Evaluation the preventive effect of Selenium on acute kidney injury following on-pump cardiac surgery

Introduction: patients who undergo on-pump cardiac surgery are at risk of acute kidney injury following the operation. This is mainly due to some ischemic events and also pre- and postoperative stress responses which can result in postoperative organ dysfunction. Selenium as an antioxidant may help to reduce the inflammation and subsequent related complications. In this study we tested that if administration of oral Se compliment before and following the on-pump cardiac surgery can reduce the incidence or severity of kidney injury following the operation. Methods: In a randomized double-blind trial we divided the randomly selected patients who were candidate for on-pupm cardiac surgery into two groups of those who received selenium and control group. In selenium group we administrated 500 µg of selenium orally 14 and 2 hours before surgery and every 12 hours postoperatively for 2 days (overall 3000 µg) while the control group received only the routine and standard care. Subsequently patients were closely observed for serum creatinine rise and incidence of post-operative AKI during their hospitalization period in both groups using both Rifle and AKIN criteria separately. Besides, some additional data including: ICU-stay, duration of the operation and need for Blood products during the operation were recorded. At the end, the statistical analysis was carried out using SPSS 11.5 software in order to determine any significant difference in case and control group. Results: The study population included 120 patients divided in two equal groups of 60, consisting of 46 (38.3%) males and 74 (61.7%) females with the mean age of 52.8±16.7 years. Both groups were similar regarding the demographics and comorbidities. Also statistics showed no significant difference regarding Cardiac Operative Risk Evaluation (EuroSCORE) in both groups. Considering the RIFLR criteria, AKI occurred in 11 (17.9%) patients in selenium group and 13 (21.4%) patients in control group while based on AKIN criteria figures were 17 (28.6%) and 21 (35.7%) in selenium and the control group , respectively. The most frequent stage of AKI among patients was the first stage in both group and the highest rate of AKI occurred in 3-4 days after surgery in both groups. Conclusion: According to our research Administrating oral Selenium was not beneficial in order to prevent AKI after on-pump cardiac surgery.