Elevated Serum Levels of Erythropoietin after Xenon Anesthesia in Cardiac Surgery: A Secondary Analysis of a Randomized Controlled Trial

Objectives: The noble gas xenon has recently been amended to the list of prohibited substances because it is supposed to trigger the production of HIF-1α and subsequently erythropoietin. While any performance-enhancing treatments are strictly prohibited in sport competitions researcher and clinician have opened a debate about the potential transfer of these promising findings into clinical context. Methods: The objective of this study was to evaluate the effect of xenon anesthesia on serum levels of erythropoietin in patients that underwent cardiac surgery. Therefore we performed a secondary analysis of serum samples and dataset of patients from a prospective randomized controlled trial in cardiac surgery. Serum levels of erythropoietin and testosterone were measured in serum samples that were collected prior to surgery, at admission to the ICU and 24 hours thereafter. In 30 patients, we evaluated the effect of xenon anesthesia on the perioperative serum levels of erythropoietin and its association with testosterone and postoperative hemoglobin levels. Results: Patients in the xenon group showed a significant increase of circulating serum levels of erythropoietin 24 hours after xenon anesthesia (12.9 ± 7.4 versus 8.7 ± 4.3 at baseline; p = 0.017) The testosterone levels were comparable between the xenon and sevoflurane group. The postoperative hemoglobin levels trended to be higher in the xenon group, whereas no difference was found with respect to the intraoperative administration of fluids or blood products (Fig. 1). Conclusion: This study provides first evidence for a xenon triggered effect on circulating serum levels of erythropoietin during cardiac surgery. Further validation in a larger trial is needed.