1 Department of Anesthesiology and Postoperative Intensive Care, Faculty of Medicine, School of Health Sciences, University of Ioannina, Ioannina, Greece.
2 Cardiothoracic Anesthesia, Anesthesia, Surgical Intensive Care and Pain Medicine, College of Medicine, Mansoura University, Mansoura, Egypt; Anesthesiology Department, College of Medicine, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia. Electronic address: mohamedrefaateltahan@yahoo.com.