1. Department of Anesthesiology; AZ Turnhout; Turnhout Belgium
2. Department of Anatomy and Embryology; Maastricht University; Maastricht The Netherlands
3. CAPHRI School for Public Health and Primary Care; Maastricht The Netherlands
4. Department of Anesthesiology; Jan Yperman Ziekenhuis; Ieper Belgium
5. Department of Anesthesiology and Multidisciplinary Pain Center; Ziekenhuis Oost-Limburg; Genk Belgium
6. Department of Anesthesiology and Pain Management; University Medical Center Maastricht; Maastricht The Netherlands