1. Department of Anesthesiology, Clinique Saint Pierre, Ottignies, Belgium
2. Department of Anesthesiology, Cliniques universitaires, Saint-Luc, Brussels, Belgium
3. Department of Anesthesiology, Centre Hospitalier Wallonie-Picarde, Tournai, B-7500, Belgium
4. Department of Anesthesiology and Perioperative Medicine, Universitair Ziekenhuis Brussel (UZ Brussel), Brussels, Belgium