Illness Weakness, Polyneuropathy and Myopathy: Diagnosis, treatment, and long-term outcomes

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

BACKGROUND AND AIMS

Muscle wasting results in weakness for patients with critical illness. We aim to explore ultrasound-derived rates of change in skeletal muscle in the intensive care unit (ICU) and following discharge to the post-ICU ward.

DESIGN

Post hoc analysis of a multicentre randomised controlled trial of functional-electrical stimulated cycling, recumbent cycling, and usual care delivered in intensive care.

METHOD

Participants underwent ultrasound assessment of rectus femoris at ICU admission, weekly in the ICU, upon awakening, ICU discharge, and hospital discharge. The primary outcome was rate of change in rectus femoris cross-sectional area (ΔRFCSA) in mm2/day in the ICU (enrolment to ICU discharge) and in the post-ICU ward (ICU discharge to hospital discharge). Secondary outcomes included rate of change in echo intensity (ΔEI), standard deviation of echo intensity (ΔEISD), and the intervention effect on ultrasound measures. Echo intensity is a quantitative assessment of muscle quality. Elevated echo intensity may indicate fluid infiltration, adipose tissue, and reduced muscle quality.

RESULTS

154 participants were included (mean age: 58 ± 15 years, 34% female). Rectus femoris cross-sectional area declined in the ICU (-4 mm2/day [95% confidence interval {CI}: -9 to 1]) and declined further in the ward (-9 mm2/day [95% CI: -14 to -3]) with a mean difference between ICU and ward of -5 mm2/day ([95% CI: -2, to 11]; p = 0.1396). There was a nonsignificant difference in ΔEI between in-ICU and the post-ICU ward of 1.2 ([95% CI: -0.1 to 2.6]; p = 0.0755), a statistically significant difference in ΔEISD between in-ICU and in the post-ICU ward of 1.0 ([95% CI, 0.5 to 1.5]; p = 0.0003), and no difference in rate of change in rectus femoris cross-sectional area between groups in intensive care (p = 0.411) or at hospital discharge (p = 0.1309).

CONCLUSIONS

Muscle wasting occurs in critical illness throughout the hospital admission. The average rate of loss in muscle cross-sectional area does not slow after ICU discharge, even with active rehabilitation.

[Role of neuromuscular blocking agents in the development of polyneuropathy and myopathy in critically ill patients]

BACKGROUND

Acquired critical illness weakness (AWCIP) is the most frequent neuromuscular disease in intensive care medicine departments. Its importance is given by the prolongation of hospital stay and the delayed recovery it causes to patients after hospitalization. The main objective of this study was to investigate the association between neuromuscular blocking agents and the development of acquired weakness in critically ill patients.

MATERIAL AND METHODS

We conducted a prospective study of 103 critically ill patients who were periodically monitored with electromyography.

RESULTS

The development of AWCIP was observed in 63 patients. The group of patients who developed AWCIP had a significantly higher utilization of neuromuscular blocking agents than the group who did not develop AWCIP [79.4% vs 50%, OR:3.85 (1.63-9.39), p <0.02]; likewise, this group of patients had a longer ICU stay [32 days vs 14 days, OR: 1.11 (1.06-1.17), p <0. 001] and a longer mechanical ventilation time [24 days vs 9 days, OR:1.2 (1.11-1.32), p <0.001].

CONCLUSION

Neuromuscular blocking agents are a factor associated with the occurrence of AWCIP.

A scoping review of preclinical intensive care unit-acquired weakness models

Background

Animal models focusing on neuromuscular outcomes are crucial for understanding the mechanisms of intensive care unit-acquired weakness (ICU-AW) and exploring potential innovative prevention and treatment strategies.

Aim

To analyse and evaluate preclinical ICU-AW models.

Methods

We manually searched five English and four Chinese databases from 1 January 2002, to 1 February 2024, and reviewed related study references. Full-text publications describing animal models of muscle weakness and atrophy in critical illness were included. Detailed information about model types, animal species, sex, age, induction methods, outcome measures, drawbacks and strengths was extracted from each included study.

Results

A total of 3,451 citations were initially retrieved, with 84 studies included in the final analysis. The most frequently studied animal model included rodents (86.9%), 64.3% of which were male animals. ICU-AW animal models were mostly induced by comprehensive intensive care unit (ICU) interventions (38.1%) and sepsis (51.2%). Most studies focused on limb muscles (66.7%), diaphragm muscles (21.4%) or both (9.5%). Reported outcomes primarily included muscular pathological changes (83.3%), electrophysiological examinations of muscles (57.1%) and animal grip strength (16.6%). However, details such as animal age, mortality data, experimental design, randomisation, blinding, sample size and interventions for the experimental group and/or control group were inadequately reported.

Conclusion

Many preclinical models are used to study ICU-AW, but the reporting of methodological details is often incomplete. Although current ICU animal models can mimic the characteristics of human ICU-AW, there is no standard model. Future preclinical studies should develop a standard ICU-AW animal model to enhance reproducibility and improve scientific rigor in exploring the mechanisms and potential treatment of ICU-AW.

Effect of an evidence-based early rehabilitation program on adult patients with venovenous extracorporeal membrane oxygenation: A cohort study

OBJECTIVES

To assess the efficacy of early rehabilitation program for VV-ECMO patients and observe the influence on the respiratory and skeletal muscles.

DESIGN

A cohort study.

SETTING

The study was conducted with VVECMO patients in a comprehensive ICU with 32 beds.

MAIN OUTCOME MEASURES

Ultrasound measurements were performed on each patients on day 1, 4, 7, 10, and 14, including diaphragmatic excursion (DE), diaphragmatic thickening fraction (DTF), intercostal muscle thickening fraction (ICMTF), thickness of the rectus femoris (RF), thickness of vastus intermedius (VI), and rectus femoris cross-sectional area (RF-CSA). Data on basic characteristics, results of ultrasound measurements, patients outcomes and adverse events were collected.

RESULTS

22 patients received usual rehabilitation measures were set as the control group and 23 patients underwent early rehabilitation program were set as the study group. There were no differences in diaphragmatic excursion, diaphragmatic thickening fraction, intercostal muscle thickening fraction, thickness of rectus femoris, thickness of vastus intermedius, rectus femoris cross-sectional area between two groups on day 1 after VV-ECMO treatment (P > 0.05). The variation of diaphragmatic thickening fraction and intercostal muscle thickening fraction decreased on the day 7 and 14 after treatment (P < 0.05). The variation of vastus intermedius thickness and rectus femoris cross-sectional area in the study group was less compared with those in the control group on day 4, 7, 10 and 14. The ECMO duration in the study group was shorter than that in the control group (12.00 [10.00-16.25] days vs. 8.00 [6.00-12.25] days, P = 0.002), but there was no difference in the duration of mechanical ventilation.

CONCLUSION

Early rehabilitation program can ameliorate muscle atrophy. We recommend implementation of our rehabilitation program in VV-ECMO patients. This program can improve skeletal muscle atrophy and dysfunction in patients with VV-ECMO effectively and perhaps improve quality of life for patients in the future.

IMPLICATIONS FOR CLINICAL PRACTICE

Early rehabilitation program put higher demands bedside nurses. It requires them to observe conditions of VVECMO patients closely, assess the feasibility of rehabilitation promptly, and monitor for any adverse reactions. Ultrasound measurement is a noninvasive and useful tool to assess muscle atrophy in ICU patients. Early rehabilitation program can improve skeletal muscle atrophy and dysfunction in patients with VV-ECMO effectively.

Long-term outcomes in critically ill patients with acute respiratory failure

PURPOSE OF REVIEW

This review aims to explore the latest evidence on long-term outcomes in patients admitted to the ICU because of acute respiratory failure (ARF).

RECENT FINDINGS

As the survival rate of critically ill patients with acute respiratory failure improves, long-term mortality and disability still influence the quality of life of survivors and their caregivers. Patients admitted to the ICU because of ARF are at risk of developing the postintensive care syndrome, which presents with physical, cognitive and mental symptoms, all of which may impair their quality of life. Caregivers seem to be affected as well, which may lead to intergenerational trauma. The need for more care, including prone positioning, invasive support (e.g. mechanical ventilation, ECMO) and deep sedation are probably adjunctive risk factors for poor long-term outcomes.

SUMMARY

There is not much data on the long-term outcomes of patients who have survived ARF. More follow-up studies should be conducted, especially in centers providing higher levels of costly care (e.g. ECMO). Randomized controlled trials on interventions for ARF should include patient-centered long-term outcomes in addition to mortality rates. The high mortality rates associated with ARF mandate collaboration among multiple centers to achieve an adequate sample size for studying the long-term outcomes of survivors.

Accelerometer-derived movement features as predictive biomarkers for muscle atrophy in neurocritical care: a prospective cohort study

BACKGROUND

Physical inactivity and subsequent muscle atrophy are highly prevalent in neurocritical care and are recognized as key mechanisms underlying intensive care unit acquired weakness (ICUAW). The lack of quantifiable biomarkers for inactivity complicates the assessment of its relative importance compared to other conditions under the syndromic diagnosis of ICUAW. We hypothesize that active movement, as opposed to passive movement without active patient participation, can serve as a valid proxy for activity and may help predict muscle atrophy. To test this hypothesis, we utilized non-invasive, body-fixed accelerometers to compute measures of active movement and subsequently developed a machine learning model to predict muscle atrophy.

METHODS

This study was conducted as a single-center, prospective, observational cohort study as part of the MINCE registry (metabolism and nutrition in neurointensive care, DRKS-ID: DRKS00031472). Atrophy of rectus femoris muscle (RFM) relative to baseline (day 0) was evaluated at days 3, 7 and 10 after intensive care unit (ICU) admission and served as the dependent variable in a generalized linear mixed model with Least Absolute Shrinkage and Selection Operator regularization and nested-cross validation.

RESULTS

Out of 407 patients screened, 53 patients (age: 59.2 years (SD 15.9), 31 (58.5%) male) with a total of 91 available accelerometer datasets were enrolled. RFM thickness changed - 19.5% (SD 12.0) by day 10. Out of 12 demographic, clinical, nutritional and accelerometer-derived variables, baseline RFM muscle mass (beta - 5.1, 95% CI - 7.9 to - 3.8) and proportion of active movement (% activity) (beta 1.6, 95% CI 0.1 to 4.9) were selected as significant predictors of muscle atrophy. Including movement features into the prediction model substantially improved performance on an unseen test data set (including movement features: R2 = 79%; excluding movement features: R2 = 55%).

CONCLUSION

Active movement, as measured with thigh-fixed accelerometers, is a key risk factor for muscle atrophy in neurocritical care patients. Quantifiable biomarkers reflecting the level of activity can support more precise phenotyping of ICUAW and may direct tailored interventions to support activity in the ICU. Studies addressing the external validity of these findings beyond the neurointensive care unit are warranted.

TRIAL REGISTRATION

DRKS00031472, retrospectively registered on 13.03.2023.

Impact of Protein Intake after Intensive Care Unit on Discharge Destination for Critically Ill Patients: A Single-Center Prospective Observational Study

INTRODUCTION

Although nutritional therapy may be able to enable intensive care unit (ICU) survivors to return home instead of being discharged to a rehabilitation facility, post-ICU discharge nutritional therapy lacks investigation. This study evaluated the impact of nutritional therapy after ICU on discharge destination in critically ill patients.

METHODS

We enrolled consecutive adult patients who spent >72 h in the ICU from December 2020 to March 2023. The primary outcome was discharge destination. Energy and protein intake during the ICU stay and on days 7 and 14 after ICU discharge were evaluated. The target protein intake during the intensive treatment and general ward phases were 0.8 and 1.0 g/kg/day, respectively. Patients were categorized into home discharge (group A) and rehabilitation transfer (group B) groups. Factors affecting the discharge destination were evaluated using logistic regression analysis.

RESULTS

Of the 183 patients included, 134 belonged to group A and 49 to group B. In group A, more patients reached the protein intake target than in group B. Logistic regression analysis identified achieving the protein intake target as an independent predictor of home discharge.

CONCLUSION

Further studies are required to confirm the relationship between nutritional therapy during general ward and patient outcomes.

Longitudinal Assessment of Blood-Based Inflammatory, Neuromuscular, and Neurovascular Biomarker Profiles in Intensive Care Unit-Acquired Weakness: A Prospective Single-Center Cohort Study

BACKGROUND

The diagnosis of intensive care unit (ICU)-acquired weakness (ICUAW) and critical illness neuromyopathy (CINM) is frequently hampered in the clinical routine. We evaluated a novel panel of blood-based inflammatory, neuromuscular, and neurovascular biomarkers as an alternative diagnostic approach for ICUAW and CINM.

METHODS

Patients admitted to the ICU with a Sequential Organ Failure Assessment score of ≥ 8 on 3 consecutive days within the first 5 days as well as healthy controls were enrolled. The Medical Research Council Sum Score (MRCSS) was calculated, and motor and sensory electroneurography (ENG) for assessment of peripheral nerve function were performed at days 3 and 10. ICUAW was defined by an MRCSS < 48 and CINM by pathological ENG alterations, both at day 10. Blood samples were taken at days 3, 10, and 17 for quantitative analysis of 18 different biomarkers (white blood cell count, C-reactive protein, procalcitonin, C-terminal agrin filament, fatty-acid-binding protein 3, growth and differentiation factor 15, syndecan 1, troponin I, interferon-γ, tumor necrosis factor-α, interleukin-1α [IL-1α], IL-1β, IL-4, IL-6, IL-8, IL-10, IL-13, and monocyte chemoattractant protein 1). Results of the biomarker analysis were categorized according to the ICUAW and CINM status. Clinical outcome was assessed after 3 months.

RESULTS

Between October 2016 and December 2018, 38 critically ill patients, grouped into ICUAW (18 with and 20 without) and CINM (18 with and 17 without), as well as ten healthy volunteers were included. Biomarkers were significantly elevated in critically ill patients compared to healthy controls and correlated with disease severity and 3-month outcome parameters. However, none of the biomarkers enabled discrimination of patients with and without neuromuscular impairment, irrespective of applied classification.

CONCLUSIONS

Blood-based biomarkers are generally elevated in ICU patients but do not identify patients with ICUAW or CINM.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT02706314.

Characteristics of the Cerebrospinal Fluid in Septic Patients with Critical Illness Polyneuropathy - A Retrospective Cohort Study

Background

Critical illness polyneuropathy (CIP) is a complex disease commonly occurring in septic patients which indicates a worse prognosis. Herein, we investigated the characteristics of cerebrospinal fluid (CSF) in septic patients with CIP.

Methods

This retrospective study was conducted between Match 1, 2018, and July 1, 2022. Patients with sepsis who underwent a CSF examination and nerve electrophysiology were included. The levels of protein, glucose, lipopolysaccharide, white blood cell (WBC), interleukin (IL)-1, IL-6, IL-8, and tumor necrosis factor (TNF) α in CSF were measured. The fungi and bacteria in CSF were also assessed.

Results

Among the 175 septic patients, 116 (66.3%) patients were diagnosed with CIP. 28-day Mortality in CIP patients was higher than that in non-CIP patients (25.0% vs. 10.2%, P = 0.02) which was confirmed by survival analysis. The results of propensity score matching analysis (PSMA) indicated a significant difference in the level of protein, WBC, IL-1, IL-6, IL-8, and TNFα present in the CSF between CIP patients and non-CIP patients. The results of the receiver operating characteristic (ROC) analysis showed that IL-1, WBC, TNFα, and their combined indicator had a good diagnostic value with an AUC > 0.8.

Conclusion

The increase in the levels of WBC, IL-1, and TNFα in CSF might be an indicator of CIP in septic patients.

Critical illness-associated limb and diaphragmatic weakness

PURPOSE OF REVIEW

In the current review, we aim to highlight the evolving evidence on the diagnosis, prevention and treatment of critical illness weakness (CIW) and critical illness associated diaphragmatic weakness (CIDW).

RECENT FINDINGS

In the ICU, several risk factors can lead to CIW and CIDW. Recent evidence suggests that they have different pathophysiological mechanisms and impact on outcomes, although they share common risk factors and may overlap in several patients. Their diagnosis is challenging, because CIW diagnosis is primarily clinical and, therefore, difficult to obtain in the ICU population, and CIDW diagnosis is complex and not easily performed at the bedside. All of these issues lead to underdiagnosis of CIW and CIDW, which significantly increases the risk of complications and the impact on both short and long term outcomes. Moreover, recent studies have explored promising diagnostic techniques that are may be easily implemented in daily clinical practice. In addition, this review summarizes the latest research aimed at improving how to prevent and treat CIW and CIDW.

SUMMARY

This review aims to clarify some uncertain aspects and provide helpful information on developing monitoring techniques and therapeutic interventions for managing CIW and CIDW.

Improving management of ARDS: uniting acute management and long-term recovery

Acute Respiratory Distress Syndrome (ARDS) is an important global health issue with high in-hospital mortality. Importantly, the impact of ARDS extends beyond the acute phase, with increased mortality and disability for months to years after hospitalization. These findings underscore the importance of extended follow-up to assess and address the Post-Intensive Care Syndrome (PICS), characterized by persistent impairments in physical, cognitive, and/or mental health status that impair quality of life over the long-term. Persistent muscle weakness is a common physical problem for ARDS survivors, affecting mobility and activities of daily living. Critical illness and related interventions, including prolonged bed rest and overuse of sedatives and neuromuscular blocking agents during mechanical ventilation, are important risk factors for ICU-acquired weakness. Deep sedation also increases the risk of delirium in the ICU, and long-term cognitive impairment. Corticosteroids also may be used during management of ARDS, particularly in the setting of COVID-19. Corticosteroids can be associated with myopathy and muscle weakness, as well as prolonged delirium that increases the risk of long-term cognitive impairment. The optimal duration and dosage of corticosteroids remain uncertain, and there's limited long-term data on their effects on muscle weakness and cognition in ARDS survivors. In addition to physical and cognitive issues, mental health challenges, such as depression, anxiety, and post-traumatic stress disorder, are common in ARDS survivors. Strategies to address these complications emphasize the need for consistent implementation of the evidence-based ABCDEF bundle, which includes daily management of analgesia in concert with early cessation of sedatives, avoidance of benzodiazepines, daily delirium monitoring and management, early mobilization, and incorporation of family at the bedside. In conclusion, ARDS is a complex global health challenge with consequences extending beyond the acute phase. Understanding the links between critical care management and long-term consequences is vital for developing effective therapeutic strategies and improving the quality of life for ARDS survivors.

Intensive Care Unit-Acquired Weakness after Liver Transplantation: Analysis of Seven Cases and a Literature Review

Intensive Care Unit (ICU)-Acquired Weakness (ICU-AW) is a generalized muscle weakness that is clinically detected in critical patients and has no plausible etiology other than critical illness. ICU-AW is uncommon in patients undergoing orthotopic liver transplantation (OLT). Our report sheds light on the highest number of ICU-AW cases observed in a single center on OLT patients with early allograft dysfunction. Out of 282 patients who underwent OLT from January 2015 to June 2023, 7 (2.5%) developed generalized muscle weakness in the ICU and underwent neurophysiological investigations. The neurologic examination showed preserved extraocular, flaccid quadriplegia with the absence of deep tendon reflexes in all patients. Neurophysiological studies, including electromyography and nerve conduction studies, showed abnormalities with fibrillation potentials and the rapid recruitment of small polyphasic motor units in the examined muscles, as well as a reduced amplitude of the compound muscle action potential and sensory nerve action potential, with an absence of demyelinating features. Pre-transplant clinical status was critical in all patients. During ICU stay, early allograft dysfunction, acute kidney injury, prolonged mechanical ventilation, sepsis, hyperglycemia, and high blood transfusions were observed in all patients. Two patients were retransplanted. Five patients were alive at 90 days; two patients died. In non-cooperative OLT patients, neurophysiological investigations are essential for the diagnosis of ICU-AW. In this setting, the high number of red blood cell transfusions is a potential risk factor for ICU-AW.