Current opinion in clinical nutrition and metabolic care
-
Curr Opin Clin Nutr Metab Care · Nov 2006
ReviewBiomarkers of oxidative stress in critically ill patients: what should be measured, when and how?
This review is dedicated to updating the knowledge on oxidative stress in critically ill patients with an intense inflammatory reaction, and to link it with recent findings supporting the possible involvement of oxidative injuries in systems and organs that frequently fail in the critically ill. ⋯ The assessment of oxidative stress, defined as the association between an increased production of oxygen-derived species and an exhaustion of the stores of antioxidants, requires a multimodal approach. Oxidative damage itself can be much better estimated by quantifying the oxidative byproducts of the lipids and proteins associated with an evaluation of the remaining stores of the corresponding functional antioxidants, or the activity of antioxidant enzymes, than by global tests of the total oxidative damage or the total antioxidant stores. Recent clinical data confirm an important role of increased oxidative stress in the acute dysfunctions of the respiratory, renal and cerebral systems.
-
Curr Opin Clin Nutr Metab Care · Nov 2006
ReviewUpdate on clinical micronutrient supplementation studies in the critically ill.
During the past 2 years a number of studies, meta-analyses and reviews have shown that micronutrient supplementation may be beneficial in critical illness. Selenium is emerging as a particularly important micronutrient. This paper reviews the evidence from trials in the critically ill, putting mechanisms, methods and shortcomings into perspective. ⋯ Plasma micronutrient concentrations are low during critical illness, as a result of losses, low intakes and dilution, and redistribution from plasma to tissues. An assessment of status is difficult. Micronutrient supplements appear beneficial in conditions such as major burns, trauma and sepsis and stroke, and are most likely to benefit patients with previous or actual depletion. The intravenous route seems more efficient than the enteral. Although chronic high intakes may be harmful, short-term interventions appear to be free of deleterious effects. Further research is required to determine the optimal micronutrient combinations and the doses required according to the timing of intervention and severity of disease.