Assessing the antioxidative status in critically ill patients.
OBJECTIVE
Oxidative stress is caused by a higher production of reactive oxygen and reactive nitrogen species or a decrease in endogenous protective antioxidative capacity. In all types of critical illness, such as sepsis, trauma, burn injury, acute pancreatitis, liver injury, severe diabetes, acute respiratory distress syndrome, AIDS and kidney failure, the occurrence of increased oxidative stress or a reduced antioxidative status is described. Whereas in the past, reactive oxygen and reactive nitrogen species were mainly known as harmful agents, recent investigations have given a new insight into the (patho)physiological importance of these substances as powerful messenger molecules involved in gene regulation, thereby enabling the synthesis of cytokines or adhesion molecules necessary for defending inflammatory processes. As shown in this review, there are numerous possibilities for the quantification of oxidative stress.


RESULTS
Several investigations showed a close association of single or multiple parameters, such as total antioxidative capacity, lipid peroxidation, vitamins C and E, the activation of nuclear factor kappa B, and respiratory burst, with the patient's outcome. However, no recommendation for a single parameter to be measured can be given because the assays described do not allow the definition of an overall "antioxidative status" for patients.


CONCLUSIONS
The occurrence of oxidative stress in critically ill patients is associated with a poor prognosis. The measurement of a cluster of assays representative of the quantification of reactive species or of antioxidants may improve the usefulness of therapeutic intervention and increase knowledge of pathophysiological alterations.
Roth
Erich
E
Department of Surgery, Research Laboratories, University of Vienna General Hospital, Waehringer Guertel 18-20, A-1090 Vienna, Austria. erich.roth@akh-wien.ac.at
Manhart
Nicole
N
Wessner
Barbara
B
D000975:Antioxidants / Q000008:administration & dosage* / Q000032:analysis; D003422:Critical Care; D016638:Critical Illness; D006801:Humans; D015227:Lipid Peroxidation; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D017382:Reactive Oxygen Species / Q000032:analysis / Q000378:metabolism; D016897:Respiratory Burst
D000975:Antioxidants; D017382:Reactive Oxygen Species