What is the definition of Intensive Care Unit (ICU) acquired weakness, specifically neuromuscular weakness?

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From the Guidelines

ICU-acquired weakness (ICUAW) is a neuromuscular disorder characterized by symmetrical limb weakness that develops during an intensive care unit stay with no other identifiable cause, typically affecting both the peripheral nerves and muscles. This condition is a significant concern in the ICU setting, as it can lead to prolonged hospital stays, delayed weaning from mechanical ventilation, and long-term functional disability. The definition of ICUAW is crucial for early identification and management, as it can significantly impact patient outcomes, including morbidity, mortality, and quality of life. Some key factors that contribute to the development of ICUAW include systemic inflammation, medication side effects, immobility, hyperglycemia, and impaired microcirculation 1. Patients with ICUAW often present with symmetrical flaccid weakness, decreased or absent deep tendon reflexes, and may require electrophysiological studies (EMG/NCS) and muscle biopsy for diagnosis. Management of ICUAW focuses on prevention through minimizing sedation, early mobilization, glycemic control, and judicious use of corticosteroids and neuromuscular blockers, as well as supportive treatment with intensive physical and occupational therapy once the condition has developed 1. It is essential to prioritize prevention and early intervention to mitigate the risk of ICUAW and its associated complications, as the condition can have a profound impact on patient outcomes and quality of life. Key considerations in the management of ICUAW include:

  • Early mobilization and physical therapy to prevent muscle atrophy and weakness
  • Minimizing sedation and promoting wakefulness to reduce the risk of delirium and cognitive impairment
  • Glycemic control to prevent hyperglycemia and its associated complications
  • Judicious use of corticosteroids and neuromuscular blockers to minimize medication-related side effects. By prioritizing these strategies, healthcare providers can reduce the risk of ICUAW and improve patient outcomes, including morbidity, mortality, and quality of life.

From the Research

Definition of ICU Acquired Weakness Neuromuscular

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 2. This condition is a frequent complication occurring in critically ill patients and can be classified into three subcategories using electrophysiological methods:

  • Critical illness polyneuropathy
  • Critical illness myopathy
  • Critical illness neuromyopathy

Causes and Risk Factors

The causes of ICU-AW are not well defined, but it is likely that inflammatory injury of nerve and/or muscle plays a role, potentiated by functional denervation and corticosteroids 3. Risk factors for ICU-AW include:

  • Sepsis
  • Corticosteroid administration
  • Hyperglycemia
  • Neuromuscular blockade
  • Increasing severity of illness
  • Age
  • Parenteral nutrition
  • Drugs
  • Immobility

Diagnosis and Prognosis

ICU-AW can be diagnosed using electrophysiological methods, and its prognosis is generally poor, with patients often experiencing delayed withdrawal of mechanical ventilation, extended hospitalization, and limited mobility 4, 5. The only intervention proven to reduce the incidence of ICU-AW is intensive insulin therapy 3.

Management and Treatment

The management of ICU-AW is essentially preventive, focusing on avoiding modifiable risk factors, especially duration of sedation and immobilization 2. Pharmacological approaches have been studied, but none have proven efficacy. Additional research is necessary to better delineate the causes and pathogenesis of ICU-AW and to identify potential preventive and therapeutic strategies 3, 6.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Intensive care unit-acquired weakness.

Handbook of clinical neurology, 2017

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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