Acquired weakness in the Intensive Care Unit: Polyneuropathy and myopathy of the critically ill patient

In recent years it has been increasingly recognized the presence of acquired neuromuscular disease in the critically ill patient, either as a form of acute myopathy, polyneuropathy or persistent blockade by neuromuscular relaxing agents. Critical illness polyneuropathy (CIP) and myopathy (CIM) are characterized for the presence of weakness, manifested as a quadriparesia, usually flaccid and symmetrical with reduction and/or absence of deep tendon reflexes. Involvement of phrenic nerve, intercostal and accessory respiratory muscles, atrophy and contractile dysfunction of the diaphragm have been described as a cause of delayed mechanical ventilation weaning. Although routine electrophys'ological examination sometimes cannot discriminate between patients with CIM and CIP, mainly because they usually coexist, it is useful to rule out other causes of neuromuscular weakness, being able to be practiced before sedation withdrawal. Despite some clinical trials propose as treatment options nutritional interventions with diverse supplements and antioxidants, intravenous immunoglobulin administration or activated protein C, none of them has demonstrated clinical utility. The only management so far is preventive, with emphasis on reducing or discontinuing glucocorticoids and neuromuscular blockers as soon as possible, reaching strict control on blood glucose with insulin, aggressive management of sepsis, early use of spontaneous breathing tests in patients with mechanical ventilation, anticipation of further medical complications and early rehabilitation.