Abstract
Intensive Care Unit-Acquired Weakness (ICUAW) is a common complication of intensive care that places significant impact on the long-term outcome. ICUAW is associated with systemic inflammatory response syndrome (SIRS) and is now considered an aspect of the multiple-organ failure syndrome at the level of peripheral nerves and muscles.
The membrane of the peripheral nerve is hyperpolarized and is inexcitable at least in part due to the changes of both the number and features of the Na+ channels. Within the muscles, the intracellular Ca2+ fluctuation pattern flattens during the cycle of contraction-relaxation.
There is also a decrease in the contractile protein content, and in the reduction of the number of both the nuclei and mitochondria. Thus, the muscle involvement in ICUAW includes both functional changes (myopathy) and a net loss of muscle tissue (sarcopenia).
The diagnosis of ICUAW is difficult and often delayed. Direct assessment of the extent to which the muscles and nerves contribute to weakness is often not worthy, as no specific therapy is yet available.
The prevention and management of ICUAW now consist of avoiding risk factors, providing adequate nutrition and encouraging the culture of early mobilization of ICU patients.