The biochemical basis of antioxidant therapy in critical illness.

During critical illness free radical production may increase as a result of, for example, sepsis or tissue trauma. In addition, because of a potential for increased losses, and the possibility of inadequate nutrition, the antioxidant defences of the body may become compromised. Thus, the delicate balance between free radicals and antioxidants may be disturbed. Various nutritional and pharmacological strategies to enhance antioxidant defences have been proposed, which aim either to maintain or enhance endogenous antioxidant stores or to provide alternative antioxidant agents. Trace elements and amino acids are particularly important, and their synergistic role in the maintenance of the body's antioxidant defence network will be discussed.