Skeletal Muscle Wasting and Function Impairment in Intensive Care Patients With Severe COVID-19

Unveiling the detrimental vicious cycle linking skeletal muscle and COVID-19: A systematic review and meta-analysis

OBJECTIVE

Skeletal muscle catabolism supports multiple organs and systems during severe trauma and infection, but its role in COVID-19 remains unclear. This study investigates the interactions between skeletal muscle and COVID-19.

METHODS

The PubMed, EMbase, and The Cochrane Library databases were systematically searched from January 2020 to August 2023 for cohort studies focusing on the impact of skeletal muscle on COVID-19 prevalence and outcomes, and longitudinal studies examining skeletal muscle changes caused by COVID-19. Skeletal muscle quantity (SMQN) and quality (SMQL) were assessed separately. The random-effect model was predominantly utilized for statistical analysis.

RESULTS

Seventy studies with moderate to high quality were included. Low SMQN/SMQL was associated with an increased risk of COVID-19 infection (OR = 1.62, p < 0.001). Both the low SMQN and SMQL predicted COVID-19-related mortality (OR = 1.53, p = 0.016; OR = 2.18, p = 0.001, respectively). Mortality risk decreased with increasing SMQN (OR = 0.979, p = 0.009) and SMQL (OR = 0.972, p = 0.034). Low SMQN and SMQL were also linked to the need for intensive care unit/mechanical ventilation, increased COVID-19 severity, and longer hospital stays. Significant skeletal muscle wasting, characterized by reduced volume and strength, was observed during COVID-19 infection and the pandemic.

CONCLUSIONS

This study reveals a detrimental vicious circle between skeletal muscle and COVID-19. Effective management of skeletal muscle could be beneficial for treating COVID-19 infections and addressing the broader pandemic. These findings have important implications for the management of future virus pandemics.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42023395476.

Functional Dependence Prior to ICU Admission is Associated with Worse Clinical and Functional Outcomes in Individuals with COVID-19: A Prospective Observational Study

Objectives: To determine whether low functional capacity (FC) prior to intensive care unit (ICU) admission due to coronavirus disease 2019 (COVID-19) might be associated with worse clinical outcomes. To monitor FC until discharge from the ICU. To identify associations between physical outcomes and decreased FC at discharge from the ICU. Design: Prospective observational study conducted from March to August 2021. Setting: ICU for adult patients with COVID-19. Participants: Adults (≥18 years) with COVID-19. Interventions: Not applicable. Main outcome measures: Clinical and demographic data were obtained from medical records. At ICU admission, evaluation was made of FC using the Barthel index (BI), and of the level of mobility using the ICU mobility scale. At ICU discharge, FC and mobility level were reassessed, and muscle strength was measured using the Medical Research Council (MRC) scale and the handgrip test. Results: The study was performed with 108 individuals. At the initial assessment, 73.1% of the patients were functionally independent. Length of hospital stay (odds ratio [OR]  =  1.05; 95%confidence interval [CI]  =  1.00-1.10) and death (OR  =  5.27; 95%CI  =  1.37-20.28) were related to functional status prior to ICU admission. Between ICU admission and discharge, the BI evaluation indicated a functional decline of 22.5 points. Low mobility level (P  =  .003) and low muscle strength assessed by the MRC scale (P < .001), measured at ICU discharge, were associated with a greater decrease of FC during the ICU stay. Conclusions: Patients with COVID-19 who were functionally dependent prior to ICU admission presented worse clinical outcomes, with low functional status being associated with longer hospitalization and higher mortality. However, irrespective of the initial functionality status, the surviving individuals suffered from functional decline at ICU discharge. Greater functional decline during the ICU stay was associated with lower muscle strength and lower mobility level at ICU discharge.

Association between protocol change to a higher-protein formula with lower energy targets and nutrient delivery in critically ill patients with COVID-19: A retrospective cohort study

BACKGROUND

Guidelines recommend prioritizing protein provision while avoiding excessive energy delivery to critically ill patients with coronavirus disease 2019 (COVID-19), but there are no prospective studies evaluating such a targeted approach in this group. We aimed to evaluate the effect of a "higher-protein formula protocol" on protein, energy, and volume delivery when compared with standard nutrition protocol.

METHODS

This was a retrospective cohort study of adult patients with COVID-19 who received mechanical ventilation for >72 h and enteral nutrition. Before October 2021, the standard nutrition protocol for patients was 0.7 ml/kg/h ideal body weight (IBW) of a 63 g/L protein and 1250 kcal/L formula. From October 2021, we implemented a higher-protein formula protocol for patients with COVID-19. The initial prescription was 0.5 ml/kg/h IBW of a 100 g/L protein and 1260 kcal/L formula with greater emphasis on energy targets being directed by indirect calorimetry when possible. Measured outcomes included protein, energy, and volume delivered.

RESULTS

There were 114 participants (standard protocol, 48; higher-protein protocol, 66) with 1324 days of nutrition support. The median (95% CI) differences in protein, energy, and volume delivery between targeted and standard protocol periods were 0.08 g/kg/day (-0.02 to 0.18 g/kg/day), -1.71 kcal/kg/day (-3.64 to 0.21 kcal/kg/day) and -1.5 ml/kg/day (-2.9 to -0.1 ml/kg/day). Thirty-three patients (standard protocol, 7; higher-protein protocol, 26) had 44 indirect calorimetry assessments. There was no difference in measured energy expenditure over time (increased by 0.49 kcal/kg/day [-0.89 to 1.88 kcal/kg/day]).

CONCLUSION

Implementation of a higher-protein formula protocol to patients with COVID-19 modestly reduced volume administration without impacting protein and energy delivery.

Timing to out-of-bed mobilization and mobility levels of COVID-19 patients admitted to the ICU: Experiences in Brazilian clinical practice

INTRODUCTION

At the beginning of the coronavirus disease 2019 (COVID-19) pandemic, there was scarce data about clinical/functional conditions during hospitalization or after hospital discharge. Little was known about COVID-19 repercussions and how to do early mobilization in intensive care unit (ICU).

OBJECTIVE

Identify the time to the initiation of out-of-bed mobilization and the levels of mobility (sitting over the edge of the bed, sitting in a chair, standing, and ambulating) reached by critically ill patients with COVID-19 during hospitalization and the factors that could impact early mobilization.

METHODS

This was a retrospective observational study of patients with COVID-19 in the ICU.

RESULTS

There were 157 surviving COVID-19 patients included in the study (median age: 61 years; median ICU length of stay: 12 days). The median time to initiate out-of-bed mobilization in the ICU was 6 days; between patients who received mechanical ventilation (MV) compared with those who did not, this time was 8 vs. 2.5 days (p < .001). Most patients who used MV were mobilized after extubation (79.6%). During ICU stays, 88.0% of all patients were mobilized out of bed, and 41.0% were able to ambulate either with assistance or independently. The time to initiate out-of-bed mobilization is associated with sedation time and MV time.

CONCLUSION

Despite the pandemic scenario, patients were quickly mobilized out of bed, and most of the patients achieved higher mobility levels in the ICU and at hospital discharge. Sedation time and MV time were associated with delays in initiating mobilization.

Physical condition and perceived fatigue in post-covid patients: An observational descriptive study

BACKGROUND

Patients with severe coronavirus disease 2019 (COVID-19) often require hospital admission and experience sequelae such as chronic fatigue or low muscle mass.

OBJECTIVE

To analyze the functional capacity of a cohort of patients with severe acute respiratory syndrome coronavirus 2 who required hospitalization.

DESIGN AND SETTING

An observational descriptive study was conducted on post-COVID-19 patients referred to the Rehabilitation Department of Gregorio Marañón Hospital (Madrid, SPAIN).

METHODS

Cardiorespiratory fitness, muscle strength, body composition, and perception of fatigue and dyspnea were analyzed. Furthermore, the existing correlations between clinical variables and physical conditions were analyzed.

RESULTS

Forty-two patients who required hospital admission (80 ± 22.45 days) or intensive care unit (ICU) admission (58 ± 10.52 days) were analyzed. They presented with decreased strength, respiratory capacity, and moderate-to-severe perceived fatigue. Additionally, an inverse correlation was found between right-handgrip strength and days in the ICU, as well as the 6-minute walk test for women. Similarly, strength and fitness were negatively associated with perceived fatigue.

CONCLUSIONS

Post-COVID-19 patients showed low muscle function and low levels of physical fitness associated with high perceived fatigue.

SARS-CoV-2 and its Multifaceted Impact on Bone Health: Mechanisms and Clinical Evidence

PURPOSE OF REVIEW

SARS-CoV-2 infection, the culprit of the COVID-19 pandemic, has been associated with significant long-term effects on various organ systems, including bone health. This review explores the current understanding of the impacts of SARS-CoV-2 infection on bone health and its potential long-term consequences.

RECENT FINDINGS

As part of the post-acute sequelae of SARS-CoV-2 infection, bone health changes are affected by COVID-19 both directly and indirectly, with multiple potential mechanisms and risk factors involved. In vitro and preclinical studies suggest that SARS-CoV-2 may directly infect bone marrow cells, leading to alterations in bone structure and osteoclast numbers. The virus can also trigger a robust inflammatory response, often referred to as a "cytokine storm", which can stimulate osteoclast activity and contribute to bone loss. Clinical evidence suggests that SARS-CoV-2 may lead to hypocalcemia, altered bone turnover markers, and a high prevalence of vertebral fractures. Furthermore, disease severity has been correlated with a decrease in bone mineral density. Indirect effects of SARS-CoV-2 on bone health, mediated through muscle weakness, mechanical unloading, nutritional deficiencies, and corticosteroid use, also contribute to the long-term consequences. The interplay of concurrent conditions such as diabetes, obesity, and kidney dysfunction with SARS-CoV-2 infection further complicates the disease's impact on bone health. SARS-CoV-2 infection directly and indirectly affects bone health, leading to potential long-term consequences. This review article is part of a series of multiple manuscripts designed to determine the utility of using artificial intelligence for writing scientific reviews.

COVID-19 and Bone Loss: A Review of Risk Factors, Mechanisms, and Future Directions

PURPOSE OF REVIEW

SARS-CoV-2 drove the catastrophic global phenomenon of the COVID-19 pandemic resulting in a multitude of systemic health issues, including bone loss. The purpose of this review is to summarize recent findings related to bone loss and potential mechanisms.

RECENT FINDINGS

The early clinical evidence indicates an increase in vertebral fractures, hypocalcemia, vitamin D deficiencies, and a loss in BMD among COVID-19 patients. Additionally, lower BMD is associated with more severe SARS-CoV-2 infection. Preclinical models have shown bone loss and increased osteoclastogenesis. The bone loss associated with SARS-CoV-2 infection could be the result of many factors that directly affect the bone such as higher inflammation, activation of the NLRP3 inflammasome, recruitment of Th17 cells, the hypoxic environment, and changes in RANKL/OPG signaling. Additionally, SARS-CoV-2 infection can exert indirect effects on the skeleton, as mechanical unloading may occur with severe disease (e.g., bed rest) or with BMI loss and muscle wasting that has also been shown to occur with SARS-CoV-2 infection. Muscle wasting can also cause systemic issues that may influence the bone. Medications used to treat SARS-CoV-2 infection also have a negative effect on the bone. Lastly, SARS-CoV-2 infection may also worsen conditions such as diabetes and negatively affect kidney function, all of which could contribute to bone loss and increased fracture risk. SARS-CoV-2 can negatively affect the bone through multiple direct and indirect mechanisms. Future work will be needed to determine what patient populations are at risk of COVID-19-related increases in fracture risk, the mechanisms behind bone loss, and therapeutic options. This review article is part of a series of multiple manuscripts designed to determine the utility of using artificial intelligence for writing scientific reviews.

Recovery of skeletal muscle strength and physical function in a patient with (post) COVID-19 requiring extra-corporeal membrane oxygenation

BACKGROUND

The ongoing coronavirus-19 disease (COVID-19) has taught us that early mobilization is essential for functional recovery during and after prolonged intensive care unit (ICU) stay. This especially applies for patients receiving a challenging combination of prolonged invasive treatments such as mechanical ventilation (MV) and extra-corporeal membrane oxygenation (ECMO). This case report describes the recovery of skeletal muscle strength and physical function in a patient (post) COVID-19 during ICU stay.

CASE DESCRIPTION

A 54 year old female patient was diagnosed with COVID-19 pneumonia, and ultimately needed ICU treatment with MV and ECMO for 69 days during which she received physiotherapy treatment.

OUTCOMES

The patient recovered from intensive care acquired muscle weakness (ICUAW) at day 53, resulting in the ability to walk at day 62. She was discharged from the ICU after 69 days with the ability to walk 20 meters with support of one person and a mobility aid. No evident adverse events were noted during or after physiotherapy sessions.

DISCUSSION

Early mobilization is feasible and safe in a patient (post) COVID-19 with prolonged ECMO treatment and facilitates functional recovery during ICU stay. This single case observation should be handled with caution and needs further validation.

Effects of a telerehabilitation program and detraining on cardiorespiratory fitness in patients with post-COVID-19 sequelae: A randomized controlled trial

BACKGROUND

This study aimed to evaluate the effects of a 15-week telerehabilitation program and a detraining period on cardiorespiratory fitness and mechanical efficiency in patients with post-COVID-19 sequelae.

METHODS

131 patients with post-COVID-19 sequelae were randomly assigned to one of two groups: patients who carried out the supervised telerehabilitation program (TRG, n = 66) and a control group (CG, n = 65). An incremental cardiopulmonary exercise testing (CPET) was performed on cycle ergometer to compare cardioventilatory responses between experimental groups.

RESULTS

A significant increase in the CPET duration, peak power output, and mechanical efficiency was observed in TRG compared to CG after the telerehabilitation program (p ≤ 0.001). A significant increase in the CPET duration, peak power output, and mechanical efficiency was verified at 3 months compared to the pretest and after detraining in TRG (p < 0.001). A significant increase in peak oxygen uptake (V̇O2peak ) was identified after the intervention and in the detraining period compared to the pretest in both experimental groups (p < 0.001). A higher ventilatory efficiency was observed after the telerehabilitation program (p = 0.021) than in pretest only in TRG.

CONCLUSIONS

A 15-week supervised home telerehabilitation program improved exercise capacity, power output, and mechanical efficiency in TRG compared to a CG. The telerehabilitation program was not more effective in improving V̇O2peak than the activities of the CG. However, ventilatory efficiency was improved only after the telerehabilitation program. The reported results after the detraining period highlight the need to maintain the rehabilitation program over time.

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.

Sarcopenia and Mortality in Critically Ill COVID-19 Patients

COVID-19 can manifest as either asymptomatic or progressing to a severe phase in some patients, which may require hospitalization. These patients may experience dyspnea and hypoxia, leading to the development of acute respiratory distress syndrome. Studies have reported an increased risk of severe sarcopenia in COVID-19 patients during and after recovery. This narrative review aimed to summarize and synthesize available studies on the association between sarcopenia and mortality in critically ill COVID-19 patients. A total of 22 studies conducted on hospitalized COVID-19 patients were included in this review. Of those, 17 studies reported a direct association, while 5 studies showed no association between sarcopenia and mortality in severe COVID-19 patients. It is important to maintain muscle quality and quantity in defense against COVID-19. The measurement of lean muscle mass should be included in the risk assessment of severely ill COVID-19 patients as part of the therapy plan.

Functional recovery of chronically critically ill patients in the first days after discharge from the intensive care unit: Feasibility of the 6-minute step test

BACKGROUND

Survivors of chronic critical illness often experience weakness and functional dependence to various degrees after their intensive care unit (ICU) stay. Evaluating their functional status with the traditional six-minute walk test is challenging due to space constraints or patient intolerance.

OBJECTIVE

Our aim was to evaluate the feasibility of using the six-minute step test (6MST) as a measure of functional capacity in chronically critically ill patients early after ICU discharge.

METHODS

This prospective study was undertaken in a private Brazilian hospital. From July 2019 to July 2020, all chronically critically ill patients were asked to participate 48 hours after ICU discharge. On the day of study inclusion and a week later, those who consented underwent functional assessment comprised of the 6MST, peripheral muscle strength using handgrip strength (HGS), and mobility using the ICU mobility scale (IMS).

RESULTS

A total of 40 patients were included. The 6MST was feasible in 40% on the first evaluation and 57% on the second. The median 6MST was 0 [0-5] on the first evaluation and 3.5 [0-7.75] on the second (P = 0.005). The median HGS increased from 11.50 [9.25-18] on the first evaluation to 14.5 [10-20] on the second (P = 0.006). The median IMS was 4.5 [3.25-7] on the first evaluation and 6 [3.25-7] on the second (P<0.001). Despite the significant improvement, all parameters measured remained well below normal.

CONCLUSION

The 6MST was a feasible measure of functional capacity in chronically critically ill patients early after ICU discharge. Patients had functional capacity well below predicted values.

Clinical Utility of Ultrasound Imaging for Measuring Anterior Thigh Thickness after Anterior Cruciate Ligament Injury in an Individual Patient to Assess Postsurgery Outcome

The present study investigated the clinical utility of ultrasound imaging (USI) for assessing changes in an individual's quadriceps muscle and subcutaneous fat (SF) thickness of the anterior thigh and their relative proportions. A patient was studied prior to and after anterior cruciate ligament reconstruction (ACLR) surgery and during rehabilitation. This case study involved an 18-year-old female recreational athlete with a complete tear of the anterior cruciate ligament (ACL). Tissue thickness (SF and quadriceps muscle) was measured from transverse USI of the anterior thigh before surgery, at weekly intervals during 12 weeks of postsurgery, and then every 2 weeks for the following 12 weeks (total of 21 measurement sets). Statistically significant differences presurgery to postrehabilitation were found for muscle thickness (p = 0.04) and SF tissue thickness (p = 0.04) measurements. There was no difference in muscle to fat ratio (p = 0.08). Changes in measurements greater than the reported minimal detectable change (MDC) demonstrate the sensitivity of the USI technique as an objective tool to assess clinically useful changes in an individual's anterior thigh muscle thickness post-ACLR surgery and during rehabilitation.

Construct and criterion validity of muscle ultrasonography for assessment of skeletal muscle in patients recovering from COVID-19

Background: The purpose was to investigate the content, construct, and criterion validity of muscle ultrasound in a mixed cohort of participants recovering from mild and critical COVID-19. Methods: A secondary analysis of a prospective cross-sectional study was conducted on data obtained from a battery of muscle and physical function assessments including a muscle biopsy and muscle ultrasonography (US). Rectus femoris (RF) muscle thickness (mT), quadricep complex (QC) mT, RF muscle cross-sectional area (CSA) using 2D freeform trace and estimated from Feret's diameter, and RF echo intensity (EI) were assessed with US. Muscle fiber CSA, fiber type, protein content in muscle fibers, extracellular matrix content (ECM; wheat-germ agglutin), and percent area of collagen in ECM (picrosirius red) were examined from vastus lateralis muscle biopsies. Spearman rho correlations (r) were performed to assess validity of ultrasound parameters. Results: Thirty-three individuals participated including 11 patients surviving critical COVID-19, 15 individuals recovering from mild-COVID, and 7 controls. There were several significant correlations between RF mT, QC mT, RF CSA, and RF EI with age, comorbid burden, body-mass index, and measures of muscle strength, muscle power, and physical function (range r = 0.35-0.83). RF Feret's CSA correlated to CSA of type II muscle fibers (r = 0.41, p = 0.022) and the average size of all muscle fibers (r = 0.39, p = 0.031). RF EI was correlated with collagen in muscle ECM (r = 0.53, p = 0.003) and protein content in muscle tissue (r = -0.52, p = 0.012). Conclusion: Muscle size and quality measured using US has moderate content and construct validity, and to lesser extent, fair to moderate criterion validity in a mixed cohort of individuals recovering from COVID. Muscle ultrasound quality (EI) appears to be sensitive at detecting muscle dysfunction as it is associated with strength, power, physical function, and collagen distribution in a mixed group of individuals recovering from COVID-19.

Neuromuscular defects after infection with a beta coronavirus in mice

COVID-19 affects primarily the lung. However, several other systemic alterations, including muscle weakness, fatigue and myalgia have been reported and may contribute to the disease outcome. We hypothesize that changes in the neuromuscular system may contribute to the latter symptoms observed in COVID-19 patients. Here, we showed that C57BL/6J mice inoculated intranasally with the murine betacoronavirus hepatitis coronavirus 3 (MHV-3), a model for studying COVID-19 in BSL-2 conditions that emulates severe COVID-19, developed robust motor alterations in muscle strength and locomotor activity. The latter changes were accompanied by degeneration and loss of motoneurons that were associated with the presence of virus-like particles inside the motoneuron. At the neuromuscular junction level, there were signs of atrophy and fragmentation in synaptic elements of MHV-3-infected mice. Furthermore, there was muscle atrophy and fiber type switch with alteration in myokines levels in muscles of MHV-3-infected mice. Collectively, our results show that acute infection with a betacoronavirus leads to robust motor impairment accompanied by neuromuscular system alteration.

Effects of a 16-week home-based exercise training programme on health-related quality of life, functional capacity, and persistent symptoms in survivors of severe/critical COVID-19: a randomised controlled trial

BACKGROUND

Long-lasting effects of COVID-19 may include cardiovascular, respiratory, skeletal muscle, metabolic, psychological disorders and persistent symptoms that can impair health-related quality of life (HRQoL). We investigated the effects of a home-based exercise training (HBET) programme on HRQoL and health-related outcomes in survivors of severe/critical COVID-19.

METHODS

This was a single-centre, single-blinded, parallel-group, randomised controlled trial. Fifty survivors of severe/critical COVID-19 (5±1 months after intensive care unit discharge) were randomly allocated (1:1) to either a 3 times a week (~60-80 min/session), semi-supervised, individualised, HBET programme or standard of care (CONTROL). Changes in HRQoL were evaluated through the 36-Item Short-Form Health Survey, and physical component summary was predetermined as the primary outcome. Secondary outcomes included cardiorespiratory fitness, pulmonary function, functional capacity, body composition and persistent symptoms. Assessments were performed at baseline and after 16 weeks of intervention. Statistical analysis followed intention-to-treat principles.

RESULTS

After the intervention, HBET showed greater HRQoL score than CONTROL in the physical component summary (estimated mean difference, EMD: 16.8 points; 95% CI 5.8 to 27.9; effect size, ES: 0.74), physical functioning (EMD: 22.5 points, 95% CI 6.1 to 42.9, ES: 0.83), general health (EMD: 17.4 points, 95% CI 1.8 to 33.1, ES: 0.73) and vitality (EMD: 15.1 points, 95% CI 0.2 to 30.1, ES: 0.49) domains. 30-second sit-to-stand (EMD: 2.38 reps, 95% CI 0.01 to 4.76, ES: 0.86), and muscle weakness and myalgia were also improved in HBET compared with CONTROL (p<0.05). No significant differences were seen in the remaining variables. There were no adverse events.

CONCLUSION

HBET is an effective and safe intervention to improve physical domains of HRQoL, functional capacity and persistent symptoms in survivors of severe/critical COVID-19.

TRIAL REGISTRATION NUMBER

NCT04615052.

Assessment of body composition in adults hospitalized with acute COVID-19: a scoping review

Introduction

Body composition (BC) assessment can supply accurate information for in-hospital nutritional evaluation. The aim of this study was to explore in the literature how the studies assessed BC, for what purpose, and investigate the role of BC findings in COVID-19 hospitalized patients' outcomes.

Methods

A scoping review was conducted according to the methodology available on the Joanna Briggs Institute website. We used the PCC acronym for the systematic search (population: adults with COVID-19, concept: assessment of BC, context: hospital setting) and performed it on PubMed, Scopus, and the Web of Science on 16 September 2022. Eligibility criteria consisted of the utilization of BC assessment tools in COVID-19 patients. Studies in which BC was solely measured with anthropometry (perimeters and skinfolds) were excluded. No language restriction was applied.

Results

Fifty-five studies were eligible for the review. Out of the 55 studies, 36 used computed tomography (CT), 13 used bioelectrical impedance (BIA), and 6 used ultrasound (US). No studies with D3-creatinine, 24  h urine excretion, dual-energy X-ray absorptiometry, or magnetic resonance were retrieved. BC was mainly assessed to test associations with adverse outcomes such as disease severity and mortality.

Discussion

Studies assessing BC in hospitalized patients with COVID-19 used mainly CT and BIA and associated the parameters with severity and mortality. There is little evidence of BC being assessed by other methods, as well as studies on BC changes during hospitalization.

Resistance Training in Post-COVID Recovery: Rationale and Current Evidence

During hospitalisation with COVID-19, individuals may experience prolonged periods of immobilisation. Combined with the inflammatory effects of the virus, this may lead to a significant reduction in both muscle mass and strength. Data from several long-term studies suggest that these symptoms may not fully resolve within one year. Owing to its effectiveness at inducing muscle fibre hypertrophy and improving neuromuscular efficiency, resistance training is of great interest in the rehabilitation of this population. This narrative review aims to identify the rationale and potential efficacy of resistance training for restoring physical function following infection with SARS-CoV-2, as well as evidence of its use in clinical practice. The studies included in this narrative review consisted mostly of multi-component rehabilitation trials. Of these, widespread improvements in muscle strength were reported using intensities of up to 80% of participants' 1-repetition-maximum. Evidence thus far indicates that resistance training may be safe and effective in patients following COVID-19, although its individual contribution is difficult to discern. Future exercise intervention studies investigating the efficacy of resistance training as a sole modality are needed.

Blood flow restriction as a potential therapy to restore physical function following COVID-19 infection

Accumulating evidence indicates that some COVID-19 survivors display reduced muscle mass, muscle strength, and aerobic capacity, which contribute to impairments in physical function that can persist for months after the acute phase of illness. Accordingly, strategies to restore muscle mass, muscle strength, and aerobic capacity following infection are critical to mitigate the long-term consequences of COVID-19. Blood flow restriction (BFR), which involves the application of mechanical compression to the limbs, presents a promising therapy that could be utilized throughout different phases of COVID-19 illness. Specifically, we hypothesize that: 1) use of passive BFR modalities can mitigate losses of muscle mass and muscle strength that occur during acute infection and 2) exercise with BFR can serve as an effective alternative to high-intensity exercise without BFR for regaining muscle mass, muscle strength, and aerobic capacity during convalescence. The various applications of BFR may also serve as a targeted therapy to address the underlying pathophysiology of COVID-19 and provide benefits to the musculoskeletal system as well as other organ systems affected by the disease. Consequently, we present a theoretical framework with which BFR could be implemented throughout the progression from acute illness to outpatient rehabilitation with the goal of improving short- and long-term outcomes in COVID-19 survivors. We envision that this paper will encourage discussion and consideration among researchers and clinicians of the potential therapeutic benefits of BFR to treat not only COVID-19 but similar pathologies and cases of acute critical illness.

Mechanisms and Severity of Exercise Intolerance Following COVID-19 and Similar Viral Infections: A Comparative Review

Approximately 19% of the population is suffering from "Long COVID", also known as post-acute sequelae of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (PASC), which often results in exercise intolerance. As COVID infections continue to be common, studying the long-term consequences of coronavirus disease (COVID) on physical function has become increasingly important. This narrative review will aim to summarize the current literature surrounding exercise intolerance following COVID infection in terms of mechanism, current management approaches, and comparison with similar conditions and will aim to define limitations in the current literature. Multiple organ systems have been implicated in the onset of long-lasting exercise intolerance post-COVID, including cardiac impairment, endothelial dysfunction, decreased VO_{2 max} and oxygen extraction, deconditioning due to bed rest, and fatigue. Treatment modalities for severe COVID have also been shown to cause myopathy and/or worsen deconditioning. Besides COVID-specific pathophysiology, general febrile illness as commonly experienced during infection will cause hypermetabolic muscle catabolism, impaired cooling, and dehydration, which acutely cause exercise intolerance. The mechanisms of exercise intolerance seen with PASC also appear similar to post-infectious fatigue syndrome and infectious mononucleosis. However, the severity and duration of the exercise intolerance seen with PASC is greater than that of any of the isolated mechanisms described above and thus is likely a combination of the proposed mechanisms. Physicians should consider post-infectious fatigue syndrome (PIFS), especially if fatigue persists after six months following COVID recovery. It is important for physicians, patients, and social systems to anticipate exercise intolerance lasting for weeks to months in patients with long COVID. These findings underscore the importance of long-term management of patients with COVID and the need for ongoing research to identify effective treatments for exercise intolerance in this population. By recognizing and addressing exercise intolerance in patients with long COVID, clinicians can provide proper supportive interventions, such as exercise programs, physical therapy, and mental health counseling, to improve patient outcomes.

Sepsis-Associated Muscle Wasting: A Comprehensive Review from Bench to Bedside

Sepsis-associated muscle wasting (SAMW) is characterized by decreased muscle mass, reduced muscle fiber size, and decreased muscle strength, resulting in persistent physical disability accompanied by sepsis. Systemic inflammatory cytokines are the main cause of SAMW, which occurs in 40-70% of patients with sepsis. The pathways associated with the ubiquitin-proteasome and autophagy systems are particularly activated in the muscle tissues during sepsis and may lead to muscle wasting. Additionally, expression of muscle atrophy-related genes Atrogin-1 and MuRF-1 are seemingly increased via the ubiquitin-proteasome pathway. In clinical settings, electrical muscular stimulation, physiotherapy, early mobilization, and nutritional support are used for patients with sepsis to prevent or treat SAMW. However, there are no pharmacological treatments for SAMW, and the underlying mechanisms are still unknown. Therefore, research is urgently required in this field.

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.

Electrical stimulation to regain lower extremity muscle perfusion and endurance in patients with post-acute sequelae of SARS CoV-2: A randomized controlled trial

Muscle deconditioning and impaired vascular function in the lower extremities (LE) are among the long-term symptoms experienced by COVID-19 patients with a history of severe illness. These symptoms are part of the post-acute sequelae of Sars-CoV-2 (PASC) and currently lack evidence-based treatment. To investigate the efficacy of lower extremity electrical stimulation (E-Stim) in addressing PASC-related muscle deconditioning, we conducted a double-blinded randomized controlled trial. Eighteen (n = 18) patients with LE muscle deconditioning were randomly assigned to either the intervention (IG) or the control (CG) group, resulting in 36 LE being assessed. Both groups received daily 1 h E-Stim on both gastrocnemius muscles for 4 weeks, with the device functional in the IG and nonfunctional in the CG. Changes in plantar oxyhemoglobin (OxyHb) and gastrocnemius muscle endurance (GNMe) in response to 4 weeks of daily 1 h E-Stim were assessed. At each study visit, outcomes were measured at onset (t₀ ), 60 min (t₆₀ ), and 10 min after E-Stim therapy (t₇₀ ) by recording ΔOxyHb with near-infrared spectroscopy. ΔGNMe was measured with surface electromyography at two time intervals: 0-5 min (Intv₁ ) and: 55-60 min (Intv₂ ). Baseline OxyHb decreased in both groups at t₆₀ (IG: p = 0.046; CG: p = 0.026) and t₇₀ (IG = p = 0.021; CG: p = 0.060) from t₀ . At 4 weeks, the IG's OxyHb increased from t₆₀ to t₇₀ (p < 0.001), while the CG's decreased (p = 0.003). The IG had higher ΔOxyHb values than the CG at t₇₀ (p = 0.004). Baseline GNMe did not increase in either group from Intv₁ to Intv₂ . At 4 weeks, the IG's GNMe increased (p = 0.031), whereas the CG did not change. There was a significant association between ΔOxyHb and ΔGNMe (r = 0.628, p = 0.003) at 4 weeks in the IG. In conclusion, E-Stim can improve muscle perfusion and muscle endurance in individuals with PASC experiencing LE muscle deconditioning.

Musculoskeletal involvement: COVID-19 and post COVID 19

The worldwide pandemic of coronavirus disease 2019 (COVID-19) was known to predominantly affect the lungs, but it was realized that COVID-19 had a large variety of clinical involvement. Cardiovascular, gastrointestinal, neurological, and musculoskeletal systems are involved by direct or indirect mechanisms with various manifestations. The musculoskeletal involvement can manifest during COVID-19 infection, due to medications used for the treatment of COVID-19, and in the post/long COVID-19 syndrome. The major symptoms are fatigue, myalgia/arthralgia, back pain, low back pain, and chest pain. During the last two years, musculoskeletal involvement increased, but no clear consensus was obtained about the pathogenesis. However, there is valuable data that supports the hypothesis of angiotensinconverting enzyme 2, inflammation, hypoxia, and muscle catabolism. Additionally, medications that were used for treatment also have musculoskeletal adverse effects, such as corticosteroid-induced myopathy and osteoporosis. Therefore, while deciding the drugs, priorities and benefits should be taken into consideration. Symptoms that begin three months from the onset of the COVID-19 infection, continue for at least two months, and cannot be explained by another diagnosis is accepted as post/long COVID-19 syndrome. Prior symptoms may persist and fluctuate, or new symptoms may manifest. In addition, there must be at least one symptom of infection. Most common musculoskeletal symptoms are myalgia, arthralgia, fatigue, back pain, muscle weakness, sarcopenia, impaired exercise capacity, and physical performance. In addition, the female sex, obesity, elderly patients, hospitalization, prolonged immobility, having mechanical ventilation, not having vaccination, and comorbid disorders can be accepted as clinical predictors for post/long COVID-19 syndrome. Musculoskeletal pain is also a major problem and tends to be in chronic form. There is no consensus on the mechanism, but inflammation and angiotensin-converting enzyme 2 seem to play an important role. Localized and generalized pain may occur after COVID-19, and general pain is at least as common as localized pain. An accurate diagnosis allows physicians to initiate pain management and proper rehabilitation programs.

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.

Ultrasound imaging assessment of the diaphragm and abdominal muscles in people with a recent history of moderate Covid-19 infection and healthy participants: A cross-sectional pilot study

Coronavirus disease (Covid-19) is a highly infectious disease caused by the SARS-CoV-2 virus and is associated with a decrease of respiratory, physical, and psychological function, subsequently affecting quality of life. The aim of the present pilot study was to use ultrasound imaging (USI) to evaluate and compare the thickness of the diaphragm and abdominal muscles between individuals recently diagnosed with moderate Covid-19 infection and healthy individuals.

METHODS

A cross-sectional observational pilot study was performed. A total sample of 24 participants were recruited from a private medical center (Madrid, Spain): Covid-19 (n = 12) and healthy controls (n = 12). The external oblique (EO), internal oblique (IO), transversus abdominis (TrA), rectus abdominis (RA), interrecti distance (IRD) and diaphragm thickness were assessed using USI during inspiration, expiration and during contraction.

RESULTS

USI measurements of the thickness of EO, IO, TrA, RA, IRD and the diaphragm did not differ significantly between groups during inspiration, expiration or during contraction (all P > 0.05).

CONCLUSIONS

These preliminary results suggest that the morphology of the abdominal muscles and diaphragm is not altered in people with a recent history of moderate Covid-19 infection.

Ultrasonographic findings in long COVID: A cross-sectional study of 312 patients

Background

Fatigue and muscle weakness are common complaints in COVID-19 survivors. However, little is still known about the skeletal muscle qualitative and quantitative characteristics after hospitalization due to moderate and severe COVID-19.

Objectives

To assess rectus femoris and vastus intermedius muscle thickness (MT) and rectus femoris echo intensity (EI) and to establish its association with demographic, clinical, functional, and inflammatory parameters in long COVID patients after hospital discharge.

Methods

Cross-sectional study with 312 COVID-19 patients (53.53% male; age: 54.59 ± 13.50 years), with a laboratory-confirmed diagnosis of COVID-19. Patients were assessed 3-11 months after hospital discharge. We evaluated MT of the right rectus femoris and vastus intermedius and EI of the right rectus femoris using a portable ultrasound system, 6-13 MHz, broadband linear transducer. We corrected EI using the subcutaneous fat thickness. Ultrasonographic parameters were tested in association with demographic (sex and age); functional (Handgrip strength measurement, Timed Up and Go, 1 min Sit-to-Stand test, EuroQoL-5 Dimensions-5 Levels, World Health Organization Disability Assessment Schedule (WHODAS 2.0), Post-COVID-19 Functional Status, Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT), Medical Research Council (MRC) sum score, Borg Dyspnea Scale, MRC Dyspnea score, Visual Analogue Scale (VAS), Epworth Sleepiness Scale, Insomnia Severity Index, Functional Independence Measurement (FIM), and Functional Oral Intake Scale); clinical (length of hospital stay, intubation, and presence of comorbidities such as systemic hypertension, diabetes, obesity, chronic obstructive pulmonary disease, asthma), and inflammatory data assessed by the C-reactive protein and D-dimer serum concentrations.

Results

Rectus femoris MT was associated with age, handgrip strength, Epworth Sleepiness Scale, and subcutaneous fat thickness (r² = 27.51%; p < 0.0001). Vastus intermedius MT was associated with age, pain intensity, handgrip strength, Epworth Sleepiness scale, FIM, and time since hospital discharge (r² = 21.12%; p < 0.0001). Rectus femoris EI was significantly associated with the male sex, TUG, Epworth Sleepiness Scale, and C-Reactive Protein levels (r² = 44.39%; p < 0.0001). Mean MT of rectus femoris and vastus intermedius are significantly different (p < 0.001).

Conclusion

After hospital discharge, long COVID patients present qualitative and quantitative skeletal muscle characteristics associated with a combination of demographic, clinical, and functional parameters.

Reduced muscle strength in patients with long-COVID-19 syndrome is mediated by limb muscle mass

Understanding the impact of COVID-19 on muscle strength may help to elucidate the organ systems that contribute to acute and chronic COVID-19 sequelae. We questioned whether patients with postdischarge symptoms after COVID-19 had compromised muscle strength compared with a control group, and if this potential relationship was mediated by the lower appendicular lean mass index (ALMI). A total of 99 patients with long-COVID-19 and 97 control participants were screened. Maximal grip strength was assessed with a TKK 5101 digital dynamometer, and leg extension 1RM was measured using EGYM Smart Strength machines. Body composition (fat mass percentage, lean mass, visceral fat, and appendicular lean mass index) was determined using a whole body dual-energy X-ray densitometer. Results showed that grip strength and leg extension strength were significantly higher in controls than in COVID-19 survivors (mean [SD], 32.82 [10.01] vs. 26.94 [10.33] kg; difference, 5.87 kg; P < 0.001) and (mean [SD], 93.98 [33.73] vs. 71.59 [33.70] kg; difference, 22.38 kg; P < 0.001), respectively). The relationship between long-COVID syndrome and grip/leg strength levels was partly mediated by ALMI, which explained 52% of the association for grip strength and 39% for leg extension. Our findings provide novel insights into the mechanisms underlying the relationship between long-COVID syndrome and grip/leg strength levels, supporting the negative effects of long-COVID syndrome on muscle function.NEW & NOTEWORTHY The causes of post-COVID-19 syndrome are uncertain. Limb muscle wasting common to patients with COVID-19 limits daily activities and exercise. In this cross-sectional study, we found that patients with long-COVID-19 syndrome had significantly lower absolute and relative muscle strength measurements than control participants. Interestingly, we identified that these relationships were mostly mediated by limb muscle mass. Our data thus suggest that the evident reduced upper and lower muscle mass is a putative cause of-or contributor to-the functional limitation of patients with long-COVID-19 syndrome.

The syndromic triad of COVID-19, type 2 diabetes, and malnutrition

The coronavirus disease 2019 (COVID-19) pandemic challenges our collective understanding of transmission, prevention, complications, and clinical management of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Risk factors for severe infection, morbidity, and mortality are associated with age, environment, socioeconomic status, comorbidities, and interventional timing. Clinical investigations report an intriguing association of COVID-19 with diabetes mellitus and malnutrition but incompletely describe the triphasic relationship, its mechanistic pathways, and potential therapeutic approaches to address each malady and their underlying metabolic disorders. This narrative review highlights common chronic disease states that interact epidemiologically and mechanistically with the COVID-19 to create a syndromic phenotype-the COVID-Related Cardiometabolic Syndrome-linking cardiometabolic-based chronic disease drivers with pre-, acute, and chronic/post-COVID-19 disease stages. Since the association of nutritional disorders with COVID-19 and cardiometabolic risk factors is well established, a syndromic triad of COVID-19, type 2 diabetes, and malnutrition is hypothesized that can direct, inform, and optimize care. In this review, each of the three edges of this network is uniquely summarized, nutritional therapies discussed, and a structure for early preventive care proposed. Concerted efforts to identify malnutrition in patients with COVID-19 and elevated metabolic risks are needed and can be followed by improved dietary management while simultaneously addressing dysglycemia-based chronic disease and malnutrition-based chronic disease.

Elevated plasma CAF22 are incompletely restored six months after COVID-19 infection in older men

INTRODUCTION

The long-term complications of COVID-19 appear as significant health problems. However, the long-term muscle decline in these patients is poorly characterized.

METHODS

We investigated the age-related muscle decline, termed sarcopenia, before and following the COVID-19 infection in older male patients (n = 87). We evaluated handgrip strength (HGS) and functional capacity (short physical performance battery; SPPB) in COVID-19 patients 7-42 days before and one week and 6-month after COVID-19 infection. We used ELISA tests to measure plasma c-terminal agrin fragment-22 (CAF22), c-reactive protein (CRP), and 8-isoprostanes as markers of degraded neuromuscular junctions, inflammation, and oxidative stress, respectively.

RESULTS

Before the COVID-19 infection, 54 patients were non-sarcopenic, and 25 patients were sarcopenic, while eight patients subsequently developed sarcopenia. All patients exhibited reduced HGS and SPPB, while elevated CAF22, CRP, and 8-isoprostane levels one week post-COVID-19 infection (all p < 0.05). At six months post-COVID-19 infection, the HGS, SPPB, CAF22, CRP, and 8-isoprostanes were partly restored to baseline levels (all p < 0.05). Correlation analysis revealed that the plasma CAF22 had a significant correlation with HGS, SPPB, and COVID-19 disease severity. CAF22 also demonstrated significant areas under the curves in diagnosing sarcopenia at all three time-points.

CONCLUSION

Altogether, the muscle detriment due to COVID-19 persists six months post-infection, and plasma CAF22 may be helpful to detect muscle and functional decline in these patients. Timely evaluation and intervention of sarcopenia may be critical in COVID-19 treatment.

Functional Recovery Groups in Critically Ill COVID-19 Patients and Their Associated Factors: From ICU to Hospital Discharge

OBJECTIVES

To analyze functional recovery groups of critically ill COVID-19 survivors during their hospital stay and to identify the associated factors.

DESIGN

Prospective observational multicenter study.

SETTING

Demographic, clinical, and therapeutic variables were collected, and physical and functional status were evaluated. The Barthel index was evaluated at three time points: 15 days before hospitalization, at ICU discharge, and at hospital discharge from the ward.

PATIENTS

Patients with functional independence before COVID-19 diagnosis were recruited from four hospitals and followed up until hospital discharge.

MEASUREMENTS AND MAIN RESULTS

Three groups of functional recovery were described for 328 patients: functional independence ( n = 144; 44%), which included patients who preserved their functional status during hospitalization; recovered functionality ( n = 109; 33.2%), which included patients who showed dependence at ICU discharge but recovered their independence by hospital discharge; and functional dependency ( n = 75; 22.8%), which included patients who were dependent at ICU discharge and had not recovered their functional status at hospital discharge. The factors associated with becoming functionally dependent at ICU discharge were time to out-of-bed patient mobilization (odds ratio [OR], 1.20; 95% CI, 1.11-1.29), age (OR, 1.02; 95% CI, 1.01-1.04), hyperglycemia (OR, 2.52; 95% CI, 1.56-4.07), and Simplified Acute Physiology Score (OR, 1.022; 95% CI, 1.01-1.04). Recovery to baseline independence during ward stays was associated with ICU length of stay (OR, 0.97; 95% CI, 0.94-0.99) and muscle strength (Medical Research Council test) at ICU discharge (OR, 1.13; 95% CI, 1.08-1.18).

CONCLUSIONS

Age, hyperglycemia, and time for patient mobilization out of bed were independent factors associated with becoming physically dependent after their ICU stay. Recovery of physical function at hospital discharge was associated with muscle strength at ICU discharge and length of ICU stay.

Intra- and Inter-Rater Reliability and Agreement of Ultrasound Imaging of Muscle Architecture and Patellar Tendon in Post-COVID-19 Patients Who Had Experienced Moderate or Severe COVID-19 Infection

COVID-19 is associated with musculoskeletal disorders. Ultrasound is a tool to assess muscle architecture and tendon measurements, offering an idea of the proportion of the consequences of the disease, since significant changes directly reflect the reduction in the ability to produce force and, consequently, in the functionality of the patient; however, its application in post-COVID-19 infection needs to be determined. We aimed to assess the intra- and inter-rater reliability of ultrasound measures of the architecture of the vastus lateralis (VL), rectus femoris (RF), vastus medialis (VM), gastrocnemius lateralis (GL), gastrocnemius medialis (GM), soleus (SO), and tibialis anterior (TA) muscles, as well as the patellar tendon (PT) cross-sectional area (CSA) in post-COVID-19 patients. An observational, prospective study with repeated measures was designed to evaluate 20 post-COVID-19 patients, who were measured for the pennation angle (θp), fascicular length (Lf), thickness, echogenicity of muscles, CSA and echogenicity of the PT. The intra-class correlation coefficient (ICC) and 95% limits of agreement were used. The intra-rater reliability presented high or very high correlations (ICC = 0.71-1.0) for most measures, except the θp of the TA, which was classified as moderate (ICC = 0.69). Observing the inter-rater reliability, all the evaluations of the PT, thickness and echogenicity of the muscles presented high or very high correlations. For the Lf, only the RF showed as low (ICC = 0.43), for the θp, RF (ICC = 0.68), GL (ICC = 0.70) and TA (ICC = 0.71) moderate and the SO (ICC = 0.40) low. The ultrasound reliability was acceptable for the muscle architecture, muscle and tendon echogenicity, and PT CSA, despite the low reliability for the Lf and θp of the RF and SO, respectively.

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

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

Physiological factors affecting the mechanical performance of peripheral muscles: A perspective for long COVID patients through a systematic literature review

Background: Peripheral muscle weakness can be measured quantitatively in long COVID patients. Mechanomyography (MMG) is an alternative tool to measure muscle strength non-invasively.

Objective: This literature review aims to provide evidence on the efficacy of MMG in measuring muscle strength for long COVID patients and to determine the physiological factors that may affect the use of MMG in assessing muscle performance.

Methods: A systematic literature review was conducted using EBSCO’s MEDLINE Complete. A total of five out of 2,249 potential publications fulfilled the inclusion criteria.

Results: The selected studies addressed muscle performance based on the physiological effects of age, gender, and physical activity level. MMG is sensitive in measuring muscle strength for long COVID patients due to its higher signal-to-noise ratio and lightweight accelerometers. Its neglectable skin impedance and low risk of influences during the recording of surface motions make MMG a reliable tool.

Conclusion: Muscle performance is affected by age, gender, and physical activity level. Sensors, such as MMG, as well as the length of the muscle and the characteristics of the muscle activity, are important considerations when choosing a sensor for diagnostic evaluation. The efficacy of MMG in measuring muscle strength for long COVID patients and the physiological factors that may affect the use of MMG in assessing muscle performance are discussed.

Implementation of Early Rehabilitation in Severe COVID-19 Respiratory Failure

The purpose of this scoping review is to describe current clinical practice guidelines (CPGs) for early rehabilitation for individuals hospitalized in an intensive care unit with COVID-19 and examine practice patterns for implementation of mobility-related interventions.

Methods

PubMed, EMBASE, and CINAHL databases were searched from January 1, 2020, through April 1, 2022. Selected studies included individuals hospitalized with severe COVID-19 and provided objective criteria for clinical decision making for mobility interventions. A total of 1464 publications were assessed for eligibility and data extraction. The PRISMA-ScR Checklist and established guidelines for reporting for scoping reviews were followed.

Results

Twelve articles met inclusion criteria: 5 CPGs and 7 implementation articles. Objective clinical criteria and guidelines for implementation of early rehabilitation demonstrated variable agreement across systems. No significant adverse events were reported.

Conclusions

Sixty percent (3/5) of CPGs restrict mobility for individuals requiring ventilatory support of more than 60% Fio₂ (fraction of inspired oxygen) and/or positive end-expiratory pressure (PEEP) greater than 10-cm H₂O (positive end-expiratory pressure). Preliminary evidence from implementation studies may suggest that some individuals with COVID-19 requiring enhanced ventilatory support outside of established parameters may be able to safely participate in mobility-related interventions, though further research is needed to determine safety and feasibility to guide clinical decision making.

The Effects of COVID-19 on Skeletal Muscles, Muscle Fatigue and Rehabilitation Programs Outcomes

Background and Objectives: Consequences due to infection with SARS-CoV-2 virus can have a direct impact on skeletal muscle, due to the fact that both cardiac and skeletal muscle tissue show robust ACE2(angiotensin-converting enzyme 2) expression, suggesting a potential susceptibility to SARS-CoV-2 infection in both types of tissues. From the articles analyzed we concluded that the musculoskeletal damage is firstly produced by the inflammatory effects, cytokine storm and muscle catabolism. However, myopathy, polyneuropathy and therapies such as corticoids were also considered important factors in muscle fatigue and functional incapacity. Pulmonary rehabilitation programs and early mobilization had a highly contribution during the acute phase and post-illness recovery process and helped patients to reduce dyspnea, increase the capacity of physical effort, overcome psychological disorders and improved the quality of their life. Materials and Methods: We have included in this review 33 articles that contain data on muscle damage following SARS-CoV-2 infection. We used the following keywords to search for articles: SARS-CoV-2, COVID-19, muscle weakness, muscle disease, muscle fatigue, neurological disorders. As a search strategy we used PubMed, Cochrane Database of Systematic Reviews; Database of Abstracts of Reviews of Effects and Health Technology Assessment Database to collect the information. We also have chosen the most recent articles published in the last 5 years. Conclusions: Muscular damage, as well as the decrease in the quality of life, are often a consequence of severe SARS-CoV-2 infection through: systemic inflammation, corticotherapy, prolonged bed rest and other unknown factors. Pulmonary rehabilitation programs and early mobilization had a highly contribution during the acute phase and post-illness recovery process and helped patients to reduce dyspnea, increase the capacity of physical effort, overcome psychological disorders and improve the quality of their life.

Overstimulation of the ergoreflex—A possible mechanism to explain symptoms in long COVID

Long COVID refers to a multitude of symptoms that persist long after SARS-CoV-2 infection. Fatigue and breathlessness are the most common symptoms of long COVID across a range of studies. They are also cardinal symptoms of chronic heart failure (CHF). In this review, we propose that fatigue and breathlessness in patients with long COVID may be explained by skeletal muscle abnormalities, in a manner similar to patients with CHF. The ergoreflex is a cardiorespiratory reflex activated by exercise, which couples ventilation and cardiovascular function to exercise intensity. At least part of the symptomatology of CHF is related to abnormal skeletal muscle and an enhanced ergoreflex, resulting in heightened sympathetic, vasoconstrictor and ventilator drives. Similarly, SARS-CoV-2 infection results in a hyperinflammatory and hypercatabolic state. This leads to reduction in skeletal muscle mass and altered function. We postulate that the ergoreflex is chronically overstimulated, resulting in fatigue and breathlessness. Exercise training preserves muscle mass and function as well as reduces ergoreflex activation; therefore may have a role in improving symptoms associated with long COVID. Should the ergoreflex be proven to be an important pathophysiological mechanism of long COVID, tailored exercise interventions should be trialed with the aim of improving both symptoms and perhaps outcomes in patients with long COVID.

Poor Nutritional Status and Dynapenia Are Highly Prevalent in Post-Acute COVID-19

Poor nutritional status is common (estimated prevalence 5–69%) in acute coronavirus disease-2019 (COVID-19), and has been associated with hospitalization, the need for intensive care, and mortality. Body composition (BC) and muscle function have also been related in such patients to poor disease outcomes.

As the evidence in the literature is limited, a cross-sectional study was carried out to determine the frequency of malnutrition in a cohort of post-acute COVID-19 patients referred to a rehabilitation center after hospital discharge. BC and muscle strength were assessed and the differences between bedridden and not bedridden patients were specifically evaluated.

The study sample was composed of 144 post-acute COVID-19 patients (mean age 64.8 years; males = 95), 37% of whom were bedridden (males = 60%). Nutritional status was evaluated with Mini-Nutritional Assessment (MNA) and Controlling Nutritional status (CONUT). Fat-free mass (FFM) and skeletal muscle mass (SM) were estimated using bioelectrical impedance analysis (BIA). Raw BIA variables (phase angle = PhA and impedance ratios = IRs) were also determined and handgrip strength (HGS) was measured. Dynapenia was identified according to the 2019 EWGSOP criteria.

According to MNA, 18% (n. 26) of patients were malnourished and 62% (n. 89) were at risk of malnutrition. As for CONUT, 21% (n. 31) of cases had moderate–severe malnutrition and 58% (n. 83) had light malnutrition. Abnormalities of raw BIA variables (low PhA and high IRs) and low HGS were more common in bedridden patients, in those who were malnourished, or had low FFM or SM. Dynapenic patients were 65% men and 47% women.

In conclusion, malnutrition, BC alterations, and low HGS occur in post-acute COVID-19 patients and are more common in bedridden patients. Further studies are needed to identify reliable algorithms for assessing nutritional status in post-acute COVID-19 patients undergoing rehabilitation.

Resistance Training before, during, and after COVID-19 Infection: What Have We Learned So Far?

At the end of 2019, a severe acute respiratory syndrome caused by SARS-CoV-2 started a pandemic, leading to millions of deaths and many important political and social changes. Even in the absence of contamination, the mobility reduction, social distancing and closing of exercise facilities negatively affected physical activity and conditioning, which is associated with muscle atrophy, loss of muscle strength, and reductions in functional capacity. In cases of infection, it has been shown that increased physical capacity is associated with decreased hospitalization and mortality risk. Although millions of people have died from COVID-19, most contaminated individuals survived the infection, but carried different sequelae, such as the severe loss of physical function and a reduced quality of life. Among different physical exercise models that might help to prevent and treat COVID-19-related conditions, resistance training (RT) might be particularly relevant. Among its benefits, RT can be adapted to be performed in many different situations, even with limited space and equipment, and is easily adapted to an individual's characteristics and health status. The current narrative review aims to provide insights into how RT can be used in different scenarios to counteract the negative effects of COVID-19. By doing this, the authors expect to provide insights to help deal with the current pandemic and similar events the world may face in the future.

Human skeletal muscle size with ultrasound imaging: a comprehensive review

Skeletal muscle size is an important factor in assessing adaptation to exercise training and detraining, athletic performance, age-associated atrophy and mobility decline, clinical conditions associated with cachexia, and overall skeletal muscle health. Magnetic resonance (MR) imaging and computed tomography (CT) are widely accepted as the gold standard methods for skeletal muscle size quantification. However, it is not always feasible to use these methods (e.g., field studies, bedside studies, large cohort studies). Ultrasound has been available for skeletal muscle examination for more than 50 years and the development, utility, and validity of ultrasound imaging are underappreciated. It is now possible to use ultrasound in situations where MR and CT imaging are not suitable. This review provides a comprehensive summary of ultrasound imaging and human skeletal muscle size assessment. Since the first study in 1968, more than 600 articles have used ultrasound to examine the cross-sectional area and/or volume of 107 different skeletal muscles in more than 27,500 subjects of various ages, health status, and fitness conditions. Data from these studies, supported by decades of technological developments, collectively show that ultrasonography is a valid tool for skeletal muscle size quantification. Considering the wide-ranging connections between human health and function and skeletal muscle mass, the utility of ultrasound imaging will allow it to be employed in research investigations and clinical practice in ways not previously appreciated or considered.

The Musculoskeletal Involvement After Mild to Moderate COVID-19 Infection

COVID-19, a disease caused by the novel coronavirus SARS-CoV-2, has been drastically affecting the daily lives of millions of people. COVID-19 is described as a multiorgan disease that affects not only the respiratory tract of infected individuals, but it has considerable effects on the musculoskeletal system, causing excessive fatigue, myalgia, arthralgia, muscle weakness and skeletal muscle damage. These symptoms can persist for months, decreasing the quality of life of numerous individuals. Curiously, most studies in the scientific literature focus on patients who were hospitalized due to SARS-CoV-2 infection and little is known about the mechanism of action of COVID-19 on skeletal muscles, especially of individuals who had the mild to moderate forms of the disease (non-hospitalized patients). In this review, we focus on the current knowledge about the musculoskeletal system in COVID-19, highlighting the lack of researches investigating the mild to moderate cases of infection and pointing out why it is essential to care for these patients. Also, we will comment about the need of more experimental data to assess the musculoskeletal manifestations on COVID-19-positive individuals.

Neuromuscular Electrical Stimulation in Patients With Severe COVID-19 Associated With Sepsis and Septic Shock

BACKGROUND

Neuromuscular electrical stimulation (NMES) can be applied to critically ill patients. However, its results on muscle strength and functionality in patients with COVID-19 are unknown.

OBJECTIVE

Evaluate the effects of intervention with NMES on muscle mass and functionality of patients with severe COVID-19 associated with sepsis and septic shock.

METHODS

Seven patients with COVID-19 associated with sepsis or septic shock were selected, but only 5 patients completed all days of the intervention with NMES. The intervention was performed by a single physiotherapist on 7 consecutive days in a daily session of 40 min. The outcome measures were the femoris cross-sectional area; thickness of the anterior compartment of the quadriceps muscle; rectus femoris echogenicity; International Classification of Functioning, Disability, and Health (ICF)-muscle strength; PFIT-s, DEMMI, and the SOMS; feasibility, and safety. The patients were evaluated on days 1, 5, and 8.

RESULTS

The rectus femoris cross-sectional area decreased significantly from days 1 to 8, but showed maintenance of the thickness of the anterior compartment of the quadriceps muscle from days 1 to 8. The MRC score increased significantly from days 1 to 5 and kept this improvement until day 8. All patients showed an increase in the MRC score and reduction of the ICF-muscle strength, meaning improved muscle strength from days 1 to 8. The PFIT-s increased significantly from days 1 to 5 and improved until day 8 compared to day 5. DEMMI and SOMS score increased significantly on day 8 compared to days 1 and 5.

CONCLUSION

Rehabilitation with NMES showed improvement in muscle strength and functionality of patients in this study with a potential protective effect on muscle mass loss in patients with critical COVID-19 associated with sepsis and septic shock. This study is the first report of the potential effects of neuromuscular electrical stimulation in patients with severe COVID-19 associated with sepsis and septic shock.

Skeletal muscle alterations in patients with acute Covid-19 and post-acute sequelae of Covid-19

Skeletal muscle-related symptoms are common in both acute coronavirus disease (Covid)-19 and post-acute sequelae of Covid-19 (PASC). In this narrative review, we discuss cellular and molecular pathways that are affected and consider these in regard to skeletal muscle involvement in other conditions, such as acute respiratory distress syndrome, critical illness myopathy, and post-viral fatigue syndrome. Patients with severe Covid-19 and PASC suffer from skeletal muscle weakness and exercise intolerance. Histological sections present muscle fibre atrophy, metabolic alterations, and immune cell infiltration. Contributing factors to weakness and fatigue in patients with severe Covid-19 include systemic inflammation, disuse, hypoxaemia, and malnutrition. These factors also contribute to post-intensive care unit (ICU) syndrome and ICU-acquired weakness and likely explain a substantial part of Covid-19-acquired weakness. The skeletal muscle weakness and exercise intolerance associated with PASC are more obscure. Direct severe acute respiratory syndrome coronavirus (SARS-CoV)-2 viral infiltration into skeletal muscle or an aberrant immune system likely contribute. Similarities between skeletal muscle alterations in PASC and chronic fatigue syndrome deserve further study. Both SARS-CoV-2-specific factors and generic consequences of acute disease likely underlie the observed skeletal muscle alterations in both acute Covid-19 and PASC.

Skeletal Muscle in Hypoxia and Inflammation: Insights on the COVID-19 Pandemic

SARS-CoV-2 infection is often associated with severe inflammation, oxidative stress, hypoxia and impaired physical activity. These factors all together contribute to muscle wasting and fatigue. In addition, there is evidence of a direct SARS-CoV-2 viral infiltration into skeletal muscle. Aging is often characterized by sarcopenia or sarcopenic obesity These conditions are risk factors for severe acute COVID-19 and long-COVID-19 syndrome. From these observations we may predict a strong association between COVID-19 and decreased muscle mass and functions. While the relationship between physical inactivity, chronic inflammation, oxidative stress and muscle dysfunction is well-known, the effects on muscle mass of COVID-19-related hypoxemia are inadequately investigated. The aim of this review is to highlight metabolic, immunity-related and redox biomarkers potentially affected by reduced oxygen availability and/or muscle fatigue in order to shed light on the negative impact of COVID-19 on muscle mass and function. Possible countermeasures are also reviewed.

The Predictive Value of Myoglobin for COVID-19-Related Adverse Outcomes: A Systematic Review and Meta-Analysis

Objective: Cardiac injury is detected in numerous patients with coronavirus disease 2019 (COVID-19) and has been demonstrated to be closely related to poor outcomes. However, an optimal cardiac biomarker for predicting COVID-19 prognosis has not been identified.

Methods: The PubMed, Web of Science, and Embase databases were searched for published articles between December 1, 2019 and September 8, 2021. Eligible studies that examined the anomalies of different cardiac biomarkers in patients with COVID-19 were included. The prevalence and odds ratios (ORs) were extracted. Summary estimates and the corresponding 95% confidence intervals (95% CIs) were obtained through meta-analyses.

Results: A total of 63 studies, with 64,319 patients with COVID-19, were enrolled in this meta-analysis. The prevalence of elevated cardiac troponin I (cTnI) and myoglobin (Mb) in the general population with COVID-19 was 22.9 (19–27%) and 13.5% (10.6–16.4%), respectively. However, the presence of elevated Mb was more common than elevated cTnI in patients with severe COVID-19 [37.7 (23.3–52.1%) vs.30.7% (24.7–37.1%)]. Moreover, compared with cTnI, the elevation of Mb also demonstrated tendency of higher correlation with case-severity rate (Mb, r = 13.9 vs. cTnI, r = 3.93) and case-fatality rate (Mb, r = 15.42 vs. cTnI, r = 3.04). Notably, elevated Mb level was also associated with higher odds of severe illness [Mb, OR = 13.75 (10.2–18.54) vs. cTnI, OR = 7.06 (3.94–12.65)] and mortality [Mb, OR = 13.49 (9.3–19.58) vs. cTnI, OR = 7.75 (4.4–13.66)] than cTnI.

Conclusions: Patients with COVID-19 and elevated Mb levels are at significantly higher risk of severe disease and mortality. Elevation of Mb may serve as a marker for predicting COVID-19-related adverse outcomes.

Prospero Registration Number:https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42020175133, CRD42020175133.