Is the Concentration of Trace Elements Zinc, Selenium, Copper, Manganese, and Iron a Predictor of Clinical Outcomes in Critically Ill Trauma Patients?

Trace elements (TE) function as essential micronutrients involved in the biochemical and physiological processes of the human body. We evaluated the baseline serum concentrations of TE as a predictor of clinical outcomes in critically ill trauma patients and monitored the concentrations of TE during the patients intensive care unit (ICU) stay. A total of 89 patients were enrolled. Within the first 24 h of patients' admission, concentrations of TE, zinc (Zn), selenium (Se), copper (Cu), manganese (Mn), and iron (Fe) were measured and monitored on the 5th and 10th day of patients ICU stay. The concentrations of Zn, Se, Cu and Mn were determined from serum using atomic absorption spectrophotometry, whereas the concentration of Fe using the photometric method. ANOVA and logistic regression analyses were used for statistical analysis with the level of significance set at 0.05. At the time of ICU admission, deficiency of Cu was observed in 11 out of 89 (0.13), Zn in 82 (0.92), Se in 5 (0.06) and Fe in 52 (0.58) patients, while excess of Mn was detected in 27 (0.30) and Cu in 3 (0.03) patients. A significant increase of Zn and Cu concentrations was observed from admission to 10th day (P < 0.001 for both), although Zn concentrations did not reach the lower limit of the reference interval. Logistic regression analysis found that only a low concentration of Zn at admission was associated with mechanical ventilation (OR = 0.78; 95%CI: 0.64-0.96; P = 0.018). Furthermore, the concentrations of TE at admission in critically ill trauma patients did not have an impact on the overall length of the ICU and hospital stay, nor on mortality.