Intensive care unit-acquired weakness: unanswered questions and targets for future research

Effect of dimethyl fumarate on mitochondrial metabolism in a pediatric porcine model of asphyxia-induced in-hospital cardiac arrest

Neurological and cardiac injuries are significant contributors to morbidity and mortality following pediatric in-hospital cardiac arrest (IHCA). Preservation of mitochondrial function may be critical for reducing these injuries. Dimethyl fumarate (DMF) has shown potential to enhance mitochondrial content and reduce oxidative damage. To investigate the efficacy of DMF in mitigating mitochondrial injury in a pediatric porcine model of IHCA, toddler-aged piglets were subjected to asphyxia-induced CA, followed by ventricular fibrillation, high-quality cardiopulmonary resuscitation, and random assignment to receive either DMF (30 mg/kg) or placebo for four days. Sham animals underwent similar anesthesia protocols without CA. After four days, tissues were analyzed for mitochondrial markers. In the brain, untreated CA animals exhibited a reduced expression of proteins of the oxidative phosphorylation system (CI, CIV, CV) and decreased mitochondrial respiration (p < 0.001). Despite alterations in mitochondrial content and morphology in the myocardium, as assessed per transmission electron microscopy, mitochondrial function was unchanged. DMF treatment counteracted 25% of the proteomic changes induced by CA in the brain, and preserved mitochondrial structure in the myocardium. DMF demonstrates a potential therapeutic benefit in preserving mitochondrial integrity following asphyxia-induced IHCA. Further investigation is warranted to fully elucidate DMF's protective mechanisms and optimize its therapeutic application in post-arrest care.

Predicting intensive care unit-acquired weakness: A multilayer perceptron neural network approach

In this editorial, we comment on the article by Wang and Long, published in a recent issue of the World Journal of Clinical Cases. The article addresses the challenge of predicting intensive care unit-acquired weakness (ICUAW), a neuromuscular disorder affecting critically ill patients, by employing a novel processing strategy based on repeated machine learning. The editorial presents a dataset comprising clinical, demographic, and laboratory variables from intensive care unit (ICU) patients and employs a multilayer perceptron neural network model to predict ICUAW. The authors also performed a feature importance analysis to identify the most relevant risk factors for ICUAW. This editorial contributes to the growing body of literature on predictive modeling in critical care, offering insights into the potential of machine learning approaches to improve patient outcomes and guide clinical decision-making in the ICU setting.

Outcome, predictors and longitudinal trajectories of subjects with critical illness polyneuropathy and myopathy (CINAMOPS): study protocol of an observational cohort study in a clinical and post-clinical setting

INTRODUCTION

Critical illness polyneuropathy and myopathy (CIP/CIM) are frequent complications in the intensive care unit (ICU) with major consequences for the progress and outcome of subjects. CIP/CIM delays the weaning process, prolongs the hospital stay and increases the mortality rate. Additionally, it may have long-term consequences beyond the hospitalisation phase with prolonged disability. Even though there is growing interest in CIP/CIM, research about the clinical and post-clinical course as well as the middle-term and long-term outcomes of subjects with CIP/CIM is scarce. A large prospective study of critically ill subjects is needed with accurate diagnosis during the acute stage and comprehensive assessment during long-term follow-up.

METHODS AND ANALYSIS

This prospective observational cohort study aims to compare the clinical and post-clinical course of chronically critically ill subjects with and without the diagnosis of CIP/CIM and to determine predictors for the middle-term and long-term outcomes of subjects with CIP/CIM. In addition, the influence of the preclinical health status and the preclinical frailty on the long-term outcome of subjects with CIP/CIM will be investigated.This single-centre study will include 250 critically ill patients who were invasively ventilated for at least 5 days at the ICU and show reduced motor strength. At five study visits at admission and discharge to neurological rehabilitation, and 12, 18 and 24 months after disease onset, a comprehensive test battery will be applied including assessments of functioning and impairment, independence, health-related quality of life, activity and participation, cognition, gait and balance, fatigue, mental health and frailty.Secondary objectives are the documentation of therapy goals, therapy content and achieved milestones during the rehabilitation, to evaluate the clinimetric properties of the Mini-BESTest in critically ill patients, and to evaluate the time course and outcome of subjects with CIP/CIM after SARS-CoV-2 infection.

ETHICS AND DISSEMINATION

The study was approved by the ethical committee of the Ludwig-Maximilians University Munich. Participants will be included in the study after having signed informed consent.Results will be published in scientific, peer-reviewed journals and at national and international conferences.

TRIAL REGISTRATION NUMBER

German Clinical Trial Register (DRKS00021753).

Early Mobilization and Rehabilitation of Critically-Ill Patients

Post-intensive care unit (ICU) syndrome may occur after ICU treatment and includes ICU-acquired weakness (ICU-AW), cognitive decline, and mental problems. ICU-AW is muscle weakness in patients treated in the ICU and is affected by the period of mechanical ventilation. Diaphragmatic weakness may also occur because of respiratory muscle unloading using mechanical ventilators. ICU-AW is an independent predictor of mortality and is associated with longer duration of mechanical ventilation and hospital stay. Diaphragm weakness is also associated with poor outcomes. Therefore, pulmonary rehabilitation with early mobilization and respiratory muscle training is necessary in the ICU after appropriate patient screening and evaluation and can improve ICU-related muscle weakness and functional deterioration.

Functional electrical stimulation cycling-based muscular evaluation method in mechanically ventilated patients

BACKGROUND

Intensive care acquired muscle weakness is a common feature in critically ill patients. Beyond the therapeutic uses, FES-cycling could represent a promising nonvolitional evaluation method for detecting acquired muscle weakness.

OBJECTIVES

To assess whether FES-cycling is able to identify muscle dysfunctions, and to evaluate the survival rate in patients with detected muscle dysfunction.

METHODS

A prospective observational study was carried out, with 29 critically ill patients and 20 healthy subjects. Maximum torque and power achieved were recorded, in addition to the stimulation cost, and patients were followed up for six months.

RESULTS

Torque (2.64 [1.53 to 4.81] vs 6.03 [4.56 to 6.73] Nm) and power (3.31 [2.33 to 6.37] vs 6.35 [5.22 to 10.70] watts) were lower and stimulation cost (22 915 [5069 to 37 750] vs 3411 [2080 to 4024] μC/W) was higher in patients compared to healthy people (p < 0.05). Surviving patients showed a nonsignificant difference in power and torque in relation to nonsurvivors (p > 0.05), but they had a lower stimulation cost (4462 [3598 to 11 788] vs 23 538 [10 164 to 39 836] μC/W) (p < 0.05). In total, 34% of all patients survived during the six months of follow-up. Furthermore, 62% of patients with a stimulation cost below 15 371 μC/W and 7% of patients with a stimulation cost above 15 371 μC/W survived.

CONCLUSIONS

FES-cycling has good sensitivity and specificity for detecting muscle disorders. Critical patients have low torque and power and a high stimulation cost. Stimulation cost is related to survival. A low stimulation cost was related to a 3 times greater chance of survival.

Effectiveness of massage and range of motion exercises on muscle strength and intensive care unit-acquired weakness in Iranian patients with COVID-19: a randomized parallel-controlled trial

BACKGROUND

Muscle weakness is prevalent in intensive care patients. This study focused on comparing the effects of massage and range of motion (ROM) exercises on muscle strength and intensive care unit-acquired weakness (ICU-AW) among patients with coronavirus disease 2019 (COVID-19).

METHODS

This study was a randomized clinical trial that recruited patients (n=45) with COVID-19 admitted to the ICU and divided them into three groups (ROM exercises, massage, and control). We evaluated muscle strength and ICU-AW in the arms and legs using a hand dynamometer. The Medical Research Council sum score was determined before and after the intervention.

RESULTS

The study findings were that 0%, 20%, and 100% of the participants in the ROM exercises, massage, and control groups had ICU-AW on the 7th day of ICU admission. The ROM exercise group had greater muscle strength in the hands and legs than the massage and control groups, and the massage group had greater muscle strength than the control group.

CONCLUSIONS

Massage and ROM exercises could improve muscle strength and reduce ICU-AW in COVID-19 patients admitted to the ICU.

Intensive care unit-acquired weakness: Recent insights

Intensive care unit-acquired weakness (ICU-AW) is a common complication in critically ill patients and is associated with a variety of adverse outcomes. These include the need for prolonged mechanical ventilation and ICU stay; higher ICU, in-hospital, and 1-year mortality; and increased in-hospital costs. ICU-AW is associated with multiple risk factors including age, underlying disease, severity of illness, organ failure, sepsis, immobilization, receipt of mechanical ventilation, and other factors related to critical care. The pathological mechanism of ICU-AW remains unclear and may be considerably varied. This review aimed to evaluate recent insights into ICU-AW from several aspects including risk factors, pathophysiology, diagnosis, and treatment strategies; this provides new perspectives for future research.

Exercise ventilatory response after COVID-19: comparison between ambulatory and hospitalized patients

Inefficient ventilatory response during cardiopulmonary exercise testing (CPET) has been suggested as a cause of post-COVID-19 dyspnea. It has been described in hospitalized patients (HOSP) with lung parenchymal sequelae but also after mild infection in ambulatory patients (AMBU). We hypothesize that AMBU and HOSP have different ventilatory responses to exercise, due to different etiologies. We analyzed CPET realized between July 2020 and May 2022 of patients with persisting respiratory symptoms 3 mo after COVID-19. Chest computed tomography (CT) scan, pulmonary function tests, quality of life, and respiratory questionnaires were collected. CPET data were specifically explored as a function of ventilation (V̇e) and time. Seventy-nine consecutive patients were included (42 AMBU and 37 HOSP, median: 54 [44-60] yr old, 57% female). Patients were hospitalized for a median of 20 [8-34] days, with pneumonia (41%) or acute respiratory distress syndrome (ARDS; 30%). Among HOSP, 12(32%) patients had abnormal values for spirometry and 18(51%) for carbon monoxide diffusing capacity (P < 0.001). CPET showed no differences between AMBU and HOSP in peak absolute O2 uptake (V̇o2) (1.59 [1.22-2.11] mL·min-1; P = 0.65). Tidal volume (VT) as a function of V̇e, was lower in AMBU than in HOSP (P < 0.01) toward the end of exercise. The slope of the V̇e-CO2 production was higher than normal in both groups (30.9 [26.1-34.3]; P = 0.96). In conclusion, the severity of COVID-19 did not influence the exercise capacity, but AMBU demonstrated a less efficient ventilatory response to exercise as compared with HOSP. CPET with exploration of data as a function of V̇e and throughout the exercise better unveil ventilatory inefficiency.NEW & NOTEWORTHY We evaluated the exercise ventilatory response in patients with persisting dyspnea after severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) infection. We found that despite similar peak power and peak absolute O2 uptake, tidal volume as a function of ventilation was lower in ambulatory than in hospitalized patients toward the end of exercise, reflecting ventilatory inefficiency. We call for evaluation of minute ventilation with the exploration of data throughout the exercise and not only peak data to better unveil ventilatory inefficiency.

A Cross-Sectional Study of the Impact of ICU-Acquired Weakness: Prevalence, Associations, and Severity

Background and objective ICU-acquired weakness (ICU-AW) refers to a group of neuromuscular lesions that can develop in the ICU. It leads to decreased physical function, increased in-ICU and in-hospital mortality, and increased healthcare costs. Given its high prevalence and significant impact on patient outcomes, it is essential to have a deeper understanding of ICU-AW. In light of this, this study aimed to ascertain the prevalence, associations, and severity of ICU-AW at a tertiary hospital in the Kingdom of Saudi Arabia (KSA) and to evaluate physician awareness of this condition. Methods A cross-sectional study was conducted in the ICU of Al Madina General Hospital, Medina, KSA, from April 22 to August 22, 2022, involving patients who were 18 years or older and met the inclusion criteria (n=101). The overall muscle strength was assessed daily by using the Medical Research Council (MRC) scale for muscle strength. ICU-AW was identified in patients who experienced a decline in their MRC-Sum Score (MRC-SS) during their ICU stay. Results A total of 101 patients were enrolled in the study. The incidence of ICU-AW was 16.8% (n=17), with 23.5% exhibiting significant weakness and 76.5% having severe weakness. Post hoc comparisons showed that females had a higher incidence of ICU-AW. Fisher's exact test revealed a statistically significant relationship between ICU-AW and the longer duration of ICU stay (p=0.001), use of mechanical ventilation (p=0.034), and low hemoglobin levels (p=0.037). Conclusions ICU-AW was observed in 16.8% (n=17) of patients in our cohort, highlighting the significance of this condition. The study revealed a noteworthy correlation between ICU-AW and female sex, extended ICU stays, mechanical ventilation, and anemia.

The optimal dose of mobilisation therapy in the ICU: a prospective cohort study

BACKGROUND

This study aimed to assess the impact of duration of early mobilisation on survivors of critical illness. The hypothesis was that interventions lasting over 40 min, as per the German guideline, positively affect the functional status at ICU discharge.

METHODS

Prospective single-centre cohort study conducted in two ICUs in Germany. In 684 critically ill patients surviving an ICU stay > 24 h, out-of-bed mobilisation of more than 40 min was evaluated.

RESULTS

Daily mobilisation ≥ 40 min was identified as an independent predictor of an improved functional status upon ICU discharge. This effect on the primary outcome measure, change of Mobility-Barthel until ICU discharge, was observed in three different models for baseline patient characteristics (average treatment effect (ATE), all three models p < 0.001). When mobilisation parameters like level of mobilisation, were included in the analysis, the average treatment effect disappeared [ATE 1.0 (95% CI - 0.4 to 2.4), p = 0.16].

CONCLUSIONS

A mobilisation duration of more than 40 min positively impacts functional outcomes at ICU discharge. However, the maximum level achieved during ICU stay was the most crucial factor regarding adequate dosage, as higher duration did not show an additional benefit in patients with already high mobilisation levels.

TRIAL REGISTRATION

Prospective Registry of Mobilization-, Routine- and Outcome Data of Intensive Care Patients (MOBDB), NCT03666286. Registered 11 September 2018-retrospectively registered, https://classic.

CLINICALTRIALS

gov/ct2/show/NCT03666286 .

Early detection and assessment of intensive care unit-acquired weakness: a comprehensive review

Intensive care unit-acquired weakness (ICU-AW) is a serious complication in critically ill patients. Therefore, timely and accurate diagnosis and monitoring of ICU-AW are crucial for effectively preventing its associated morbidity and mortality. This article provides a comprehensive review of ICU-AW, focusing on the different methods used for its diagnosis and monitoring. Additionally, it highlights the role of bedside ultrasound in muscle assessment and early detection of ICU-AW. Furthermore, the article explores potential strategies for preventing ICU-AW. Healthcare providers who manage critically ill patients utilize diagnostic approaches such as physical exams, imaging, and assessment tools to identify ICU-AW. However, each method has its own limitations. The diagnosis of ICU-AW needs improvement due to the lack of a consensus on the appropriate approach for its detection. Nevertheless, bedside ultrasound has proven to be the most reliable and cost-effective tool for muscle assessment in the ICU. Combining the Sequential Organ Failure Assessment (SOFA) score, Acute Physiology and Chronic Health Evaluation (APACHE) II score assessment, and ultrasound can be a convenient approach for the early detection of ICU-AW. This approach can facilitate timely intervention and prevent catastrophic consequences. However, further studies are needed to strengthen the evidence.

Muscle strength/intensive care unit acquired weakness in COVID-19 and non-COVID-19 patients

BACKGROUND

Intensive care unit acquired weakness (ICU-AW) affects both coronavirus disease 19 (COVID-19) and non-COVID-19 patients. ICU-AW can result in a variety of consequences, including increased patient mortality.

AIMS

The current study aimed to compare muscle strength and ICU-AW in COVID-19 and non-COVID-19 patients.

STUDY DESIGN

This was a cross-sectional, descriptive-analytical pilot study.

METHODS

Fifteen conscious COVID-19 patients and 15 conscious non-COVID-19 patients admitted to the ICUs of a public hospital were selected by convenience sampling. Muscle strength in arms and legs was assessed by a hand-held dynamometer (HHD), and ICU-AW was measured with the medical research council sum score (MRC-SS) scale on the first, fourth, and seventh days of admission to ICUs.

RESULTS

The results showed that muscle strength in the arms and legs of the COVID-19 patients assessed by a HHD and MRC was significantly lower than that of non-COVID-19 patients. On the fourth day of ICU admission, 80% of the COVID-19 patients and 40% of the non-COVID-19 patients had ICU-AW. All COVID-19 patients and 86.8% of the non-COVID-19 patients had ICU-AW on the seventh day of ICU admission.

CONCLUSIONS

Decreased muscle strength and ICU-AW are more likely in COVID-19 patients who must stay in the ICU compared with non-COVID-19 patients.

RELEVANCE TO CLINICAL PRACTICE

Health systems should plan to provide rehabilitation facilities for COVID-19 patients and prevent prolonged complications of COVID-19.

Reliability of ultrasound in the assessment of muscle thickness in critically ill children

INTRODUCTION

Ultrasound has been used to quantify and qualify muscle morphology in critically ill children and can detect changes in muscle thickness. The aim of this study was to assess the reliability of ultrasound measurement of muscle thickness in critically ill children and to compare the assessments made by an expert with those made by inexperienced sonographers.

MATERIAL AND METHODS

Cross-sectional observational study conducted in the paediatric intensive care unit of a tertiary care university hospital in Brazil. The sample included patients aged 1 month to 12 years who received invasive mechanical ventilation for at least 24 h. Ultrasound images of the biceps brachii/brachialis and quadriceps femoris were obtained by one experienced sonographer and several inexperienced sonographers. We assessed intrarater and inter-rater reliability by means of the intraclass correlation coefficient (ICC) and Bland-Altman plot analysis.

RESULTS

Muscle thickness was measured in 10 children with a mean age of 15.5 months. The mean thickness of the assessed muscles as 1.14 cm for the biceps brachii/brachialis (standard deviation [SD], 0.27) and 1.85 cm for the quadriceps femoris (SD, 0.61). The intrarater and inter-rater reliability were good for all sonographers (ICC > 0.81). The differences were small, there was no significant bias in the Bland-Altman plots and all measurements were within the limits of agreement, except for 1 measurement of biceps and quadriceps.

CONCLUSION

Sonography can be used in critically ill children to accurately assess changes in muscle thickness, even by different evaluators. More studies are needed to establish a standardised approach to the use of ultrasound for monitoring muscle loss in order to incorporate it in clinical practice.

Comparison of resting energy expenditure measured with metabolic cart and calculated with predictive formulas in critically ill patients on mechanical ventilation

INTRODUCTION

The purpose was to compare the resting energy expenditure (REE) measured with the Q-NRG™+ metabolic-cart (MREE) with REE predicted by equations (the Harris-Benedict formula and an equation developed in ward, REE-HB and REE-W, respectively). We also aimed to assess the agreement of the measurements of oxygen consumption (V̇O₂) and carbon dioxide production (V̇CO₂) at different inspired fractions of oxygen (FiO₂).

METHODS

27 mechanically ventilated ICU patients were enrolled. V̇O₂ and V̇CO₂ were measured by Q-NRG™+ during breathing 40% and 60% FiO₂. MREE was compared with REE-W and REE-HB normalized for body weight.

RESULTS

V̇O₂ was 233.0 (95.2) ml/min and 217.5 (89.8) ml/min at FiO₂ 40% and 60%, respectively (NS). V̇CO₂ was 199.0 (91.7) ml/min at FiO₂ 40%, and 197.5 (85.5) ml/min at FiO₂ 60% (NS). The REE estimated from the equations was significantly different from the MREE. The best agreement was found for the Harris-Benedict equation without correction for stress-factors. Harris-Benedict equation corrected overestimates REE.

CONCLUSIONS

This new metabolic cart Q-NRG™+ provides a concordance of values for V̇O₂ and V̇CO₂ when measured at different FiO₂, and is a reliable tool for estimating energy expenditure and assessing the nutritional needs of the patient. This study demonstrates that the estimation of REE using predictive formulas does not allow accurate calculation of metabolic demands in ventilated intensive care patient. However, predictive equations allow for a rapid assessment of REE and calculation of the amount of energy derived from different substrates.

Neurological complications of sepsis

PURPOSE OF REVIEW

Sepsis, defined as life-threatening organ dysfunction caused by a dysregulated host response to infection, is a leading cause of hospital and ICU admission. The central and peripheral nervous system may be the first organ system to show signs of dysfunction, leading to clinical manifestations such as sepsis-associated encephalopathy (SAE) with delirium or coma and ICU-acquired weakness (ICUAW). In the current review, we want to highlight developing insights into the epidemiology, diagnosis, prognosis, and treatment of patients with SAE and ICUAW.

RECENT FINDINGS

The diagnosis of neurological complications of sepsis remains clinical, although the use of electroencephalography and electromyography can support the diagnosis, especially in noncollaborative patients, and can help in defining disease severity. Moreover, recent studies suggest new insights into the long-term effects associated with SAE and ICUAW, highlighting the need for effective prevention and treatment.

SUMMARY

In this manuscript, we provide an overview of recent insights and developments in the prevention, diagnosis, and treatment of patients with SAE and ICUAW.

Effectiveness of physical exercise and neuromuscular electrical stimulation interventions for preventing and treating intensive care unit-acquired weakness: A systematic review of randomized controlled trials

OBJECTIVE

Intensive care unit-acquired weakness is a frequent problem that develops as a secondary disorder while patients are suffering from life-threatening conditions. This study aimed to evaluate the effectiveness of physical exercise or neuromuscular electrical stimulation interventions on (i) preventing loss of muscle mass and weakness in critically ill patients admitted to intensive care units; (ii) recovering patients discharged from the intensive care unit with acquired weakness.

METHODS

A systematic review of randomized controlled trials was carried out, with studies identified in PubMed, Scopus, and Web of Science. The studies included assessed muscle mass and muscle strength, and performed a time × group analysis of effects. The risk of bias assessment was performed using the Revised Cochrane risk-of-bias tool for randomized trials.

RESULTS

Six trials with low risk of bias examined muscle mass, muscle strength, and functionality in 182 adult patients. In critically ill patients admitted to intensive care units, both neuromuscular electrical stimulation and bed/chair cycling for five to ten days prevented significant muscle loss. neuromuscular electrical stimulation in lower and upper limbs resulted in a significant reduction in the length of the hospitalization. In addition, cycle ergometer increased muscle strength and functionality. In patients discharged from the intensive care unit with acquired weakness, both neuromuscular electrical stimulation and physical exercise interventions increased muscle strength, but only physical exercise increased functionality.

CONCLUSIONS

Physical exercise and neuromuscular electrical stimulation interventions prevent excessive muscle mass loss in critically ill patients admitted to the intensive care unit and increase muscle strength in patients discharged from the intensive care unit with acquired weakness. Physical exercise seems more adequate for improving functionality.

Inpatient rehabilitation can improve functional outcomes of post-intensive care unit COVID-19 patients-a prospective study

PURPOSE

To evaluate the impact of an inpatient multimodal and intensive rehabilitation program on neuromuscular, respiratory, and functional impairments of post-ICU COVID-19 patients.

MATERIALS AND METHODS

Prospective study including post-ICU COVID-19 survivors consecutively admitted to a rehabilitation centre. Rehabilitation was conducted by an interdisciplinary team. Medical Research Council (MRC) score, maximum expiratory pressure (MEP), maximum inspiratory pressure (MIP), peak cough flow (PCF), Functional Oral Intake Scale (FOIS), Brief Balance Evaluation Systems Test (Brief-BESTest), Timed Up and Go (TUG) test, 1 min Sit to Stand Test (1' STST), 6 min Walking Test (6MWT), Fatigue Assessment Scale (FAS), Functional Independence Measure (FIM) were assessed at admission (T0) and discharge (T1).

RESULTS

A total of 42 patients were included. After 32.00;26.00 days of inpatient rehabilitation, there was a significant improvement in limb and respiratory muscle strength, cough effectiveness, fatigue, balance, exercise capacity, and in the ability to perform activities of daily living. Advanced age, longer acute care hospitalization, depressive symptoms, and cognitive deficits were associated with poorer functional outcomes.

CONCLUSION

Post-ICU COVID-19 patients present multiple sequelae with detrimental functional impact. An adapted interdisciplinary rehabilitation program is essential for a thorough evaluation of these patients and results in significant functional gains.IMPLICATIONS FOR REHABILITATIONPost-ICU COVID-19 survivors present multiple sequelae and disabilities.An intensive and interdisciplinary inpatient rehabilitation results in significant improvement in limb and respiratory muscle strength, cough effectiveness, fatigue, balance, exercise capacity, and ability to perform activities of daily living.Timely referral from the acute care setting to rehabilitation services is crucial to minimize the functional impact of severe multisystemic disease and prolonged hospitalization.

Do Cerebral Cortex Perfusion, Oxygen Delivery, and Oxygen Saturation Responses Measured by Near-Infrared Spectroscopy Differ Between Patients Who Fail or Succeed in a Spontaneous Breathing Trial? A Prospective Observational Study

BACKGROUND

Alterations in perfusion to the brain during the transition from mechanical ventilation (MV) to a spontaneous breathing trial (SBT) remain poorly understood. The aim of the study was to determine whether changes in cerebral cortex perfusion, oxygen delivery (DO₂), and oxygen saturation (%StiO₂) during the transition from MV to an SBT differ between patients who succeed or fail an SBT.

METHODS

This was a single-center prospective observational study conducted in a 16-bed medical intensive care unit of the University Hospital Leuven, Belgium. Measurements were performed in 24 patients receiving MV immediately before and at the end of a 30-min SBT. Blood flow index (BFI), DO₂, and %StiO₂ in the prefrontal cortex, scalene, rectus abdominis, and thenar muscle were simultaneously assessed by near-infrared spectroscopy using the tracer indocyanine green dye. Cardiac output, arterial blood gases, and systemic oxygenation were also recorded.

RESULTS

During the SBT, prefrontal cortex BFI and DO₂ responses did not differ between SBT-failure and SBT-success groups (p > 0.05). However, prefrontal cortex %StiO₂ decreased in six of eight patients (75%) in the SBT-failure group (median [interquartile range 25-75%]: MV = 57.2% [49.1-61.7] vs. SBT = 51.0% [41.5-62.5]) compared to 3 of 16 patients (19%) in the SBT-success group (median [interquartile range 25-75%]: MV = 65.0% [58.6-68.5] vs. SBT = 65.1% [59.5-71.1]), resulting in a significant differential %StiO₂ response between groups (p = 0.031). Similarly, a significant differential response in thenar muscle %StiO₂ (p = 0.018) was observed between groups. A receiver operating characteristic analysis identified a decrease in prefrontal cortex %StiO₂ > 1.6% during the SBT as an optimal cutoff, with a sensitivity of 94% and a specificity of 75% to predict SBT failure and an area under the curve of 0.79 (95% CI: 0.55-1.00). Cardiac output, systemic oxygenation, scalene, and rectus abdominis BFI, DO₂, and %StiO₂ responses did not differ between groups (p > 0.05); however, during the SBT, a significant positive association in prefrontal cortex BFI and partial pressure of arterial carbon dioxide was observed only in the SBT-success group (SBT success: Spearman's ρ = 0.728, p = 0.002 vs. SBT failure: ρ = 0.048, p = 0.934).

CONCLUSIONS

This study demonstrated a reduced differential response in prefrontal cortex %StiO₂ in the SBT-failure group compared with the SBT-success group possibly due to the insufficient increase in prefrontal cortex perfusion in SBT-failure patients. A > 1.6% drop in prefrontal cortex %StiO₂ during SBT was sensitive in predicting SBT failure. Further research is needed to validate these findings in a larger population and to evaluate whether cerebral cortex %StiO₂ measurements by near-infrared spectroscopy can assist in the decision-making process on liberation from MV.

Frailty and long-COVID: is COVID-19 responsible for a transition in frailty status among older adults who survived hospitalization for COVID-19?

BACKGROUND

There is a paucity of knowledge about the effects of COronaVIrus Disease-19 (COVID-19) on long-term frailty development or progression over time.

AIM

This study aims to assess transitions in frailty status in older adults who survived hospitalization for COVID-19.

METHODS

This is a longitudinal panel study. A multidisciplinary outpatient follow-up service was established since summer 2020, for the evaluation of individuals discharged alive, after hospitalization due to COVID-19. Frailty status was assessed in-hospital and at follow-up using the clinical frailty scale (CFS). Main patients' characteristics, including health, functional, cognitive, and psychological status were collected.

RESULTS

A total of 177 patients aged 65 years and older were evaluated until June 2022. They were predominantly male, with a median age of 70 (Q1-Q3 67-75) years and a median body mass index of 27.5 (Q1-Q3 24.9-30.6) kg/m² at hospital admission. The median follow-up time was 6.3 (Q1-Q3 3.7-10.9) months. Sixty-one patients (34.5%) scored worse at CFS follow-up compared to hospital admission, and twenty-two patients (12.4%) became frail.

DISCUSSION AND CONCLUSION

This study shows that one out of three older patients previously hospitalized for COVID-19 had an unfavorable transition in CFS score during a median follow-up of nearly 6 months. Specific interventions to prevent frailty development or progression should be considered for patients at risk. Further studies are required to confirm our findings.

Early detection of ICU-acquired weakness in septic shock patients ventilated longer than 72 h

PURPOSE

ICU-acquired weakness, comprising Critical Illness Polyneuropathy (CIP) and Myopathy (CIM) is associated with immobilization and prolonged mechanical ventilation. This study aims to assess feasibility of early detection of CIP and CIM by peroneal nerve test (PENT) and sensory sural nerve action potential (SNAP) screening in patients with septic shock and invasively ventilated for more than 72 h.

METHODS

We performed repetitive PENT screening from 72 h after intubation until detecting a pathological response. We tested SNAPs in pathological PENT to differentiate CIP from CIM. We performed muscle strength examination in awake patients and recorded time from intubation to first in-bed and out-of-bed mobilization.

RESULTS

Eighteen patients were screened with PENT and 88.9% had abnormal responses. Mean time between intubation and first screening was 94.38 (± 22.41) hours. Seven patients (38.9%) had CIP, two (11.1%) had CIM, one (5.6%) had CIP and CIM, six (33.3%) had a pathological response on PENT associated with ICU-acquired weakness (but no SNAP could be performed to differentiate between CIP and CIM) and two patients had (11.1%) had no peripheral deficit. In patients where it could be performed, muscle strength testing concorded with electrophysiological findings. Twelve patients (66.7%) had out-of-bed mobilization 10.8 (± 7.4) days after admission.

CONCLUSION

CIP and CIM are frequent in septic shock patients and can be detected before becoming symptomatic with simple bedside tools. Early detection of CIP and CIM opens new possibilities for their timely management through preventive measures such as passive and active mobilization.

Multimodal assessment of intensive care unit-acquired weakness in severe stroke patients

BACKGROUND

Intensive care unit-acquired weakness (ICUAW) defines generalized muscle weakness seen in critically ill patients in the absence of other causative factors. Herein, we aimed to evaluate ICUAW in stroke patients by electrodiagnostic testing, histopathology, and assessment of respiratory complex activities (RCA), to define the frequency of ICUAW in this patient group, and to reach new parameters for early prediction and diagnosis.

METHODS

We prospectively recruited twenty-four severe acute stroke patients during a sixteen-month period. In addition to serial nerve conduction studies (NCS), we performed muscle biopsy and RCA analysis on the non-paretic side when ICUAW developed. Patients undergoing orthopedic surgery without metabolic and neuromuscular diseases constituted the control group for RCA. Survival and longitudinal data were analyzed by joint modeling to determine the relationship between electrophysiological parameters and ICUAW diagnosis.

RESULTS

Eight patients (33%) developed ICUAW, and six of them within the first two weeks. Extensor digitorum brevis, abductor digiti minimi (ADM), rectus femoris and vastus medialis (VM) compound muscle action potential (CMAP) amplitudes showed a significant decrease in the ICUAW group. VM CMAP amplitude (BIC = 358.1574) and ADM CMAP duration (BIC = 361.1028) were the best-correlated parameters with ICUAW diagnosis. The most informative electrophysiological findings during the entire study were obtained within the first 11 days. Muscle biopsies revealed varying degrees of type 2 fiber atrophy. Complex I (p = 0.003) and IV (p = 0.018) activities decreased in patients with ICUAW compared to controls.

CONCLUSION

VM CMAP amplitude and ADM CMAP duration correlate well with ICUAW diagnosis, and may aid in the early diagnosis.

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.

Intensive care unit-acquired weakness: From molecular mechanisms to its impact in COVID-2019

Intensive Care Unit-Acquired Weakness (ICU-AW) is a generalized and symmetric neuromuscular dysfunction associated with critical illness and its treatments. Its incidence is approximately 80% in intensive care unit patients, and it manifests as critical illness polyneuropathy, critical illness myopathy, and muscle atrophy. Intensive care unit patients can lose an elevated percentage of their muscle mass in the first days after admission, producing short- and long-term sequelae that affect patients’ quality of life, physical health, and mental health. In 2019, the world was faced with coronavirus disease 2019 (COVID-19), caused by the acute respiratory syndrome coronavirus 2. COVID-19 produces severe respiratory disorders, such as acute respiratory distress syndrome, which increases the risk of developing ICU-AW. COVID-19 patients treated in intensive care units have shown early diffuse and symmetrical muscle weakness, polyneuropathy, and myalgia, coinciding with the clinical presentation of ICU-AW. Besides, these patients require prolonged intensive care unit stays, invasive mechanical ventilation, and intensive care unit pharmacological therapy, which are risk factors for ICU-AW. Thus, the purposes of this review are to discuss the features of ICU-AW and its effects on skeletal muscle. Further, we will describe the mechanisms involved in the probable development of ICU-AW in severe COVID-19 patients.

Exploring the Muscle Metabolomics in the Mouse Model of Sepsis-Induced Acquired Weakness

Background/Aim

We aimed to identify the differentially expressing metabolites (DEMs) in the muscles of the mouse model of sepsis-induced acquired weakness (sepsis-AW) using liquid chromatography-mass spectrometry (LC-MS).

Materials and Methods

Sepsis by cecal ligation puncture (CLP) with lower limb immobilization was used to produce a sepsis-AW model. After this, the grip strength of the C57BL/6 male mice was investigated. The transmission electron microscopy was utilized to determine the pathological model. LC-MS was used to detect the metabolic profiles within the mouse muscles. Additionally, a statistically diversified analysis was carried out.

Results

Compared to the sepsis group, 30 DEMs, including 17 upregulated and 13 down-regulated metabolites, were found in the sepsis-AW group. The enriched metabolic pathways including purine metabolism, valine/leucine/isoleucine biosynthesis, cGMP-PKG pathway, mTOR pathway, FoxO pathway, and PI3K-Akt pathway were found to differ between the two groups. The targeted metabolomics analysis explored significant differences between four amino acid metabolites (leucine, cysteine, tyrosine, and serine) and two energy metabolites (AMP and cAMP) in the muscles of the sepsis-AW experimental model group, which was comparable to the sepsis group.

Conclusion

The present work identified DEMs and metabolism-related pathways within the muscles of the sepsis-AW mice, which offered valuable experimental data for diagnosis and identification of the pathogenic mechanism underlying sepsis-AW.

A Global Survey on Diagnostic, Therapeutic and Preventive Strategies in Intensive Care Unit-Acquired Weakness

Background and Objectives: Intensive care unit-acquired weakness (ICU-AW) is one of the most frequent neuromuscular complications in critically ill patients. We conducted a global survey to evaluate the current practices of diagnostics, treatment and prevention in patients with ICU-AW. Materials and Methods: A pre-survey was created with international experts. After revision, the final survey was endorsed by the European Society of Intensive Care Medicine (ESICM) using the online platform SurveyMonkey®. In 27 items, we addressed strategies of diagnostics, therapy and prevention. An invitation link was sent by email to all ESICM members. Furthermore, the survey was available on the ESICM homepage. Results: A total of 154 healthcare professionals from 39 countries participated in the survey. An ICU-AW screening protocol was used by 20% (28/140) of participants. Forty-four percent (62/141) of all participants reported performing routine screening for ICU-AW, using clinical examination as the method of choice (124/141, 87.9%). Almost 63% (84/134) of the participants reported using current treatment strategies for patients with ICU-AW. The use of treatment and prevention strategies differed between intensivists and non-intensivists regarding the reduction in sedatives (80.0% vs. 52.6%, p = 0.002), neuromuscular blocking agents (76.4% vs. 50%, p = 0.004), corticosteroids (69.1% vs. 37.2%, p < 0.001) and glycemic control regimes (50.9% vs. 23.1%, p = 0.002). Mobilization and physical activity are the most frequently reported treatment strategies for ICU-AW (111/134, 82.9%). The availability of physiotherapists (92/134, 68.7%) and the lack of knowledge about ICU-AW within the medical team (83/134, 61.9%) were the main obstacles to the implementation of the strategies. The necessity to develop guidelines for the screening, diagnosing, treatment and prevention of ICU-AW was recognized by 95% (127/133) of participants. Conclusions: A great heterogeneity regarding diagnostics, treatment and prevention of ICU-AW was reported internationally. Comprehensive guidelines with evidence-based recommendations for ICU-AW management are needed.

Occurrence and Effects on Weaning From Mechanical Ventilation of Intensive Care Unit Acquired and Diaphragm Weakness: A Pilot Study

Purpose

Limb intensive care unit (ICU)-acquired weakness (ICUAW) and ICU acquired diaphragm weakness (DW) occur frequently in mechanically ventilated (MV) patients; their coexistence in cooperative and uncooperative patients is unknown. This study was designed to (1) describe the co-occurrence of the two conditions (2) evaluate the impact of ICUAW and DW on the ventilator-free days (VFDs) at 28 days and weaning success, and (3) assess the correlation between maximal inspiratory pressure (MIP) and thickening fraction (TFdi) in patients with DW.

Methods

This prospective pilot study was conducted in a single-center on 73 critically ill MV patients. Muscle weakness was defined as a Medical Research Council score &lt; 48 in cooperative patients or a bilateral mean simplified peroneal nerve test &lt; 5.26 mV in uncooperative patients. Diaphragm dysfunction was defined as MIP &lt; 30 cm H2O or as a TFdi &lt; 29%. Weaning success was defined according to weaning according to a new definition (WIND).

Results

Fifty-seven patients (78%) had ICUAW and 59 (81%) had DW. The coexistence of the two conditions occurred in 48 patients (65%), without association (χ2 = 1.06, p = 0.304). In the adjusted analysis, ICUAW was independently related to VFDs at 28-days (estimate difference 6 days, p = 0.016), and WIND (OR of 3.62 for having WIND different than short weaning), whereas DW was not. The linear mixed model showed a significant but weak correlation between MIP and TFdi (p &lt; 0.001).

Conclusion

This pilot study is the first to explore the coexistence of ICUAW and DW in both cooperative and uncooperative patients; a lack of association was found between DW and ICUAW when considering both cooperative and uncooperative patients. We found a strong correlation between ICUAW but not DW with the VFDs at 28 days and weaning success. A future larger study is warranted in order to confirm our results, and should also investigate the use of transdiaphragmatic twitch pressure measurement during bilateral anterior magnetic phrenic nerve stimulation for the diagnosis of DW.

Nutritional support for successful weaning in patients undergoing prolonged mechanical ventilation

Successful weaning from ventilators not only improves the quality of life of patients, but also reduces medical expenses. The aim of this study was to explore the association between nutritional provision and successful ventilator weaning. In this retrospective study data from the Respiratory Care Center of Chung Shan Medical University Hospital between October, 2017 and July, 2019 on patient characteristics, amount of nutrition delivered, and clinical outcomes were retrieved. A total of 280 ventilated patients were enrolled and divided into successful extubation and failed weaning groups. There were 178 males (63.6%) and 102 females (36.4%) with a mean age of 67.3 ± 16.9 years. The successful extubation group consisted of patients who tended towards ideal body weight during the weaning process (BMI 23.9 ± 5.0 versus 22.7 ± 4.8 kg/m², p < 0.001). Patients from both groups initially received the same nutritional intervention, while patients of successful extubation received significantly more calories and protein after weaning (23.8 ± 7.8 kcal versus 27.8 ± 9.1 kcal, p < 0.001 and 0.97 ± 0.36 g versus 1.14 ± 0.42 g, p < 0.001). Successful weaning was associated with higher survival rate (p = 0.016), shortened hospital stay (p = 0.001), and reduced medical costs (p < 0.001). Overall, nutritional support with high calories and protein was associated with the probability of successful ventilator weaning in patients undergoing prolonged mechanical ventilation. Adequate nutrition is a determinant of successful ventilator weaning.

microRNA-181a Promotes Mitochondrial Dysfunction and Inflammatory Reaction in a Rat Model of Intensive Care Unit-Acquired Weakness by Inhibiting IGFBP5 Expression

This study investigated mechanisms by which microRNA (miR)-181a orchestrates mitochondrial dysfunction and inflammation in a rat model of intensive care unit-acquired weakness (ICU-AW). Expression of miR-181a and insulin-like growth factor binding protein 5 (IGFBP5) was detected and then miR-181a was overexpressed or inhibited and IGFBP5 was overexpressed in the ICU-AW rats. The expression of UCP-3, metaphase chromosome protein 1 (MCP1), mitochondrial DNA (mtDNA), inflammatory factors, phosphorylation (p)-JAK1, p-STAT1, and p-STAT2 were measured in skeletal muscle tissues; binding of miR-181a to IGFBP5 was evaluated by a dual-luciferase reporter assay. The results demonstrated high expression of miR-181a and low expression of IGFBP5 in ICU-AW versus control rats; IGFBP5 was identified as a target gene of miR-181a. Further experiments demonstrated that ICU-AW rats suffered from marked loss of grip strength and decreased adenosine triphosphate production, mtDNA content, and UCP-3 mRNA expression in skeletal muscles; this was accompanied by elevated TNF-α, IL-6, IL-1β, MCP1, p-JAK1, p-STAT1, and p-STAT2 levels. Importantly, miR-181a suppression alleviated strength loss, inflammatory reaction, and mitochondrial dysfunction and diminished the phosphorylation levels of JAK1, STAT1, and STAT2 whereas IGFBP5 upregulation rescued the effect of miR-181a overexpression in ICU-AW rats. These results indicate that miR-181a promotes mitochondrial dysfunction and inflammation by activating the JAK/STAT pathway via IGFBP5 in ICU-AW model rats.

Efficacy of Physiotherapy Interventions on Weaning in Mechanically Ventilated Critically Ill Patients: A Systematic Review and Meta-Analysis

Mechanical ventilation (MV) is currently considered a life-saving intervention. However, growing evidence highlighted that prolonged MV significantly affects functional outcomes and length of stay. In this scenario, controversies are still open about the optimal rehabilitation strategies for improving MV duration in ICU patients. In addition, the efficacy of physiotherapy interventions in critical ill patients without positive history of chronic respiratory conditions is still debated. Therefore, this systematic review of randomized controlled trials (RCTs) with meta-analysis aimed at characterizing the efficacy of a comprehensive physiotherapy intervention in critically ill patients. PubMed, Scopus, and Web of Science databases were systematically searched up to October 22, 2021 to identify RCTs assessing acute patients mechanical ventilated in ICU setting undergoing a rehabilitative intervention. The primary outcomes were MV duration, extubation, and weaning time. The secondary outcomes were weaning successful rate, respiratory function, ICU discharge rate and length of stay. Out of 2503 records, 12 studies were included in the present work. The meta-analysis performed in 6 RCTs showed a significant improvement in terms of MV duration (overall effect size: −3.23 days; 95% CI = −5.79, −0.67, p = 0.01; Z = 2.47) in patients treated with a comprehensive physiotherapy intervention including early mobilization, positioning, airway clearance techniques, lung expansion and respiratory muscle training. The quality assessment underlined 9 studies (75%) of good quality and 3 studies of fair quality according to the PEDro scale. In conclusion, our results provided previously unavailable data about the role of comprehensive physiotherapy intervention in improving MV duration in critical ill patients without chronic respiratory conditions. Further studies are needed to better characterize the optimal combination of rehabilitation strategies enhancing the improvements in critical ill patients without chronic respiratory disorders.

Recovery and long term functional outcome in people with critical illness polyneuropathy and myopathy: a scoping review

BACKGROUND

Intensive care unit acquired weakness (ICUAW), embraces an array of disorders labeled "critical illness polyneuropathy" (CIP), "critical illness myopathy" (CIM) or "critical illness polyneuromyopathy" (CIPNM). Several studies have addressed the various characteristics of ICUAW, but the recovery is still unclear.

OBJECTIVE

The present review investigated the recovery and the long-term functional outcome of subjects with ICUAW, whether the types of ICUAW have different outcomes and whether there is any supporting evidence.

METHODS

Literature search was performed from MEDLINE/PubMed, CINAHL, EMBASE, PeDro, Web of Science and Scopus. Inclusion criteria were: i) sample size including five or more subjects; ii) subjects who suffered from ICUAW and/or CIP, CIM and CIP/CIM; iii) ICUAW ascertained by EMG. Follow-ups longer than one year were defined as long-term.

RESULTS

Twenty-nine studies met the inclusion criteria. In total, 788 subjects with ICUAW were enrolled: 159 (20.1%) died and 588 (74.6%) were followed. Of all the included patients, 613 (77.7%) had CIP, 82 (10.4%) CIM and 56 (7.1%) CIP/CIM. Overall, 70.3% of the subjects with ICUAW fully recovered. Seven (24.1%) studies had a follow-up longer than 1 year (range 2-8) with 173 (21.9%) subjects enrolled globally and 108 followed. Of these subjects, 88.8% gained full recovery. Most of the studies did not use proper functional scales and only 4 and 3 studies employed the Barthel scale and the Functional Independence Measure (FIM) scale. Differentiation between the types of ICUAW was performed in 7 studies, but only 3 studies reported that subjects with CIM had a better prognosis and earlier recovery than subjects with CIP/CIM.

CONCLUSIONS

Subjects with ICUAW could achieve good recovery and could improve at follow-up. However, the quality of the published studies due to short follow-ups and the paucity of defined outcome measures require confirms.

High-Intensity Inspiratory Muscle Training Improves Scalene and Sternocleidomastoid Muscle Oxygenation Parameters in Patients With Weaning Difficulties: A Randomized Controlled Trial

Background

Critically ill patients who have difficulties weaning from the mechanical ventilator are prone to develop respiratory muscle weakness. Inspiratory muscle training (IMT) can improve respiratory muscle strength. Whether IMT can improve scalene and sternocleidomastoid muscle oxygenation parameters is unknown.

Aim

To compare changes in muscle oxygenation parameters of scalene and sternocleidomastoid inspiratory muscles during a standardized task between patients with weaning difficulties who received either high-intensity IMT (intervention) or sham low-intensity IMT (control).

Method

Forty-one patients performed daily IMT sessions (4 sets, 6–10 breaths) until weaning success or for 28 consecutive days. The training load was progressively adjusted in the intervention group (n = 22) to the highest tolerable load, whilst the control group (n = 19) kept training at 10% of their baseline maximal inspiratory pressure (PImax). Breathing characteristics (i.e., work and power of breathing, PoB), respiratory muscle function [i.e., PImax and forced vital capacity (FVC)] were measured during a standardized loaded breathing task against a load of 30% of baseline PImax before and after the IMT period. In addition, during the same loaded breathing task, absolute mean and nadir changes from baseline in local scalene and sternocleidomastoid muscle oxygen saturation index (Δ%StiO2) (an index of oxygen extraction) and nadir Δ%StiO2 normalized for the PoB were measured by near-infrared spectroscopy.

Results

At post measures, only the intervention group improved mean PoB compared to pre measures (Pre: 0.42 ± 0.33 watts, Post: 0.63 ± 0.51watts, p-value &lt; 0.01). At post measures, both groups significantly improved nadir scalene muscles StiO2% normalized for the mean PoB (ΔStiOnadir%/watt) compared to pre measurements and the improvement was not significant different between groups (p-value = 0.40). However, at post measures, nadir sternocleidomastoid muscle StiO2% normalized for the mean PoB (ΔStiOnadir%/watt) was significantly greater improved in the intervention group (mean difference: +18.4, 95%CI: −1.4; 38.1) compared to the control group (mean difference: +3.7, 95%CI: −18.7; 26.0, between group p-value &lt; 0.01). Both groups significantly improved PImax (Intervention: +15 ± 13 cmH2O p-value &lt; 0.01, Control: +13 ± 15 cmH2O p-value &lt; 0.01). FVC only significantly improved in the intervention group (+0.33 ± 0.31 L p &lt; 0.01) report also change in control group.

Conclusion

This exploratory study suggests that high-intensity IMT induces greater improvements in scalene and sternocleidomastoid muscle oxygenation parameters attributed for oxygen delivery, utilization and oxygen saturation index compared to low-intensity IMT in patients with weaning difficulties.

Experimental Approach of Quadriceps Strength Measurement: Implications for Assessments in Critically Ill Survivors

(1) Background: The supine testing position is suitable for early quadriceps strength (QS) assessment in intensive care unit, while a seated position is more appropriate for survivors who have regained mobility. Acquiring consistent measurements is essential for longitudinal follow-up. We compared the QS generated in different settings in healthy volunteers. (2) Methods: Isometric QS was assessed using a MicroFet2 and standardised protocols comparing different modalities. Hip and knee flexion angles were, respectively, 45° and 40° (H45-K40) in the supine position, and both at 90° (H90-K90) in the seated position. Dynamometer was either handheld (non-fixed configuration, NFC), or fixed (FC) in a cubicle. (3) Results: QS in H90–K90 and H45-K40 positions were strongly correlated, but QS was higher in the later position regardless of the configuration. Compared to H45-K40, biases of 108.2N (or 28.05%) and 110.3N (27.13%) were observed in H90-K90 position, respectively, in the NFC and FC. These biases were independently and positively associated with QS (p < 0.001). For both position, there were no significant differences between QS measured in NFC or FC. (4) Conclusions: The quadriceps was less efficient in the seated position, compared to the supine position, in healthy volunteers. These findings have practical implications for further assessments and research in critically ill patients.

Magnetic twitch assessment of diaphragm and quadriceps weakness in critically ill mechanically ventilated patients

Critically ill mechanically ventilated (MV) patients develop significant muscle weakness, which has major clinical consequences. There remains uncertainty, however, regarding the severity of leg weakness, the precise relationship between muscle strength and thickness, and the risk factors for weakness in MV patients. We therefore measured both diaphragm (PdiTw) and quadriceps (QuadTw) strength in MV patients using magnetic stimulation and compared strength to muscle thickness. Both PdiTw and QuadTw were profoundly reduced for MV patients, with PdiTw 19 % of normal and QuadTw 6% of normal values. There was a poor correlation between strength and thickness for both muscles, with thickness often remaining in the normal range when strength was severely reduced. Regression analysis revealed reductions in PdiTw correlated with presence of infection (p = 0.006) and age (p = 0.007). QuadTw best correlated with duration of MV (p = 0.036). Limb muscles are profoundly weak in critically ill patients, with a severity that mirrors the level of weakness observed in the diaphragm.

[Severe SARS-CoV-2 infection: Clinical assessment and biomechanical functional evaluation one month after hospital discharge]

OBJECTIVE

To describe by an observational cross-sectional study the clinical and functional situation, at one month after hospital discharge, of patients admitted with COVID-19 in the hospital ICU between March and December 2020.

MATERIAL AND METHODS

59 patients were studied using different clinical scales and biomechanical analysis tests (hand dynamometry, fall risk assessment, gait and balance analysis).

RESULTS

At one month after discharge, patients reported persistent symptoms: dyspnea (47.5%), arthromyalgia (45%) and cough (22%). In the EQ-5D-5L questionnaire up to 73% of patients reported levels of anxiety or depression. 74.6% and 69.5% presented alterations in the strength of the right and left hand, respectively. The risk of falls in 38% of patients was moderate to very high. The somatosensory index remained within normal parameters, while the vestibular and, to a lesser extent, the visual indexes were altered. In gait, 81.4% of patients showed no abnormalities outside the normal range, with a normal average walking speed.

CONCLUSIONS

In the short term after severe COVID-19, patients have persistent symptomatology, anxiety/depression, impaired balance with increased risk of falls and loss of grip strength in both hands.

A novel ex vivo model for critical illness neuromyopathy using freshly resected human colon smooth muscle

Patients suffering from critical illness are at risk to develop critical illness neuromyopathy (CINM). The underlying pathophysiology is complex and controversial. A central question is whether soluble serum factors are involved in the pathogenesis of CINM. In this study, smooth muscle preparations obtained from the colon of patients undergoing elective surgery were used to investigate the effects of serum from critically ill patients. At the time of blood draw, CINM was assessed by clinical rating and electrophysiology. Muscle strips were incubated with serum of healthy controls or patients in organ baths and isometric force was measured. Fifteen samples from healthy controls and 98 from patients were studied. Ratios of responses to electric field stimulation (EFS) before and after incubation were 118% for serum from controls and 51% and 62% with serum from critically ill patients obtained at day 3 and 10 of critical illness, respectively (p = 0.003, One-Way-ANOVA). Responses to carbachol and high-K⁺ were equal between these groups. Ratios of post/pre-EFS responses correlated with less severe CINM. These results support the existence of pathogenic, i.e. neurotoxic factors in the serum of critically ill patients. Using human colon smooth muscle as a bioassay may facilitate their future molecular identification.

Physical capacities assessment in critically ill patients: An exploratory study

BACKGROUND

The severity of muscle weakness after critical illness is very heterogeneous. To identify those patients who may maximally benefit from early exercises would be highly valuable. This implies an assessment of physical capacities, comprised at least of strength measurement and functional tests.

OBJECTIVES

The objective of this study was to investigate the relationship between muscle strength and functional tests in an intensive care unit (ICU) setting.

METHODS

Adults with ICU length of stay ≥2 days were included. Handgrip strength (HG) and maximal isometric quadriceps strength (QS) were assessed using standardised protocols as soon as patients were alert and able to obey commands. At the same time, their maximal level of mobilisation capabilities and their autonomy were assessed using ICU Mobility Scale (ICU-MS) and Barthel Index, respectively.

RESULTS

Ninety-three patients with a median age of 64 [57-71.5] years, body mass index of 26.4 [23.4-29.6] kg/m², and Simplified Acute Physiology Score II of 33 [27.7-41] were included. Absolute and relative QS were, respectively, 146.7 [108.5-196.6] N and 1.87 [1.43-2.51] N/kg. HG was 22 [16-31] kg. The ICU-MS score was 4 [1-5]. A significant positive correlation was observed between HG and absolute QS (r_s = 0.695, p < 0.001) and between HG and relative QS (r_s = 0.428, p < 0.001). The ICU-MS score correlated with HG, with a weak positive relationship (r_s = 0.215, p = 0.039), but not with QS. The ICU-MS score did not statistically differ between the weakest and strongest patients for absolute or relative QS, but was lower in patients with the lowest HG values (p = 0.01). A weak positive correlation was observed between the Barthel Index and muscle strengths (maximum r_s = 0.414, p < 0.001).

CONCLUSIONS

The present results suggest that, during ICU stay, there is no strong association between muscle strength and functional test such as the ICU-MS or Barthel Index. Muscle dynamometry and functional tests are probably complementary tools for physical capacities quantification.

L-carnitine: Searching for New Therapeutic Strategy for Sepsis Management

In this review, we discussed the biological targets of carnitine, its effects on immune function, and how L-carnitine supplementation may help critically ill patients. L-carnitine is a potent antioxidant. L-carnitine depletion has been observed in prolonged intensive care unit (ICU) stays, while L-carnitine supplementation has beneficial effects in health promotion and regulation of immunity. It is essential for the uptake of fatty acids into mitochondria. By inhibiting the ubiquitin-proteasome system, down-regulation of apelin receptor in cardiac tissue, and reducing β-oxidation of fatty acid, carnitine may decrease vasopressor requirement in septic shock and improve clinical outcomes of this group of patients. We also have an overview of animal and clinical studies that have been recruited for evaluating the beneficial effects of L-carnitine in the management of sepsis/ septic shock. Additional clinical data are required to evaluate the optimal daily dose and duration of L-carnitine supplementation.

Perceptions and ideas of critically ill patients, their family and staff members regarding family participation in the physiotherapy-related care of critically ill patients: a qualitative study

BACKGROUND

Involvement of families in physiotherapy-related tasks of critically ill patients could be beneficial for both patients and their family. Before designing an intervention regarding family participation in the physiotherapy-related care of critically ill patients, there is a need to investigate the opinions of critically ill patients, their family and staff members in detail.

OBJECTIVE

Exploring the perceptions of critically ill patients, their family and staff members regarding family participation in physiotherapy-related tasks of critically ill patients and the future intervention.

METHODS

A multicenter study with a qualitative design is presented. Semistructured interviews were conducted with critically ill patients, family and intensive care staff members, until theoretical saturation was reached. The conventional content method was used for data analyses.

RESULTS

Altogether 18 interviews were conducted between May 2019 and February 2020. In total, 22 participants were interviewed: four patients, five family members, and 13 ICU staff members. Six themes emerged: 1) prerequisites for family participation (e.g., permission and capability); 2) timing and interactive aspects of engaging family (e.g., communication); 3) eligibility of patients and family (e.g., first-degree relatives and spouses, and long stay patients); 4) suitability of physiotherapy-related tasks for family (e.g., passive, active and breathing exercises); 5) expected effects (e.g., physical recovery and psychological wellbeing); and 6) barriers and facilitators, which may affect the feasibility (e.g., safety, privacy, and responsibility).

CONCLUSION

Patients, family members and staff members supported the idea of increased family participation in physiotherapy-related tasks and suggested components of an intervention. These findings are necessary to further design and investigate family participation in physiotherapy-related tasks.

Physical recovery of COVID-19 pneumosepsis ICU survivors compared with non-COVID pneumosepsis ICU survivors during post-ICU hospitalization: The RECOVID retrospective cohort study

Background

Coronavirusdisease 2019 (COVID‐19) pneumosepsis survivors are at a high risk of developing intensive care unit (ICU)–acquired weakness (ICUAW) because of high incidence of acute respiratory distress syndrome and the common need for prolonged invasive ventilation. It remains unknown whether regular postpneumosepsis physical rehabilitation strategies are suitable for this extraordinary patient category.

Methods

We retrospectively compared the physical recovery of COVID‐19 and non‐COVID pneumosepsis ICU survivors during post‐ICU hospitalization, defined as the difference in performance on the Medical Research Council Sum‐Score (MRC‐SS), Chelsea Critical Care Physical Assessment tool (CPAx), and percentage of predicted handgrip strength (POP‐HGS). An analysis of covariance model was built using age, sex, Barthel index, body mass index, admission Acute Physiology And Chronic Health Evaluation II score, adequacy of protein delivery during ICU stay, and ward length of stay as covariates.

Results

Thirty‐five COVID‐19 ICU patients could be compared with 21 non‐COVID pneumosepsis ICU survivors. All patients scored ≤48 on the MRC‐SS at ICU discharge, indicating ICUAW. When controlling for covariates, COVID‐19 patients performed worse on all physical assessments upon ICU discharge, but had improved more at hospital discharge on the MRC‐SS (ɳ² = 0.214, P =.002) and CPAx (ɳ² = 0.153, P =.011). POP‐HGS remained lower in COVID‐19 patients throughout hospital stay.

Conclusion

COVID‐19 ICU survivors are vulnerable to ICUAW, but they show better tendency towards physical rehabilitation than non‐COVID pneumosepsis ICU survivors during the post‐ICU hospitalization period regarding MRC‐SS and CPAx. COVID‐19 ICU patients might benefit from early, more intensive physical therapy.

A Prospective Study Evaluating Sleep Quality and Disorders in Post-ARDS Patients

Introduction

Critically ill patients are predisposed to developing sleep disorders due to multiple factors like pre-existing sleep disorders, severe acute illness, sleep-altering medical interventions, and the disturbing intensive care unit (ICU) environment. In the current study, a multi-modality approach has been attempted to capture the different aspects of sleep disturbances, including insomnia (using ISI), daytime sleepiness (using ESS), sleep quality (using PSQI), sleep architecture, and SDB (using PSG).

Materials and Methods

The eligible ARDS survivor patients were updated about the study's design prior to hospital discharge. At admission, data regarding demographic details, clinical history, etiology of ARDS, and PaO₂/FiO₂ (P/F) ratio at presentation, Acute Physiology and Chronic Health Evaluation II (APACHE II) and Sequential Organ Failure Assessment (SOFA) scores was collected. All enrolled patients were evaluated twice (early-within 7 days of admission and late-after 6 weeks of discharge) by the Richards-Campbell Sleep Questionnaire (RCSQ), Insomnia severity index (ISI), and level 1 PSG. Additionally, ESS questionnaire and the Pittsburgh Sleep Quality Index (PSQI) were also recorded in late evaluation. Abnormal sleep was defined if one or more of the following characteristics met: ISI > 15, ESS > 10, global PSQI > 5, AHI ≥ 5 events/h.

Results

Thirty patients were recruited out of the total of 88 ARDS patients screened at admission. The median (IQR) PaO₂/FiO₂ ratio and APACHE II scores were 176 (151-191.5) and 14 (14-16), respectively. The median (IQR) duration of stay in the ICU was 10 (7.3-19.5) days. The median RCSQ score in the early and late evaluation was 42 and 69, respectively. The mean ISI score in the early evaluation was 16.67 ± 4.72, which decreased to 11.70 ± 5.03 in late evaluation (p < 0.05). ISI score > 15 (clinical insomnia) was found in 18 out of 30 subjects (60%) in early evaluation and 11 out of 30 (36%) in late evaluation. During the early evaluation, sleep efficiency was low (median 59.9% and predominantly N1 and N2) which improved in late evaluation (median 80.6%). Of the 30 patients, only 4 had AHI > 5 in early evaluation and none in late evaluation. Neither of P/F ratio, SOFA, and APACHE II scores did correlate with ICU events in the early and late evaluations. Regression analysis showed subjects with ICU stay more than 10 days, duration of IMV more than 7 days, Fentanyl more than 7 mg, duration of sedative use more than 7 days was independently associated with poor objective sleep quality (low sleep efficiency, low TST and high arousal index) during the early and late evaluations after ICU discharge compared to counterparts (p value < 0.05).

Conclusion

We conclude that sleep quality in ARDS survivors was poor within 7 days of ICU discharge, characterized by severe disruption of sleep architecture and sleep-disordered breathing. After 6 weeks of ICU discharge sleep quality showed significant improvement in the N3 stage and AHI, however persistent insomnia was observed even at 6 weeks. Therefore, prior identification of risk factors and early diagnosis of sleep quality disorders in post-ARDS patients is essential.

ICU Acquired Weakness in patients with respiratory failure

Background:Most patients with severe respiratory failure in intensive care unit (ICU) require bed rest. The limitation of physical activity leads to some adverse consequences such as ICU Acquired Weakness (ICUAW). Progression of respiratory failure, including that caused by the new coronavirus infection (COVID-19), can lead to the development of acute respiratory distress syndrome, the treatment of which contributes to a combination of risk factors for the development of ICUAW. Traditional diagnostic methods have certain limitations. Muscle ultrasonography is a modern tool for early detection of muscle mass loss.Aims:To compare different methods of early ICUAW screening and to estimate the incidence and peculiarities of ICUAW in patients with respiratory failure of infectious genesis.Methods:31 patients with severe coronavirus pneumonia (COVID-19+) and 13 patients with viral and/or bacterial lung infection (COVID-19 -) were included in the study. The muscle mass loss percent from day 1 to day 7 was higher in the COVID-19 - group (p=0.022). These patients also had longer durations of the ICU and hospital stay but a significantly lower mortality (2.5 times).Results:The analysis of the parameters of deceased and living patients regardless of the lung damage etiology showed a correlation between the indices of hand grip strength dynamometry (handgrip test) and ultrasonography of the thigh muscles: F1 and D1 (rho=0.6, p=0.003), F1 and S1 (rho=0.6, p=0.005), D1 and F7 (rho=0.9, p=0.001). In addition, the examined levels of the ICUAW markers were associated with age - F1 (rho=-0.6, p=0.001), D1 (rho=-0.4, p=0.003), S1 (rho=-0.4, p=0.004).Conclusions:During the critical illness, ICUAW develops by the 3d day of bed rest in two thirds of patients with respiratory failure of different infectious genesis. The correlation between the investigated markers of ICUAW and age indicates that elderly patients are the most vulnerable category in respect to the formation and progression of muscle weakness in the ICU. The handgrip test can serve as a reliable and simple method of ICUAW screening. Early identification of patients with ICUAW should provide the improvement of nutritional support and individualization of rehabilitation.

A reappraisal of the strength-duration test to assess neuromuscular impairment of critically ill patients

INTRODUCTION

Neuromuscular impairment (NMI) affects almost half of critically ill patients. The purpose was to investigate the role of neuromuscular electrical stimulation (NMES) to gain more insight into the nature of the NMI associated with ICU admission. To this aim, we analyzed the strength-duration (S-D) curves of the rectus femoris muscles of ICU patients compared to healthy volunteers.

METHODS

S-D curves were recorded from 44 healthy volunteers and 29 ICU patients. Three electrophysiological parameters were used to classify the neuromuscular function, from grade 0 (normal function), to grade 3 (no evocable muscle contraction). ICU patients underwent electroneurographic peroneal nerve testing (PENT) to analyze NMI by electroneurography (ENG).

RESULTS

Three patients were classified as Grade 0; nine as mild NMI (Grade 1), 13 as Grade 2, and four showed unexcitable muscles (Grade 3). Mean CMAP amplitudes were 6.1, 3.4, 2.9 and 0.81 mV from Grade 0 to Grade 3, respectively. CMAP was inversely correlated to NMI grade (-1.7 mV, R² = 0.946, p < 0.05).

CONCLUSIONS

The normative parameters of the S-D curves obtained by NMES in healthy volunteers allowed identification of NMI in ICU patients. NMES was an affordable tool to evaluate NMI in ICU patients, providing additional information to that obtained by ENG.

Bedside voluntary and evoked forces evaluation in intensive care unit patients: a narrative review

Around one third of intensive care unit (ICU) patients will develop severe neuromuscular alterations, known as intensive care unit-acquired weakness (ICUAW), during their stay. The diagnosis of ICUAW is difficult and often delayed as a result of sedation or delirium. Indeed, the clinical evaluation of both Medical Research Council score and maximal voluntary force (e.g., using handgrip and/or handheld dynamometers), two independent predictors of mortality, can be performed only in awake and cooperative patients. Transcutaneous electrical/magnetic stimulation applied over motor nerves combined with the development of dedicated ergometer have recently been introduced in ICU patients in order to propose an early and non-invasive measurement of evoked force. The aim of this narrative review is to summarize the different tools allowing bedside force evaluation in ICU patients and the related experimental protocols. We suggest that non-invasive electrical and/or magnetic evoked force measurements could be a relevant strategy to characterize muscle weakness in the early phase of ICU and diagnose ICUAW.

Brain Injury in Extracorporeal Membrane Oxygenation: A Multidisciplinary Approach

Extracorporeal membrane oxygenation (ECMO) represents an established technique to provide temporary cardiac and/or pulmonary support. ECMO, in veno-venous, veno-arterial or in extracorporeal carbon dioxide removal modality, is associated with a high rate of brain injuries. These complications have been reported in 7 to 15% of adults and 20% of neonates, and are associated with poor survival. Thromboembolic events, loss of cerebral autoregulation, alteration of the blood-brain barrier, and hemorrhage related to anticoagulation represent the main causes of severe brain injury during ECMO. The most frequent forms of acute neurological injuries in ECMO patients are intracranial hemorrhage (2-21%), ischemic stroke (2-10%), seizures (2-6%), and hypoxic-ischemic brain injury; brain death may also occur in this population. Other frequent complications are infarction (1-8%) and cerebral edema (2-10%), as well as neuropsychological and psychiatric sequelae, including posttraumatic stress disorder.

Chinesisation, adaptation and validation of the Chelsea Critical Care Physical Assessment Tool in critically ill patients: a cross-sectional observational study

PURPOSE

To translate and adapt the Chelsea Critical Care Physical Assessment Tool (CPAx) into Chinese version ('CPAx-Chi'), test the reliability and validity of CPAx-Chi, and verify the cut-off point for the diagnosis of intensive care unit-acquired weakness (ICU-AW).

STUDY DESIGN

Cross-sectional observational study.

METHODS

Forward and back translation, cross-cultural adaptation and pretesting of CPAx into CPAx-Chi were based on the Brislin model. Participants were recruited from the general ICU of five third-grade class-A hospitals in western China. Two hundred critically ill adult patients (median age: 53 years; 64% men) with duration of ICU stay ≥48 hours and Glasgow Coma Scale ≥11 were included in this study. Two researchers simultaneously and independently assessed eligible patients using the Medical Research Council Muscle Score (MRC-Score) and CPAx-Chi.

RESULTS

The content validity index of items was 0.889. The content validity index of scale was 0.955. Taking the MRC-Score scale as standard, the criterion validity of CPAx-Chi was r=0.758 (p<0.001) for researcher A, and r=0.65 (p<0.001) for researcher B. Cronbach's α was 0.939. The inter-rater reliability was 0.902 (p<0.001). The area under the receiver operating characteristic curves of CPAx-Chi for diagnosing ICU-AW based on MRC-Score ≤48 were 0.899 (95% CI 0.862 to 1.025) and 0.874 (95% CI 0.824 to 0.925) for researcher B. The best cut-off point for CPAx-Chi for the diagnosis of ICU-AW was 31.5. The sensitivity was 87% and specificity was 77% for researcher A, whereas it was 0.621, 31.5, 75% and 87% for researcher B, respectively. The consistency was high when taking CPAx-Chi ≤31 and MRC-Score ≤48 as the cut-off points for the diagnosis of ICU-AW. Cohen's kappa=0.845 (p=0.02) in researcher A and 0.839 (p=0.04) for researcher B.

CONCLUSIONS

CPAx-Chi demonstrated content validity, criterion-related validity and reliability. CPAx-Chi showed the best accuracy in assessment of patients at risk of ICU-AW with good sensitivity and specificity at a recommended cut-off of 31.

Pathophysiology and management of critical illness polyneuropathy and myopathy

Critical illness-associated weakness (CIAW) is an umbrella term used to describe a group of neuromuscular disorders caused by severe illness. It can be subdivided into three major classifications based on the component of the neuromuscular system (i.e. peripheral nerves or skeletal muscle or both) that are affected. This includes critical illness polyneuropathy (CIP), critical illness myopathy (CIM), and an overlap syndrome, critical illness polyneuromyopathy (CIPNM). It is a common complication observed in people with critical illness requiring intensive care unit (ICU) admission. Given CIAW is found in individuals experiencing grave illness, it can be challenging to study from a practical standpoint. However, over the past 2 decades, many insights into the pathophysiology of this condition have been made. Results from studies in both humans and animal models have found that a profound systemic inflammatory response and factors related to bioenergetic failure as well as microvascular, metabolic, and electrophysiological alterations underlie the development of CIAW. Current management strategies focus on early mobilization, achieving euglycemia, and nutritional optimization. Other interventions lack sufficient evidence, mainly due to a dearth of large trials. The goal of this Physiology in Medicine article is to highlight important aspects of the pathophysiology of these enigmatic conditions. It is hoped that improved understanding of the mechanisms underlying these disorders will lead to further study and new investigations for novel pharmacologic, nutritional, and exercise-based interventions to optimize patient outcomes.

Long-term outcomes after critical illness: recent insights

Intensive care survivors often experience post-intensive care sequelae, which are frequently gathered together under the term “post-intensive care syndrome” (PICS). The consequences of PICS on quality of life, health-related costs and hospital readmissions are real public health problems. In the present Viewpoint, we summarize current knowledge and gaps in our understanding of PICS and approaches to management.