Use of electrophysiologic testing

To define the electrophysiologic tests to diagnose critical illness myopathy and critical illness polyneuropathy in intensive care unit patients.

Literature review.

Critical illness myopathy and neuropathy are common complications in the critically ill patient. Myopathy and neuropathy are equally common, and often coexist. Electrophysiological alterations of peripheral nerves and muscle have an early onset in the first days of intensive care unit stay or shortly after sepsis, and precede the structural alterations. Conventional electrophysiologic evaluation can be performed easily on most intensive care unit patients, including patients with altered consciousness; in conjunction with direct muscle stimulation, it can differentiate myopathy from neuropathy, which might be important to define the long-term prognosis. However, electrophysiologic tests are not universally available; their interpretation requires special expertise; and their application is time consuming. A recently proposed simplified test of peroneal nerve stimulation could be used as a screening method to select patients who merit in-depth neurologic evaluation.

Early identification of neuromuscular alterations by means of electrophysiologic tests may be of value for targeted treatments and to anticipate the risk of short-term disability. Complete neurologic and electrophysiological evaluation is important to define the risk of long-term disability after intensive care unit discharge.