High-dose selenium supplementation to reduce ischemia/reperfusion injury - Novel approach in intensive care: Selenium does make a difference!

Selenium serves as an antioxidant in our body, interacting at various levels with important mediators. Its central role is to hamper oxidative stress, no matter whether it comes from ischemic/reperfusion injury after acute events such as strokes or heart attacks, or from elective surgery in which vessels are intentionally ligated, depriving the surrounding tissue of oxygen. Initially, the lack of oxygen during ischemia leads to tissue damage, but reperfusion triggers further harm, E. Müller, Herne, Germany, explained. He reminded the audience of the altered microcirculation after an acute stroke, and the inflammatory cascade which gets activated during sepsis, a condition associated with an increase in reactive oxygen species and a reduced endogenous anti-oxidative capacity. "Reperfusion injury is a problem under investigation," he said, a problem which occurs after myocardial infarction, ischemic stroke, organ transplantation, vascular and reconstructive surgery and sepsis.

In an attempt to minimize tissue damage after such severe events, hypothermia has become standard procedure in the operating theater. An additional effective, safe and cheap way to improve reperfusion, for example after myocardial infarction or vascular surgery, is selenium supplementation. A logical approach, since researchers lately found that plasma selenium levels in critically ill patients - with a systemic inflammatory response syndrome and severe sepsis/septic shock - were below standard values of healthy subjects and decreased even further during hospitalization in the ICU, in particular in patients with organ failure and especially when attributed to infection. These findings, published by Sakr et al. [1], showed that selenium concentrations correlated well with survival. Lower plasma selenium concentrations seem to be associated with greater tissue damage, infections, organ failure and an increased ICU mortality (fig. [1]).

Fig. 1 Sakr et al. 2007: Survivors have higher selenium levels (slide: Müller).

Literatur

• 01 Sakr Y . et al . British Journal of Anesthesia. 2007;  98 775-784
• 02 Angstwurm MWA . Crit Care Med. 2007;  35 118-126
• 03 Nathens AB . et al . Ann Surg. 2002;  236 814-822
• 04 Howe et al . SCCM 2005. 
• 05 Altekin E . et al . J Trace Elem Med Biol. 2005;  18 235-242
• 06 Riesinger J . et al . Am J of Emergency Medicine. 2009;  27 176-181