Neuromuscular manifestations of critical illness

β-hydroxybutyrate exposure restores mitochondrial function in skeletal muscle satellite cells of critically ill patients

BACKGROUND & AIM

Dysfunction of skeletal muscle satellite cells might impair muscle regeneration and prolong ICU-acquired weakness, a condition associated with disability and delayed death. This study aimed to elucidate the distinct metabolic effects of critical illness and β-OH-butyrate on satellite cells isolated from these patients.

METHODS

Satellite cells were extracted from vastus lateralis muscle biopsies of patients with ICU-acquired weakness (n = 10) and control group of healthy volunteers or patients undergoing elective hip replacement surgery (n = 10). The cells were exposed to standard culture media supplemented with β-OH-butyrate to assess its influence on cell proliferation by ELISA, mitochondrial functions by extracellular flux analysis, electron transport chain complexes by high resolution respirometry, and ROS production by confocal microscopy.

RESULTS

Critical illness led to a decline in maximal respiratory capacity, ATP production and glycolytic capacity and increased ROS production in ICU patients' cells. Notably, the function of complex II was impaired due to critical illness but restored to normal levels upon exposure to β-OH-butyrate. While β-OH-butyrate significantly reduced ROS production in both control and ICU groups, it had no significant impact on global mitochondrial functions.

CONCLUSION

Critical illness induces measurable bioenergetic dysfunction of skeletal muscle satellite cells. β-OH-butyrate displayed a potential in rectifying complex II dysfunction caused by critical illness and this warrants further exploration.

Revisiting the compound muscle action potential (CMAP)

The compound muscle action potential (CMAP) is among the first recorded waveforms in clinical neurography and one of the most common in clinical use. It is derived from the summated muscle fiber action potentials recorded from a surface electrode overlying the studied muscle following stimulation of the relevant motor nerve fibres innervating the muscle. Surface recorded motor unit potentials (SMUPs) are the fundamental units comprising the CMAP. Because it is considered a basic, if not banal signal, what it represents is often underappreciated. In this review we discuss current concepts in the anatomy and physiology of the CMAP. These have evolved with advances in instrumentation and digitization of signals, affecting its quantitation and measurement. It is important to understand the basic technical and biological factors influencing the CMAP. If these influences are not recognized, then a suboptimal recording may result. The object is to obtain a high quality CMAP recording that is reproducible, whether the study is done for clinical or research purposes. The initial sections cover the relevant CMAP anatomy and physiology, followed by how these principles are applied to CMAP changes in neuromuscular disorders. The concluding section is a brief overview of CMAP research where advances in recording systems and computer-based analysis programs have opened new research applications. One such example is motor unit number estimation (MUNE) that is now being used as a surrogate marker in monitoring chronic neurogenic processes such as motor neuron diseases.

Critical Illness Polyneuropathy in a Child: A Case Report

Critical illness polyneuropathy (CIP) and myopathy (CIM) are underreported conditions in critically ill children with prolonged intensive care unit stays and mechanical ventilation. We report a case of a 10-year-old boy with pneumococcal meningoencephalitis with severe sepsis and multiorgan dysfunction. The child required prolonged ventilation, sedation, and inotropic support. He had repeated extubation failures and the development of quadriparesis with areflexia. Electrophysiology studies were consistent with CIP with acute motor and sensory axonal polyneuropathy and elevated muscle enzymes. He was treated with supportive measures and physiotherapy along with management of the underlying condition. He recovered slowly over 68 days with a good recovery with a modified Rankin's scale score of 4 on discharge. There is a need to pay attention to all critically ill children and should have a high index of suspicion for the development of CIP/CIM which can have an impact on course and outcome.

Safety and effectiveness of neuromuscular electrical stimulation in cardiac surgery: A systematic review

BACKGROUND

Lack of mobilization and prolonged stay in the intensive care unit (ICU) are major factors resulting in the development of ICU-acquired muscle weakness (ICUAW). ICUAW is a type of skeletal muscle dysfunction and a common complication of patients after cardiac surgery, and may be a risk factor for prolonged duration of mechanical ventilation, associated with a higher risk of readmission and higher mortality. Early mobilization in the ICU after cardiac surgery has been found to be low with a significant trend to increase over ICU stay and is also associated with a reduced duration of mechanical ventilation and ICU length of stay. Neuromuscular electrical stimulation (NMES) is an alternative modality of exercise in patients with muscle weakness. A major advantage of NMES is that it can be applied even in sedated patients in the ICU, a fact that might enhance early mobilization in these patients.

AIM

To evaluate safety, feasibility and effectiveness of NMES on functional capacity and muscle strength in patients before and after cardiac surgery.

METHODS

We performed a search on Pubmed, Physiotherapy Evidence Database (PEDro), Embase and CINAHL databases, selecting papers published between December 2012 and April 2023 and identified published randomized controlled trials (RCTs) that included implementation of NMES in patients before after cardiac surgery. RCTs were assessed for methodological rigor and risk of bias via the PEDro. The primary outcomes were safety and functional capacity and the secondary outcomes were muscle strength and function.

RESULTS

Ten studies were included in our systematic review, resulting in 703 participants. Almost half of them performed NMES and the other half were included in the control group, treated with usual care. Nine studies investigated patients after cardiac surgery and 1 study before cardiac surgery. Functional capacity was assessed in 8 studies via 6MWT or other indices, and improved only in 1 study before and in 1 after cardiac surgery. Nine studies explored the effects of NMES on muscle strength and function and, most of them, found increase of muscle strength and improvement in muscle function after NMES. NMES was safe in all studies without any significant complication.

CONCLUSION

NMES is safe, feasible and has beneficial effects on muscle strength and function in patients after cardiac surgery, but has no significant effect on functional capacity.

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.

Temporary and highly variable recovery of neuromuscular dysfunction by electrical stimulation in the follow-up of acute critical illness neuromyopathy: a pilot study

BACKGROUND

In sepsis-associated critical illness neuromyopathy (CIPNM) serial electrical stimulation of motor nerves induces a short-lived temporary recovery of compound muscle action potentials (CMAPs) termed facilitation phenomenon (FP). This technique is different from other stimulation techniques published. The identification of FP suggests a major functional component in acute CIPNM.

METHODS

From our previous study cohort of 18 intensive care unit patients with sepsis associated CIPNM showing profound muscle weakness and low or missing CMAPs on nerve conduction studies, six patients with different severity could be followed. In a pilot sub-study we analyzed the variability of FP during follow up. Over up to 6 weeks we performed 2-6 nerve conduction studies with our novel stimulation paradigm. Motor nerves were stimulated at 0.2-0.5 Hz with 60-100 mA at 0.2-0.5 ms duration, and CMAP responses were recorded. Standard motor nerve conduction velocities (NCV) could be done when utilizing facilitated CMAPs. Needle electromyography was checked once for spontaneous activity to discover potential denervation and muscle fiber degeneration. Serum electrolytes were checked before any examination and corrected if abnormal.

RESULTS

In all six patients a striking variability in the magnitude and pattern of FP could be observed at each examination in the same and in different motor nerves over time. With the first stimulus most CMAPs were below 0.1 mV or absent. With slow serial pulses CMAPs could gradually recover with normal shape and near normal amplitudes. With facilitated CMAPs NCV measurements revealed low normal values. With improvement of muscle weakness subsequent tests revealed larger first CMAP amplitudes and smaller magnitudes of FP. Needle EMG showed occasional spontaneous activity in the tibialis anterior muscle.

CONCLUSION

In this pilot study striking variability and magnitude of FP during follow-up was a reproducible feature indicating major fluctuations of neuromuscular excitability that may improve during follow-up. FP can be assessed by generally available electrophysiological techniques, even before patients could be tested for muscle strength. Large scale prospective studies of the facilitation phenomenon in CIPNM with or without sepsis are needed to define diagnostic specificity and to better understand the still enigmatic pathophysiology.

TRIAL REGISTRATION

This trial was registered at the Leipzig University Medical Center in 2021 after approval by the Ethics Committee.

Serum neurofilament light chain as an early diagnostic biomarker for critical illness polyneuropathy

BACKGROUND

Critical illness polyneuropathy (CIP) commonly occurs in critical care unit (CCU) patients, but timely diagnosis can be challenging. Therefore, new biomarkers, such as serum neurofilament light chain (sNfL), could help to improve early identification of patients with this condition.

METHODS

CIP was diagnosed or excluded with neurological assessment and nerve conduction measurement in a prospective study of CCU patients. sNfL and secondary predictors for neuropathy (neuron-specific enolase (NSE), S100, folic acid, and vitamin B12) were measured at admission. Cases and controls were compared regarding the predictors.

RESULTS

Nineteen patients met the inclusion criteria. CIP was considered definitely or most likely present in seven (37%, cases) and definitely or most likely absent in 12 individuals (63%, controls). At admission, sNfL levels were significantly higher in the cases than in the controls: 405 (IQR 77 to 835) vs. 27 (IQR 12 to 90) pg/mL; difference of medians 375, 95% confidence interval [14, 736], pg/mL; P=0.04. We found no significant differences regarding the secondary predictors at baseline. Cases had longer durations of CCU stay (median 19 (IQR 11 to 44) vs. 8 (IQR five to ten) and increased mortality (57% vs. 33% deceased) compared to controls.

CONCLUSIONS

Levels of serum neurofilament light chain are higher in patients who develop CIP soon after CCU admission and might be helpful in identifying those individuals early.

Lower serum cholesterol levels as a risk factor for critical illness polyneuropathy: a matched case-control study

Critical illness polyneuropathy (CIP) is a frequent and underdiagnosed phenomenon among intensive care unit patients. The lipophilic nature of neuronal synapses may result in the association of low serum cholesterol levels with a higher rate of CIP development. We aimed to investigate this issue in critically ill patients. All cases diagnosed with CIP in our tertiary care hospital between 2013 and 2017 were 1:1 matched with controls without the condition by age, sex, and ICD diagnoses. The main risk factors examined were the differences in change between initial and minimum serum total cholesterol levels, and minimum serum total cholesterol levels between matched pairs. Other predictors were serum markers of acute inflammation. We included 67 cases and 67 controls (134 critically ill patients, 49% female, 46% medical). Serum total cholesterol levels decreased more profoundly in cases than controls (median: -74 (IQR -115 to -24) vs. -39 (IQR -82 to -4), median difference: -28, 95% CI [-51, -5]), mg/dl). Minimum serum total cholesterol levels were lower in the cases (median difference: -24, 95% CI [-39, -9], mg/dl). We found significant median differences across matched pairs in maximum serum C-reactive protein (8.9, 95% CI [4.6, 13.2], mg/dl), minimum albumin (-4.2, 95% CI [-6.7, -1.7], g/l), decrease in albumin (-3.9, 95% CI [-7.6, -0.2], g/l), and lowest cholinesterase levels (-0.72, 95% CI [-1.05, -0.39], U/l). Subsequently, more pronounced decreases in serum total cholesterol levels and lower minimum total cholesterol levels during critical care unit hospitalizations may be a risk factor for CIP.

Neurologic Complications of Critical Medical Illness

OBJECTIVE

This article reviews the neurologic complications encountered in patients admitted to non-neurologic intensive care units, outlines various scenarios in which a neurologic consultation can add to the diagnosis or management of a critically ill patient, and provides advice on the best diagnostic approach in the evaluation of these patients.

LATEST DEVELOPMENTS

Increasing recognition of neurologic complications and their adverse impact on long-term outcomes has led to increased neurology involvement in non-neurologic intensive care units. The COVID-19 pandemic has highlighted the importance of having a structured clinical approach to neurologic complications of critical illness as well as the critical care management of patients with chronic neurologic disabilities.

ESSENTIAL POINTS

Critical illness is often accompanied by neurologic complications. Neurologists need to be aware of the unique needs of critically ill patients, especially the nuances of the neurologic examination, challenges in diagnostic testing, and neuropharmacologic aspects of commonly used medications.

Ultrasound-based neuropathy diagnosis in COVID-19 patients in post-intensive care rehabilitation settings. A retrospective observational study

OBJECTIVES

using ultrasound scanning to examine the correlation between increase of Common Fibular Nerve's (CFN) Cross Sectional Area (CSA) and functional impairment of foot dorsiflexor muscles as an early sign of peripheral neuropathy.

DESIGN

retrospective observational study.

SETTING

in-patient rehabilitation unit between November 2020 and July 2021.

PARTICIPANTS

26 inpatients who underwent prolonged hospitilization in ICU'S and were diagnosed with CRYMINE after SARS-COV-2 infection. Physical examination and ultrasound scanning of the CFN and EMG/ENG were carried out on each patient.

INTERVENTIONS

not applicable MAIN OUTCOME MEASURE(S): CFN's CSA at the peroneal head.

RESULTS

we verified a significant increase in the CSA of the CFN measured at the peroneal head in more than 90% of the nerves tested. A cut off value of CFN's CSA of 0,20 cm was used to identify pathological nerves. No correlations with other variables (BMI, ICU days) were found.

CONCLUSION

US scanning of the CFN appears to be an early and specific test in the evaluation of CPN's abnormalities in post COVID-19 patients. US scanning is a reproducible, cost effective, safe and easily administered bedside tool to diagnose a loss of motor function when abnormalities in peripheral nerves are present.

Elderly Patients and Management in Intensive Care Units (ICU): Clinical Challenges

There is a growing population of older adults requiring admission to the intensive care unit (ICU). This population outpaces the ability of clinicians with geriatric training to assist in their management. Specific training and education for intensivists in the care of older patients is valuable to help understand and inform clinical care, as physiologic changes of aging affect each organ system. This review highlights some of these aging processes and discusses clinical implications in the vulnerable older population. Other considerations when caring for these older patients in the ICU include functional outcomes and morbidity, as opposed to merely a focus on mortality. An overall holistic approach incorporating physiology of aging, applying current evidence, and including the patient and their family in care should be used when caring for older adults in the ICU.

Critical illness-associated weakness and related motor disorders

Weakness of limb and respiratory muscles that occurs in the course of critical illness has become an increasingly common and serious complication of adult and pediatric intensive care unit patients and a cause of prolonged ventilatory support, morbidity, and prolonged hospitalization. Two motor disorders that occur singly or together, namely critical illness polyneuropathy and critical illness myopathy, cause weakness of limb and of breathing muscles, making it difficult to be weaned from ventilatory support, commencing rehabilitation, and extending the length of stay in the intensive care unit, with higher rates of morbidity and mortality. Recovery can take weeks or months and in severe cases, and may be incomplete or absent. Recent findings suggest an improved prognosis of critical illness myopathy compared to polyneuropathy. Prevention and treatment are therefore very important. Its management requires an integrated team approach commencing with neurologic consultation, creatine kinase (CK) measurement, detailed electrodiagnostic, respiratory and neuroimaging studies, and potentially muscle biopsy to elucidate the etiopathogenesis of the weakness in the peripheral and/or central nervous system, for which there may be a variety of causes. These tenets of care are being applied to new cases and survivors of the coronavirus-2 disease pandemic of 2019. This chapter provides an update to the understanding and approach to critical illness motor disorders.

Nutritional status in post SARS-Cov2 rehabilitation patients

BACKGROUND & AIMS

After prolonged hospitalization, the assessment of nutritional status and the identification of adequate nutritional support is of paramount importance. In this observational study, we aimed at assessing the presence of a malnutrition condition in SARS-Cov2 patients after the acute phase and the effects of a multidisciplinary rehabilitation program on nutritional and functional status.

METHODS

We recruited 48 patients (26 males/22 females) admitted to our Rehabilitation Unit after discharge from acute Covid Hospitals in northern Italy with negative swab for SARS-Cov2. We used the Global Leadership Initiative on Malnutrition (GLIM) criteria to identify patients with different degrees of malnutrition. Patients underwent a 3 to 4-week individual multidisciplinary rehabilitation program consisting of nutritional intervention (energy intake 27to30 kcal/die/kg and protein intake 1-1.3 g/die/kg), exercise for total body conditioning and progressive aerobic exercise with cycle- and arm-ergometer (45 min, 5 days/week). At admission and discharge from our Rehabilitation Unit, body composition and phase angle (PhA) (BIA101 Akern), muscle strength (handgrip, HG) and physical performance (Timed-Up-and-Go, TUG) were assessed.

RESULTS

At admission in all patients the mean weight loss, as compared to the habitual weight, was -12.1 (7.6)%, mean BMI was 25.9 (7.9) kg/m², mean Appendicular Skeletal Muscle Index (ASMI) was 6.6 (1.7) kg/m² for males and 5.4 (1.4) kg/m² for females, mean phase angle was 2.9 (0.9)°, mean muscle strength (HG) was 21.1 (7.8) kg for males and 16.4 (5.9) kg for females, mean TUG value was 23.7 (19.2) s. Based on GLIM criteria 29 patients (60% of the total) showed a malnutrition condition. 7 out of those 29 patients (24%) presented a mild/moderate grade and 22 patients (76%) a severe grade. After a rehabilitation program of an average duration of 25 days (range 13-46) ASMI increased, with statistically significant differences only in females (p = 0.001) and HG improved only in males (p = 0.0014). In all of the patients, body weight did not change, CRP/albumin (p < 0.05) and TUG (p < 0.001) were reduced and PhA increased (p < 0.01).

CONCLUSIONS

We diagnosed a malnutrition condition in 60% of our post SARS-Cov2 patients. An individualized nutritional intervention with adequate energy and protein intake combined with tailored aerobic and strengthening exercise improved nutritional and functional status.

Management of Polyneuromyopathy in a Critically Ill Patient with a Left Ventricular Assist Device

Critical illness polyneuromyopathy after cardiac surgery is often unrecognized and is a rarely reported clinical condition. It is characterized by more proximal than distal symmetrical flaccid muscle weakness and difficulty in weaning from a respirator. When done in a timely manner, rehabilitation prevents early complications and reduces the length of hospitalization. Rehabilitation leads to better motor outcome, improves short-term and long-term functionality, and results in a better quality of life.

A systematic review and meta-analysis of risk factors for intensive care unit acquired weakness

BACKGROUND

The aim of this meta-analysis is to systematically evaluate and summarize the risk factors of intensive care unit acquired weakness (ICU-AW), to provide evidence-based evidence for the formulation of prevention strategies for ICU-AW.

METHODS

PubMed, EMBASE, Web of Science, CBM (China Biology Medicine, China), Chinese National Knowledge Infrastructure, Chinese WANFANG, and VIP will be searched to define relevant risk factors for ICU-AW. The databases search period is from January 1, 2005 to August 13, 2021. The Newcastle Ottawa Scale (NOS) is used to evaluate the quality of the included studies. RevMan 5.3 analysis software will be used for meta-analysis.

RESULTS

This systematic review and meta-analysis included a total of 12 cohort studies, including 9 international journals and 3 Chinese journals, with a total of 1950 patients, of which 856 had ICU-AW. The results showed that the significant risk factors for ICU-AW included female (odds ratio [OR] = 1.34, 95% confidence interval [CI]: 1.06-1.71; P = .02), mechanical ventilation days (OR = 3.04, 95% CI: 1.82-4.26; P < .00001), age (OR = 6.33, 95% CI: 5.05-7.61; P < .00001), length of intensive care unit (ICU) stay (OR = 3.78, 95% CI: 2.06-5.51; P < .0001), infectious disease (OR = 1.67, 95% CI: 1.20-2.33; P = .002), renal replacement therapy (OR = 1.59, 95% CI: 1.11-2.28; P = .01), use of aminoglucoside drugs (OR = 2.51, 95% CI: 1.54-4.08; P = .0002), sepsis related organ failure assessment (SOFA) score (OR = 1.07, 95% CI: 0.24-1.90; P = .01), hyperglycemia (OR = 2.95, 95% CI: 1.70-5.11; P = .0001).

CONCLUSION

This meta-analysis provides comprehensive evidence-based on the assessment of the risk factors for ICU-AW, their multifactorial etiology was confirmed. This study indicated that female, mechanical ventilation days, age, length of ICU stay, infectious disease, renal replacement therapy, use of aminoglucoside drugs, SOFA score, and hyperglycemia are independent risk factors for ICU-AW. We have not found consistent evidence that corticosteroids, neuromuscular blockers, sepsis have any effect on ICU-AW risk.

Inflammation: Roles in Skeletal Muscle Atrophy

Various diseases can cause skeletal muscle atrophy, usually accompanied by inflammation, mitochondrial dysfunction, apoptosis, decreased protein synthesis, and enhanced proteolysis. The underlying mechanism of inflammation in skeletal muscle atrophy is extremely complex and has not been fully elucidated, thus hindering the development of effective therapeutic drugs and preventive measures for skeletal muscle atrophy. In this review, we elaborate on protein degradation pathways, including the ubiquitin-proteasome system (UPS), the autophagy-lysosome pathway (ALP), the calpain and caspase pathways, the insulin growth factor 1/Akt protein synthesis pathway, myostatin, and muscle satellite cells, in the process of muscle atrophy. Under an inflammatory environment, various pro-inflammatory cytokines directly act on nuclear factor-κB, p38MAPK, and JAK/STAT pathways through the corresponding receptors, and then are involved in muscle atrophy. Inflammation can also indirectly trigger skeletal muscle atrophy by changing the metabolic state of other tissues or cells. This paper explores the changes in the hypothalamic-pituitary-adrenal axis and fat metabolism under inflammatory conditions as well as their effects on skeletal muscle. Moreover, this paper also reviews various signaling pathways related to muscle atrophy under inflammatory conditions, such as cachexia, sepsis, type 2 diabetes mellitus, obesity, chronic obstructive pulmonary disease, chronic kidney disease, and nerve injury. Finally, this paper summarizes anti-amyotrophic drugs and their therapeutic targets for inflammation in recent years. Overall, inflammation is a key factor causing skeletal muscle atrophy, and anti-inflammation might be an effective strategy for the treatment of skeletal muscle atrophy. Various inflammatory factors and their downstream pathways are considered promising targets for the treatment and prevention of skeletal muscle atrophy.

Case Report: Delayed Guillain-Barré syndrome following trauma: A case series and manage considerations

Aim

To analyze clinical associations between Guillain-Barré syndrome (GBS) and trauma.

Material and Methods

We retrospectively reviewed the data of eight patients with post-traumatic GBS between July 2011 and December 2018 at the Second Xiangya Hospital, China, and analyzed the triggers, clinical manifestation, examination results, treatment, prognosis, and potential mechanism related to post-traumatic GBS.

Results

The included patients had GBS preceded by no risk factors other than trauma. Their age ranged from 15 to 60 years (the median age was 52 years), and six patients were males. The potential traumatic triggers included spinal surgery (n = 2), high-intensity exercise (n = 2), traumatic brain injury (n = 1), excessive fatigue (n = 1), ischemic stroke (n = 1), and cardiopulmonary resuscitation (n = 1). The major manifestation was symmetrical limb weakness and/or numbness in all patients. The diagnosis of GBS was based on the results of electromyography, albumino-cytological dissociation, or antiganglioside antibody in cerebrospinal fluid, and other diseases were excluded. Immunotherapy improved symptoms, except in one patient who died.

Conclusions

Trauma is a probable risk factor for GBS that is very easily overlooked, thereby leading to misdiagnosis in clinical practice. We emphasize a new concept of post-traumatic GBS to promote doctors' awareness when they meet people with weakness and sensory deficits after trauma, which benefit early diagnosis, timely treatment, and reduced mortality rate of GBS.

Perceived utility of electrodiagnostic testing in critical illness myopathy and polyneuropathy: A survey of intensive care unit providers

INTRODUCTION/AIMS

Critical illness myopathy (CIM) and critical illness polyneuropathy (CIP) are common disorders associated with substantial morbidity. Electrodiagnostic studies (EDx) are effective in diagnosing CIM/CIP and identifying mimicking conditions. We surveyed intensive care unit (ICU) providers to better understand their approach to ICU-acquired weakness (ICU-AW) and the perceived utility of EDx.

METHODS

This was a single health system, Web-based survey of ICU providers.

RESULTS

Survey responses were received from 52 providers with a response rate of 22.1%. Most providers were somewhat familiar with CIM/CIP and median perceived prevalence was 30-49%. The majority (92.3%) of providers had no standard evaluation approach for ICU-AW. Electrodiagnostic testing was commonly considered, but many providers obtained it infrequently in presumed CIM/CIP cases. Electrodiagnostic studies were used to rule out other causes of weakness or to confirm the diagnosis of CIM/CIP. Many providers ordered EDx within 1 wk of identifying weakness. Finally, EDx were overshadowed by personal experience as the most helpful management tool for ICU-AW.

DISCUSSION

Overall, ICU providers perceive that CIM/CIP are commonly encountered, but they may not have a standard approach to evaluation. Clinical experience increased familiarity of ICU-AW and is central to management. EDx results are usually thought to be helpful, albeit not often ordered, and more study is needed to determine when implementation is of most assistance. Increasing education and developing institutional standards may lead to increased awareness and improved evaluation of CIM/CIP, but more study is needed to determine if algorithmic approaches would change patient outcomes.

Muscle dysfunction in the long coronavirus disease 2019 syndrome: Pathogenesis and clinical approach

In long coronavirus disease 2019 (long COVID‐19), involvement of the musculoskeletal system is characterised by the persistence or appearance of symptoms such as fatigue, muscle weakness, myalgia, and decline in physical and functional performance, even at 4 weeks after the onset of acute symptoms of COVID‐19. Muscle injury biomarkers are altered during the acute phase of the disease. The cellular damage and hyperinflammatory state induced by severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infection may contribute to the persistence of symptoms, hypoxaemia, mitochondrial damage, and dysregulation of the renin‐angiotensin system. In addition, the occurrence of cerebrovascular diseases, involvement of the peripheral nervous system, and harmful effects of hospitalisation, such as the use of drugs, immobility, and weakness acquired in the intensive care unit, all aggravate muscle damage. Here, we review the multifactorial mechanisms of muscle tissue injury, aggravating conditions, and associated sequelae in long COVID‐19.

The effect of lipoic acid on the content of SOD-1 and TNF-α in rat striated muscle

Background

The aim of the study was to present the effect of lipoic acid (LA) on oxidative stress induced by lipopolysaccharide (LPS).

Materials/Methods

The studies were conducted on male rats of the Wistar strain. The animals were divided into four groups. I: the controls received saline (0.2 ml); II: LPS, received LPS (Escherichia coli 026: B6) at a dose of 6 mg/kg body weight; III: LA, received LA at a dose of 60 mg/kg body weight; IV: LA + LPS, received LA (60 mg/kg b.w.) and after 30 min received LPS (6 mg/kg b.w.). All compounds were administered to the tail vein. After 5 hours of the experiment, the animals were anesthetized and striated muscle from the thigh was prepared. The isolated muscle was homogenized. Concentrations of superoxide dismutase-1 (SOD-1) and tumor necrosis factor alpha (TNF-α) were determined in the homogenates with the application of ELISA.

Results

The study showed a significant decrease in SOD-1 content and an increase in TNF-α in striated muscle after LPS administration. LA given 30 min before administration of LPS caused a significant increase in the level of SOD-1 and decreased levels of TNF-α in homogenates.

Conclusion

LA reduced the parameters of LPS oxidative stress, thus contributing to an increase in the body's antioxidant defense.

Paediatric Acute Respiratory Distress Syndrome Neuromuscular Blockade study (PAN-study): a phase IV randomised controlled trial of early neuromuscular blockade in moderate-to-severe paediatric acute respiratory distress syndrome

Background

Paediatric acute respiratory distress syndrome (PARDS) is a manifestation of severe, life-threatening lung injury necessitating mechanical ventilation with mortality rates ranging up to 40–50%. Neuromuscular blockade agents (NMBAs) may be considered to prevent patient self-inflicted lung injury in PARDS patients, but two trials in adults with severe ARDS yielded conflicting results. To date, randomised controlled trials (RCT) examining the effectiveness and efficacy of NMBAs for PARDS are lacking. We hypothesise that using NMBAs for 48 h in paediatric patients younger than 5 years of age with early moderate-to-severe PARDS will lead to at least a 20% reduction in cumulative respiratory morbidity score 12 months after discharge from the paediatric intensive care unit (PICU).

Methods

This is a phase IV, multicentre, randomised, double-blind, placebo-controlled trial performed in level-3 PICUs in the Netherlands. Eligible for inclusion are children younger than 5 years of age requiring invasive mechanical ventilation with positive end-expiratory pressure (PEEP) ≥ 5 cm H₂O for moderate-to-severe PARDS occurring within the first 96 h of PICU admission. Patients are randomised to continuous infusion of rocuronium bromide or placebo for 48 h. The primary endpoint is the cumulative respiratory morbidity score 12 months after PICU discharge, adjusted for confounding by age, gestational age, family history of asthma and/or allergy, season in which questionnaire was filled out, day-care and parental smoking. Secondary outcomes include respiratory mechanics, oxygenation and ventilation metrics, pulmonary and systemic inflammation markers, prevalence of critical illness polyneuropathy and myopathy and metrics for patient outcome including ventilator free days at day 28, length of PICU and hospital stay, and mortality

Discussion

This is the first paediatric trial evaluating the effects of muscular paralysis in moderate-to-severe PARDS. The proposed study addresses a huge research gap identified by the Paediatric Acute Lung Injury Consensus Collaborative by evaluating practical needs regarding the treatment of PARDS. Paediatric critical care practitioners are inclined to use interventions such as NMBAs in the most critically ill. This liberal use must be weighed against potential side effects. The proposed study will provide much needed scientific support in the decision-making to start NMBAs in moderate-to-severe PARDS.

Trial registration

ClinicalTrials.govNCT02902055. Registered on September 15, 2016.

Intensive Care Unit-Acquired Weakness and the COVID-19 Pandemic: A Clinical Review

Patients with severe cases of coronavirus disease 2019 (COVID-19) often become critically ill requiring intensive care unit (ICU) management. These individuals are at risk for developing ICU-acquired weakness (ICUAW), a multifactorial condition in which polyneuropathy, myopathy, and/or disuse muscle atrophy result in motor weakness. This weakness is thought to contribute to the long-term functional disability frequently observed in survivors of critical illness. This review discusses the current evidence regarding the epidemiology, pathophysiology, evaluation, risk factors, and rehabilitation-specific management of ICUAW in patients with COVID-19. Due to the novelty of COVID-19, the exact prevalence of ICUAW is not well delineated among COVID-19 patients. However, ICUAW has been reported in this population with retrospective studies showing weakness occurring in up to 45.5% of patients with severe COVID-19. There are multiple risk factors for developing ICUAW among COVID-19 patients which include premorbid health status, sepsis, multiple organ failure, mechanical ventilation, immobilization, neuromuscular blockade, corticosteroid use, and glycemic control. ICUAW is more likely to occur after prolonged mechanical ventilation and long hospital stays and can be diagnosed with manual muscle and electrodiagnostic testing. While the long-term sequela of COVID-19 after ICU stays is not fully studied, increasing evidence indicates significant risk for this population developing long-term functional impairments. Establishing post-acute rehabilitation programs for COVID-19 survivors will be important for recovery of endurance, mobility, and function. This article is protected by copyright. All rights reserved.

Early Neuromuscular Blockade in Moderate-to-Severe Pediatric Acute Respiratory Distress Syndrome

Objectives

The use of neuromuscular blocking agents (NMBAs) in pediatric acute respiratory distress syndrome (PARDS) is common but unsupported by efficacy data. We sought to compare the outcomes between patients with moderate-to-severe PARDS receiving continuous NMBA during the first 48 hours of endotracheal intubation (early NMBA) and those without.

Design

Secondary analysis of data from the Randomized Evaluation of Sedation Titration for Respiratory Failure (RESTORE) clinical trial, a pediatric multicenter cluster randomized trial of sedation.

Setting

Thirty-one PICUs in the United States.

Patients

Children 2 weeks to 17 years receiving invasive mechanical ventilation (MV) for moderate-to-severe PARDS (i.e., oxygenation index >= 8 and bilateral infiltrates on chest radiograph on days 0-1 of endotracheal intubation).

Interventions

NMBA for the entire duration of days 1 and 2 after intubation.

Measurements and Main Results

Among 1,182 RESTORE patients with moderate-to-severe PARDS, 196 (17%) received early NMBA for a median of 50.0% ventilator days (interquartile range, 33.3-60.7%). The propensity score model predicting the probability of receiving early NMBA included high-frequency oscillatory ventilation on days 0-2 (odds ratio [OR], 7.61; 95% CI, 4.75-12.21) and severe PARDS on days 0-1 (OR, 2.16; 95% CI, 1.50-3.12). After adjusting for risk category, early use of NMBA was associated with a longer duration of MV (hazard ratio, 0.57; 95% CI, 0.48-0.68; p < 0.0001), but not with mortality (OR, 1.62; 95% CI, 0.92-2.85; p = 0.096) compared with no early use of NMBA. Other outcomes including cognitive, functional, and physical impairment at 6 months post-PICU discharge were similar. Outcomes did not differ when comparing high versus low NMBA usage sites or when patients were stratified by baseline PaO2/FIO2 less than 150.

Conclusions

Early NMBA use was associated with a longer duration of MV. This propensity score analysis underscores the need for a randomized controlled trial in pediatrics.

Intensive care unit-acquired weakness: Questions the clinician should ask

Intensive care unit (ICU)-acquired weakness (ICU-AW) is defined as clinically detected weakness in critically ill patients in whom there is no plausible etiology other than critical illness. Using electrophysiological methods, patients with ICU-AW are classified in three subcategories: critical illness polyneuropathy, critical illness myopathy and critical illness neuromyopathy. ICU-AW is a frequent complication occurring in critical ill patients. Risk factors include illness severity and organ failure, age, hyperglycemia, parenteral nutrition, drugs and immobility. Due to short- and long-term complications, ICU-AW results in longer hospital stay and increased mortality. Its management is essentially preventive avoiding modifiable risk factors, especially duration of sedation and immobilization that should be as short as possible. Pharmacological approaches have been studied but none have proven efficacy. In the present review, we propose practical questions that the clinician should ask in case of acquired weakness during ICU stay: when to suspect ICU-AW, what risk factors should be identified, how to diagnose ICU-AW, what is the prognosis and how can recovery be improved?

Sepsis induces muscle atrophy by inhibiting proliferation and promoting apoptosis via PLK1-AKT signalling

Sepsis and sepsis-induced skeletal muscle atrophy are common in patients in intensive care units with high mortality, while the mechanisms are controversial and complicated. In the present study, the atrophy of skeletal muscle was evaluated in sepsis mouse model as well as the apoptosis of muscle fibres. Sepsis induced atrophy of skeletal muscle and apoptosis of myofibres in vivo and in vitro. In cell-based in vitro experiments, lipopolysaccharide (LPS) stimulation also inhibited the proliferation of myoblasts. At the molecular level, the expression of polo-like kinase 1 (PLK1) and phosphorylated protein kinase B (p-AKT) was decreased. Overexpression of PLK1 partly rescued LPS-induced apoptosis, proliferation suppression and atrophy in C2C12 cells. Furthermore, inhibiting the AKT pathway deteriorated LPS-induced atrophy in PLK1-overexpressing C2C12 myotubes. PLK1 was found to participate in regulating apoptosis and E3 ubiquitin ligase activity in C2C12 cells. Taken together, these results indicate that sepsis induces skeletal muscle atrophy by promoting apoptosis of muscle fibres and inhibiting proliferation of myoblasts via regulation of the PLK1-AKT pathway. These findings enhance understanding of the mechanism of sepsis-induced skeletal muscle atrophy.

Long-Term Outcomes in Acute Respiratory Distress Syndrome: Epidemiology, Mechanisms, and Patient Evaluation

Survivors of acute respiratory distress syndrome (ARDS) experience challenges that persist well beyond the time of hospital discharge. Impairment in physical function, cognitive function, and mental health are common and may last for years. The current coronavirus disease 2019 pandemic is drastically increasing the incidence of ARDS worldwide, and long-term impairments will remain lasting effects of the pandemic. Evaluation of the ARDS survivor should be comprehensive, and common domains of impairment that have emerged from long-term outcomes research over the past 2 decades should be systematically evaluated.

Intensive Care Unit-Acquired Weakness and Positioning-Related Peripheral Nerve Injuries in COVID-19: A Case Series of Three Patients and the Latest Literature Review

A subgroup of COVID-19 patients requires intensive respiratory care. The prolonged immobilization and aggressive treatments predispose these patients to develop intensive care unit-acquired weakness (ICUAW). Furthermore, this condition could increase the chance of positioning-related peripheral nerve injuries. On the basis of the latest literature review, we describe a case series of three patients with COVID-19 who developed ICUAW complicated by positioning-related peripheral nerve injuries Every patient presented sensorimotor axonal polyneuropathy and concomitant myopathy in electrophysiological studies. Furthermore, muscle MRI helped the diagnosis of ICUAW, showing massive damage predominantly in the proximal muscles. Notably, nerve ultrasound detected positioning-related peripheral nerve injuries, even though the concomitant ICUAW substantially masked their clinical features. During the acute phase of severe COVID-19 infection, most medical attention tends to be assigned to critical care management, and neuromuscular complications such as ICUAW and positioning-related peripheral nerve injuries could be underestimated. Hence, when starting post-ICU care for COVID-19 cases, the combination of electrophysiological and imaging studies will aid appropriate evaluation on the patients with COVID-19-related ICUAW.

High-dose intravenous immunoglobulins as a therapeutic option in critical illness polyneuropathy accompanying SARS-CoV-2 infection: A case-based review of the literature (Review)

The still ongoing COVID-19 pandemic has exposed the medical community to a number of major challenges. A significant number of patients require admission to intensive care unit (ICU) services due to severe respiratory, thrombotic and septic complications and require long-term hospitalization. Neuromuscular weakness is a common complication in critically ill patients who are treated in ICUs and are mechanically ventilated. This complication is frequently caused by critical illness myopathy (CIM) or critical illness polyneuropathy (CIP) and leads to difficulty in weaning from the ventilator. It is thought to represent an important neurologic manifestation of the systemic inflammatory response syndrome (SIRS). COVID-19 infection is known to trigger strong immune dysregulation, with an intense cytokine storm, as a result, the frequency of CIP is expected to be higher in this setting. The mainstay in the diagnosis of this entity beside the high level of clinical awareness is the electrophysiological examination that provides evidence of axonal motor and sensory polyneuropathy. The present article presents the case of a 54-year-old woman with severe COVID 19 infection who developed neuromuscular weakness, which turned out to be secondary to CIP and was treated successfully with a high dose of human intravenous immunoglobulins. Related to this case, we reviewed the relevant literature data regarding the epidemiology, pathophysiology and clinical features of this important complication and discussed also the treatment options and prognosis.

Sepsis and the muscle tissue. A narrative review

Sepsis and septic shock are considered major factors in the development of myopathy in critically ill patients, which is correlated with increased morbidity rates and ICU length of stay. The underlying pathophysiology is complex, involving mitochondrial dysfunction, increased protein breakdown and muscle inexcitability. Sepsis induced myopathy is characterized by several electrophysiological and histopathological abnormalities of the muscle, also has clinical consequences such as flaccid weakness and failure to wean from ventilator. In order to reach definite diagnosis, clinical assessment, electrophysiological studies and muscle biopsy must be performed, which can be challenging in daily practice. Ultrasonography as a screening tool can be a promising alternative, especially in the ICU setting. Sepsis and mechanical ventilation have additive effects leading to diaphragm dysfunction thus complicating the patient's clinical course and recovery. Here, we summarize the effects of the septic syndrome on the muscle tissue based on the existing literature.

Peripheral Nervous System Involvement in Non-Primary Pediatric Cancer: From Neurotoxicity to Possible Etiologies

Peripheral neuropathy is a well described complication in children with cancer. Oncologists are generally well aware of the toxicity of the main agents, but fear the side effects of new drugs. As chemotherapeutic agents have been correlated with the activation of the immune system such as in Chemotherapy Induced Peripheral Neuropathy (CIPN), an abnormal response can lead to Autoimmune Peripheral Neuropathy (APN). Although less frequent but more severe, Radiation Induced Peripheral Neuropathy may be related to irreversible peripheral nervous system (PNS). Pediatric cancer patients also have a higher risk of entering a Pediatric Intensive Care Unit for complications related to therapy and disease. Injury to peripheral nerves is cumulative, and frequently, the additional stress of a malignancy and its therapy can unmask a subclinical neuropathy. Emerging risk factors for CIPN include treatment factors such as dose, duration and concurrent medication along with patient factors, namely age and inherited susceptibilities. The recent identification of individual genetic variations has advanced the understanding of physiopathological mechanisms and may direct future treatment approaches. More research is needed on pharmacological agents for the prevention or treatment of the condition as well as rehabilitation interventions, in order to allow for the simultaneous delivery of optimal cancer therapy and the mitigation of toxicity associated with pain and functional impairment. The aim of this paper is to review literature data regarding PNS complications in non-primary pediatric cancer.

Critical illness polyneuropathy, myopathy and neuronal biomarkers in COVID-19 patients: A prospective study

Objective

The aim was to characterize the electrophysiological features and plasma biomarkers of critical illness polyneuropathy (CIN) and myopathy (CIM) in coronavirus disease 2019 (COVID-19) patients with intensive care unit acquired weakness (ICUAW).

Methods

An observational ICU cohort study including adult patients admitted to the ICU at Uppsala University Hospital, Uppsala, Sweden, from March 13th to June 8th 2020. We compared the clinical, electrophysiological and plasma biomarker data between COVID-19 patients who developed CIN/CIM and those who did not. Electrophysiological characteristics were also compared between COVID-19 and non-COVID-19 ICU patients.

Results

111 COVID-19 patients were included, 11 of whom developed CIN/CIM. Patients with CIN/CIM had more severe illness; longer ICU stay, more thromboembolic events and were more frequently treated with invasive ventilation for longer than 2 weeks. In particular CIN was more frequent among COVID-19 patients with ICUAW (50%) compared with a non-COVID-19 cohort (0%, p = 0.008). Neurofilament light chain (NfL) and glial fibrillary acidic protein (GFAp) levels were higher in the CIN/CIM group compared with those that did not develop CIN/CIM (both p = 0.001) and correlated with nerve amplitudes.

Conclusions

CIN/CIM was more prevalent among COVID-19 ICU patients with severe illness.

Significance

COVID-19 patients who later developed CIN/CIM had significantly higher NfL and GFAp in the early phase of ICU care, suggesting their potential as predictive biomarkers for CIN/CIM.

Clinical and neurophysiological characterization of muscular weakness in severe COVID-19

Objective

To report clinical and electroneuromyographic (ENMG) characteristics of patients affected by severe COVID-19 infection, evaluated for muscular weakness.

Materials and methods

ENMGs performed for evaluation of diffuse weakness in patients who could not be discharged from semi-intensive care COVID unit because of difficulties in ventilation weaning were reviewed. Patients with severe COVID-19 infection who had undergone endotracheal intubation and able to co-operate were considered. ENMG protocol was focused on neurophysiological items that excluded or confirmed critical illness polyneuropathy (CIP), myopathy (CIM), or polyneuromyopathy (CIPM). Standardized clinical evaluation was performed using Medical Research Council (MRC) sum score.

Results

Eight patients were included in the study. All presented known risk factors for intensive care unit-acquired weakness (ICU-AW), and none of them had history of underlying neuromuscular disorders. ENMG findings were normal in two patients, while only two patients had an altered MRC sum score (< 48). Neuromuscular involvement was diagnosed in 6/8 patients (75%): 2 had CIP, 1 had possible CIM, 1 had CIPM, while 1 patient, with clinically evident weakness but equivocal ENMG findings, was classified as ICU-AW. Finally, 1 patient was diagnosed with acute demyelinating neuropathy. Patients with neuromuscular involvement were those with longer intubation duration and higher levels of IL-6 at admission.

Conclusion

Neuromuscular complications are frequent in severe COVID-19 and cannot be excluded by MRC sum scores above 48. Standardized ENMG is helpful in guiding diagnosis when clinical evaluation is not reliable or possible. Elevated IL-6 at admission may be a predictor biomarker of ICU-AW in COVID-19.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10072-021-05110-8.

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.

Testosterone improves muscle function of the extensor digitorum longus in rats with sepsis

Among patients with intensive care unit-acquired weakness (ICUAW), skeletal muscle strength often decreases significantly. The present study aimed to explore the effects of testosterone propotionate on skeletal muscle using rat model of sepsis. Male SD rats were randomly divided into experimental group, model control group, sham operation group and blank control group. Rats in experimental group were given testosterone propionate two times a week, 10 mg/kg for 3 weeks. Maximal contraction force, fatigue index and cross-sectional area of the extensor digitorum longus (EDL) were measured. Myosin, IGF-1, p-AKT and p-mTOR levels in EDL were detected by Western blot. Histological changes of the testis and prostate were detected by hematoxylin and eosin staining. We found that maximal contraction force and fatigue index of EDL in experimental group were significantly higher than in model control group. Cross-sectional area of fast MHC muscle fiber of EDL in group was significantly higher than in model control group. The levels of myosin, IGF-1, p-AKT and p-mTOR of EDL in experimental group were significantly higher than in model control group. In addition, no testicle atrophy and prostate hyperplasia were detected in experimental group. In conclusion, these results suggest that testosterone propionate can significantly improve skeletal muscle strength, endurance and volume of septic rats, and the mechanism may be related to the activation of IGF-1/AKT pathway. Moreover, testosterone propionate with short duration does not cause testicular atrophy and prostate hyperplasia in septic rats. Therefore, testosterone propionate is a potential treatment for muscle malfunction in ICUAW patients.

Characteristics, treatments, and prognosis of a critical illness polyneuromyopathy patient with positive anti-GM1 after severe traumatic brain injury: A case report

To investigate the clinical features, treatment and prognosis of critical illness polyneuromyopathy (CIPNM) in patients with severe traumatic brain injury (sTBI) who had positive anti-ganglioside GM1 (anti-GM1) antibody IgG. A case of CIPNM with positive anti-GM1 antibody IgG was retrospectively analysed and followed-up for 30 months. After 1 week of treatment with large dose of short-term glucocorticoid and human immunoglobulin, the muscle strength of both lower extremities was restored to grade 1. Three months later, the muscle strength and muscle tension of the patient's limbs returned to normal except for grade 3 of bilateral dorsal extensor muscle strength. In addition, the patient can walk alone with a waddling gait. After 30 months, there was no recurrence. The application of large dose of short-term glucocorticoid and human immunoglobulin to CIPNM that are positive for anti-GM1 antibodies may be an effective treatment.

Early detection of evolving critical illness myopathy with muscle velocity recovery cycles

OBJECTIVE

To investigate the sensitivity of muscle velocity recovery cycles (MVRCs) for detecting altered membrane properties in critically ill patients, and to compare this to conventional nerve conduction studies (NCS) and quantitative electromyography (qEMG).

METHODS

Twenty-four patients with intensive care unit acquired weakness (ICUAW) and 34 healthy subjects were prospectively recruited. In addition to NCS (median, ulnar, peroneal, tibial and sural nerves) and qEMG (biceps brachii, vastus medialis and anterior tibial muscles), MVRCs with frequency ramp were recorded from anterior tibial muscle.

RESULTS

MVRC and frequency ramp parameters showed abnormal muscle fiber membrane properties with up to 100% sensitivity and specificity. qEMG showed myopathy in 15 patients (63%) while polyneuropathy was seen in 3 (13%). Decreased compound muscle action potential (CMAP) amplitude (up to 58%) and absent F-waves (up to 75%) were frequent, but long duration CMAPs were only seen in one patient with severe myopathy.

CONCLUSIONS

Altered muscle fiber membrane properties can be detected in patients with ICUAW not yet fulfilling diagnostic criteria for critical illness myopathy (CIM). MVRCs may therefore serve as a tool for early detection of evolving CIM.

SIGNIFICANCE

CIM is often under-recognized by intensivists, and large-scale longitudinal studies are needed to determine its incidence and pathogenesis.

Relationship between intensive care unit-acquired weakness, fatigability and fatigue: What role for the central nervous system?

PURPOSE

To provide a comprehensive review of studies that have investigated fatigue in intensive care unit (ICU) survivors and questions the potential link between intensive care unit-acquired weakness (ICUAW), fatigability and fatigue. We also question whether the central nervous system (CNS) may be the link between these entities.

MATERIAL AND METHODS

A narrative review of the literature that investigated fatigue in ICU survivors and review of clinical trials enabling understanding of CNS alterations in response to ICU stays.

RESULTS

Fatigue is a pervasive and debilitating symptom in ICU survivors that can interfere with rehabilitation. Due to the complex pathophysiology of fatigue, more work is required to understand the roles of ICUAW and/or fatigability in fatigue to provide a more holistic understanding of this symptom. While muscle alterations have been well documented in ICU survivors, we believe that CNS alterations developing early during the ICU stay may play a role in fatigue.

CONCLUSIONS

Fatigue should be considered and treated in ICU survivors. The causes of fatigue are likely to be specific to the individual. Understanding the role that ICUAW and fatigability may have in fatigue would allow to tailor individual treatment to prevent this persistent symptom and improve quality of life.

Intensive Care Unit-Acquired Weakness: A Review of Recent Progress With a Look Toward the Future

Intensive care unit-acquired weakness (ICU-AW), a common neuromuscular complication associated with patients in the ICU, is a type of skeletal muscle dysfunction that commonly occurs following sepsis, mobility restriction, hyperglycemia, and the use of glucocorticoids or neuromuscular blocking agents. ICU-AW can lead to delayed withdrawal of mechanical ventilation and extended hospitalization. Patients often have poor prognosis, limited mobility, and severely affected quality of life. Currently, its pathogenesis is uncertain, with unavailability of specific drugs or targeted therapies. ICU-AW has gained attention in recent years. This manuscript reviews the current research status of the epidemiology, pathogenesis, diagnosis, and treatment methods for ICU-AW and speculates the novel perspectives for future research.

Critical Illness Myopathy

Critical illness myopathy (CIM) is a primary myopathy associated with increased mortality and morbidity, which frequently develops in severely ill patients. Several risk factors have been suggested for the development of critical illness myopathy. However, neither the exact etiology nor the underlying mechanisms are known in detail. Although for definite diagnosis muscle biopsy is needed, electrophysiological tests are crucial for the diagnosis of probable critical illness myopathy and differential diagnosis. In this review, conventional electrophysiological tests such as nerve conduction studies, needle electromyography, direct muscle stimulation, and repetitive stimulation for diagnosis of critical illness myopathy are summarized. Moreover, studies using the novel method of recording muscle velocity recovery cycles are addressed.

Papaverine Has Therapeutic Potential for Sepsis-Induced Neuropathy in Rats, Possibly via the Modulation of HMGB1-RAGE Axis and Its Antioxidant Prosperities

AIM

Our aim was to investigate the possible neuroprotective properties of papaverine in sepsis-induced critical illness neuropathy (SCIN) through the evaluation of various inflammatory biochemical markers, including interleukin 6 (IL-6), C-reactive protein (CRP), and tumor necrosis factor-alpha (TNF-α), and oxidative stress biomarkers, such as malondialdehyde (MDA) and lactic acid. Additionally, evaluation of the HMGB1/RAGE interactions in SCIN was another target of this research.

METHOD

To create a sepsis model, a procedure involving intraperitoneal injection of feces was performed on 48 rats. The rats were divided into four equal groups: sham operated, controls and those receiving 20 and 40 mg/kg/day papaverine. After five-day treatments, compound muscle action potential (CMAPs) with electroneuromyography (ENMG) was recorded in all rats. Following ENMG evaluations, the plasma levels of sRAGE, HMGB1, TNF-α, IL-6, CRP, MDA and lactic acid were measured.

RESULTS

TNF-α, CRP, IL-6, HMGB1, MDA, and lactic acid levels were significantly elevated in the SCIN group, and sRAGE levels were significantly decreased. In recipients of papaverine (20 and 40 mg/kg) treatment, these biochemical findings were improved. Furthermore, electrophysiological findings also showed significant improvement in both 20 and 40 mg/kg papaverine treated groups.

CONCLUSION

Papaverine demonstrates neuroprotective effects in a rat model of SCIN. Considering its anti-inflammatory and antioxidant properties, papaverine's neuroprotective effects possibly stem from the suppression of the RAGE-HMGB1 axis.

Tracheostomy intervention in intubated COVID positive patients: A survey of current clinical practice among ENT surgeons

Introduction

The COVID‐19 pandemic has resulted in an unprecedented need for critical care intervention. Prolonged intubation and mechanical ventilation has resulted in the need for tracheostomy in some patients. The purpose of this international survey was to assess optimal timing, technique and outcome for this intervention.

Methods

An online survey was generated. Otorhinolaryngologists from both the United Kingdom and Abroad were polled with regards to their experience of tracheostomy in COVID‐19 positive ventilated patients.

Results

The survey was completed by 50 respondents from 16 nations. The number of ventilated patients totalled 3403, on average 9.7% required a tracheostomy. This was on average performed on day 14 following intubation. The majority of patients were successfully weaned (mean 7.4 days following tracheostomy).

Conclusion

The results of this brief survey suggest that tracheostomy is of benefit in selected patients. There was insufficient data to suggest improved outcomes with either percutaneous vs an open surgical technique.

COVID-19 pandemic. What should Physical and Rehabilitation Medicine specialists do? A clinician's perspective

COVID-19 pandemic is rapidly spreading all over the world, creating the risk for a healthcare collapse. While acute care and intensive care units are the main pillars of the early response to the disease, rehabilitative medicine should play an important part in allowing COVID-19 survivors to reduce disability and optimize the function of acute hospital setting. The aim of this study was to share the experience and the international perspective of different rehabilitation centers, treating COVID-19 survivors. A group of Physical Medicine and Rehabilitation specialists from eleven different countries in Europe and North America have shared their clinical experience in dealing with COVID-19 survivors and how they have managed the re-organization of rehabilitation services. In our experience the most important sequelae of severe and critical forms of COVID-19 are: 1) respiratory; 2) cognitive, central and peripheral nervous system; 3) deconditioning; 4) critical illness related myopathy and neuropathy; 5) dysphagia; 6) joint stiffness and pain; 7) psychiatric. We analyze all these consequences and propose some practical treatment options, based on current evidence and clinical experience, as well as several suggestions for management of rehabilitation services and patients with suspected or confirmed infection by SARS-CoV-2. COVID-19 survivors have some specific rehabilitation needs. Experience from other centers may help colleagues in organizing their services and providing better care to their patients.

The long-lasting effects of the acute respiratory distress syndrome

Introduction: Acute respiratory distress syndrome (ARDS) is a severe form of acute lung injury common in critically ill patients and characterized by significant morbidity and mortality. It frequently manifests long-lasting effects beyond hospitalization, from cognitive impairment to physical weakness.Areas covered: Several complications of ARDS have been identified in patients after hospital discharge. The authors conducted literature searches to identify observational studies, randomized clinical trials, systematic reviews, and guidelines. A summary of is presented here to outline the sequelae of ARDS and their risk factors with a focus on the limited but growing research into possible therapies. Long term sequelae of ARDS commonly identified in the literature include long-term cognitive impairment, psychological morbidities, neuromuscular weakness, pulmonary dysfunction, and ongoing healthcare utilization with reduced quality of life.Expert opinion: Given the public health significance of long-term complications following ARDS, the development of new therapies for prevention and treatment is of vital importance. Furthering knowledge of the pathophysiology of these impairments will provide a framework to develop new therapeutic targets to fuel future clinical trials in this area of critical care medicine.

An Unusual Case of Critical Illness Polyneuromyopathy

Critical illness myopathy (CIM), critical illness polyneuropathy (CIP), and critical illness polyneuromyopathy (CIPNM) are the group of disorders that are commonly presented as neuromuscular weakness in intensive care unit (ICU) settings. They are responsible for prolonged ICU stay and failure to wean off from mechanical ventilation. We report a case of young female who was admitted with undiagnosed type I diabetes mellitus with diabetic ketoacidosis, severe hypokalemia, sepsis developed acute onset quadriplegia, and diaphragmatic palsy within 72 hours of ICU admission. On detailed investigation, CIPNM was diagnosed. In view of high morbidity, mortality, and poor prognosis, a guided approach to diagnose and treat in earliest possible duration might give better improvement and outcome of the illness. Despite all the odds, our patient showed good clinical improvement and finally got discharged.

How to cite this article

Mahashabde M, Chaudhary G, Kanchi G, Rohatgi S, Rao P, Patil R, et al. An Unusual Case of Critical Illness Polyneuromyopathy. Indian J Crit Care Med 2020;24(2):133-135.

Life after paediatric intensive care unit

Advances in critical care medicine have led to reduced mortality but increased morbidity. Post-intensive care unit syndrome (PICS) develops after critical illness and presents as cognitive, physical and/or psychosocial impairments. PICS is prevalent in 10 - 36% of patients after discharge from paediatric intensive care unit. Multiple risk factors are associated with PICS, but there is no single causal factor. Factors range from clinical illnesses to intensive care intervention. The care plan should be aimed at prevention, early identification and post-ICU management of PICS by a multidisciplinary team.

Critical illness polyneuromyopathy in septic patients: Is it possible to diagnose it in a bedside clinical examination?

OBJECTIVE

To determine the sensitivity and specificity of peripheral and respiratory muscle strength tests in diagnosing critical illness polyneuromyopathy (CIPNM), compared with an electrophysiological examination.

METHODS

Fifty septic patients who required mechanical ventilation for at least five days, and without a previous history of muscle weakness, were included. Peripheral muscle strength was assessed using the Medical Research Council (MRC) score, handgrip strength by dynamometry, and respiratory muscle strength with maximum respiratory pressures. Diagnosis of CIPNM was either confirmed or rejected by an electrophysiological examination. Receiver operating characteristic curve analysis was performed to determine the cut-off values with the best sensitivity (SN) and specificity (SP) of the studied variables in the presence or absence of CIPNM.

RESULTS

Patients with CIPNM were older, more critical (APACHE IV/SAPS 3), had a longer hospitalization, required mechanical ventilation for longer, and had a higher rate of intensive care unit readmission. Cutoff values identified CIPNM patients using MRC scores, dynamometry according to sex, maximal expiratory and inspiratory pressures, as well as being confirmed by the electrophysiological examination, with good sensitivity and specificity: < 40 (SN: 0.893; SP: 0.955); < 7 kg (SN: 1; SP: 0.909) for men, < 4 kg (SN: 0.882; SP: 1) for women; < 34 cmH2O (SN: 0.808; SP: 0.909) and > -40 cmH2O (SN: 0.846; SP: 0.909), respectively.

CONCLUSION

The MRC score, dynamometry or maximum respiratory pressures can be used to identify patients with CIPNM at the intensive care bedside assessment. The healthcare professional can choose any of the methods studied to evaluate the patient, based on his experience and the resource available.