Hermans G, Van den Berghe G.
Clinical review: intensive care unit acquired weakness.
Crit Care. 2015 Aug 5;19(1):274. doi: 10.1186/s13054-015-0993-7. Epub 2015 Aug 5.
Abstract/Text
A substantial number of patients admitted to the ICU because of an acute illness, complicated surgery, severe trauma, or burn injury will develop a de novo form of muscle weakness during the ICU stay that is referred to as "intensive care unit acquired weakness" (ICUAW). This ICUAW evoked by critical illness can be due to axonal neuropathy, primary myopathy, or both. Underlying pathophysiological mechanisms comprise microvascular, electrical, metabolic, and bioenergetic alterations, interacting in a complex way and culminating in loss of muscle strength and/or muscle atrophy. ICUAW is typically symmetrical and affects predominantly proximal limb muscles and respiratory muscles, whereas facial and ocular muscles are often spared. The main risk factors for ICUAW include high severity of illness upon admission, sepsis, multiple organ failure, prolonged immobilization, and hyperglycemia, and also older patients have a higher risk. The role of corticosteroids and neuromuscular blocking agents remains unclear. ICUAW is diagnosed in awake and cooperative patients by bedside manual testing of muscle strength and the severity is scored by the Medical Research Council sum score. In cases of atypical clinical presentation or evolution, additional electrophysiological testing may be required for differential diagnosis. The cornerstones of prevention are aggressive treatment of sepsis, early mobilization, preventing hyperglycemia with insulin, and avoiding the use parenteral nutrition during the first week of critical illness. Weak patients clearly have worse acute outcomes and consume more healthcare resources. Recovery usually occurs within weeks or months, although it may be incomplete with weakness persisting up to 2 years after ICU discharge. Prognosis appears compromised when the cause of ICUAW involves critical illness polyneuropathy, whereas isolated critical illness myopathy may have a better prognosis. In addition, ICUAW has shown to contribute to the risk of 1-year mortality. Future research should focus on new preventive and/or therapeutic strategies for this detrimental complication of critical illness and on clarifying how ICUAW contributes to poor longer-term prognosis.
Zorowitz RD.
ICU-Acquired Weakness: A Rehabilitation Perspective of Diagnosis, Treatment, and Functional Management.
Chest. 2016 Oct;150(4):966-971. doi: 10.1016/j.chest.2016.06.006. Epub 2016 Jun 14.
Abstract/Text
ICU-acquired weakness (ICUAW) occurs with reported incidence rates from 25% to 100%. Risk factors include immobility, sepsis, persistent systemic inflammation, multiorgan system failure, hyperglycemia, glucocorticoids, and neuromuscular blocking agents. The pathophysiology remains unknown. Clinical features may be neuropathic, myopathic, or a combination of both. Although manual muscle testing is more practical in diagnosing ICUAW, the "gold standard" for the diagnosis of ICUAW remains electromyography and nerve conduction studies. The only potential interventions known to date to prevent ICUAW include insulin therapy and early rehabilitation, but patients still may develop activity limitations in the acute care hospital. For these patients, rehabilitation may continue in long-term care hospitals, inpatient rehabilitation facilities, or skilled nursing facilities. ICUAW is a catastrophic and debilitating condition that potentially leaves patients with permanent residual activity limitations and participation restrictions. Further research on ICUAW needs to better understand its pathophysiology so that more definitive preventive and therapeutic interventions may be developed.
Copyright © 2016 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.
Fan E, Cheek F, Chlan L, Gosselink R, Hart N, Herridge MS, Hopkins RO, Hough CL, Kress JP, Latronico N, Moss M, Needham DM, Rich MM, Stevens RD, Wilson KC, Winkelman C, Zochodne DW, Ali NA; ATS Committee on ICU-acquired Weakness in Adults; American Thoracic Society.
An official American Thoracic Society Clinical Practice guideline: the diagnosis of intensive care unit-acquired weakness in adults.
Am J Respir Crit Care Med. 2014 Dec 15;190(12):1437-46. doi: 10.1164/rccm.201411-2011ST.
Abstract/Text
RATIONALE: Profound muscle weakness during and after critical illness is termed intensive care unit-acquired weakness (ICUAW).
OBJECTIVES: To develop diagnostic recommendations for ICUAW.
METHODS: A multidisciplinary expert committee generated diagnostic questions. A systematic review was performed, and recommendations were developed using the Grading, Recommendations, Assessment, Development, and Evaluation (GRADE) approach.
MEASUREMENT AND MAIN RESULTS: Severe sepsis, difficult ventilator liberation, and prolonged mechanical ventilation are associated with ICUAW. Physical rehabilitation improves outcomes in heterogeneous populations of ICU patients. Because it may not be feasible to provide universal physical rehabilitation, an alternative approach is to identify patients most likely to benefit. Patients with ICUAW may be such a group. Our review identified only one case series of patients with ICUAW who received physical therapy. When compared with a case series of patients with ICUAW who did not receive structured physical therapy, evidence suggested those who receive physical rehabilitation were more frequently discharged home rather than to a rehabilitative facility, although confidence intervals included no difference. Other interventions show promise, but fewer data proving patient benefit existed, thus precluding specific comment. Additionally, prior comorbidity was insufficiently defined to determine its influence on outcome, treatment response, or patient preferences for diagnostic efforts. We recommend controlled clinical trials in patients with ICUAW that compare physical rehabilitation with usual care and further research in understanding risk and patient preferences.
CONCLUSIONS: Research that identifies treatments that benefit patients with ICUAW is necessary to determine whether the benefits of diagnostic testing for ICUAW outweigh its burdens.
庄司進一: 筋疾患の診断と治療．永井書店，1988.
Haymaker W: Bing’s local diagnosis in neurological diseases. Saint Louis: Mosby,1969.
Singer MB, Chong J, Lu D, Schonewille WJ, Tuhrim S, Atlas SW.
Diffusion-weighted MRI in acute subcortical infarction.
Stroke. 1998 Jan;29(1):133-6. doi: 10.1161/01.str.29.1.133.
Abstract/Text
BACKGROUND AND PURPOSE: Conventional imaging lacks sensitivity and specificity for the detection of early subcortical cerebral infarction. The purposes of our study were (1) to determine the accuracy of diffusion-weighted (DW) MRI for early subcortical infarction and (2) to determine the efficacy of DW MRI for differentiating acute from nonacute subcortical infarctions when conventional MR demonstrates multiple infarctions.
METHODS: Thirty-nine patients with clinically diagnosed acute subcortical infarction and 17 control subjects were imaged with both conventional and DW MRI from 7 hours to 4 days (mean, 2.0 days) after onset of symptoms. All images were read blinded to specific clinical findings. In all cases, the precise neuroanatomic locations of lesions were noted. These lesions were subsequently correlated by an experienced stroke neurologist to determine whether their locations correlated to the patients' symptoms.
RESULTS: The accuracy of DW MRI for acute subcortical infarction was 94.6%. In 4 of 39 cases, the acute infarction was not detected on conventional MRI. In 24 of 39 cases, conventional MRI showed the acute lesion as well as multiple other subcortical lesions. In each of these 24 cases, the DW MRI showed a single lesion to be acute, and in all 24 cases, that lesion corresponded to the patients' acute symptoms.
CONCLUSIONS: DW MRI has very high accuracy for acute subcortical infarction and can differentiate acute from nonacute lesions. These data have significant implications in guiding patient management and patient selection for clinical trials.
