Muscular disease in ICU. When should they be evoked? How to advance in the diagnosis?

Abstract

Muscular and neuromuscular junction diseases include several hundreds entities. Some are acquired like inflammatory myopathy, drug-induced myopathy, and myasthenia gravis; others are inborn like muscular dystrophy, congenital myopathy, metabolic myopathy, and channelopathy.

Even if scarce, they can be encountered in the intensive care unit (ICU), mainly in three situations: (1) severe worsening or complication of a known muscular disease; (2) suspicion of muscular disease in a patient presenting with acute motor weakness, severe bulbar dysfunction, rhabdomyolysis, acute respiratory distress or cardiac dysfunction (altered systolic function, impaired heart conduction or arrhythmia); (3) occurrence of muscle disease acquired while the patient is hospitalized in the ICU, that can be responsible for prolonged mechanical ventilation and increased mortality. Some muscular diseases should be suspected when patients present with encephalopathy, epilepsy, metabolic or ionic disturbance (acidosis, hypo- or hyperkaliemia) even in the absence of muscular symptoms.

We will successively discuss which circumstances may suggest an underlying muscular or neuromuscular junction disease, how diagnosis can be assessed, and finally which are the main muscular or neuromuscular diseases according to their clinical presentation in the ICU.