1. Students’ Scientific Society, Department of Anesthesiology and Intensive Care, Faculty of Medical Sciences in Katowice, Medical University of Silesia, Katowice, Poland
2. Central Laboratory, University Clinical Center of Medical University of Silesia, Katowice, Poland
3. Department of Anesthesiology and Intensive Care, Faculty of Medical Sciences in Katowice, Medical University of Silesia, Katowice, Poland
4. Transfusion Committee, University Clinical Center of Medical University of Silesia, Katowice, Poland