What is critical illness myopathy?
Critical illness myopathy is a primary myopathy that develops acutely over days in critically ill patients usually with sepsis or multiorgan failure.
It is characterized by severe flaccid paralysis that can affect all muscles, including respiratory muscles.
EMG may show reduction in compound muscle action potential amplitudes with prolonged durations and normal sensory nerve action potentials, reduced muscle excitability on direct stimulation, and myopathic motor unit action potentials.
Muscle biopsy shows loss of thick myosin filaments and necrosis. Critical illness polyneuropathy can be concurrent.
With supportive care, the prognosis for recovery is variable (weeks to 1 year), but there may be considerable morbidity.
