Neuromuscular disorders in critically ill patients: review and update

Prevalence and Risk Factors of Intensive Care Unit-acquired Weakness in Patients With COVID-19: A Systematic Review and Meta-analysis

BACKGROUND

Intensive care unit acquired weakness (ICUAW) is a common neuromuscular complication of critical illness, impacting patients' recovery and long-term outcomes. However, limited evidence is available on pooled prevalence and risk factors of ICUAW specifically in the COVID-19-infected population.

METHODS

We searched on PubMed, Embase, Cochrane Library, Web of Science, PEDro, and EBSCOhost/CINAHL up to January 31, 2024. Data synthesis was conducted using the Freeman-Tukey double-arcsine transformation model for the pooled prevalence rate and odds ratios with corresponding 95% confidence intervals was used to identify risk factors.

RESULTS

The pooled prevalence of ICUAW in COVID-19 patients was 55% in eight studies on 868 patients. Risk factors for developing ICUAW in these patients were: old age (WMD 4.78, 95% CI, 1.06-8.49), pre-existing hypertension (OR = 1.63, 95% CI, 1.02-2.61), medical intervention of prone position (OR = 5.21, 95% CI, 2.72-9.98), use of neuromuscular blocking agents (NMBA) (OR = 12.04, 95% CI, 6.20-23.39), needed tracheostomy (OR = 18.07, 95% CI, 5.64-57.92) and renal replacement therapy (RRT) (OR = 5.24, 95% CI = 2.36-11.63).

CONCLUSIONS

The prevalence of ICUAW in patients with COVID-19 was considered relatively high. Older age, pre-existing hypertension, medical intervention of prone position, NMBA use, needed tracheostomy and RRT were likely risk factors. In the future, interdisciplinary medical team should pay attention to high-risk groups for ICUAW prevention and early treatments.

Safety and feasibility of a functional electrical stimulation cycling-based muscular dysfunction diagnostic method in mechanically ventilated patients

BACKGROUND

A nonvolitional diagnostic method based on FES-Cycling technology has recently been demonstrated for mechanically ventilated patients. This method presents good sensitivity and specificity for detecting muscle dysfunction and survival prognosis, even in unconscious patients. As the clinical relevance of this method has already been reported, we aimed to evaluate its safety and feasibility.

METHODS

An observational prospective study was carried out with 20 critically ill, mechanically ventilated patients. The FES-cycling equipment was set in a specific diagnostic mode. For safety determination, hemodynamic parameters and peripheral oxygen saturation were measured before and immediately after the diagnostic protocol, as well as venous oxygen saturation and blood lactate. The creatine phosphokinase level (CPK) was measured before and 24, 48, and 72 h after the test. The time taken to carry out the entire diagnostic protocol and the number of patients with visible muscle contraction (capacity of perceptive muscular recruitment) were recorded to assess feasibility.

RESULTS

Heart rate [91 ± 23 vs. 94 ± 23 bpm (p = 0.0837)], systolic [122 ± 19 vs. 124 ± 19 mm Hg (p = 0.4261)] and diastolic blood pressure [68 ± 13 vs. 70 ± 15 mm Hg (p = 0.3462)], and peripheral [98 (96-99) vs. 98 (95-99) % (p = 0.6353)] and venous oxygen saturation [71 ± 14 vs. 69 ± 14% (p = 0.1317)] did not change after the diagnostic protocol. Moreover, blood lactate [1.48 ± 0.65 vs. 1.53 ± 0.71 mmol/L (p = 0.2320)] did not change. CPK did not change up to 72 h after the test [99 (59-422) vs. 125 (66-674) (p = 0.2799) vs. 161 (66-352) (p > 0.999) vs. 100 (33-409) (p = 0.5901)]. The time taken to perform the diagnostic assessment was 11.3 ± 1.1 min. In addition, 75% of the patients presented very visible muscle contractions, and 25% of them presented barely visible muscle contractions.

CONCLUSIONS

The FES cycling-based muscular dysfunction diagnostic method is safe and feasible. Hemodynamic parameters, peripheral oxygen saturation, venous oxygen saturation, and blood lactate did not change after the diagnostic protocol. The muscle damage marker (CPK) did not increase up to 72 h after the diagnostic protocol.

Incidence of Upper Extremity Neuropathies at a Single Tertiary Care Institution in the United States: Trends in Recent Years, Including the COVID-19 Pandemic

OBJECTIVE

This study examined trends in upper extremity (UE) neuropathies at a large urban tertiary care center in the Northeastern United States over the past five years, including the period of the COVID-19 pandemic.

METHOD

A retrospective medical record review was conducted from 2018 to 2022. We collected data from unique patient records identified using International Classification of Diseases, Tenth Revision (ICD-10) codes for UE neuropathies. We characterized subjects by age, demographics, and duration of symptoms.  Results: This study included 288 pediatric patients and 51,997 adult patients newly diagnosed with UE neuropathy. Most patients were aged 55+; 0.4% of all patients diagnosed with UE neuropathy were children. Across all ages, there was an overall increase in UE neuropathy diagnoses in the past five years, with the most noticeable increases from 2018 to 2019 (+5,761 diagnosed individuals, or +122%) and from 2020 to 2021 (+2,769 diagnosed individuals, or +28.8%).

CONCLUSION

Our institution's UE neuropathy diagnoses have increased in the past five years. Of note, there was a significantly increased rate of UE neuropathy diagnoses from 2020 to 2021. This increase coincides with the COVID-19 pandemic, which is leading to a changing environment for many Americans. These societal changes will likely become indelible after the pandemic; safety practices should be enacted to avoid these debilitating neuropathies.

Physical and Cognitive Impairment in Acute Respiratory Failure

Recent research has brought renewed attention to the multifaceted physical and cognitive dysfunction that accompanies acute respiratory failure (ARF). This state-of-the-art review provides an overview of the evidence landscape encompassing ARF-associated neuromuscular and neurocognitive impairments. Risk factors, mechanisms, assessment tools, rehabilitation strategies, approaches to ventilator liberation, and interventions to minimize post-intensive care syndrome are emphasized. The complex interrelationship between physical disability, cognitive dysfunction, and long-term patient-centered outcomes is explored. This review highlights the need for comprehensive, multidisciplinary approaches to mitigate morbidity and accelerate recovery.

Early mobilisation within 72 hours after admission of critically ill patients in the intensive care unit: A systematic review with network meta-analysis

INTRODUCTION

Early mobilisation within 72 hours of intensive care unit admission counteracts complications caused by critical illness. The effect of different interventions on intensive care unit length of stay and other outcomes is unclear. We aimed to investigate the effectiveness of various early mobilisation interventions within 72 hours of admission to the intensive care unit on length of stay and other outcomes.

METHODS

A systematic review and (network) meta-analysis examining the effect of early mobilisation on length of stay in the intensive care unit and other outcomes, conducting searches in four databases. Randomised controlled trials were included from inception to 10/08/2022. Early mobilisation was defined as interventions that initiates and/or supports passive/active range-of-motion exercises within 72 hours of admission. In multi-arm studies, interventions used in other studies were declared as early intervention and were included in subgroup meta-analysis. Risk-of-bias was assessed using RoB2.

RESULTS

Of 29,680 studies screened, 18 studies with 1923 patients (three high, eleven some, four low risk-of-bias) and seven discriminable interventions of early mobilisation met inclusion criteria. Early mobilisation alone (WMD 0.78 days, 95 %CI [-1.38;-0.18], 11 studies, n = 1124) and early mobilisation with early nutrition (WMD -1.19 days, 95 %CI [-2.34;-0.03], 1 study, n = 100) were able to significantly shorten length of stay. Early mobilisation alone could also substantially shorten hospital length of stay (WMD -1.05 days, 95 %CI [-1.74;-0.36], 8 studies, n = 977). This effect in hospital length of stay was furthermore seen in the early intervention group compared with standard care (WMD -1.71 days, 95 %CI [-2.99;-0.43], 14 studies, n = 1587). Also, functionality and quality of life could significantly be improved by an early start of mobilisation.

CONCLUSION

In the network meta-analysis, early mobilisation alone and early mobilisation with early nutrition demonstrated a significant effect on intensive care length of stay. Early mobilisation could also reduce hospital length of stay and positively influence functionality and quality of life.

IMPLICATION FOR CLINICAL PRACTICE

Early mobilisation and early mobilisation with early nutrition seemed to be beneficial compared to other interventions like cycling on intensive care length of stay.

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.

Serum metabolomics analysis for quantification of muscle loss in critically ill patients: An explorative study

BACKGROUND

During Intensive Care Unit (ICU) admission, patients demonstrate up to 15% muscle loss per week, contributing to neuromuscular weakness, complicating recovery and delaying return to daily life. Biomarkers for muscle loss could aid in early detection of patients at risk and help guide resources to mitigate muscle loss, e.g. physical therapy and protein supplementation.

AIMS

To explore serum biomarkers for muscle mass and muscle loss in ICU patients using a metabolomics approach.

METHODS

Mechanically ventilated patients with an unplanned ICU admission between June and December 2021 were prospectively studied. The cross-sectional area of the rectus femoris muscle was assessed using ultrasound (RFcsa) and 188 serum metabolites were assessed using the Biocrates™ AbsoluteIDQ p180 kit for targeted metabolomics. Patients were eligible for analysis when a serum sample drawn within 5 days of ICU admission and at least 1 RFcsa were available. In patients with sequential RFcsa measurements, muscle loss was defined as the negative slope of the regression line fitted to the RFcsa measurements per patient in the first 10 days of ICU admission. Correlations between baseline metabolite concentrations and baseline muscle mass, as well as between baseline metabolite concentrations and muscle loss were assessed using Pearson's test for correlations. To correct for multiple testing, the Benjamini-Hochberg procedure was used.

RESULTS

Seventeen patients were eligible for analysis. Mean age was 62 (SD ± 9) years and the cohort was predominantly male (76%). Four metabolites correlated with baseline muscle mass: creatinine (R = 0.5, p = 0.041), glycerophospholipid PC_ae_C30_0 (R = 0.5, p = 0.034) and two acylcarnitines: C14_2 (R = 0.5, p = 0.042) and C10_2 (R = 0.5, p = 0.049). For muscle loss, significant associations were found for histidine (R = -0.8, p = 0.002) and three glycerophospholipids; PC_aa_C40_2 (R = 0.7, p = 0.015), PC_ae_C40_1 (R = 0.6, p = 0.032) and PC_aa_C42_1 (R = 0.6, p = 0.037). After correction for multiple testing, no significant associations remained.

CONCLUSIONS

This exploratory analysis found certain metabolites to be associated with muscle mass and muscle loss. Future research, specifically addressing these metabolites is necessary to confirm or refute an association with muscle loss and determine their role as potential muscle loss marker.

Swallowing biomechanics in tracheostomised critically ill patients compared to age- and gender-matched healthy controls

Objective

The mechanistic effects of a tracheostomy on swallowing are unclear. Pharyngeal high-resolution manometry with impedance (P-HRM-I) is a novel swallow assessment tool providing quantifiable metrics. This study aimed to characterise swallowing biomechanics in tracheostomised critically ill (non-neurological) patients.

Design

Cohort study.

Setting

Australian tertiary hospital intensive care unit.

Participants

Tracheostomised adults, planned for decannulation.

Main outcome measures

Swallowing assessment using P-HRM-I, compared to healthy age- and gender-matched controls.

Results

In this tracheostomised cohort (n = 10), the Swallow Risk Index, a global measure of swallow function, was significantly elevated (p < 0.001). At the upper oesophageal sphincter (UOS), hypopharyngeal intrabolus pressure and UOS integrated relaxation pressure were significantly elevated (control 0.65 mmHg [-1.02, 2.33] v tracheostomy 13.7 mmHg [10.4, 16.9], P < 0.001; control -4.28 mmHg [-5.87, 2.69] v tracheostomy 12.2 mmHg [8.83, 15.6], P < 0.001, respectively). Furthermore, UOS opening extent and relaxation time were reduced (control 4.83 mS [4.60, 5.07] v tracheostomy 4.33 mS [3.97, 4.69], P = 0.002; control 0.52 s [0.49, 0.55] v tracheostomy 0.41 s [0.37, 0.45], P < 0.001, respectively). Total pharyngeal contractility (PhCI) measuring pharyngeal pressure generation was significantly elevated (control 199.5 mmHg cm.s [177.4, 221.6] v tracheostomy 326.5 mmHg cm.s [253.3, 399.7]; P = 0.001).

Conclusion

In a critically ill tracheostomised cohort, UOS dysfunction was the prevalent biomechanical feature, with elevated pharyngeal pressures. Pharyngeal weakness is not contributing to dysphagia in this cohort. Instead, elevated pharyngeal pressures may represent a compensatory mechanism to overcome the UOS dysfunction. Further studies to extend these findings may inform the development of timely and targeted rehabilitation.

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?

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.

What's going on following acute covid-19? Clinical characteristics of patients in an out-patient rehabilitation program

BACKGROUND

Coronavirus disease 2019 (COVID-19) patients present long-lasting physical and neuropsychological impairment, which may require rehabilitation.

OBJECTIVES

The current cross-sectional study characterizes post COVID-19 sequelae and persistent symptoms in patients in an outpatient rehabilitation program.

METHODS

Thirty patients [16 post-ICU and 14 non-ICU; median age = 54(43.8-62) years; 19 men] presenting sequelae and/or persistent symptoms (>3 months after acute COVID-19) were selected of 41 patients referred for neurorehabilitation. Patients underwent physical, neuropsychological and respiratory evaluation and assessment of impact of fatigue and quality of life.

RESULTS

The main reasons for referral to rehabilitation were: fatigue (86.6%), dyspnea (66.7%), subjective cognitive impairment (46.7%) and neurological sequelae (33.3%). Post-ICU patient presented sequelae of critical illness myopathy and polyneuropathy, stroke and encephalopathy and lower forced vital capacity compared to non-ICU patients. Cognitive impairment was found in 63.3% of patients, with a similar profile in both sub-groups. Increased physical fatigue, anxiety and depression and low quality of life were prevalent irrespective of acute COVID-19 severity.

CONCLUSIONS

The variability of post COVID-19 physical and neuropsychological impairment requires a complex screening process both in ICU and non-ICU patients. The high impact of persistent symptoms on daily life activities and quality of life, regardless of acute infection severity, indicate need for rehabilitation.

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.

Brachial Plexus Neuropathies During the COVID-19 Pandemic: A Retrospective Case Series of 15 Patients in Critical Care

OBJECTIVE

The use of the prone position to treat patients with COVID-19 pneumonia who are critically ill and mechanically ventilated is well documented. This case series reports the location, severity, and prevalence of focal peripheral nerve injuries involving the upper limb identified in an acute COVID-19 rehabilitation setting. The purpose of this study was to report observations and to explore the challenges in assessing these patients.

METHODS

Participants were patients with suspected peripheral nerve injuries following discharge from COVID-19 critical care who were referred to the peripheral nerve injury multidisciplinary team. Data were collected retrospectively on what peripheral neuropathies were observed, with reference to relevant investigation findings and proning history.

RESULTS

During the first wave of the COVID-19 pandemic in the United Kingdom, 256 patients were admitted to COVID-19 critical care of Queen Elizabeth Hospital, Birmingham, United Kingdom. From March to June 2020, a total of 114 patients required prone ventilation. In this subgroup, a total of 15 patients were identified with clinical findings of peripheral nerve injuries within the upper limb. In total, 30 anatomical nerve injuries were recorded. The most commonly affected nerve was the ulnar nerve (12/30) followed by the cords of the brachial plexus (10/30). Neuropathic pain and muscle wasting were identified, signifying a high-grade nerve injury.

CONCLUSION

Peripheral nerve injuries can be associated with prone positioning on intensive care units, although other mechanisms, such as those of a neuroinflammatory nature, cannot be excluded.

IMPACT

Proning-related upper limb peripheral nerve injuries are not discussed widely in the literature and could be an area of further consideration when critical care units review their proning protocols. Physical therapists treating these patients play a key part in the management of this group of patients by optimizing the positioning of patients during proning, making early identification of peripheral nerve injuries, providing rehabilitation interventions, and referring to specialist services if necessary.

LAY SUMMARY

During the COVID-19 pandemic, patients who are very ill can be placed for long periods of time on their stomach to improve their chances of survival. The potential consequences of prolonged time in this position are weakness and pain in the arms due to potential nerve damage. There are some recommended treatments to take care of these problems.

Intensive Care Unit Admission Following Surgery for Pediatric Spinal Deformity: An Analysis of the ACS-NSQIP Pediatric Spinal Fusion Procedure Targeted Dataset

STUDY DESIGN

Retrospective cohort.

OBJECTIVE

To understand which patient and surgical factors are predictive of an increased odds of undergoing an admission and a prolonged stay >2 days in an intensive care unit (ICU) following corrective surgery for pediatric deformity.

METHODS

The 2016 American College of Surgeons-National Surgical Quality Improvement Program (ACS-NSQIP) Pediatric Spinal Fusion Procedure Targeted database records, merged with original 2016 ACS-NSQIP Pediatric file variables, were used for this study. Univariate and multivariate analyses were used to identify independent risk factors associated with admission, as well as a prolonged length of stay in the ICU following surgery.

RESULTS

A total of 1398 (39.5%) patients required an ICU admission following the procedure-out of whom 416 (29.8%) stayed for more than 2 days. Following adjusted analysis, patient and surgical factors independently associated with an ICU admission were black/African American versus white race, anterior fusion, combined fusion, nonidiopathic scoliosis, preoperative ventilator dependence, asthma, having structural pulmonary abnormality, developmental delay, having a neuromuscular disorder, requiring nutritional support and a total operative time >270 minutes. The only significant factors associated with a prolonged length of ICU stay >2 days were preoperative ventilator dependence, nutritional support requirement, and undergoing anterior or combined fusion.

CONCLUSIONS

This study is the first of its kind to identify significant patient- and procedure-level factors associated with an ICU admission, and also explores predictors for a prolonged stay in the ICU. Surgeons can use this data to preoperatively counsel families and ensure postoperative course of care is appropriately planned ahead of time.

Beatmung bei neuromuskulären Erkrankungen

Neuromuskuläre Erkrankungen betreffen das erste und zweite Motoneuron, die peripheren Nerven, die neuromuskulären Übertragung und die Muskelzelle. Es handelt sich um eine heterogene Gruppe von erblichen, degenerativen und autoimmunen Erkrankungen. Eine korrekte diagnostische Einordnung ist erforderlich, da zentralnervöse, kardiale, endokrine und weitere Begleitsymptome vorliegen können und für einige Erkrankungen bereits medikamentöse Therapien zur Verfügung stehen. Neuromuskuläre Erkrankungen haben eine große Bedeutung in der neuromuskulären Beatmungsmedizin. Die respiratorische Symptomatik resultiert in der Regel aus Paresen der am Atmen, Schlucken oder Husten beteiligten Muskulatur mit konsekutiver ventilatorischer Insuffienz, Dysphagie bis hin zur Speichelaspiration und Sekretretention. Mittels eines strukturierte Sekretmanagements und einer effektive nichtinvasive oder invasive Beatmungstherapie können neuromuskuläre Patienten viele Jahre mit guter Lebensqualität überleben. Themen dieses Kapitels sind ein Überblick über die neuromuskulären Erkrankungen, die Indikationen und Strategien der nichtinvasiven und der invasiven Beatmung und eine ausführliche Darstellung beatmungsmedizinisch besonders relevanter neuromuskulärer Erkrankungen wie der amyotrophe Lateralsklerose, des Guillain-Barré-Syndroms, der Myasthenia gravis und der Critical-Illness-Polyneuropathie/-Myopathie.

Correspondence: Guillain-Barré syndrome and hemorrhagic fever with renal syndrome

Jiao and colleagues reported a case of hemorrhagic fever with renal syndrome who developed respiratory failure and symmetrical flaccid paralysis of all extremities. Electrophysiology revealed peripheral nerve injuries mainly in axons. They reached a diagnosis of Guillain-Barré syndrome (GBS) associated with hemorrhagic fever with renal syndrome. Although the case is interesting, the diagnosis of GBS in such a patient should be with caution. Critical illness polyneuropathy (CIP) is an important and common differential diagnosis of GBS, especially in intensive care settings. Differentiating CIP from the axonal variants of GBS may be difficult on purely clinical grounds. Albumino-cytologic dissociation in CSF can help differentiate GBS from other disorders.

Electrodiagnostic studies in the intensive care unit: A comparison study 2 decades later

INTRODUCTION

Since the late 1980s, critical illness myopathy (CIM) and critical illness polyneuropathy (CIP) have been increasingly recognized in the intensive care unit (ICU). We explored whether these causes of ICU weakness were now more likely to lead to electrodiagnostic studies (EDX) at our institution than they were 19-20 years earlier.

METHODS

We reviewed 100 consecutive ICU patients who underwent EDX from 2009 to 2015 and compared them to a previously reported study population from 1990-1995.

RESULTS

Thirty-seven (39%) had CIM, CIP, or both versus 55% in the previous study (P = 0.04). Thirty-four (36%) were diagnosed with "traditional" pre-ICU causes of weakness, such as motor neuron disease or Guillain-Barre syndrome, versus 29% in the earlier study (P = 0.3).

DISCUSSION

CIM and CIP continue to be common disorders that lead to ICU EDX, but their proportion declined compared with 19-20 years earlier, possibly due to the perceived role and selective use of EDX in the ICU. Muscle Nerve 57: 772-776, 2018.

The neurology of solid organ transplantation

Transplantation is the rescue treatment for end-stage organ failure with more than 110,000 solid organs transplantations performed worldwide annually. Recent advances in transplantation procedures and posttransplantation management have improved long-term survival and quality of life of transplant recipients, shifting the focus from acute perioperative critical care needs toward long-term chronic medical problems. Neurologic complications affect up to 30-60 % of solid organ transplant recipients. Common etiologies include opportunistic infections and toxicities of antirejection medications, and wide spectrum of toxic and metabolic disturbances. Most complications are common to all allograft types, but some are relatively specific for individual allograft types (e.g., central pontine myelinolysis in liver transplant recipients). Close collaboration between neurologists and other transplant team members is essential for effective management. Early recognition of complications and accurate diagnosis leading to timely treatment is essential to reduce the morbidity and improve the overall transplant outcome.

Quantitative neuromuscular ultrasound in intensive care unit-acquired weakness: A systematic review

Intensive care unit-acquired weakness (ICU-AW) causes significant morbidity and impairment in critically ill patients. Recent advances in neuromuscular ultrasound (NMUS) allow evaluation of neuromuscular pathology early in critical illness. Here we review application of ultrasound in ICU-AW. MEDLINE-indexed articles were searched for terms relevant to ultrasound and critical illness. Two reviewers evaluated the resulting abstracts (n = 218) and completed full-text review (n = 13). Twelve studies and 1 case report were included. Ten studies evaluated muscle thickness or cross-sectional area (CSA): 8 reported a decrease, and 2 reported no change. Two studies reported preservation of muscle thickness in response to neuromuscular electrical stimulation, and 1 found no preservation. One study found decreases in gray-scale standard deviation, but no change in echogenicity. One study described increases in echogenicity and fasciculations. Ultrasound reliability in ICU-AW is not fully established. Further investigation is needed to identify ultrasound measures that reliably predict clinical, electrodiagnostic, and pathologic findings of ICU-AW.

Critical illness polyneuropathy and myopathy in a rural area in Vietnam

INTRODUCTION

Critical illness polyneuropathy, myopathy and polyneuromyopathy, grouped under the term CIP/CIM, share several risk factors and are associated with debilitating outcomes.

OBJECTIVE

To assess the incidence and distribution of CIP/CIM subtypes and evaluate the risk factors and outcomes of CIP/CIM in a rural hospital in Vietnam.

METHOD

One hundred and thirty three critically ill patients treated more than ten days in the ICU were enrolled. The Medical Research Council (MRC) sum scores and the Overall Neuropathy Limitations Scale (ONLS) score were calculated and risk factors were monitored. Extensive electrodiagnostic investigations were performed to confirm the diagnosis of CIP/CIM.

RESULTS

CIP/CIM was diagnosed in 73 (55%) patients. The distribution of polyneuropathy, myopathy and polyneuromyopathy was 35 (48%), 16 (22%) and 22 (30%), respectively. Independent risk factors included systemic inflammatory response syndrome, shock, and electrolyte disturbances. Compared to patients without CIP/CIM, patients with CIP/CIM experienced a mortality rate of 49% vs. 30%, a length of stay in ICU of 20.3days vs. 14.3days, an ONLS score at day thirty of 4.2 vs. 1.3 and at day ninety of 2.7 vs. 1.8.

CONCLUSION

The study revealed that the diagnosis of CIP/CIM was associated with significantly poorer outcomes in comparison to controls.

Life-threatening necrotizing myometritis, due to Group A streptococcus - still a life-threatening condition

Puerperal infection with Group A streptococcus (GAS) can present with few symptoms and rapidly progress to a life-threatening condition. Often, the infection can be treated with antibiotics. Delay in diagnosis increases risk of sepsis, multiorgan failure, and death. GAS infection is a differential diagnose for all postpartum women with unexplained symptoms.

Critical illness polyneuropathy and myopathy: a systematic review

Critical illness polyneuropathy and critical illness myopathy are frequent complications of severe illness that involve sensorimotor axons and skeletal muscles, respectively. Clinically, they manifest as limb and respiratory muscle weakness. Critical illness polyneuropathy/myopathy in isolation or combination increases intensive care unit morbidity via the inability or difficulty in weaning these patients off mechanical ventilation. Many patients continue to suffer from decreased exercise capacity and compromised quality of life for months to years after the acute event. Substantial progress has been made lately in the understanding of the pathophysiology of critical illness polyneuropathy and myopathy. Clinical and ancillary test results should be carefully interpreted to differentiate critical illness polyneuropathy/myopathy from similar weaknesses in this patient population. The present review is aimed at providing the latest knowledge concerning the pathophysiology of critical illness polyneuropathy/myopathy along with relevant clinical, diagnostic, differentiating, and treatment information for this debilitating neurological disease.

Associations between muscle-related cytokines and selected patient outcomes in the ICU

INTRODUCTION

Systemic cytokines produced by contracting skeletal muscles may affect the onset and severity of intensive care unit (ICU)-acquired weakness after critical illness.

AIMS

The purpose of this research was to determine the serum levels of interleukin (IL)-8, IL-15, and tumor necrosis factor-α (TNF-α) among patients receiving mechanical ventilation for >48 hr and examine the relationships of these myokines to outcomes of patient delirium, muscle strength, activities of daily living (ADLs), duration of mechanical ventilation, and length of ICU stay.

METHODS

In this exploratory, repeated-measures interventional study, the 36 participants received 20 min of once-daily in-bed or out-of-bed activity using an established early progressive mobility protocol after physiologic stability had been demonstrated for >4 hr in the ICU. Blood samples were drawn on 3 consecutive days, beginning on the day of study enrollment, for serum cytokine quantification.

RESULTS

IL-8, IL-15, and TNF-α were highly variable and consistently elevated in participants compared to normal healthy adults. About 1/3 of participants were positive for significant muscle weakness at discharge from ICU. Repeated values of mean postactivity IL-8 serum values were significantly associated only with ADL following ICU discharge. There were no significant associations with repeated values of mean postactivity IL-15 or TNF-α serum values and outcomes.

CONCLUSION

Results provide preliminary data for exploring the potential effects of elevated serum values IL-8 and IL-15 in muscle health and TNF-α for muscle damage, including effect sizes to calculate the sample sizes needed for future studies.

The posterior cricoarytenoid muscle is spared from MuRF1-mediated muscle atrophy in mice with acute lung injury

Background

Skeletal muscle wasting in acute lung injury (ALI) patients increases the morbidity and mortality associated with this critical illness. The contribution of laryngeal muscle wasting to these outcomes is unknown, though voice impairments and aspiration are common in intensive care unit (ICU) survivors. We evaluated the intrinsic laryngeal abductor (PCA, posterior cricoarytenoid), adductor (CT, cricothyroid) and limb (EDL, extensor digitorum longus) muscles in a mouse model of ALI.

Methods

Escherichia coli lipopolysaccharides were instilled into the lungs of adult male C57Bl6J mice (ALI mice). Limb and intrinsic laryngeal muscles were analyzed for fiber size, type, protein expression and myosin heavy chain (MyHC) composition by SDS-PAGE and mass spectroscopy.

Results

Marked muscle atrophy occurred in the CT and EDL muscles, while the PCA was spared. The E3 ubiquitin ligase muscle ring finger-1 protein (MuRF1), a known mediator of limb muscle atrophy in this model, was upregulated in the CT and EDL, but not in the PCA. Genetic inhibition of MuRF1 protected the CT and EDL from ALI-induced muscle atrophy. MyHC-Extraocular (MyHC-EO) comprised 27% of the total MyHC in the PCA, distributed as hybrid fibers throughout 72% of PCA muscle fibers.

Conclusion

The vocal cord abductor (PCA) contains a large proportion of fibers expressing MyHC-EO and is spared from muscle atrophy in ALI mice. The lack of MuRF1 expression in the PCA suggests a previously unrecognized mechanism whereby this muscle is spared from atrophy. Atrophy of the vocal cord adductor (CT) may contribute to the impaired voice and increased aspiration observed in ICU survivors. Further evaluation of the sparing of muscles involved in systemic wasting diseases may lead to potential therapeutic targets for these illnesses.

Mechanisms for muscle health in the critically ill patient

Human skeletal muscles are continually remodeled to match the function required of them. Diameter, strength, and vascular supply are altered when a muscle group experiences contraction and resistance. The purpose of this article is to describe selected muscle signaling pathways that contribute to muscle remodeling. Multiple factors affect the cellular and molecular remodeling of muscles and at least 2 of them-exercise and protein/calorie delivery-are under the direct care of intensive care unit (ICU) clinicians. Activating signaling pathways may promote preservation of muscle mass and function. Interventions to prevent muscle atrophy have potential to reduce ICU-acquired weakness and positively affect quality of life in survivors after ICU hospitalization. Exploring information generated by genomic and proteomic investigations about muscle signaling pathways can help the ICU clinician evaluate the benefits and risks of interventions to maintain muscle health early in critical illness.

Muscle weakness predicts pharyngeal dysfunction and symptomatic aspiration in long-term ventilated patients

BACKGROUND

Prolonged mechanical ventilation is associated with muscle weakness, pharyngeal dysfunction, and symptomatic aspiration. The authors hypothesized that muscle strength measurements can be used to predict pharyngeal dysfunction (endoscopic evaluation-primary hypothesis), as well as symptomatic aspiration occurring during a 3-month follow-up period.

METHODS

Thirty long-term ventilated patients admitted in two intensive care units at Massachusetts General Hospital were included. The authors conducted a fiberoptic endoscopic evaluation of swallowing and measured muscle strength using medical research council score within 24 h of each fiberoptic endoscopic evaluation of swallowing. A medical research council score less than 48 was considered clinically meaningful muscle weakness. A retrospective chart review was conducted to identify symptomatic aspiration events.

RESULTS

Muscle weakness predicted pharyngeal dysfunction, defined as either valleculae and pyriform sinus residue scale of more than 1, or penetration aspiration scale of more than 1. Area under the curve of the receiver-operating curves for muscle strength (medical research council score) to predict pharyngeal, valleculae, and pyriform sinus residue scale of more than 1, penetration aspiration scale of more than 1, and symptomatic aspiration were 0.77 (95% CI, 0.63-0.97; P = 0.012), 0.79 (95% CI, 0.56-1; P = 0.02), and 0.74 (95% CI, 0.56-0.93; P = 0.02), respectively. Seventy percent of patients with muscle weakness showed symptomatic aspiration events. Muscle weakness was associated with an almost 10-fold increase in the symptomatic aspiration risk (odds ratio = 9.8; 95% CI, 1.6-60; P = 0.009).

CONCLUSION

In critically ill patients, muscle weakness is an independent predictor of pharyngeal dysfunction and symptomatic aspiration. Manual muscle strength testing may help identify patients at risk of symptomatic aspiration.

Electrophysiology of neuromuscular disorders in critical illness

INTRODUCTION

Neuromuscular disorders, predominantly critical illness myopathy (CIM) and critical illness polyneuropathy (CIP) occur in approximately one-third of patients in intensive care units. The aim of this study was to review the important role of electrophysiology in this setting.

RESULTS

In CIM, sarcolemmal inexcitability causes low amplitude compound muscle action potentials (CMAPs) that may have prolonged durations. Needle electrode examination usually reveals early recruitment of short duration motor unit potentials, often with fibrillation potentials. In CIP, the findings are usually those of a generalized axonal sensorimotor polyneuropathy. Direct muscle stimulation aids in differentiating CIP and CIM and in identifying mixed disorders along with other electrodiagnostic and histopathologic studies. Identifying evolving reductions in fibular CMAP amplitudes in intensive care unit (ICU) patients predicts development of neuromuscular weakness.

CONCLUSIONS

Knowledge of the various neuromuscular disorders in critically ill patients, their risk factors, and associated electrodiagnostic findings can lead to development of a rational approach to diagnosis of the cause of neuromuscular weakness in ICU patients.

[Critical illness polyneuropathy and critical illness myopathy]

Critical illness polyneuropathy (CIP) and critical illness myopathy (CIM) are frequent complications in critically ill patients and both are associated with sepsis, systemic inflammatory response syndrome (SIRS) and multiorgan failure. Major signs are muscle weakness and problems of weaning from the ventilator. Both CIP and CIM lead to elongated times of ventilation, elongated hospital stay, elongated times of rehabilitation and increased mortality. Electrophysiological measurements help to detect CIP and CIM early in the course of the disease. State of the art sepsis therapy is the major target to prevent the development of CIP and CIM. Although no specific therapy of CIP and CIM has been established in the past, the diagnosis generally improves the therapeutic management (weaning from the ventilator, early physiotherapy, etc.). This review provides an overview of clinical and diagnostic features of CIP and CIM and summarizes current pathophysiological and therapeutic concepts.