Evaluation of the Preventive Effect of Selenium on Acute Kidney Injury Following On-pump Cardiac Surgery

Patients undergoing on-pump cardiac surgery are at risk of postoperative acute kidney injury (AKI). This is mainly due to some ischemic events and also pre-and postoperative stress responses which can result in postoperative organ dysfunction. Selenium (Se) as an antioxidant may help reduce inflammation and subsequent related complications. This study aimed to test if administration of oral Se complement before and after the on-pump cardiac surgery can reduce the incidence or severity of AKI following the operation.

In this randomized double-blind trial, the patients who were a candidate for on-pump cardiac surgery were randomly divided into two groups of intervention and control who received Se (n=60) or nothing (n=60), respectively. In the Se group, 500 µg of Se was administrated orally 14 and 2 h before surgery and every 12 h postoperatively for 2 days (overall 3000 µg), while the control group only received the routine and standard care. The patients were closely observed for the incidence and severity of postoperative AKI, using both Risk/Injury/Failure/Loss/End-stage (RIFLE) and the Acute Kidney Injury Network (AKIN) criteria.

The study sample included 46 (38.3%) males and 74 (61.7%) females with a mean±SD age of 52.8±16.7 years. Both groups were similar in terms of demographic characteristics, comorbidities, and Euro-SCORE. According to the RIFLE criteria, AKI occurred in 11 (17.9%) and 13 (21.4%) patients in the Se and control group, respectively. However, based on AKIN criteria, there were 17 (28.6%) and 21 (35.7%) cases of AKI in the Se and the control group, respectively (P=0.73). The most frequent stage of AKI among patients was the first stage in both groups and the highest rate of AKI was observed within 3-4 days after the surgery in both groups.

The obtained results did not approve the effect of Se in AKI prevention in coronary artery bypass grafting patients.