Selenium blood concentrations in patients undergoing elective cardiac surgery and receiving perioperative sodium selenite

Abstract

Objectives: We recently reported that cardiac surgical patients in our institution exhibited low selenium blood levels preoperatively, which were further aggravated during surgery and independently associated with the development of postoperative multiorgan failure. Low circulating selenium levels result in a decreased antioxidant capacity. Both can be treated effectively by sodium-selenite administration. Little is known about the kinetics of exogenously administered sodium-selenite during acute perioperative oxidative stress. The aim of this study was to assess the effects of perioperative high-dose sodium-selenite administration on selenium blood concentrations in cardiac surgical patients.

Methods: One hundred four cardiac surgical patients were enrolled in this prospective observational trial. Patients received an intravenous bolus of 2000 μg selenium after an induction of anesthesia and 1000 μg selenium every day further during their intensive care unit (ICU) stay. Selenium blood levels were measured at regular intervals.

Results: Preoperative sodium-selenite administration increased selenium blood concentrations to normal values on ICU admission, but failed to prevent a significant decrease of circulating selenium on the first postoperative day. During the further ICU stay, selenium blood levels were normalized by the administration strategy and did not exceed the German reference range. No acute selenium-specific side effects occurred. When matching the participating patients to a historical control group without sodium-selenite administration, the chosen strategy was associated with a decrease in SAPS II (23 ± 7 versus 29 ± 8, P = 0.005) and SOFA scores (4 ± 3 versus 7 ± 2, P = 0.007) on the first postoperative day, but was unable to improve the postoperative outcome in patients staying >1 d in ICU.

Conclusions: Despite preemptive high-dose sodium-selenite administration, cardiac surgical patients experienced a significant decrease in circulating selenium levels on the first postoperative day.