1. Hospital Pablo Tobon Uribe; Department of Surgery; Interventional Radiology & Pain Relief Clinic; Medellin Antioquia Colombia
2. Department of Anesthesia & Pain Clinic; Clinica Las Americas; Medellin Antioquia, Colombia
3. Department of Anesthesia and Alan Edwards McGill Pain Center; McGill University Health Centre; Montreal Quebec, Canada
4. Pain Clinic; Clinica Las Americas; Medellin Antioquia Colombia
5. Palliative Care & Support Unit; Cancerology Institute & Clinica Las Americas; Medellin Antioquia Colombia
6. University Clinic Leon XIII; Medellin Antioquia Colombia