Critical illness myopathy and polyneuropathy

Area of Science:

• Neurology
• Intensive Care Medicine
• Pathophysiology

Background:

• Neuromuscular weakness is a common complication in critically ill patients.
• This weakness can lead to delayed recovery and prolonged mechanical ventilation.
• Critical illness polyneuropathy (CIP) and critical illness myopathy (CIM) are primary causes.

Purpose of the Study:

• To review the clinical and electrophysiologic features of CIP and CIM.
• To explore the underlying pathophysiology of these neuromuscular disorders.
• To provide insights into the diagnosis and management of critical illness-related weakness.

Main Methods:

• Literature review of clinical and electrophysiologic findings.
• Analysis of putative pathophysiological mechanisms.
• Inclusion of evidence from animal models for critical illness myopathy.

Main Results:

• Critical illness polyneuropathy (CIP) affects up to one-third of patients with systemic inflammatory response syndrome (sepsis).
• Critical illness myopathy (CIM) frequently occurs with corticosteroid and neuromuscular blocking agent use.
• Animal models suggest CIM involves muscle membrane inexcitability due to altered sodium currents and myosin loss.

Conclusions:

• CIP and CIM are distinct but often co-existing disorders in critical illness.
• Understanding their specific features and pathophysiology aids in evaluation and management.
• Further research into mechanisms may lead to targeted therapies for neuromuscular weakness.