The effect of selenium administration on complete blood count in elderly patients admitted to critical care unit

Abstract

Low serum selenium levels have been shown in critical illness, which is associated with poor clinical outcomes and a higher mortality rate. Selenium plays an important role in inflammation and oxidative stress. The aim of this study is evaluation of the effect of selenium administration on complete blood count in elderly patients admitted to critical care unit. Materials and Methods: This research was a clinical trial study and the target population was patients over 60 years of age hospitalized in the intensive care unit of Shahada Hospital and the general intensive care unit of Imam Reza Hospital in Tabriz city with an APACHE II score above 15 in 2021. The final sample size was 60 people, who were divided into two groups of 30 people, selenium and placebo. The sampling method in this study was available. Patients were randomly divided into selenium and placebo groups. Selenium group patients initially received 3000 micrograms of selenium all at once and within 3 hours, and then received 1500 micrograms daily for 10 days as a one-hour infusion. Control group patients were injected with normal saline for 10 days. A venous blood sample of 7 ml was collected on the first and tenth days of the study. CBC examination was performed to measure mean platelet volume, neutrophil to lymphocyte ratio and RDW. Results: In this study, among the demographic and clinical characteristics of the studied patients in two groups of selenium and placebo, only the length of hospitalization in the selenium group was significantly less than the placebo group (P=0.03). Among the hematological parameters on the 10th day, the mean platelet volume (MPV) (P=0.03) and red blood cell distribution width (RDW) (P=0.005) were significantly lower in the selenium group than in the placebo group, but there was no statistically significant difference in the ratio of neutrophils to lymphocytes between the two groups of selenium and placebo (P>0.05). Also, among the hematological parameters in the selenium group, the mean platelet volume (MPV) (P<0.001) and red blood cell distribution width (RDW) (P<0.001) on the tenth day were significantly lower than the first day, but there was no statistically significant difference in the ratio of neutrophils to lymphocytes between before and after the intervention (P>0.05); While in the placebo group, the only variable of red blood cell distribution width (RDW) (P<0.001) on the tenth day was significantly lower than the first day, but there was no statistically significant difference between the mean platelet volume (MPV) and the ratio of neutrophils to lymphocytes between before and after the intervention (P>0.05). All hematological factors mean platelet volume (MPV), red blood cell distribution width (RDW) and neutrophil to lymphocyte ratio both on the first day and on the tenth day had an inverse and statistically significant relationship with mortality (P<0.05).