A 65 year old man with a spinal cord stimulation electrode (MES) system to control pain secondary to ischaemia due to peripheral artery disease and induction of vasodilatation. Despite therapeutic efforts, the poor evolution of the disease led to the amputation of the right lower limb in November 1998. The following month, the patient began to report symptoms compatible with phantom limb pain.
Double anticonvulsant therapy, antidepressants and minor analgesics and adjustment of EEM parameters were started. The pain was partially controlled, but episodes of lancinating pain persisted with visual analogue scale (VAS) = 8.
In 2005, the patient was preferentially referred to the gastrointestinal medicine department for consultation, as he had MES and the possible implication for scalpel management with diathermy for endoscopic polypectomy.
Following the supplier's specifications, the digestive medicine department was informed of the impossibility of using shortwave diathermy and microwave diathermy, as this could cause heating of the electrode interface in the tissue, which could cause tissue damage. Therefore, the use of bipolar electrocoagulation was recommended. The digestive service commented that endoscopic polypectomy with bipolar electrocautery could not be performed; furthermore, after consultation with the general surgery service, it was considered that only a total colectomy should be performed after biopsy and anatomopathological diagnosis of the lesions.
In view of this clinical situation, it was decided to assess the real effectiveness of the EEM after 7 years of operation and, if ineffective, to remove it in order to be able to perform endoscopic polypectomy using standard diathermy. To this end, the EEM was switched off and the patient was scheduled for assessment after 1 month.
At this appointment the patient assessed his baseline pain with a VAS = 4 with episodes of paroxysmal pain of VAS = 7. His degree of disability was similar whether the electrode was on or off. After 6 months of follow-up with the electrode off and no change in the clinical situation, it was decided to remove the EEM and proceed with endoscopic polypectomy.
The phantom limb pain worsened over the years with partial response to anticonvulsants and antidepressants. The patient continued to have a baseline VAS of 4 and increasingly frequent episodes of lancinating pain of 10. With regard to his quality of life, the Lattinen index had a value of 12 and, in addition, the patient was depressed and his family life was affected.
In view of this situation, it was decided, after reviewing the bibliography, to schedule him for continuous perfusion of ketamine at a dose of 0.4 mg/kg in 60 min, in daily sessions for 1 week. Midazolam 1 mg was administered as premedication.
The only adverse effects reported by the patient during the infusions were dizziness and drowsiness.
The patient was evaluated at 1, 3 and 6 months, with a VAS at 6 months of 0 at rest and a decrease in lancinating pain episodes of less than 2 per week, with a VAS in these episodes of 6 and lasting a maximum of 10 s, Lattinen of 5 and a very significant improvement in mood. He was discharged from the unit after one year of follow-up, given the almost complete abolition of the picture without medication.