Neuromuscular disorders in critical illness

Neuromuscular disorders in the background of critical illness are under diagnosed. Standardized screening for weakness in the intensive care unit (ICU) setting is uncommon and persistent weakness as a sequel of critical illness is usually not recognized by physicians in the ICU for whom survival from acute illness is the primary outcome. The spectrum of illness ranges from isolated nerve entrapment with focal pain or weakness, to disuse muscle atrophy with mild weakness, and to severe myopathy or neuropathy with associated severe, prolonged weakness. This update focuses on neuromuscular disorders occurring in the critical care set up associated with diffuse and severe weakness.     

Neurological complications of sepsis: critical illness polyneuropathy and myopathy

Sepsis may cause not only failure of parenchymal organs but can also cause damage to peripheral nerves and skeletal muscles. It is now recognized that sepsis-mediated disorders of the peripheral nerves and the muscle, called critical illness polyneuropathy (CIP) and critical illness myopathy, are responsible for weakness and muscle atrophy occurring de novo in intensively treated patients. CIP represents an acute axonal neuropathy that develops during treatment of severely ill patients and remits spontaneously, once the critical condition is under control. The course is monophasic and self-limiting. Among the critical illness myopathies, three main types have been identified: a non-necrotizing “cachectic” myopathy (critical illness myopathy in the strict sense), a myopathy with selective loss of myosin filaments (“thick filament myopathy”) and an acute necrotizing myopathy of intensive care. Clinical manifestations of both critical illness myopathies and CIP include delayed weaning from the respirator, muscle weakness, and prolonging of the mobilization phase. The pathogenesis of these neuromuscular complications of sepsis is not understood in detail but most authors assume that the inflammatory factors that mediate systemic inflammatory response and multiple organ failure are closely involved. In thick filament myopathy and acute necrotizing myopathy, administration of steroids and neuromuscular blocking agents may act as triggers. Specific therapies have not been discovered. Stabilization of the underlying critical condition and elimination of sepsis appear to be of major importance. Steroids and muscle relaxants should be avoided or administered at the lowest dose possible. Received: 12 April 2001, Accepted: 23 April 2001     

Causes of neuromuscular weakness in the intensive care unit: A study of ninety-two patients

The spectrum of neuromuscular disorders among intensive care unit (ICU) patients has shifted toward disorders acquired within the ICU and away from “traditional” neuromuscular disorders that lead to ICU admission. We sought to assess this spectrum by determining the causes and relative frequencies of neuromuscular disorders that led to electromyography (EMG) examinations in our ICU population. Ninety-two patients were studied over a 4½-year period. Twenty-six (28%) had neuromuscular disorders (mainly Guillain–Barré syndrome, myopathy, and motor neuron disease) that led to ICU admission. Among patients who developed weakness in the ICU, there was a predominance of organ transplant patients and patients with the systemic inflammatory response syndrome and multiorgan dysfunction. Thirty-nine (42%) developed acute myopathy (consistent with critical illness myopathy in most), and 13% developed acute axonal sensorimotor polyneuropathy (mainly critical illness polyneuropathy). Patients with acute myopathy and acute axonal sensorimotor polyneuropathy had similar functional outcomes. We conclude that among patients who underwent EMG in our ICU population, acute myopathy is three times as common as acute axonal polyneuropathy, and the outcomes from acute myopathy and acute axonal polyneuropathy may be similar. © 1998 John Wiley & Sons, Inc. Muscle Nerve 21:610–617, 1998.     

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

ObjectiveThe 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).MethodsAn 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.Results111 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.ConclusionsCIN/CIM was more prevalent among COVID-19 ICU patients with severe illness.SignificanceCOVID-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.     

Optimizing testing methods and collection of reference data for differentiating critical illness polyneuropathy from critical illness MYOPATHIES

Introduction: In severe acute quadriplegic myopathy in intensive care unit (ICU) patients, muscle fibers are electrically inexcitable; in critical illness polyneuropathy, the excitability remains normal. Conventional electrodiagnostic methods do not provide the means to adequately differentiate between them. In this study we aimed to further optimize the methodology for the study of critically ill ICU patients and to create a reference database in healthy controls. Methods: Different electrophysiologic protocols were tested to find sufficiently robust and reproducible techniques for clinical diagnostic applications. Results: Many parameters show large test–retest variability within the same healthy subject. Reference values have been collected and described as a basis for studies of weakness in critical illness. Conclusions: Using the ratio of neCMAP/dmCMAP (response from nerve and direct muscle stimulation), refractory period, and stimulus–response curves may optimize the electrodiagnostic differentiation of patients with critical illness myopathy from those with critical illness polyneuropathy. Muscle Nerve 53 : 555–563, 2016     

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

ObjectiveTo 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).MethodsTwenty-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.ResultsMVRC 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.ConclusionsAltered 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.SignificanceCIM is often under-recognized by intensivists, and large-scale longitudinal studies are needed to determine its incidence and pathogenesis.     

Successful Enteral Nutritional Support in the Neurocritical Care Unit

Purpose  Adequate caloric intake is associated with improved outcome in neurocritical illness, but factors influencing the provision of enteral nutrition (EN) have not been systematically evaluated. The primary goal of the study was to determine the EN intake of neurosurgical intensive care unit (ICU) patients within the first week of illness and investigate the factors contributing to achieving caloric goals. Methods  A retrospective cohort of adult patients admitted to the neurosurgery service (NS) during August 2005–August 2006 were randomly selected and stratified into three groups based on their ICU-admission Glasgow Coma Scale Score (GCS) (GCS > 11, GCS 8–11, GCS 4–7). Daily EN intake, GCS, and other clinical data were collected. Results  A total of 71 patients were included (GCS > 11 = 23, GCS 8–11 = 23, GCS 4–7 = 25). Admitting diagnoses included traumatic brain injury (TBI) (32%), subarachnoid hemorrhage (SAH) (32%), and intracerebral hemorrhage (17%). The overall in-hospital mortality was 23.9%. Overall, the maximum daily mean calories provided was 1,100 kcal (mean of 55% of caloric goal on hospital day 6). The median time to feeding was approximately 3 days in each group. GCS did not appear to significantly affect the mean % of caloric goal administered in patients with a minimum daily GCS ≤ 11 (P = 0.053). Multivariate analysis revealed that clinical care factors, such as time to EN orders and enteral access confirmation, were significant impediments to EN provision (P = 0.001). Conclusion  System-based clinical care factors appear to have great impact on the successful provision of EN in the first week of neurocritical illness.     

Role of geriatric hospitals for dementia care in the community

In dementia care, behavioural and psychological symptoms of dementia and physical illness in patients with dementia impose a marked care burden and require medical intervention. Therefore, it is important for patients and their families to select appropriate medical institutions and facilities with nursing units specializing in the care of behavioural and psychological symptoms of dementia, such as geriatric hospitals, which are required to deal with various aspects of dementia. Geriatric hospitals should offer two treatment approaches: a care unit for patients with behavioural and psychological symptoms of dementia or dementia with physical illness, and a multidisciplinary team approach involving physicians, nurses, psychologists, and social workers who provide coping strategies for dementia patients.     

Small‐nerve‐fiber pathology in critical illness documented by serial skin biopsies

Introduction: Small‐fiber pathology can develop in the acute phase of critical illness and may explain chronic sensory impairment and pain in critical care survivors. Methods: Eleven adult ischemic stroke patients in a neurocritical care unit were enrolled in an observational cohort study. Intraepidermal nerve fiber density (IENFD) in the distal leg was assessed on admission to the intensive care unit and 10–14 days later, together with electrophysiological testing. Results: Of the 11 patients recruited, 9 (82%) had sepsis or multiple‐organ failure. Median IENFD on admission (5.05 fibers/mm) decreased significantly to 2.18 fibers/mm (P < 0.001), and abnormal IENFD was found in 6 patients (54.5%). Electrodiagnostic signs of large‐fiber neuropathy and/or myopathy were found in 6 patients (54.5%), and autonomic dysfunction was found in 2 patients (18.2%). Conclusion: Serial IENFD measurements confirmed the development of small‐fiber sensory involvement in the acute phase of critical illness. Muscle Nerve 52 : 28–33, 2015     

Neuromuscular involvement in COVID-19 critically ill patients

ObjectiveCoronavirus disease 2019 (COVID-19) has a high incidence of intensive care admittance due to the severe acute respiratory syndrome (SARS). Intensive care unit (ICU)-acquired weakness (ICUAW) is a common complication of ICU patients consisting of symmetric and generalised weakness. The aim of this study was to determine the presence of myopathy, neuropathy or both in ICU patients affected by COVID-19 and whether ICUAW associated with COVID-19 differs from other aetiologies.MethodsTwelve SARS CoV-2 positive patients referred with the suspicion of critical illness myopathy (CIM) or polyneuropathy (CIP) were included between March and May 2020. Nerve conduction and concentric needle electromyography were performed in all patients while admitted to the hospital. Muscle biopsies were obtained in three patients.ResultsFour patients presented signs of a sensory-motor axonal polyneuropathy and seven patients showed signs of myopathy. One muscle biopsy showed scattered necrotic and regenerative fibres without inflammatory signs. The other two biopsies showed non-specific myopathic findings.ConclusionsWe have not found any distinctive features in the studies of the ICU patients affected by SARS-CoV-2 infection.SignificanceFurther studies are needed to determine whether COVID-19-related CIM/CIP has different features from other aetiologies. Neurophysiological studies are essential in the diagnosis of these patients.     

Enhanced Skills Training and Health Care Management for Older Persons with Severe Mental Illness

This report describes a combined skills training (ST) and health management (HM) intervention for older adults with severe mental illness (SMI) and one-year pilot study outcomes. Findings are reported for twelve older persons with SMI (age 60+) who received ST+HM and twelve who received only HM. ST addressed interpersonal and independent living skills. HM included promotion of preventive health care. ST+HM was associated with improved social functioning and independent living skills, whereas functioning remained constant or declined for the HM only group. Both groups receiving HM demonstrated increased use of preventive health services and identification of previously undetected medical disorders.     

Anxiety disorders and comorbid medical illness

OBJECTIVE: To provide an overview of the role of anxiety disorders in medical illness. METHOD: The Anxiety Disorders Association of America held a multidisciplinary conference from which conference leaders and speakers reviewed presentations and discussions, considered literature on prevalence, comorbidity, etiology and treatment, and made recommendations for research. Irritable bowel syndrome (IBS), asthma, cardiovascular disease (CVD), cancer and chronic pain were reviewed. RESULTS: A substantial literature supports clinically important associations between psychiatric illness and chronic medical conditions. Most research focuses on depression, finding that depression can adversely affect self-care and increase the risk of incident medical illness, complications and mortality. Anxiety disorders are less well studied, but robust epidemiological and clinical evidence shows that anxiety disorders play an equally important role. Biological theories of the interactions between anxiety and IBS, CVD and chronic pain are presented. Available data suggest that anxiety disorders in medically ill patients should not be ignored and could be considered conjointly with depression when developing strategies for screening and intervention, particularly in primary care. CONCLUSIONS: Emerging data offer a strong argument for the role of anxiety in medical illness and suggest that anxiety disorders rival depression in terms of risk, comorbidity and outcome. Research programs designed to advance our understanding of the impact of anxiety disorders on medical illness are needed to develop evidence-based approaches to improving patient care.     

Approach to neuromuscular disorders in the intensive care unit

Neuromuscular disorders increasingly are recognized as a complication in patients in the intensive care unit (ICU) and represent a common cause of prolonged ventilator dependency. The distinct syndromes of critical illness myopathy, prolonged neuromuscular blockade, and critical illness polyneuropathy (CIP) may arise as a consequence of sepsis, multi-organ failure, and exposure to various medications—notably, intravenous corticosteroids and neuromuscular blocking agents—but the pathophysiology of these disorders remains poorly understood. More than one syndrome may occur simultaneously, and the distinctions may be difficult in a particular patient, but a specific diagnosis usually can be established after careful clinical, electrodiagnostic, and, when necessary, histological evaluation. For example, asthmatics requiring treatment with corticosteroids and neuromuscular blocking agents may develop an acute myopathy characterized by generalized weakness, preserved eye movements, elevated creatine kinase levels, and myopathic motor units on electromyography (EMG). Muscle biopsy demonstrates distinctive features of thick (myosin) filament loss on ultrastructural studies. Conversely, those with a prolonged ICU course that is complicated by episodes of sepsis with failure to wean from the ventilator, distal or generalized flaccid limb weakness, and areflexia probably have CIP. EMG in these patients demonstrates reduced or absent motor and sensory potentials with neurogenic motor units. Prolonged neuromuscular blockade most commonly occurs in patients with renal failure who have received prolonged infusions of neuromuscular blockers. There is severe flaccid, areflexic paralysis with normal sensation, facial weakness, and ophthalmoparesis that persists for days or weeks after the neuromuscular blockers have been discontinued. Repetitive nerve stimulation shows a decrement of the compound muscle action potential and, in most cases, establishes a disorder of neuromuscular transmission. With the recent epidemic of West Nile virus infection, a clinical syndrome of acute flaccid paralysis with several features indistinguishable from poliomyelitis has emerged. This article critically examines the clinical, electrophysiological, and pathological features of these and other acute neuromuscular syndromes that arise in the context of ICU care and summarizes the current understanding of the pathophysiology and treatment of these disorders.     

Outcomes for Rural Medicaid Clients with Severe Mental Illness in Fee for Service versus Managed Care

This study compared outcomes for rural Medicaid clients with severe mental illness in fee for service versus managed care programs. Interviews were conducted with 305 Medicaid clients in rural Oregon (166 in fee for service and 139 in managed care). Logistic and multivariate regression analyses were used to examine client satisfaction, safety, symptoms, functioning, and family satisfaction in the fee for service versus managed care groups. There was no evidence that conversion of the Medicaid mental health system from fee for service to managed care led to changes in outcomes for rural clients with severe mental illness.     

Is critical illness polyneuropathy associated with decreased heart rate variability?

Introduction

This pilot study assessed the association between critical illness polyneuropathy (CIP) and decreased heart rate variability (HRV) in intensive care patients.

Methods

All patients admitted to the intensive care unit and expected to be ventilated for at least 72 hours were included and underwent weekly electromyograms and HRV analyses for three weeks. HRV was assessed by time domain analysis of 24 h recording electrocardiograms, and alterations in HRV were assessed as the square root of the mean squared differences of successive RR intervals (RMSSD) ≤ 15.

Results

We evaluated 26 patients, 12 men and 14 women, median age 64 years. During follow-up, 12 patients died and 9 developed CIP. CIP was not associated with age, sex, simplified acute physiology score II and treatment agents. Altered RMSSD tended to be associated with onset of CIP (P = 0.06). Altered RMSSD occurred earlier or at the same time as electromyogram abnormalities in all CIP patients, but the difference was not significant.

Conclusion

Altered HRV, may be associated with the onset of CIP in ICU patients. Although not statistically significant (P = 0.06), altered RMSSD may be a surrogate marker of CIP in ICU patients undergoing mechanical ventilation. The physiological pathway linking HRV and CIP remains uncertain.     

Sleep and psychological health during early recovery from critical illness: An observational study

Introduction

Intensive care patients often report sleep disruption in ICU and during recovery from critical illness.

Objectives

To assess: (i) patients' self-reported sleep quality in ICU, on the hospital ward after transfer from ICU and two and six months after hospital discharge; (ii) whether patients who report sleep disruption in ICU continue to report sleep disruption in recovery and (iii) whether prehospital insomnia, experiences in intensive care, quality of life and psychological health are associated with sleep disruption six months after hospital discharge.

Methods

Patients completed self-report measures on sleep quality at five time points: prior to hospitalization, in ICU, the hospital ward, two months and six months after hospital discharge, their intensive care experiences two months after discharge and psychological health and quality of life six months after discharge.

Results

Patients (n = 222) were aged (mean ± SD) 57.2 ± 17.2 years, 35% female, had mean ICU stay of 5 ± 6 days and BMI of 26 ± 5. Over half the participants (57%) reported poor sleep at six months; for 10% this was at all time points after ICU admission. Prehospitalization insomnia (p = .0005), sleep quality on the ward (p = .006), anxiety (p = .002), and mental (p = .0005) and physical health (p = .0005) were independently associated with poorer sleep quality in survivors six months after ICU treatment.

Conclusions

Sleep is a significant issue for more than half of survivors 6 months after ICU treatment. Some influencing factors, such as hospital sleep quality, anxiety, physical health and mental health, are potentially modifiable and should be targeted in recovery programs.     

小组配合抢救模式在神经外科急危重症术前抢救中的应用效果

目的探讨小组配合抢救模式在神经外科急危重症患者术前抢救中的应用效果。方法选取我科2016年2月至2016年11月急诊入院手术患者60例为观察组,2015年5月至2016年1月急诊入院手术患者60例为对照组;观察组采用小组配合抢救模式接诊抢救,对照组采用当班护士接诊抢救。结果观察组喉罩置入建立人工气道时间、血管活性药物使用显效时间、患者入科至送入手术间时间均短于对照组(P0.05)、健康宣教落实质量均优于对照组(P0.01)、护理病历书写质量优于对照组(P0.05)。结论将小组配合抢救模式应用到神经外科急危重症患者术前抢救中,能提高护士抢救配合的主动性、准确性以及默契性,缩短术前抢救时间确保手术顺利进行,有效提高抢救成功率。     

Neuromuscular manifestations of critical illness

Critical illness, more precisely defined as the systemic inflammatory response syndrome (SIRS), occurs in 20%-50% of patients who have been on mechanical ventilation for more than 1 week in an intensive care unit. Critical illness polyneuropathy (CIP) and myopathy (CIM), singly or in combination, occur commonly in these patients and present as limb weakness and difficulty in weaning from the ventilator. Critical illness myopathy can be subdivided into thick-filament (myosin) loss, cachectic myopathy, acute rhabdomyolysis, and acute necrotizing myopathy of intensive care. SIRS is the predominant underlying factor in CIP and is likely a factor in CIM even though the effects of neuromuscular blocking agents and steroids predominate in CIM. Identification and characterization of the polyneuropathy and myopathy depend upon neurological examination, electrophysiological studies, measurement of serum creatine kinase, and, if features suggest a myopathy, muscle biopsy. The information is valuable in deciding treatment and prognosis.     

The association between physical illness and major depressive episode in general practice

Østergaard SD, Foldager L. The association between physical illness and major depressive episode in general practice. Objective: Physical illness and depression are associated. However, it remains unclear whether this association is sufficiently strong to merit systematic screening for depression among primary care patients suffering from physical illness. In the present study, we investigated the strength of the association between physical illness and depression among patients in general practice. Method: Four thousand two hundred and seventy‐one consecutive primary care patients completed a diagnostic depression questionnaire. The general practitioner evaluated the patients’ physical health, which was then compared to their diagnostic status of depression. Results: Physical illness was associated with the presence of depression. Two hundred and thirty‐six patients (5.5%) fulfilled diagnostic criteria for depression. Fourteen of these suffered from extreme physical illness, 27 from at least severe physical illness and 96 from at least moderate physical illness. The number needed to screen decreased with increasing severity and chronicity of the physical illness. Conclusions: Depression is relatively common in primary care patients suffering from physical illness, particularly if the illness is severe and chronic. However, relatively few depressed patients suffer from a comorbid physical illness. Screening for depression among patients with physical illness may therefore only have a modest impact on the under‐recognition of depression in general practice.