisciplinary ICU of a tertiary care hospital. Using a linear ultrasound probe, the thickness of the rectus femoris was measured on day 1 of admission and repeated at the same point on day 7. Sequential organ failure assessment (SOFA) scores were calculated daily during the study period. The highest SOFA score during this period was recorded. The mean difference in the thickness of the rectus femoris between day 1 and day 7 was used to predict the occurrence of muscle wasting and the correlation between this difference and the highest SOFA score was analyzed.

Results

The mean thickness of the rectus femoris on day 1 was 1.32 + 0.06 cm and on day 7 was 1.16 + 0.08 cm. The mean difference was found to be 0.16 cm (p < 0.01). There was a statistically significant difference in the thickness of the rectus femoris between day 1 and day 7. It was found to have a positive correlation with the highest SOFA score r = 0.886 (p < 0.01).

Conclusion

This study demonstrates that there is significant muscle wasting in critically ill patients and this positively correlates with the severity of illness. Our study also highlights the role of bedside ultrasound in detecting muscle wasting.

How to cite this article

Rajagopal K, Vijayan D, Thomas SM. Association of SOFA Score with Severity of Muscle Wasting in Critically Ill Patients: A Prospective Observational Study. Indian J Crit Care Med 2023;27(10):743-747.

[Intensive care unit-acquired weakness-Diagnostic value of neuromuscular ultrasound]

Intensive care unit-acquired weakness (ICUAW) is one of the most common neuromuscular complications in intensive care medicine. The clinical diagnosis and assessment of the severity using established diagnostic methods (e.g., clinical examination using the Medical Research Council Sum Score or electrophysiological examination) can be difficult or even impossible, especially in sedated, ventilated and delirious patients. Neuromuscular ultrasound (NMUS) has increasingly been investigated in ICUAW as an easy to use noninvasive and mostly patient compliance-independent diagnostic alternative. It has been shown that NMUS appears to be a promising tool to detect ICUAW, to assess the severity of muscular weakness and to monitor the clinical progression. Further studies are needed to standardize the methodology, to evaluate the training effort and to optimize outcome predication. The formulation of an interdisciplinary neurological and anesthesiological training curriculum is warranted to establish NMUS as a complementary diagnostic method of ICUAW in daily clinical practice.

Mapping peripheral and abdominal sarcopenia acquired in the acute phase of COVID-19 during 7 days of mechanical ventilation

Our aim was to map acquired peripheral and abdominal sarcopenia in mechanically ventilated adults with COVID-19 through ultrasound measurements. On Days 1, 3, 5 and 7 after admission to critical care, the muscle thickness and cross-sectional area of the quadriceps, rectus femoris, vastus intermedius, tibialis anterior, medial and lateral gastrocnemius, deltoid, biceps brachii, rectus abdominis, internal and external oblique, and transversus abdominis were measured using bedside ultrasound. A total of 5460 ultrasound images were analyzed from 30 patients (age: 59.8 ± 15.6 years; 70% men). Muscle thickness loss was found in the bilateral anterior tibial and medial gastrocnemius muscles (range 11.5-14.6%) between Days 1 and 3; in the bilateral quadriceps, rectus femoris, lateral gastrocnemius, deltoid, and biceps brachii (range 16.3-39.1%) between Days 1 and 5; in the internal oblique abdominal (25.9%) between Days 1 and 5; and in the rectus and transversus abdominis (29%) between Days 1 and 7. The cross-sectional area was reduced in the bilateral tibialis anterior and left biceps brachii (range 24.6-25.6%) between Days 1 and 5 and in the bilateral rectus femoris and right biceps brachii (range 22.9-27.7%) between Days 1 and 7. These findings indicate that the peripheral and abdominal muscle loss is progressive during the first week of mechanical ventilation and is significantly higher in the lower limbs, left quadriceps and right rectus femoris muscles in critically ill patients with COVID-19.

Update on Lean Body Mass Diagnostic Assessment in Critical Illness

Acute critical illnesses can alter vital functions with profound biological, biochemical, metabolic, and functional modifications. Despite etiology, patient's nutritional status is pivotal to guide metabolic support. The assessment of nutritional status remains complex and not completely elucidated. Loss of lean body mass is a clear marker of malnutrition; however, the question of how to investigate it still remains unanswered. Several tools have been implemented to measure lean body mass, including a computed tomography scan, ultrasound, and bioelectrical impedance analysis, although such methods unfortunately require validation. A lack of uniform bedside measurement tools could impact the nutrition outcome. Metabolic assessment, nutritional status, and nutritional risk have a pivotal role in critical care. Therefore, knowledge about the methods used to assess lean body mass in critical illnesses is increasingly required. The aim of the present review is to update the scientific evidence regarding lean body mass diagnostic assessment in critical illness to provide the diagnostic key points for metabolic and nutritional support.

Characterization of muscle mass, strength and mobility of critically ill patients with SARS-CoV-2 pneumonia: Distribution by sex, age, days on mechanical ventilation, and muscle weakness

Objective: Quantify and categorize by sex, age, and time spent on mechanical ventilation (MV), the decline in skeletal muscle mass, strength and mobility in critically ill patients infected with SARS-CoV-2 and requiring mechanical ventilation while at intensive care unit (ICU). Design: Prospective observational study including participants recruited between June 2020 and February 2021 at Hospital Clínico Herminda Martin (HCHM), Chillán, Chile. The thickness of the quadriceps muscle was evaluated by ultrasonography (US) at intensive care unit admission and awakening. Muscle strength and mobility were assessed, respectively, through the Medical Research Council Sum Score (MRC-SS) and the Functional Status Score for the Intensive Care Unit Scale (FSS-ICU) both at awakening and at ICU discharge. Results were categorized by sex (female or male), age (<60 years old or ≥60 years old) and time spent on MV (≤10 days or >10 days). Setting: Intensive care unit in a public hospital. Participants: 132 participants aged 18 years old or above (women n = 49, 60 ± 13 years; men n = 85, 59 ± 12 years) admitted to intensive care unit with a confirmed diagnosis of severe SARS-CoV-2 and requiring MV for more than 48 h were included in the study. Patients with previous physical and or cognitive disorders were excluded. Interventions: Not applicable. Results: Muscle thickness have significantly decreased during intensive care unit stay, vastus intermedius (-11%; p = 0.025), rectus femoris (-20%; p < 0.001) and total quadriceps (-16%; p < 0.001). Muscle strength and mobility were improved at intensive care unit discharge when compared with measurements at awakening in intensive care unit (time effect, p < 0.001). Patients ≥60 years old or on MV for >10 days presented greater muscle loss, alongside with lower muscle strength and mobility. Conclusion: Critically ill patients infected with SARS-CoV-2 and requiring MV presented decreased muscle mass, strength, and mobility during their intensive care unit stay. Factors associated with muscle mass, such as age >60 years and >10 days of MV, exacerbated the critical condition and impaired recovery.

Surgery-Related Muscle Loss after Pancreatic Resection and Its Association with Postoperative Nutritional Intake

To study the occurrence of surgery-related muscle loss (SRML) and its association with in-hospital nutritional intake, we conducted a prospective observational cohort study including patients who underwent pancreatic surgery because of (suspected) malignant diseases. Muscle diameter was measured by using bedside ultrasound 1 day prior to surgery and 7 days postoperatively. Clinically relevant SRML was defined as ≥10% muscle diameter loss in minimally one arm and leg muscle within 1 week after surgery. Protein and caloric intake was measured by nutritional diaries. The primary endpoint included the number of patients with SRML. Secondary endpoints included the association between SRML and postoperative nutritional intake. Of the 63 included patients (60.3% men; age 67.1 ± 10.2 years), a total of 24 patients (38.1%) showed SRML. No differences were observed in severe complication rate or length of hospital stay between patients with and without SRML. During the first postoperative week, patients with clinically relevant SRML experienced more days without any nutritional intake compared with the non-SRML group (1 [0-4] versus 0 [0-1] days, p = 0.007). Significantly lower nutritional intake was found in the SRML group at postoperative days 2, 3 and 5 (p < 0.05). Since this study shows that SRML occurred in 38.1% of the patients and most of the patients failed to reach internationally set nutritional goals, it is suggested that more awareness concerning direct postoperative nutritional intake is needed in our surgical community.

Incidence of muscle wasting in the critically ill: a prospective observational cohort study

Loss of muscle mass occurs rapidly during critical illness and negatively affects quality of life. The incidence of clinically significant muscle wasting in critically ill patients is unclear. This study aimed to assess the incidence of and identify predictors for clinically significant loss of muscle mass in this patient population. This was a single-center observational study. We used ultrasound to determine the rectus femoris cross-sectional area (RFcsa) on the first and seventh day of ICU stay. The primary outcome was the incidence of significant muscle wasting. We used a logistic regression model to determine significant predictors for muscle wasting. Ultrasound measurements were completed in 104 patients. Sixty-two of these patients (59.6%) showed ≥ 10% decreases in RFcsa. We did not identify any predictor for significant muscle wasting, however, age was of borderline significance (p = 0.0528). The 28-day mortality rate was higher in patients with significant wasting, but this difference was not statistically significant (30.6% versus 16.7%; p = 0.165). Clinically significant muscle wasting was frequent in our cohort of patients. Patient age was identified as a predictor of borderline significance for muscle wasting. The results could be used to plan future studies on this topic.Trial registration: ClinicalTrials.gov NCT03865095, date of registration: 06/03/2019.

The rate and assessment of muscle wasting during critical illness: a systematic review and meta-analysis

BACKGROUND

Patients with critical illness can lose more than 15% of muscle mass in one week, and this can have long-term detrimental effects. However, there is currently no synthesis of the data of intensive care unit (ICU) muscle wasting studies, so the true mean rate of muscle loss across all studies is unknown. The aim of this project was therefore to systematically synthetise data on the rate of muscle loss and to identify the methods used to measure muscle size and to synthetise data on the prevalence of ICU-acquired weakness in critically ill patients.

METHODS

We conducted a systematic literature search of MEDLINE, PubMed, AMED, BNI, CINAHL, and EMCARE until January 2022 (International Prospective Register of Systematic Reviews [PROSPERO] registration: CRD420222989540. We included studies with at least 20 adult critically ill patients where the investigators measured a muscle mass-related variable at two time points during the ICU stay. We followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and assessed the study quality using the Newcastle-Ottawa Scale.

RESULTS

Fifty-two studies that included 3251 patients fulfilled the selection criteria. These studies investigated the rate of muscle wasting in 1773 (55%) patients and assessed ICU-acquired muscle weakness in 1478 (45%) patients. The methods used to assess muscle mass were ultrasound in 85% (n = 28/33) of the studies and computed tomography in the rest 15% (n = 5/33). During the first week of critical illness, patients lost every day -1.75% (95% CI -2.05, -1.45) of their rectus femoris thickness or -2.10% (95% CI -3.17, -1.02) of rectus femoris cross-sectional area. The overall prevalence of ICU-acquired weakness was 48% (95% CI 39%, 56%).

CONCLUSION

On average, critically ill patients lose nearly 2% of skeletal muscle per day during the first week of ICU admission.

The time course of disuse muscle atrophy of the lower limb in health and disease

Short, intermittent episodes of disuse muscle atrophy (DMA) may have negative impact on age related muscle loss. There is evidence of variability in rate of DMA between muscles and over the duration of immobilization. As yet, this is poorly characterized. This review aims to establish and compare the time-course of DMA in immobilized human lower limb muscles in both healthy and critically ill individuals, exploring evidence for an acute phase of DMA and differential rates of atrophy between and muscle groups. MEDLINE, Embase, CINHAL and CENTRAL databases were searched from inception to April 2021 for any study of human lower limb immobilization reporting muscle volume, cross-sectional area (CSA), architecture or lean leg mass over multiple post-immobilization timepoints. Risk of bias was assessed using ROBINS-I. Where possible meta-analysis was performed using a DerSimonian and Laird random effects model with effect sizes reported as mean differences (MD) with 95% confidence intervals (95% CI) at various time-points and a narrative review when meta-analysis was not possible. Twenty-nine studies were included, 12 in healthy volunteers (total n = 140), 18 in patients on an Intensive Therapy Unit (ITU) (total n = 516) and 3 in patients with ankle fracture (total n = 39). The majority of included studies are at moderate risk of bias. Rate of quadriceps atrophy over the first 14 days was significantly greater in the ITU patients (MD -1.01 95% CI -1.32, -0.69), than healthy cohorts (MD -0.12 95% CI -0.49, 0.24) (P < 0.001). Rates of atrophy appeared to vary between muscle groups (greatest in triceps surae (-11.2% day 28), followed by quadriceps (-9.2% day 28), then hamstrings (-6.5% day 28), then foot dorsiflexors (-3.2% day 28)). Rates of atrophy appear to decrease over time in healthy quadriceps (-6.5% day 14 vs. -9.1% day 28) and triceps surae (-7.8% day 14 vs. -11.2% day 28), and ITU quadriceps (-13.2% day 7 vs. -28.2% day 14). There appears to be variability in the rate of DMA between muscle groups, and more rapid atrophy during the earliest period of immobilization, indicating different mechanisms being dominant at different timepoints. Rates of atrophy are greater amongst critically unwell patients. Overall evidence is limited, and existing data has wide variability in the measures reported. Further work is required to fully characterize the time course of DMA in both health and disease.

Therapeutic Potential of Electromyostimulation (EMS) in Critically Ill Patients—A Systematic Review

Ample evidence exists that intensive care unit (ICU) treatment and invasive ventilation induce a transient or permanent decline in muscle mass and function. The functional deficit is often called ICU-acquired weakness with critical illness polyneuropathy (CIP) and/or myopathy (CIM) being the major underlying causes. Histopathological studies in ICU patients indicate loss of myosin filaments, muscle fiber necrosis, atrophy of both muscle fiber types as well as axonal degeneration. Besides medical prevention of risk factors such as sepsis, hyperglycemia and pneumonia, treatment is limited to early passive and active mobilization and one third of CIP/CIM patients discharged from ICU never regain their pre-hospitalization constitution. Electromyostimulation [EMS, also termed neuromuscular electrical stimulation (NMES)] is known to improve strength and function of healthy and already atrophied muscle, and may increase muscle blood flow and induce angiogenesis as well as beneficial systemic vascular adaptations. This systematic review aimed to investigate evidence from randomized controlled trails (RCTs) on the efficacy of EMS to improve the condition of critically ill patients treated on ICU. A systematic search of the literature was conducted using PubMed (Medline), CENTRAL (including Embase and CINAHL), and Google Scholar. Out of 1,917 identified records, 26 articles (1,312 patients) fulfilled the eligibility criteria of investigating at least one functional measure including muscle function, functional independence, or weaning outcomes using a RCT design in critically ill ICU patients. A qualitative approach was used, and results were structured by 1) stimulated muscles/muscle area (quadriceps muscle only; two to four leg muscle groups; legs and arms; chest and abdomen) and 2) treatment duration (≤10 days, >10 days). Stimulation parameters (impulse frequency, pulse width, intensity, duty cycle) were also collected and the net EMS treatment time was calculated. A high grade of heterogeneity between studies was detected with major cofactors being the analyzed patient group and selected outcome variable. The overall efficacy of EMS was inconclusive and neither treatment duration, stimulation site or net EMS treatment time had clear effects on study outcomes. Based on our findings, we provide practical recommendations and suggestions for future studies investigating the therapeutic efficacy of EMS in critically ill patients.

Systematic Review Registration: [https://www.crd.york.ac.uk/prospero/], identifier [CRD42021262287].

Diaphragm dysfunction and peripheral muscle wasting in septic shock patients: Exploring their relationship over time using ultrasound technology (the MUSiShock protocol)

Background

Intensive Care Unit (ICU) patients are known to lose muscle mass and function during ICU stay. Ultrasonography (US) application for the assessment of the skeletal muscle is a promising tool and might help detecting muscle changes and thus several dysfunctions during early stages of ICU stay. MUSiShock is a research project aiming to investigate structure and function of diaphragm and peripheral muscles using ultrasound techniques in septic shock patients, and to assess their relevance in several clinical outcomes such as the weaning process.

Methods and design

This is a research protocol from an observational prospective cohort study. We plan to assess eighty-four septic shock patients during their ICU stay at the following time-points: at 24 hours of ICU admission, then daily until day 5, then weekly, at extubation time and at ICU discharge. At each time-point, we will measure the quadriceps rectus femoris and diaphragm muscles, using innovative US muscle markers such as Shear-Wave Elastography (SWE). In parallel, the Medical Research Council (MRC) sum score for muscle testing and the Airway occlusion pressure (P_0.1) will also be collected. We will describe the association between SWE assessment and other US markers for each muscle. The association between the changes in both diaphragm and rectus femoris US markers over time will be explored as well; finally, the analysis of a combined model of one diaphragm US marker and one limb muscle US marker to predict weaning success/failure will be tested.

Discussion

By using muscle ultrasound at both diaphragm and limb levels, MUSiShock aims to improve knowledge in the early detection of muscle dysfunction and weakness, and their relationship with muscle strength and MV weaning, in critically ill patients. A better anticipation of these short-term muscle structure and function outcomes may allow clinicians to rapidly implement measures to counteract it.

Trial registration

ClinicalTrials.gov, NCT04550143. Registered on 16 September 2020.

Muscle architecture, growth, and biological Remodelling in cerebral palsy: a narrative review

Cerebral palsy (CP) is caused by a static lesion to the brain occurring in utero or up to the first 2 years of life; it often manifests as musculoskeletal impairments and movement disorders including spasticity and contractures. Variable manifestation of the pathology across individuals, coupled with differing mechanics and treatments, leads to a heterogeneous collection of clinical phenotypes that affect muscles and individuals differently. Growth of muscles in CP deviates from typical development, evident as early as 15 months of age. Muscles in CP may be reduced in volume by as much as 40%, may be shorter in length, present longer tendons, and may have fewer sarcomeres in series that are overstretched compared to typical. Macroscale and functional deficits are likely mediated by dysfunction at the cellular level, which manifests as impaired growth. Within muscle fibres, satellite cells are decreased by as much as 40-70% and the regenerative capacity of remaining satellite cells appears compromised. Impaired muscle regeneration in CP is coupled with extracellular matrix expansion and increased pro-inflammatory gene expression; resultant muscles are smaller, stiffer, and weaker than typical muscle. These differences may contribute to individuals with CP participating in less physical activity, thus decreasing opportunities for mechanical loading, commencing a vicious cycle of muscle disuse and secondary sarcopenia. This narrative review describes the effects of CP on skeletal muscles encompassing substantive changes from whole muscle function to cell-level effects and the effects of common treatments. We discuss growth and mechanics of skeletal muscles in CP and propose areas where future work is needed to understand these interactions, particularly the link between neural insult and cell-level manifestation of CP.

Respiratory and peripheral muscular ultrasound characteristics in ICU COVID 19 ARDS patients

PURPOSE

Severe cases of coronavirus disease 2019 develop ARDS requiring admission to the ICU. This study aimed to investigate the ultrasound characteristics of respiratory and peripheral muscles of patients affected by COVID19 who require mechanical ventilation.

MATERIALS AND METHODS

This is a prospective observational study. We performed muscle ultrasound at the admission of ICU in 32 intubated patients with ARDS COVID19. The ultrasound was comprehensive of thickness and echogenicity of both parasternal intercostal and diaphragm muscles, and cross-sectional area and echogenicity of the rectus femoris.

RESULTS

Patients who survived showed a significantly lower echogenicity score as compared with those who did not survive for both parasternal intercostal muscles. Similarly, the diaphragmatic echogenicity was significantly different between alive or dead patients. There was a significant correlation between right parasternal intercostal or diaphragm echogenicity and the cumulative fluid balance and urine protein output. Similar results were detected for rectus femoris echogenicity.

CONCLUSIONS

The early changes detected by echogenicity ultrasound suggest a potential benefit of proactive early therapies designed to preserve respiratory and peripheral muscle architecture to reduce days on MV, although what constitutes a clinically significant change in muscle echogenicity remains unknown.

Reliability of ultrasonographic measurement of muscle architecture of the gastrocnemius medialis and gastrocnemius lateralis

Ultrasonography is widely used to measure gastrocnemius muscle architecture; however, it is unclear if values obtained from digitised images are sensitive enough to track architectural responses to clinical interventions. The purpose of this study was to explore the reliability and determine the minimal detectable change (MDC) of gastrocnemius medialis (GM) and gastrocnemius lateralis (GL) muscle architecture using ultrasound in a clinical setting. A trained sonographer obtained three B-mode images from each of the GM and GL muscles in 87 volunteers (44 males, 43 females; 22±9 years of age) on two separate occasions. Three independent investigators received training, then digitised the images to determine intra-rater, inter-rater, and test-retest reliability for fascicle length (FL), pennation angle (θ) and muscle thickness. Median FL, θ, and muscle thickness for GM and GL were 53.6–55.7 mm and 65.8–69.3 mm, 18.7–19.5° and 11.9–12.5°, and 12.8–13.2 mm and 15.9–16.9 mm, respectively. Intra- and inter-rater reliability of manual digitisation was excellent for all parameters. Test-retest reliability was moderate to excellent with intraclass correlation coefficient (ICC) values ≥0.80 for FL, ≥0.61 for θ, and ≥0.81 for muscle thickness, in both GM and GL. The respective MDC for GM and GL FL, θ, and muscle thickness was ≤12.1 mm and ≤18.00 mm, ≤6.4° and ≤4.2°, and ≤3.2 mm and ≤3.1 mm. Although reliable, the relatively large MDC suggest that clinically derived ultrasound measurements of muscle architecture in GM and GL are more likely to be useful to detect differences between populations than to detect changes in muscle architecture following interventions.

Qualitative and quantitative muscle ultrasound changes in patients with COVID-19-related ARDS

OBJECTIVES

Severe forms of the novel coronavirus-19 (COVID-19) are associated with systemic inflammation and hypercatabolism. The aims of this study were to compare the time course of the size and quality of both rectus femoris and diaphragm muscles between critically ill, COVID-19 survivors and non-survivors and to explore the correlation between the change in muscles size and quality with the amount of nutritional support delivered and the cumulative fluid balance.

METHODS

This was a prospective observational study in the general intensive care unit (ICU) of a tertiary care hospital for COVID-19. The right rectus femoris cross-sectional area and the right diaphragm thickness, as well as their echo densities were assessed within 24 h from ICU admission and on day 7. We recorded anthropometric and biochemical data, respiratory mechanics and gas exchange, daily fluid balance, and the number of calories and proteins administered.

RESULTS

Twenty-eight patients were analyzed (65 ± 10 y of age; 80% men, body mass index 30 ± 7.8 kg/m²). Rectus femoris and diaphragm sizes were significantly reduced at day 7 (median = -26.1 [interquartile ratio [IQR], = -37.8 to -15.2] and -29.2% [-37.8% to -19.6%], respectively) and this reduction was significantly higher in non-survivors. Both rectus femoris and diaphragm echo density were significantly increased at day 7, with a significantly higher increase in non-survivors. The change in both rectus femoris and diaphragm size at day 7 was related to the cumulative protein deficit (R = 0.664, P < 0.001 and R = 0.640, P < 0.001, respectively), whereas the change in rectus femoris and diaphragm echo density was related to the cumulative fluid balance (R = 0.734, P < 0.001 and R = 0.646, P < 0.001, respectively).

CONCLUSIONS

Early changes in muscle size and quality seem related to the outcome of critically ill COVID-19 patients, and to be influenced by nutritional and fluid management strategies.

Changes in muscle ultrasound for the diagnosis of intensive care unit acquired weakness in critically ill patients

To test diagnostic accuracy of changes in thickness (TH) and cross-sectional area (CSA) of muscle ultrasound for diagnosis of intensive care unit acquired weakness (ICU-AW). Fully conscious patients were subjected to muscle ultrasonography including measuring the changes in TH and CSA of biceps brachii (BB) muscle, vastus intermedius (VI) muscle, and rectus femoris (RF) muscles over time. 37 patients underwent muscle ultrasonography on admission day, day 4, day 7, and day 10 after ICU admission, Among them, 24 were found to have ICW-AW. Changes in muscle TH and CSA of RF muscle on the right side showed remarkably higher ROC-AUC and the range was from 0.734 to 0.888. Changes in the TH of VI muscle had fair ROC-AUC values which were 0.785 on the left side and 0.779 on the right side on the 10th day after ICU admission. Additionally, Sequential Organ Failure Assessment (SOFA), Acute Physiology, and Chronic Health Evaluation II (APACHE II) scores also showed good discriminative power on the day of admission (ROC-AUC 0.886 and 0.767, respectively). Ultrasonography of changes in muscles, especially in the TH of VI muscle on both sides and CSA of RF muscle on the right side, presented good diagnostic accuracy. However, SOFA and APACHE II scores are better options for early ICU-AW prediction due to their simplicity and time efficiency.

Muscle atrophy in critically ill patients : a review of its cause, evaluation, and prevention

Critically ill patients exhibit prominent muscle atrophy, which occurs rapidly after ICU admission and leads to poor clinical outcomes. The extent of atrophy differs among muscles as follows: upper limb: 0.7%-2.4% per day, lower limb: 1.2%-3.0% per day, and diaphragm 1.1%-10.9% per day. This atrophy is caused by numerous risk factors such as inflammation, immobilization, nutrition, hyperglycemia, medication, and mechanical ventilation. Muscle atrophy should be monitored noninvasively by ultrasound at the bedside. Ultrasound can assess muscle mass in most patients, although physical assessment is limited to almost half of all critically ill patients due to impaired consciousness. Important strategies to prevent muscle atrophy are physical therapy and electrical muscular stimulation. Electrical muscular stimulation is especially effective for patients with limited physical therapy. Regarding diaphragm atrophy, mechanical ventilation should be adjusted to maintain spontaneous breathing and titrate inspiratory pressure. However, the sufficient timing and amount of nutritional intervention remain unclear. Further investigation is necessary to prevent muscle atrophy and improve long-term outcomes. J. Med. Invest. 67 : 1-10, February, 2020.

Oral nutritional supplements (ONSs) for cirrhotic patients undergoing liver resection assessed by ultrasound measurement of rectus femoris and anterior tibialis muscles thickness. Randomized clinical trial

PURPOSE

We evaluated the effects of postoperative administration of (ONSs) on the liver function and the outcome of cirrhotic patients using ultrasound (US) assessment of rectus femoris (RF) and anterior tibialis (AT) muscles.

PATIENTS AND METHODS

Forty-three malnourished adult hepatic patients who underwent major liver resections were recruited in this study. In the conventional diet (CD) group, the patients took water at postoperative day (POD) 0 and routine soft diet starting from POD1. In the ONS group, a commercially elemental diet was started from POD1 for 7 days postoperatively, with a target endpoint of 35-40 kcal/kg and 1.2-1.5 g/kg of protein per day. US assessment of the RF and AT muscles was done preoperatively and at POD3 and 7, including anterior-posterior (AP) diameter, lateral-lateral (LL) diameter, and cross-sectional area (CSA). Muscles' echogenicity was defined by the Heckmatt scale. The outcome of the patients was also recorded.

RESULTS

Consumption of ONS preserved the measured RF and AT characteristics (AP and LL diameters and CSA) in the ONS group at POD3 and 7 compared to the CD group. Heckmatt scale was significantly increased at POD3 and 7 in the CD group compared to the ONS group. Both total protein and albumin levels at POD3 and 7 were significantly lower in the CD group compared to the ONS group [P = (0.02, 0.03) and (0.05, 0.04), respectively]. Serum phosphate was significantly lower at POD7 in the ONS group than the CD group (p = 0.04). There were significant decreases in the ICU stay and time of passing flatus (h) in the ONS group comparing with the CD group (P = 0.045 and P = 0.00, respectively).

CONCLUSIONS

ONS maintains muscle mass and echogenicity of RF and AT along with better liver function and intestinal function recovery.

Upper limb muscle atrophy associated with in-hospital mortality and physical function impairments in mechanically ventilated critically ill adults: a two-center prospective observational study

Background

Lower limb muscle atrophy is often observed in critically ill patients. Although upper limb muscles can undergo atrophy, it remains unclear how this atrophy is associated with clinical outcomes. We hypothesized that this atrophy is associated with mortality and impairments in physical function.

Methods

In this two-center prospective observational study, we included adult patients who were expected to require mechanical ventilation for > 48 h and remain in the intensive care unit (ICU) for > 5 days. We used ultrasound to evaluate the cross-sectional area of the biceps brachii on days 1, 3, 5, and 7 and upon ICU discharge along with assessment of physical functions. The primary outcome was the relationship between muscle atrophy ratio and in-hospital mortality on each measurement day, which was assessed using multivariate analysis. The secondary outcomes were the relationships between upper limb muscle atrophy and Medical Research Council (MRC) score, handgrip strength, ICU Mobility Scale (IMS) score, and Functional Status Score for the ICU (FSS-ICU).

Results

Sixty-four patients (43 males; aged 70 ± 13 years) were enrolled. The Acute Physiology and Chronic Health Evaluation (APACHE) II score was 27 (22–30), and in-hospital mortality occurred in 21 (33%) patients. The decreased cross-sectional area of the biceps brachii was not associated with in-hospital mortality on day 3 (p = 0.43) but was associated on days 5 (p = 0.01) and 7 (p < 0.01), which was confirmed after adjusting for sex, age, and APACHE II score. In 27 patients in whom physical functions were assessed, the decrease of the cross-sectional area of the biceps brachii was associated with MRC score (r = 0.47, p = 0.01), handgrip strength (r = 0.50, p = 0.01), and FSS-ICU (r = 0.56, p < 0.01), but not with IMS score (r = 0.35, p = 0.07) upon ICU discharge.

Conclusions

Upper limb muscle atrophy was associated with in-hospital mortality and physical function impairments; thus, it is prudent to monitor it. (321 words)

Trial registration

UMIN 000031316. Retrospectively registered on 15 February 2018.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40560-020-00507-7.

Interrater Reliability of Muscle Ultrasonography Image Acquisition by Physical Therapists in Patients Who Have or Who Survived Critical Illness

OBJECTIVE

Previous studies have demonstrated that muscle ultrasound (US) can be reliably performed at the patient bedside by novice assessors with minimal training. The primary objective of this study was to determine the interrater reliability of muscle US image acquisition by physical therapists and physical therapist students. Secondarily, this study was designed to elucidate the process for training physical therapists to perform peripheral skeletal muscle US.

METHODS

This was a cross-sectional observational study. Four novices and 1 expert participated in the study. Novice sonographers engaged in a structured training program prior to implementation. US images were obtained on the biceps brachii, quadriceps femoris, and tibialis anterior muscles in 3 groups: patients in the intensive care unit, patients on the hospital ward, and participants in the outpatient gym who were healthy. Reliability of image acquisition was analyzed compared with the expert sonographer.

RESULTS

Intraclass correlation coefficient values ranged from 0.76 to 0.97 with an average for all raters and all muscles of 0.903, indicating excellent reliability of image acquisition. In general, the experienced physical therapist had higher or similar intraclass correlation coefficient values compared with the physical therapist students in relation to the expert sonographer.

CONCLUSIONS

Excellent interrater reliability for US was observed regardless of the level of experience, severity of patient illness, or patient setting. These findings indicate that the use of muscle US by physical therapists can accurately capture reliable images in patients with a range of illness severity and different clinical practice settings across the continuum of care.

IMPACT

Physical therapists can utilize US to obtain images to assess muscle morphology.

LAY SUMMARY

Physical therapists can use noninvasive US as an imaging tool to assess the size and quality of peripheral skeletal muscle. This study demonstrates that physical therapists can receive training to reliably obtain muscle images in patients admitted to the intensive care unit who may be at risk for muscle wasting and may benefit from early rehabilitation.

Sonographic muscle mass assessment in patients after cardiac surgery

BACKGROUND

Patients undergoing cardiac surgery particularly those with comorbidities and frailty, experience frequently higher rates of post-operative morbidity, mortality and prolonged hospital length of stay. Muscle mass wasting seems to play important role in prolonged mechanical ventilation (MV) and consequently in intensive care unit (ICU) and hospital stay.

AIM

To investigate the clinical value of skeletal muscle mass assessed by ultrasound early after cardiac surgery in terms of duration of MV and ICU length of stay.

METHODS

In this observational study, we enrolled consecutively all patients, following their admission in the Cardiac Surgery ICU within 24 h of cardiac surgery. Bedside ultrasound scans, for the assessment of quadriceps muscle thickness, were performed at baseline and every 48 h for seven days or until ICU discharge. Muscle strength was also evaluated in parallel, using the Medical Research Council (MRC) scale.

RESULTS

Of the total 221 patients enrolled, ultrasound scans and muscle strength assessment were finally performed in 165 patients (patients excluded if ICU stay < 24 h). The muscle thickness of rectus femoris (RF), was slightly decreased by 2.2% [(95% confidence interval (CI): - 0.21 to 0.15), n = 9; P = 0.729] and the combined muscle thickness of the vastus intermedius (VI) and RF decreased by 3.5% [(95%CI: - 0.4 to 0.22), n = 9; P = 0.530]. Patients whose combined VI and RF muscle thickness was below the recorded median values (2.5 cm) on day 1 (n = 80), stayed longer in the ICU (47 ± 74 h vs 28 ± 45 h, P = 0.02) and remained mechanically ventilated more (17 ± 9 h vs 14 ± 9 h, P = 0.05). Moreover, patients with MRC score ≤ 48 on day 3 (n = 7), required prolonged MV support compared to patients with MRC score ≥ 49 (n = 33), (44 ± 14 h vs 19 ± 9 h, P = 0.006) and had a longer duration of extracorporeal circulation was (159 ± 91 min vs 112 ± 71 min, P = 0.025).

CONCLUSION

Skeletal quadriceps muscle thickness assessed by ultrasound shows a trend to a decrease in patients after cardiac surgery post-ICU admission and is associated with prolonged duration of MV and ICU length of stay.

Comparing the Effectiveness of Blood Flow Restriction and Traditional Heavy Load Resistance Training in the Post-Surgery Rehabilitation of Anterior Cruciate Ligament Reconstruction Patients: A UK National Health Service Randomised Controlled Trial

BACKGROUND

We implemented a blood flow restriction resistance training (BFR-RT) intervention during an 8-week rehabilitation programme in anterior cruciate ligament reconstruction (ACLR) patients within a National Health Service setting.

OBJECTIVE

To compare the effectiveness of BFR-RT and standard-care traditional heavy-load resistance training (HL-RT) at improving skeletal muscle hypertrophy and strength, physical function, pain and effusion in ACLR patients following surgery.

METHODS

28 patients scheduled for unilateral ACLR surgery with hamstring autograft were recruited for this parallel-group, two-arm, single-assessor blinded, randomised clinical trial following appropriate power analysis. Following surgery, a criteria-driven approach to rehabilitation was utilised and participants were block randomised to either HL-RT at 70% repetition maximum (1RM) (n = 14) or BFR-RT (n = 14) at 30% 1RM. Participants completed 8 weeks of biweekly unilateral leg press training on both limbs, totalling 16 sessions, alongside standard hospital rehabilitation. Resistance exercise protocols were designed consistent with standard recommended protocols for each type of exercise. Scaled maximal isotonic strength (10RM), muscle morphology of the vastus lateralis of the injured limb, self-reported function, Y-balance test performance and knee joint pain, effusion and range of motion (ROM) were assessed at pre-surgery, post-surgery, mid-training and post-training. Knee joint laxity and scaled maximal isokinetic knee extension and flexion strength at 60°/s, 150°/s and 300°/s were measured at pre-surgery and post-training.

RESULTS

Four participants were lost, with 24 participants completing the study (12 per group). There were no adverse events or differences between groups for any baseline anthropometric variable or pre- to post-surgery change in any outcome measure. Scaled 10RM strength significantly increased in the injured limb (104 ± 30% and 106 ± 43%) and non-injured limb (33 ± 13% and 39 ± 17%) with BFR-RT and HL-RT, respectively, with no group differences. Significant increases in knee extension and flexion peak torque were observed at all speeds in the non-injured limb with no group differences. Significantly greater attenuation of knee extensor peak torque loss at 150°/s and 300°/s and knee flexor torque loss at all speeds was observed with BFR-RT. No group differences in knee extensor peak torque loss were found at 60°/s. Significant and comparable increases in muscle thickness (5.8 ± 0.2% and 6.7 ± 0.3%) and pennation angle (4.1 ± 0.3% and 3.4 ± 0.1%) were observed with BFR-RT and HL-RT, respectively, with no group differences. No significant changes in fascicle length were observed. Significantly greater and clinically important increases in several measures of self-reported function (50-218 ± 48% vs. 35-152 ± 56%), Y-balance performance (18-59 ± 22% vs. 18-33 ± 19%), ROM (78 ± 22% vs. 48 ± 13%) and reductions in knee joint pain (67 ± 15% vs. 39 ± 12%) and effusion (6 ± 2% vs. 2 ± 2%) were observed with BFR-RT compared to HL-RT, respectively.

CONCLUSION

BFR-RT can improve skeletal muscle hypertrophy and strength to a similar extent to HL-RT with a greater reduction in knee joint pain and effusion, leading to greater overall improvements in physical function. Therefore, BFR-RT may be more appropriate for early rehabilitation in ACLR patient populations within the National Health Service.

Ultrasonography to measure quadriceps muscle in critically ill patients: A literature review of reported methodologies

Muscle wasting in the intensive care unit (ICU) is common and may impair functional recovery. Ultrasonography (US) presents a modern solution to quantify skeletal muscle size and monitor muscle wasting. However, no standardised methodology for the conduct of ultrasound-derived quadriceps muscle layer thickness or cross-sectional area in this population exists. The aim of this study was to compare methodologies reported for the measurement of quadriceps muscle layer thickness (MLT) and cross-sectional area (CSA) using US in critically ill patients. Databases PubMed, Ovid, Embase, and CINAHL were searched for original research publications that reported US-derived quadriceps MLT and/or CSA conducted in critically ill adult patients. Data were extracted from eligible studies on parameters relating to US measurement including anatomical location, patient positioning, operator technique and image analysis. It was identified that there was a clear lack of reported detail and substantial differences in the reported methodology used for all parameters. A standardised protocol and minimum reporting standards for US-derived measurement of quadriceps muscle size in ICU is required to allow for consistent measurement techniques and hence interpretation of results.

An audit of completion of diaries for rehabilitation in an intensive care unit

Intensive care unit (ICU) diaries are increasingly being used in UK hospitals as a therapeutic means to address the psychological effects of an ICU stay on patients. The National Institute for Health and Care Excellence recommends that services are developed to meet the psychological needs of patients following critical illness. This article discusses ICU diaries as a service to meet these needs. There is a greater demand for evidence-based research to support the positive effects of the diaries. Equally, there is a need to highlight the negative impact they may have on patients who would not wish to have a diary because of the traumatic experience of critical illness. To gain an insight into the use of patient diaries, an audit was conducted at one ICU, which found compliance with completing them was poor. This article gives an overview of the available literature. Recommendations are made to improve the use of ICU diaries for clinical practice in the future.

Efeitos do exercício passivo precoce em cicloergômetro na espessura muscular do quadríceps femoral de pacientes críticos: estudo-piloto randomizado controlado

RESUMO O objetivo deste estudo foi avaliar os efeitos do exercício passivo precoce em cicloergômetro na espessura muscular (EM) do quadríceps femoral (EMQ) de pacientes críticos admitidos em uma Unidade de Terapia Intensiva (UTI) de um hospital universitário terciário. O método utilizado foi um estudo-piloto randomizado controlado conduzido em uma amostra de 24 pacientes (51±18,11 anos, 16 do sexo masculino), com 24 a 48 horas de ventilação mecânica (VM), aleatoriamente divididos em dois grupos: grupo-controle (n=12), que recebeu a fisioterapia convencional; e grupo-intervenção (n=12), que recebeu o exercício passivo em cicloergômetro, uma vez ao dia, durante o período de sete dias do protocolo, em adição à fisioterapia convencional. A EMQ foi mensurada através da ultrassonografia. A primeira medida ultrassonográfica foi realizada entre as primeiras 48 horas de VM e a segunda ao término do protocolo. Não houve diferenças significativas na EMQ esquerda (27,29±5,86mm vs. 25,95±10,89mm; p=0,558) e direita (24,96±5,59mm vs 25,9±9,21mm; p=0,682) do grupo-controle e na EMQ esquerda (27,2±7,38mm vs 29,57±7,89mm; p=0,299) e direita (26,67±8,16mm vs 28,65±8,04mm; p=0,381) do grupo-intervenção. Na comparação entre os grupos, não houve alterações significativas em relação à EMQ esquerda (3,61±1,07mm; p=0,248) e a EMQ direita (2,75±0,85mm; p=0,738). Os resultados deste estudo-piloto demonstraram que a aplicação precoce do exercício passivo em cicloergômetro não promoveu mudanças significativas na espessura da camada muscular avaliada. No entanto, nossos achados sinalizam que a fisioterapia convencional foi capaz de preservar a EMQ de pacientes críticos admitidos em UTI.

Assessment of peripheral muscle thickness and architecture in healthy volunteers using hand-held ultrasound devices; a comparison study with standard ultrasound

BACKGROUND

Pocket-sized ultrasound devices are increasingly used in a variety of clinical situations, and perform well against standard ultrasound machines. We sought to investigate if a pocket-sized ultrasound device can assess muscle thickness and architecture in healthy volunteers.

METHODS

Healthy male volunteers (n = 21) across a range of ages were recruited to the study. Laying supine, ultrasound images were taken from the right anterior and lateral thigh. Thickness of the rectus femoris (RFMT), vastus intermedius (VIMT), and the two combined (anterior thigh, AMT) were measured, along with thickness of vastus lateralis (VLMT), pennation angle (VLPA) and derived fascicle length (VLFL). These scans were performed initially using a pocket-sized ultrasound (VScan) and then using a standard device (Telemed Echoblaster 128).

RESULTS

In all six variables, there was no significant difference between the two sets of measurements. Intra-class correlation co-efficients (ICC) for VLMT, VLPA, and AMT were all excellent (0.93, 0.89, 0.90 respectively) with the derived value of VLFL having an ICC of 0.84. All ICC values were statistically significant. Regression analysis demonstrated no evidence of proportional bias in any of the measured or derived variables.

CONCLUSION

A pocket-sized ultrasound device gives similar measurements of lower limb muscle thickness and architecture as a standard device in healthy volunteers.

Clinical review: peripheral muscular ultrasound in the ICU

Muscular weakness developing from critical illness neuropathy, myopathy and muscle atrophy has been characterized as intensive care unit-acquired weakness (ICUAW). This entity occurs commonly during and after critical care stay. Various causal factors for functional incapacity have been proposed. Among these, individual patient characteristics (such as age, comorbidities and nutritional status), acting in association with sustained bed rest and pharmacological interventions (included the metabolic support approach), seem influential in reducing muscular mass. Long-term outcomes in heterogeneous ICUAW populations include transient disability in 30% of patients and persistent disabilities that may occur even in patients with nearly complete functional recovery. Currently available tools for the assessment of skeletal muscle mass are imprecise and difficult to perform in the ICU setting. A valid alternative to these imaging modalities is muscular ultrasonography, which allows visualization and classification of muscle characteristics by cross-sectional area, muscle layer thickness, echointensity by grayscale and the pennation angle). The aim of this narrative review is to describe the current literature addressing muscular ultrasound for the detection of muscle weakness and its potential impact on treatment and prognosis of critically ill patients when combined with biomarkers of muscle catabolism/anabolism and bioenergetic state. In addition, we suggest a practical flowchart for establishing an early diagnosis.

Recent evidence on early mobilization in critical-Ill patients

PURPOSE OF REVIEW

To examine the benefits of early mobilization and summarize the results of most recent clinical studies examining early mobilization in critically ill patients followed by a presentation of recent developments in the field.

RECENT FINDINGS

Early mobilization of ICU patients, defined as mobilization within 72 h of ICU admission, is still uncommon. In medical and surgical critically ill patients, mobilization is well tolerated even in intubated patients. In neurocritical care, evidence to support early mobilization is either lacking (aneurysmal subarachnoid hemorrhage), or the results are inconsistent (e.g. stroke). Successful implementation of early mobilization requires a cultural change; preferably based on an interprofessional approach with clearly defined responsibilities and including a mobilization scoring system. Although the evidence for the majority of the technical tools is still limited, the use of a bed cycle ergometer and a treadmill with strap system has been promising in smaller trials.

SUMMARY

Early mobilization is well tolerated and feasible, resulting in improved outcomes in surgical and medical ICU patients. Implementation of early mobilization can be challenging and may need a cultural change anchored in an interprofessional approach and integrated in a patient-centered bundle. Scoring systems should be integrated to define daily goals and used to verify patients' achievements or identify barriers immediately.

Point-of-Care Ultrasound to Evaluate Thickness of Rectus Femoris, Vastus Intermedius Muscle, and Fat as an Indicator of Muscle and Fat Wasting in Critically Ill Patients in a Multidisciplinary Intensive Care Unit

Background:

Muscular atrophy is the universal feature in patients with ICUAW. Muscles of the lower limb are more prone to early atrophy. Measurement of fat thickness is used to assess malnutrition. This study was designed to evaluate if, subcutaneous fat also reduces along with muscle thickness and if it can be reliably used as an indicator of nutritional assessment in critically ill patients using point of care ultrasound.

Materials and Methods:

An observational clinical study of 100 patients admitted to multidisciplinary intensive care units (ICUs). Total anterior thigh thickness, thickness of the rectus femoris muscle, fat thickness, and the combined thickness of vastus intermedius and rectus femoris were taken on day 1, 3, and 7 of ICU admission.

Results:

There was progressive loss of muscle mass from day 1 to day 7. Muscle loss was not only limited to rectus femoris, but vastus intermedius also showed a significant decrease as indicated by the bone to muscle measurement. Skin to bone measurement which includes both muscle and fat compartment showed a decline.

Conclusions:

There is potential utility of ultrasound for early detection and probable corrective measures to prevent ICUAW. The rectus femoris thickness, skin to bone, and bone to muscle thickness show statistically significant difference on day 3, day 7 compared to day 1. Fat layer did not show statistically significant decrease.

Development of a bedside viable ultrasound protocol to quantify appendicular lean tissue mass

BACKGROUND

Ultrasound is a non-invasive and readily available tool that can be prospectively applied at the bedside to assess muscle mass in clinical settings. The four-site protocol, which images two anatomical sites on each quadriceps, may be a viable bedside method, but its ability to predict musculature has not been compared against whole-body reference methods. Our primary objectives were to (i) compare the four-site protocol's ability to predict appendicular lean tissue mass from dual-energy X-ray absorptiometry; (ii) optimize the predictability of the four-site protocol with additional anatomical muscle thicknesses and easily obtained covariates; and (iii) assess the ability of the optimized protocol to identify individuals with low lean tissue mass.

METHODS

This observational cross-sectional study recruited 96 university and community dwelling adults. Participants underwent ultrasound scans for assessment of muscle thickness and whole-body dual-energy X-ray absorptiometry scans for assessment of appendicular lean tissue. Ultrasound protocols included (i) the nine-site protocol, which images nine anterior and posterior muscle groups in supine and prone positions, and (ii) the four-site protocol, which images two anterior sites on each quadriceps muscle group in a supine position.

RESULTS

The four-site protocol was strongly associated (R2  = 0.72) with appendicular lean tissue mass, but Bland-Altman analysis displayed wide limits of agreement (-5.67, 5.67 kg). Incorporating the anterior upper arm muscle thickness, and covariates age and sex, alongside the four-site protocol, improved the association (R2  = 0.91) with appendicular lean tissue and displayed narrower limits of agreement (-3.18, 3.18 kg). The optimized protocol demonstrated a strong ability to identify low lean tissue mass (area under the curve = 0.89).

CONCLUSIONS

The four-site protocol can be improved with the addition of the anterior upper arm muscle thickness, sex, and age when predicting appendicular lean tissue mass. This optimized protocol can accurately identify low lean tissue mass, while still being easily applied at the bedside.

Bedside Ultrasound Measurement of Rectus Femoris: A Tutorial for the Nutrition Support Clinician

Intensive care unit acquired weakness is a long-term consequence after critical illness; it has been related to muscle atrophy and can be considered as one of the main nutritional support challenges at the intensive care unit. Measuring muscle mass by image techniques has become a new area of research for the nutritional support field, extending our knowledge about muscle wasting and the impact of nutritional approaches in the critical care setting, although currently there is no universally accepted technique to perform muscle measurements by ultrasound. Because of this, we present this tutorial for nutrition support clinicians, in order to understand and perform muscle measurements by this reliable, accessible, low-cost, and easy-to-use technique. Reviewing issues such as quadriceps muscle anatomy, correct technique (do's and don'ts), identification of structures, and measurement of the rectus femoris and vastus intermedius muscles helps to acquire the basic concepts of this technique and encouraging more research in this field.