tailieunhanh - Báo cáo y học: "Selenium supplementation in critically ill patients: can too much of a good thing be a bad thing"

Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học Critical Care giúp cho các bạn có thêm kiến thức về ngành y học đề tài: Selenium supplementation in critically ill patients: can too much of a good thing be a bad thing? | Available online http content 11 4 153 Commentary Selenium supplementation in critically ill patients can too much of a good thing be a bad thing Daren K Heyland Clinical Evaluation Research Unit Angada 4 Kingston General Hospital Kingston ON K7L 2V7 Canada Corresponding author Daren K Heyland dkh2@ Published 7 August 2007 This article is online at http content 11 4 153 2007 BioMed Central Ltd Critical Care 2007 11 153 doi cc5975 See related research by Forceville et al. http content 11 4 R73 Abstract A recent study by Forceville and colleagues evaluated the effect of high-dose selenium administration as a treatment for septic shock. The study was negative and conflicts with existing clinical data regarding selenium administration in critically ill patients. Perhaps the key to understanding the differences between these discrepant observations lies in considering the dose and timing of selenium administration. Selenium is an essential nutrient for all mammalian species and in this issue of Critical Care Forceville and colleagues 1 evaluated the effect of high-dose selenium administration as a treatment for septic shock. Low levels of plasma selenium have been observed in critically ill patients and are associated with increased markers of oxidative stress worse organ failure and higher mortality rates 2 . Increasing levels of selenium are correlated with increased glutathione peroxidase a key endogenous antioxidant defense mechanism 3 . These observations have given rise to several studies providing exogenous selenium at doses less than 1 000 j-Lg day to critically ill patients. Overall these antioxidant supplementation strategies are associated with a large beneficial mortality effect risk ratio RR 95 confidence interval CI to 4 . However selenium compounds can also be considered prooxidative . As the authors suggest the pro-oxidant properties of selenite may be beneficial early in the .