Intensive care unit-acquired weakness

Intensive care unit-acquired weakness (ICUAW) is an acute clinical weakness that occurs in approximately 50% of ICU patients and is directly attributable to their critical care stay where other causes of weakness have been excluded. The condition is characterized by diffuse limb and respiratory muscle weakness with a relative sparing of the cranial/facial muscles and the autonomic nervous system. Patients with ICUAW are classified into three conditions: critical illness polyneuropathy (CIP), critical illness myopathy (CIM) or critical illness neuromyopathy (CINM) based on clinical criteria and further defined by electrophysiological studies and muscle biopsies. ICUAW is often a manifestation of immobility or a systemic inflammatory response syndrome, especially in long-term ventilated patients who have had systemic sepsis/multi-organ failure or exposure to high-dose corticosteroids, neuromuscular blockers or hyperglycaemia. It is associated with prolonged weaning from mechanical ventilation, increased mortality/length of ICU stay and long-term disability.