[1] Ziekenhuis Oost Limburg, Intens Care Med & Multidisciplinary Pain Ctr, Dept Anaesthesiol, Genk, Belgium
[2] Radboud Univ Nijmegen, Dept Cellular Anim Physiol, Fac Sci, NL-6525 ED Nijmegen, Netherlands
[3] Radboud Univ Nijmegen, Med Ctr, Dept Anaesthesiol Palliat & Chron Pain Therapy, NL-6525 ED Nijmegen, Netherlands