Generalized weakness that develops in critically ill patients: ICU-acquired weakness

Abstract

Critically ill patients in the intensive care unit (ICU) often develop acute onset diffuse limb weakness during the early course of their severe illness. This clinical entity is named as ICU-acquired weakness, and is related toprolonged mechanical ventilation and even increased mortality. The development of generalized weakness may be caused by critical illness polyneuropathy (CIP), critical illness myopathy (CIM), and a combination of both. The basic mechanisms underlying these disorders are complex and poorly understood. Several risk factors, including sepsis, hyperglycemia, steroid use, and multiple organ failure, are implicated, but remain to be clarified.Furthermore, whether each risk factor is associated with the development of CIP, CIM, or both has not been clarified thus far. Typically, the condition of patients is diagnosed on the basis of neurological findings and electrophysiological examinations, including nerve conduction study and needle electromyography. In addition, muscle biopsy and direct muscle stimulation test can be used to distinguish CIP from CIM. To date, no therapeutic approach has been established for ICU-acquired weakness, and potential preventive measures should be implemented in the daily management of the critically ill patients. Further studies are required to clarify the pathogenesis of these disorders and to identify appropriate therapeutic options.Received: December 11, 2014 / Accepted: February 20, 2015