Early neuromuscular electrical stimulation reduces the loss of muscle mass in critically ill patients - A within subject randomized controlled trial

Development and validation of early prediction models for new-onset functional impairment in patients after being transferred from the ICU

A significant number of intensive care unit (ICU) survivors experience new-onset functional impairments that impede their activities of daily living (ADL). Currently, no effective assessment tools are available to identify these high-risk patients. This study aims to develop an interpretable machine learning (ML) model for predicting the onset of functional impairment in critically ill patients. Data for this study were sourced from a comprehensive hospital in China, focusing on adult patients admitted to the ICU from August 2022 to August 2023 without prior functional impairments. A least absolute shrinkage and selection operator (LASSO) model was utilized to select predictors for inclusion in the model. Four models, logistic regression, support vector machine (SVM), random forest (RF), and extreme gradient boosting (XGBoost), were constructed and validated. Model performance was assessed using the area under the curve (AUC), accuracy, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV). Additionally, the DALEX package was employed to enhance the interpretability of the final models. The study ultimately included 1,380 patients, with 684 (49.6%) exhibiting new-onset functional impairment on the seventh day after leaving the ICU. Among the four models evaluated, the SVM model demonstrated the best performance, with an AUC of 0.909, accuracy of 0.838, sensitivity of 0.902, specificity of 0.772, PPV of 0.802, and NPV of 0.886. ML models are reliable tools for predicting new-onset functional impairments in critically ill patients. Notably, the SVM model emerged as the most effective, enabling early identification of patients at high risk and facilitating the implementation of timely interventions to improve ADL.

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.

The effects of neuromuscular electrical stimulation on hospitalised adults: systematic review and meta-analysis of randomised controlled trials

INTRODUCTION

Neuromuscular electrical stimulation (NMES) is a treatment to prevent or reverse acquired disability in hospitalised adults. We conducted a systematic review and meta-analysis of its effectiveness.

METHOD

We searched MEDLINE, EMBASE, Cumulative Index to Nursing & Allied Health (CINAHL) and the Cochrane library. Inclusion criteria: randomised controlled trials of hospitalised adult patients comparing NMES to control or usual care. The primary outcome was muscle strength. Secondary outcomes were muscle size, function, hospital length of stay, molecular and cellular biomarkers, and adverse effects. We assessed risk of bias using the Cochrane risk-of-bias tool. We used Review Manager (RevMan) software for data extraction, critical appraisal and synthesis. We assessed certainty using the Grading of Recommendations Assessment, Development and Evaluation tool.

RESULTS

A total of 42 papers were included involving 1,452 participants. Most studies had unclear or high risk of bias. NMES had a small effect on muscle strength (moderate certainty) (standardised mean difference (SMD) = 0.33; P < 0.00001), a moderate effect on muscle size (moderate certainty) (SMD = 0.66; P < 0.005), a small effect on walking performance (moderate certainty) (SMD = 0.48; P < 0.0001) and a small effect on functional mobility (low certainty) (SMD = 0.31; P < 0.05). There was a small and non-significant effect on health-related quality of life (very low certainty) (SMD = 0.35; P > 0.05). In total, 9% of participants reported undesirable experiences. The effects of NMES on length of hospital stay, and molecular and cellular biomarkers were unclear.

CONCLUSIONS

NMES is a promising intervention component that might help to reduce or prevent hospital-acquired disability.

Comparator Groups in ICU-Based Studies of Physical Rehabilitation: A Scoping Review of 125 Studies

To characterize comparator groups (CGs) in ICU-based studies of physical rehabilitation (PR), including the type, content, and reporting.

DATA SOURCES

We followed a five-stage scoping review methodology, searching five databases from inception to June 30, 2022. Study selection and data extraction were completed independently, in duplicate.

STUDY SELECTION

We screened studies by title and abstract, then full-text. We included prospective studies with greater than or equal to two arms enrolling mechanically ventilated adults (≥ 18 yr), with any planned PR intervention initiated in the ICU.

DATA EXTRACTION

We conducted a quantitative content analysis of authors' description of CG type and content. We categorized similar CG types (e.g., usual care), classified content into unique activities (e.g., positioning), and summarized these data using counts (proportions). We assessed reporting using Consensus on Exercise Reporting Template (CERT; proportion of reported items/total applicable).

DATA SYNTHESIS

One hundred twenty-five studies were included, representing 127 CGs. PR was planned in 112 CGs (88.2%; 110 studies), representing four types: usual care (n = 81, 63.8%), alternative treatment than usual care (e.g., different from intervention; n = 18, 14.2%), alternative treatment plus usual care (n = 7, 5.5%), and sham (n = 6, 4.7%). Of 112 CGs with planned PR, 90 CGs (88 studies) reported 60 unique activities, most commonly passive range of motion (n = 47, 52.2%). The remaining 22 CGs (19.6%; 22 studies) reported vague descriptions. PR was not planned in 12 CGs (9.5%; 12 studies), and three CGs (2.4%; three studies) reported no details. Studies reported a median (Q1-Q3) of 46.6% (25.0-73.3%) CERT items. Overall, 20.0% of studies reported no detail to understand planned CG activities.

CONCLUSIONS

The most common type of CG was usual care. We identified heterogeneity in planned activities and CERT reporting deficiencies. Our results could help guide the selection, design, and reporting of CGs in future ICU-based PR studies.

Skeletal Muscle Myokine Expression in Critical Illness, Association With Outcome and Impact of Therapeutic Interventions

Context

Muscle expresses and secretes several myokines that bring about benefits in distant organs.

Objective

We investigated the impact of critical illness on muscular expression of irisin, kynurenine aminotransferases, and amylase; association with clinical outcome; and impact of interventions that attenuate muscle wasting/weakness.

Methods

We studied critically ill patients who participated in 2 randomized controlled trials (EPaNIC/NESCI) and documented time profiles in critically ill mice. Included in the study were 174 intensive care unit (ICU) patients (day 8 ± 1) vs 19 matched controls, and 60 mice subjected to surgery/sepsis vs 60 pair-fed healthy mice. Interventions studied included 7-day neuromuscular electrical stimulation (NMES), and withholding parenteral nutrition (PN) in the first ICU week (late PN) vs early PN. The main outcome measures were FNDC5 (irisin- precursor), KYAT1, KYAT3, and amylase mRNA expression in skeletal muscle.

Results

Critically ill patients showed 34% to 80% lower mRNA expression of FNDC5, KYAT1, and amylases than controls (P < .0001). Critically ill mice showed time-dependent reductions in all mRNAs compared with healthy mice (P ≤ .04). The lower FNDC5 expression in patients was independently associated with a higher ICU mortality (P = .015) and ICU-acquired weakness (P = .012), whereas the lower amylase expression in ICU survivors was independently associated with a longer ICU stay (P = .0060). Lower amylase expression was independently associated with a lower risk of death (P = .048), and lower KYAT1 expression with a lower risk of weakness (P = .022). NMES increased FNDC5 expression compared with unstimulated muscle (P = .016), and late PN patients had a higher KYAT1 expression than early PN patients (P = .022).

Conclusion

Expression of the studied myokines was affected by critical illness and associated with clinical outcomes, with limited effects of interventions that attenuate muscle wasting or weakness.

Belt Electrode-Skeletal Muscle Electrical Stimulation During Early Hematopoietic Post-Transplantation To Prevent Skeletal Muscle Atrophy and Weakness

A decline in physical functions at the early stage of allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a serious issue. Belt electrode-skeletal muscle electrical stimulation (B-SES) can induce significant muscle contractions with electrical stimulation and reduce muscle weakness. However, this approach has not been used in allo-HSCT patients. This study aimed to examine the effect of B-SES on physical function, and safety in patients during the early post-transplantation period. Forty-three adult patients who underwent B-SES after allo-HSCT were stratified into 2 groups based on the intensity of electrical stimulation (high versus low). B-SES was performed in combination with exercise therapy for 4 post-transplantation weeks. Knee extensor strength (KES) in the low B-SES group decreased significantly, whereas no change was observed in the high-intervention group. A significant positive correlation was observed between total intensity and ΔKES. A reduction in the 6-minute walking distance in the high B-SES group patients was lower than that of historical data. Two patients had B-SES-related complications including muscle pain. This study is the first to propose a new rehabilitation intervention strategy for allo-HSCT. Combined use of B-SES may be a new approach to reducing the decline of physical function in the early post-transplantation period.

Electrical stimulation therapy for peripheral nerve injury

Peripheral nerve injury is common and frequently occurs in extremity trauma patients. The motor and sensory impairment caused by the injury will affect patients' daily life and social work. Surgical therapeutic approaches don't assure functional recovery, which may lead to neuronal atrophy and hinder accelerated regeneration. Rehabilitation is a necessary stage for patients to recover better. A meaningful role in non-pharmacological intervention is played by rehabilitation, through individualized electrical stimulation therapy. Clinical studies have shown that electrical stimulation enhances axon growth during nerve repair and accelerates sensorimotor recovery. According to different effects and parameters, electrical stimulation can be divided into neuromuscular, transcutaneous, and functional electrical stimulation. The therapeutic mechanism of electrical stimulation may be to reduce muscle atrophy and promote muscle reinnervation by increasing the expression of structural protective proteins and neurotrophic factors. Meanwhile, it can modulate sensory feedback and reduce neuralgia by inhibiting the descending pathway. However, there are not many summary clinical application parameters of electrical stimulation, and the long-term effectiveness and safety also need to be further explored. This article aims to explore application methodologies for effective electrical stimulation in the rehabilitation of peripheral nerve injury, with simultaneous consideration for fundamental principles of electrical stimulation and the latest technology. The highlight of this paper is to identify the most appropriate stimulation parameters (frequency, intensity, duration) to achieve efficacious electrical stimulation in the rehabilitation of peripheral nerve injury.

Evaluation of muscle loss by ultrasonography in critically ill patients

BACKGROUND

Critically ill patients have intense muscle tissue mobilization, and attenuating protein catabolism may contribute to improved outcomes.

OBJECTIVE

To evaluate short-term muscle loss in critically ill patients.

METHODS

In this prospective observational study, we evaluated the thickness of the rectus femoris muscle by ultrasonography in young and older adults of both sexes admitted to a cardiological intensive care unit within 48 h of admission (baseline) and after 7 days. The results were compared and correlated with anthropometric, clinical, and biochemical parameters. The significance level for all statistical analyses was 0.05.

RESULTS

The final sample comprised 88 patients with a mean age of 66.2 ± 11.8 years. There was an average 13.5% reduction in rectus femoris muscle thickness over the study period (P < 0.001), regardless of the thigh circumference maintenance (P = 0.229). This reduction occurred even with improved clinical parameters (C-reactive protein, Simplified Acute Physiology Score) and was greater in patients receiving mechanical ventilation and sedation and in those who died. Regarding nutrition status, malnourished and eutrophic individuals showed greater muscle loss than overweight individuals. There was also an inverse correlation of muscle loss (percentage) with body mass index, arm circumference, and calf circumference (P < 0.05), demonstrating that the lower these anthropometric measurements, the higher the muscle loss obtained by ultrasound.

CONCLUSION

Ultrasonography assessment detected muscle mass loss in the short-term more sensitively than the anthropometric method. However, it demands caution and further studies demonstrating this analysis.

Safety and Feasibility Assessment of Repetitive Vascular Occlusion Stimulus (RVOS) Application to Multi-Organ Failure Critically Ill Patients: A Pilot Randomised Controlled Trial

Muscle wasting is implicated in the pathogenesis of intensive care unit acquired weakness (ICU-AW), affecting 40% of patients and causing long-term physical disability. A repetitive vascular occlusion stimulus (RVOS) limits muscle atrophy in healthy and orthopaedic subjects, thus, we explored its application to ICU patients. Adult multi-organ failure patients received standard care +/- twice daily RVOS {4 cycles of 5 min tourniquet inflation to 50 mmHg supra-systolic blood pressure, and 5 min complete deflation} for 10 days. Serious adverse events (SAEs), tolerability, feasibility, acceptability, and exploratory outcomes of the rectus femoris cross-sectional area (RFCSA), echogenicity, clinical outcomes, and blood biomarkers were assessed. Only 12 of the intended 32 participants were recruited. RVOS sessions (76.1%) were delivered to five participants and two could not tolerate it. No SAEs occurred; 75% of participants and 82% of clinical staff strongly agreed or agreed that RVOS is an acceptable treatment. RFCSA fell significantly and echogenicity increased in controls (n = 5) and intervention subjects (n = 4). The intervention group was associated with less frequent acute kidney injury (AKI), a greater decrease in the total sequential organ failure assessment score (SOFA) score, and increased insulin-like growth factor-1 (IGF-1), and reduced syndecan-1, interleukin-4 (IL-4) and Tumor necrosis factor receptor type II (TNF-RII) levels. RVOS application appears safe and acceptable, but protocol modifications are required to improve tolerability and recruitment. There were signals of possible clinical benefit relating to RVOS application.

Chronic critical illness and post-intensive care syndrome: from pathophysiology to clinical challenges

Background

Post‐intensive care syndrome (PICS) encompasses physical, cognition, and mental impairments persisting after intensive care unit (ICU) discharge. Ultimately it significantly impacts the long‐term prognosis, both in functional outcomes and survival. Thus, survivors often develop permanent disabilities, consume a lot of healthcare resources, and may experience prolonged suffering. This review aims to present the multiple facets of the PICS, decipher its underlying mechanisms, and highlight future research directions.

Main text

This review abridges the translational data underlying the multiple facets of chronic critical illness (CCI) and PICS. We focus first on ICU-acquired weakness, a syndrome characterized by impaired contractility, muscle wasting, and persisting muscle atrophy during the recovery phase, which involves anabolic resistance, impaired capacity of regeneration, mitochondrial dysfunction, and abnormalities in calcium homeostasis. Second, we discuss the clinical relevance of post-ICU cognitive impairment and neuropsychological disability, its association with delirium during the ICU stay, and the putative role of low-grade long-lasting inflammation. Third, we describe the profound and persistent qualitative and quantitative alteration of the innate and adaptive response. Fourth, we discuss the biological mechanisms of the progression from acute to chronic kidney injury, opening the field for renoprotective strategies. Fifth, we report long-lasting pulmonary consequences of ARDS and prolonged mechanical ventilation. Finally, we discuss several specificities in children, including the influence of the child’s pre-ICU condition, development, and maturation.

Conclusions

Recent understandings of the biological substratum of the PICS’ distinct features highlight the need to rethink our patient trajectories in the long term. A better knowledge of this syndrome and precipitating factors is necessary to develop protocols and strategies to alleviate the CCI and PICS and ultimately improve patient recovery.

Early Neuromuscular Electrical Stimulation in Addition to Early Mobilization Improves Functional Status and Decreases Hospitalization Days of Critically Ill Patients

OBJECTIVES

To evaluate the impact of the additional use of early neuromuscular electrical stimulation (NMES) on an early mobilization (EM) protocol.

DESIGN

Randomized controlled trial.

SETTING

ICU of the Clinical Hospital of Ribeirão Preto, University of São Paulo, Brazil.

PATIENTS

One hundred and thirty-nine consecutive mechanically ventilated patients were included in the first 48 hours of ICU admission.

INTERVENTIONS

The patients were divided into two groups: EM and EM+NMES. Both groups received EM daily. In the EM+NMES group, patients additionally received NMES 5 days a week, for 60 minutes, starting in the first 48 hours of ICU admission until ICU discharge.

MEASUREMENTS AND MAIN RESULTS

Functional status, muscle strength, ICU and hospital length of stay (LOS), frequency of delirium, days on mechanical ventilation, mortality, and quality of life were assessed. Patients in the EM+NMES group presented a significant higher score of functional status measured by the Functional Status Score for the ICU scale when compared with the EM group in the first day awake: 22 (15-26) versus 12 (8-22) (p = 0.019); at ICU discharge: 28 (21-33) versus 18 (11-26) (p = 0.004); and hospital discharge: 33 (27-35) versus 25 (17-33) (p = 0.014), respectively. They also had better functional status measured by the Physical Function Test in the ICU scale, took less days to stand up during the ICU stay, and had a significant shorter hospital LOS, lower frequency of ICU-acquired weakness, and better global muscle strength.

CONCLUSIONS

The additional application of early NMES promoted better functional status outcomes on the first day awake and at ICU and hospital discharge. The patients in the EM+NMES group also took fewer days to stand up and had shorter hospital LOS, lower frequency of ICU-acquired weakness, and better muscle strength. Future studies are still necessary to clarify the effects of therapies associated with EM, especially to assess long-term outcomes.

A scoping review of the contralateral effects of unilateral peripheral stimulation on neuromuscular function

It is known that resistance exercise using one limb can affect motor function of both the exercised limb and the unexercised contralateral limb, a phenomenon termed cross-education. It has been suggested that cross-education has clinical implications, e.g. in rehabilitation for orthopaedic conditions or post-stroke paresis. Much of the research on the contralateral effect of unilateral intervention on motor output is based on voluntary exercise. This scoping review aimed to map the characteristics of current literature on the cross-education caused by three most frequently utilised peripheral neuromuscular stimulation modalities in this context: electrical stimulation, mechanical vibration and percutaneous needling, that may direct future research and translate to clinical practice. A systematic search of relevant databases (Ebsco, ProQuest, PubMed, Scopus, Web of Science) through to the end of 2020 was conducted following the PRISMA Extension for Scoping Review. Empirical studies on human participants that applied a unilateral peripheral neuromuscular stimulation and assessed neuromuscular function of the stimulated and/or the unstimulated side were selected. By reading the full text, the demographic characteristics, context, design, methods and major findings of the studies were synthesised. The results found that 83 studies were eligible for the review, with the majority (53) utilised electrical stimulation whilst those applied vibration (18) or needling (12) were emerging. Although the contralateral effects appeared to be robust, only 31 studies claimed to be in the context of cross-education, and 25 investigated on clinical patients. The underlying mechanism for the contralateral effects induced by unilateral peripheral stimulation remains unclear. The findings suggest a need to enhance the awareness of cross-education caused by peripheral stimulation, to help improve the translation of theoretical concepts to clinical practice, and aid in developing well-designed clinical trials to determine the efficacy of cross-education therapies.

[Intensive Care Unit-Acquired Weakness : A nationwide survey on diagnostics, monitoring and treatment strategies on German intensive care units]

Hintergrund

Die „Intensive Care Unit-Acquired Weakness“ (ICU-AW) ist eine der häufigsten Ursachen für eine neuromuskuläre Dysfunktion in der Intensivmedizin. Gegenwärtig fehlen evidenzbasierte Empfehlungen zur Diagnostik, zum Monitoring und zu therapeutischen Maßnahmen.

Ziel der Arbeit

Die Erfassung des derzeitigen Vorgehens bei Diagnostik, Monitoring und präventiven und therapeutischen Ansätzen bei der ICU-AW auf deutschen Intensivstationen.

Material und Methoden

Onlinebefragung von 448 Mitgliedern des Wissenschaftlichen Arbeitskreises Intensivmedizin (WAKI) und des Wissenschaftlichen Arbeitskreises Neuroanästhesie (WAKNA).

Ergebnisse

Insgesamt wurden 68/448 (15,2 %) Fragebogen ausgewertet. Bei 13,4 % (9/67) der Befragten existiert ein strukturiertes diagnostisches Vorgehen zur Detektion der ICU-AW. Für Screening (60/68; 88,2 %) und Verlaufsbeurteilung (57/65; 87,7 %) wird die klinische Untersuchung präferiert. Etablierte Scores, wie der „Medical Research Council sum score“ (MRC-SS) spielen für Screening und Verlaufskontrolle der ICU-AW eine untergeordnete Rolle (7/68; 10,3 % und 7/65; 10,8 %). Mobilisation (45/68; 66,2 %) und Sedativareduktion (38/68; 55,9 %) stellen die häufigsten präventiven und therapeutischen Ansätze dar. Ein Mangel an Physiotherapeuten (64/68; 94,1 %) und Pflegekräften (57/68; 83,8 %) wird als Hauptdefizit bei der Versorgung von Patienten mit ICU-AW identifiziert. Insgesamt 91,2 % (62/68) der Befragten befürworten die Erstellung evidenzbasierter Empfehlungen zur Diagnostik, zum Monitoring und zu therapeutischen Ansätzen bei ICU-AW.

Diskussion

Ein einheitliches Konzept für Diagnostik, Monitoring, Prävention und Therapie der ICU-AW auf deutschen Intensivstationen fehlt weitgehend. Innovative diagnostische Ansätze könnten in Zukunft helfen, Patienten mit einem hohem Risiko für eine ICU-AW frühzeitig zu detektieren, präventive Maßnahmen einzuleiten sowie wertvolle prognostische Informationen zu gewinnen.

Zusatzmaterial online

Die Online-Version dieses Beitrags (10.1007/s00101-022-01089-9) enthält den der Studie zugrunde liegenden Fragebogen.