title: Intrathecal granuloma formation in a patient receiving long-term spinal infusion of tramadol.
abstract: OBJECTIVE
  Intrathecal granuloma associated to the tip of subarachnoid catheters implanted in patients receiving long-term spinal infusion is a rare but potentially catastrophic complication. Its development seems to be related to the intrathecal administration of opioid drugs, although not all opioids induce granuloma formation with the same frequency.
  
  
  METHODS
  Morphine or hydromorphone-related granulomas have been reported extensively in the literature, but there are no data about any of the other opioids currently used in an off-label fashion when first-line drugs are contraindicated.
  
  
  METHODS
  In this case, we report the first documented case of intrathecal granuloma formation in a patient receiving long-term spinal infusion of tramadol, and we put forward a hypothesis for its development.
  
  
  CONCLUSIONS
  Chronic intrathecal administration of high-dose tramadol could cause an inflammatory mass as it can be caused by similar, off-label infusions of morphine or hydromorphone. Additionally, tramadol stimulates the activity of natural killers and the proliferation of lymphocytes.
authors.affiliation: Department of Anesthesia, Critical Care and Multidisciplinary Pain Management, General University Hospital, Valencia, Spain. deandres_jos@gva.es
authors.forename: José
authors.initials: J
authors.lastname: De Andrés
authors.forename: José
authors.initials: J
authors.lastname: Tatay Vivò
authors.forename: Stefano
authors.initials: S
authors.lastname: Palmisani
authors.forename: Vicente L
authors.initials: VL
authors.lastname: Villanueva Pérez
authors.forename: Ana
authors.initials: A
authors.lastname: Mínguez
mesh_terms: D000701:Analgesics, Opioid / Q000008:administration & dosage / Q000009:adverse effects*; D005260:Female; D006099:Granuloma / Q000139:chemically induced*; D006801:Humans; D007278:Injections, Spinal / Q000009:adverse effects*; D017116:Low Back Pain / Q000188:drug therapy; D008875:Middle Aged; D014147:Tramadol / Q000008:administration & dosage / Q000009:adverse effects*
chemical_list: D000701:Analgesics, Opioid; D014147:Tramadol