Management of Critical Illness Polyneuropathy and Myopathy

A syndrome of generalized weakness, areflexia, and difficulty with weaning from a ventilator is a common clinical presentation in the critically ill patient, especially in the setting of sepsis, multiorgan failure, and hyperglycemia. At first believed to be a manifestation of nerve (critical illness neuropathy, CIN) or muscle (critical illness myopathy, CIM) dysfunction, our current conceptualization is as a spectrum (critical illness neuromuscular abnormalities, CINMA) that varies in extent and site(s) of involvement, but often a similar clinical presentation. Signs and symptoms of CINMA must be identified early to foster recovery and limit morbidity and mortality. The medical history is crucial in excluding preexisting neuromuscular conditions and electrodiagnostic testing helps to establish the diagnosis and prognostication. A stepwise approach to the management of a patient with CINMA is outlined, but avoiding potential medications, and ensuring supportive care are the primary interventions to consider. Recently intensive insulin therapy for hyperglycemia has been shown to lower the risk of CINMA and decrease the time of ventilatory support, but with a greater risk of hypoglycemia. Future therapeutic interventions will require a better understanding of disease pathogenesis, but may target proinflammatory cytokine and free-radical pathways, muscle gene expression, ion channel function, or proteolytic muscle protein mechanisms. Rehabilitation is an equally essential component in a patient's management. Although prognosis depends on the extent of the underlying muscle and nerve damage, mild persistent deficits are common and severe disability may be persistent.